Back Case Studies
During a routine radiograph of a young man's back, a common congenital defect of the vertebral arch was observed. No signs of back pain were detected. What is a common developmental defect of the vertebral column?
A common developmental defect of the vertebral column is spina bifida occulta. This condition results from failure of union of the laminae of the vertebral arch and varies from a slight defect to almost complete failure of the vertebral arch to form.
Concerned friends took a female college student to the student infirmary because she suffered a sudden onset of fever, nausea, and vomiting. She told the admitting nurse that she had "a massive headache" that is worse when she is upright and walking and that it hurts to turn her head. The campus has not been experiencing episodes of flu, and the physician on call suspected meningitis. What is the anatomical basis of the increased pain?
Both tests increase tension on (stretch) the dura mater. The Kernig test is thought to do so indirectly as a result of traction on the sciatic nerve, the major nerve to the lower limb. Note that as spinal nerves penetrate the dural sac, dural mater continues as the outer covering of the nerve, the epineurium, and so stretch forces exerted on a nerve is transmitted to the dural sac.
A physician prepares to perform a lumbar puncture to establish the diagnosis in a patient with suspected intracranial bleeding. At what levels should the physician consider inserting the needle?
Lumbar puncture is usually done between the L3/L4 or L4/L5 vertebrae.
An 18-year-old woman was thrown from a horse and sustained a spinal cord injury as the result of severe hyperextension of her neck. Although she was rushed to the hospital, she died after approximately 5 minutes. An autopsy was performed. Autopsy Report: The C1 and C2 vertebrae were fractured as a result of the hyperextension. The spinal cord was severely damaged at the level of articulation of the C2 and C3 vertebrae, with extensive bleeding into the soft tissues of the neck. Diagnosis: Transection of the superior end of the spinal cord resulting from multiple fractures of the cervical vertebrae. Although one would expect the patient to be quadriplegic following a cervical spinal cord transection, what probably caused death in this case?
People with this severe injury rarely survive more than a few minutes because the injury to the spinal cord is superior to the phrenic outflow (origin of phrenic nerves). Because these nerves are the sole motor supply to the diaphragm and, in addition, the actions of the intercostal muscles are lost, unassisted respiration is not possible.
A physician examined a 68-year-old man with back and leg pain. After viewing the MRIs, the physician told the patient that his discomfort is the result of spinal stenosis. What is spinal stenosis?
Spinal stenosis (or canal stenosis) is a narrowing of the vertebral canal or the IV foramina, usually in the lumbar region of the vertebral column.
Concerned friends took a female college student to the student infirmary because she suffered a sudden onset of fever, nausea, and vomiting. She told the admitting nurse that she had "a massive headache" that is worse when she is upright and walking and that it hurts to turn her head. The campus has not been experiencing episodes of flu, and the physician on call suspected meningitis. What physical tests could the physician perform to augment his suspicions?
While supine on the examination table, the patient is asked to raise her head off the table (Brudzinski test). Positive responses include increased neck pain (but also head or back) and/or involuntary flexion in the lower limb. Another test administered from the same position is to have the patient flex her thigh at the hip while maintaining extension at the knee and dorsiflexion at the ankle (Kernig test). Positive responses are the same as for the Brudzinski test.
During a violent altercation at a local park, a 16-year-old youth was stabbed with a knife in the posterior aspect of the neck. As he ducked to avoid his attacker, he flexed his neck. Much to the surprise of his assailants, the youth fell to the ground and was completely immobilized from the neck down. How might the anatomical knowledge applied in this case study be used in the diagnosis of diseases of the nervous system and in the administration of anesthetic agents?
Similar gaps exist between the lumbar spinous processes when the back is flexed. The presence of these gaps is important because they enable access to the vertebral canal, specifically to the epidural and subarachnoid spaces for the administration of anesthetics agents and for the withdrawal of CSF for analysis.
An asymptomatic 10-year-old female visits her pediatrician for a school physical. The patient's gait is normal. When asked to "stand straight with your weight on both legs," the patient's vertebral column appears straight, but her waist seems slightly high on the left (as if she were standing with her weight on the left limb), and her right shoulder is somewhat higher than the left. When asked, the patient says she writes using her left hand. What further test can be performed to confirm the diagnosis?
1. The patient should be asked to bend forward and touch her toes while the physician stands directly behind the patient and looks for curvature in the alignment of the spinous processes. It may be helpful to mark the position of the spinous processes with a washable marker before flexion occurs. The patient's back should remain symmetrically even as the lumbar lordosis is reduced and then becomes posteriorly convex. Lateral deviations of the row of spinous processes or an asymmetrical elevation of the ribs are positive signs for scoliosis, and the patient should be referred for radiological evaluation ("scoliosis plain film series").
A 67-year-old man who has been a smoker for most of his life complains of a "stiff neck." On physical examination, his range of neck motion is markedly limited. He experiences only mild discomfort in his neck, especially in the mornings, but recently has had episodes of "pins and needles" (numbness and tingling) and some weakness in his right shoulder and arm. His history reveals that his right hip was replaced 5 years ago due to chronic pain when walking and standing. Plain film radiographs reveal a hyperextension deformity of the neck, with narrowed IV disc spaces especially at the C3/4 and C4/5 levels, with osteophytes at the margins of the vertebral bodies and articular processes. The physician diagnoses the patient with spondylosis and osteoarthritis. Explain the patient's neurological symptoms.
A decrease in the size of the IV foramen as a result of the decreased disc height, perhaps accompanied by swollen ligamenta flava and the development of osteophytes ("osteoarthritis") in relation to the capsules of the zygapophysial joint, is likely to have compressed the nerve roots of the C4 and C5 spinal nerves, causing contusion (bruising) of the nerve tissue, resulting in a tingling sensation (paresthesia). The fact that the patient's history involves isolated, unilateral joints is an indication that the condition is not a systemic (rheumatoid) arthritis.
Concerned friends took a female college student to the student infirmary because she suffered a sudden onset of fever, nausea, and vomiting. She told the admitting nurse that she had "a massive headache" that is worse when she is upright and walking and that it hurts to turn her head. The campus has not been experiencing episodes of flu, and the physician on call suspected meningitis. What procedure should be performed to confirm a diagnosis of meningitis?
A diagnosis of meningitis is confirmed by analysis of the CSF, collected by lumbar puncture.
A physician examined a 68-year-old man with back and leg pain. After viewing the MRIs, the physician told the patient that his discomfort is the result of spinal stenosis. How does stenosis produce back and leg pain?
Although in theory, a stenosis (narrowing) of upper lumbar vertebrae could cause compression of the spinal cord; in reality, it is the lumbar spinal nerves that are compressed. Symptoms include initial acute local pain, followed by chronic numbness and/or weakness in the area of the lower limb to which the nerve's fibers are distributed.
A 62-year-old man who was a heavy drinker and smoker consulted his physician about feeling a strong pulse in his abdomen. He said it felt like a second heart. He also complained about pain in his abdomen, back, and groin. The physician arranged for radiographic studies, including CT scans. Radiology Report: The plain radiographs showed calcium deposits in the wall of the abdominal aorta and an apparent aneurysm. The CT scans revealed an abdominal aortic aneurysm that was 11 cm in diameter. Before he could be admitted to the hospital for repair of the aneurysm, the patient passed out on his way home and was involved in a car accident. He was rushed to the hospital and admitted to surgery for repair of a ruptured aneurysm. During surgery, extensive mobilization of the aorta was necessary, so several segmental arteries were ligated and divided. Although the aorta was successfully repaired using a Dacron graft, the patient was paraplegic and impotent following the surgery, and his bladder and bowel functions were no longer under voluntary control. Diagnosis: Paraplegia and other neurological deficits resulting in sphincter paralysis in the urinary bladder and anal canal. Why is segmental augmentation of the longitudinal arteries of the spinal cord so important?
Although the longitudinal arteries form a continuous anastomotic chain theoretically capable of providing a means of collateral circulation, it is not always adequate to provide the collateral circulation necessary to sustain the cord when the segmental arteries are interrupted. It is most tenuous between the enlargements of the cord, especially in the midthoracic region. Arising more frequently on the left from an inferior intercostal (T6-T12) or lumbar (L1-L3) artery, the great anterior segmental medullary spinal artery enters the vertebral canal through an IV foramen. It is the largest segmental medullary artery and supplies blood—sometimes a disproportionate amount—mainly to the inferior two thirds of the spinal cord.
A 21-year-old man was involved in a head-on collision. When removed from his sports car, he complained of loss of sensation and voluntary movements in his lower limbs. Upper limb movements were also impaired, particularly in his hands. The patient was kept warm and immobilized until the ambulance arrived. Using a proper transport technique (spine board with the head and neck stabilized), the patient was taken to the emergency department. After examination at the hospital, radiographs of his vertebral column were taken. Radiology Report: Radiographs showed severe dislocation of C6 vertebra on C7 and a chip fracture of the anterosuperior corner of the body of C7. Diagnosis: Dislocation of C6 and C7 vertebrae. Surgical Treatment: Open reduction was carried out, and the spinous processes of C6 and C7 vertebrae were wired together to hold them in normal relation to each other. The reduction was maintained by immobilization of the neck in a plastic collar. What was the most likely cause of the patient's paralysis?
An initial period of spinal shock in these cases lasts from a few days to several weeks, during which time all somatic and visceral activity is abolished. On return of reflex activity, spasticity of muscles and exaggerated tendon reflexes occur inferior to the level of the lesion. Bladder and bowel functions are no longer under voluntary control.
A father takes his 12-year-old daughter across the country to visit her 75-year-old grandmother, whom neither has seen for several years. The son is shocked to see how much his mother has "aged." She has a markedly decreased stature and is "stooped over" to the point of appearing "humpbacked." She seems unsteady on her feet. At her son's insistence, she visits her physician for the first time in years. History: The patient had a hysterectomy soon after her only pregnancy. She did not nurse her baby. She was told as a child that she had a "milk allergy" and so has avoided dairy products most of her life. She is a smoker and admits to having "an alcoholic drink or two" daily. She reports that she has never taken female hormones and that her mother took on a similar appearance in her advanced years. She says she has had headaches and vision problems. She has stopped wearing her glasses (bifocals) because they seem to make her headaches worse. Physical Examination: Excess thoracic kyphosis with compensating cervical extension. She has had a decrease in her weight as well as a marked decrease in height (nearly 3 inches shorter than reported on her driver's license, which expired 5 years ago). Radiology Report: Excess thoracic kyphosis due to several wedged, flattened and biconcave thoracic vertebrae. The decrease in her bone mass is apparent radiographically. Diagnosis: Osteoporosis, markedly affecting the thoracic vertebrae. What are likely health risks for the grandmother at this point, and what are some steps she could take to reduce them?
Because the patient's bones are much more vulnerable to fracture, the risk of serious and perhaps life-changing injury from a fall are greatly increased. Removal of throw rugs, installing support devices in bathrooms, discontinuing use of step stools in housecleaning, and perhaps the use of a cane or supportive device in walking can all reduce the likelihood of a fall. This patient should have her eyes examined in view of her altered anatomy (excess thoracic kyphosis), which is probably at the root of her frustration with her bifocals. Wearing suitable glasses will also reduce the risk of a fall and is likely to help her headaches.
During a violent altercation at a local park, a 16-year-old youth was stabbed with a knife in the posterior aspect of the neck. As he ducked to avoid his attacker, he flexed his neck. Much to the surprise of his assailants, the youth fell to the ground and was completely immobilized from the neck down. Explain the basis of the victim's paralysis. What might have occurred if the knife had penetrated at a high level?
Complete transection of the spinal cord results in loss of all sensation and voluntary movement inferior to the lesion. The patient is quadriplegic when the lesion is superior to spinal cord segment C5 because the nerves supplying the upper limb are derived from segments C5-T1. Had the knife severed the spinal cord superior to segment C4, the lesion would have stopped the patient's breathing. At this site, the injury would have interfered with the segments that give rise to the phrenic nerve (segments C3, C4, and C5), which innervates the diaphragm. As a result, the patient may have died in a few minutes.
A 21-year-old man was involved in a head-on collision. When removed from his sports car, he complained of loss of sensation and voluntary movements in his lower limbs. Upper limb movements were also impaired, particularly in his hands. The patient was kept warm and immobilized until the ambulance arrived. Using a proper transport technique (spine board with the head and neck stabilized), the patient was taken to the emergency department. After examination at the hospital, radiographs of his vertebral column were taken. Radiology Report: Radiographs showed severe dislocation of C6 vertebra on C7 and a chip fracture of the anterosuperior corner of the body of C7. Diagnosis: Dislocation of C6 and C7 vertebrae. Surgical Treatment: Open reduction was carried out, and the spinous processes of C6 and C7 vertebrae were wired together to hold them in normal relation to each other. The reduction was maintained by immobilization of the neck in a plastic collar. What was the most likely cause of the patient's paralysis?
Because the vertebral canal in the cervical region is usually larger than the spinal cord, some displacement of the vertebrae can occur without causing damage to the spinal cord. However, in view of the patient's paraplegia, it is likely that the spinal cord was severely stretched and/or torn. At the moment of impact, the displacement of C6 on C7 was undoubtedly greater than shown in the radiograph. In hyperflexion injuries of the neck, the anterior longitudinal ligament is usually not torn, and when the patient's neck is placed in a position of extension, this ligament tightens and, along with the plastic cervical collar, tends to hold the vertebrae together.
A 21-year-old man was involved in a head-on collision. When removed from his sports car, he complained of loss of sensation and voluntary movements in his lower limbs. Upper limb movements were also impaired, particularly in his hands. The patient was kept warm and immobilized until the ambulance arrived. Using a proper transport technique (spine board with the head and neck stabilized), the patient was taken to the emergency department. After examination at the hospital, radiographs of his vertebral column were taken. Radiology Report: Radiographs showed severe dislocation of C6 vertebra on C7 and a chip fracture of the anterosuperior corner of the body of C7. Diagnosis: Dislocation of C6 and C7 vertebrae. Surgical Treatment: Open reduction was carried out, and the spinous processes of C6 and C7 vertebrae were wired together to hold them in normal relation to each other. The reduction was maintained by immobilization of the neck in a plastic collar. Which joints of the cervical region of the vertebral column were dislocated?
Both the IV disc and the zygapophysial joints between the bodies and vertebral arches of vertebrae C6 and C7, respectively, were dislocated in this patient.
A 67-year-old man who has been a smoker for most of his life complains of a "stiff neck." On physical examination, his range of neck motion is markedly limited. He experiences only mild discomfort in his neck, especially in the mornings, but recently has had episodes of "pins and needles" (numbness and tingling) and some weakness in his right shoulder and arm. His history reveals that his right hip was replaced 5 years ago due to chronic pain when walking and standing. Plain film radiographs reveal a hyperextension deformity of the neck, with narrowed IV disc spaces especially at the C3/4 and C4/5 levels, with osteophytes at the margins of the vertebral bodies and articular processes. The physician diagnoses the patient with spondylosis and osteoarthritis. What causes IV disc degeneration?
DDD commonly occurs in the cervical region. Disc degeneration may be associated with excess dehydration and loss of mucopolysaccharide from the nucleus pulposus, or herniations of the nucleus pulposus may occur that result in narrowing of the IV space and a reduced capacity of the discs to act as cushions between the vertebrae. Disc degeneration diminishes stature, limits mobility, and decreases the size of the IV foramina.
A 13-year-old competitive gymnast who practiced 18-20 hours a week on her routines complained of low back pain. A physical examination and radiographs revealed that she had a stress fracture of L5 vertebra. What repetitive movement of the vertebral column may result in a stress fracture of the vertebral column?
Continuous hyperextension of the vertebral column can produce stress fractures. Compressive forces from hard landings also contribute.
A 67-year-old man who has been a smoker for most of his life complains of a "stiff neck." On physical examination, his range of neck motion is markedly limited. He experiences only mild discomfort in his neck, especially in the mornings, but recently has had episodes of "pins and needles" (numbness and tingling) and some weakness in his right shoulder and arm. His history reveals that his right hip was replaced 5 years ago due to chronic pain when walking and standing. Plain film radiographs reveal a hyperextension deformity of the neck, with narrowed IV disc spaces especially at the C3/4 and C4/5 levels, with osteophytes at the margins of the vertebral bodies and articular processes. The physician diagnoses the patient with spondylosis and osteoarthritis. What sequence of events likely resulted in this condition?
During middle and older age, there is an overall decrease in bone density and strength, particularly centrally within the vertebral body, and the IV discs between them become increasingly convex if they remain normal. Consequently, the articular surfaces (end plates) typically bow inward gradually, so that both the superior and inferior surfaces of the vertebrae become increasingly concave. However, in degenerative disc disease (DDD), the discs become uniformly thin. A disc that is thinner than the one superior to it is degenerative. The bone loss combined with abnormal decrease in disc height will cause a more marked decrease than would normally occur in the height of an aging individual. In response to increased compressive forces on the anulus fibrosis, osteophytes develop around the margins of the vertebral body (along the attachments of the fibers of the anuli), especially anteriorly and posteriorly. Similarly, as altered mechanics place greater stresses on the zygapophysial joints, osteophytes and extensions of the articular cartilage ("wrap around bumpers") develop. This bony and cartilaginous growth during advanced age has traditionally been viewed as a disease process (spondylosis in the case of the vertebral bodies and osteoarthritis in the case of the zygapophysial joints), but it is more realistic to view it as normal anatomy for a particular age range. However, flattened discs, thinner than those more superiorly located, are degenerative, not just aged
While carrying a heavy box of books, a 45-year-old man suddenly experienced severe pain in his lower back. Later, he developed a dull ache in the posterolateral aspect of his left thigh that extended along the calf of his leg into his foot. Lateral deviation of the lumbar region of his vertebral column was also observed. He limped when he walked because he could not fully extend his thigh. His family physician recommended backrest and referred the patient to a back specialist. Physical Examination: The orthopedist observed that the man's back muscles were in spasm. When asked to indicate the site of the most severe pain, the man pointed to his lower lumbar region. During the examination, no ankle reflex was observed on the left side. He experienced increased pain when the physician raised his extended lower limb on that side. The orthopedist arranged for a radiographical study and MRIs of the man's lower back. Radiology Report: The radiographs showed a slight narrowing of the space between the vertebral bodies of L5 and S1. MRI showed that the nucleus pulposus of the L5/S1 IV disc was protruding. Diagnosis: Posterolateral herniation of the nucleus pulposus of the IV disc between L5 and S1. Why did the pain increase when the orthopedist raised the patient's extended lower limb?
Exacerbating pain usually occurs (although some people experience relief) when the extended lower limb is flexed passively at the hip (bending forward at the hip). When the physician raised the patient's extended lower limb at the hip joint, the sciatic nerve, including its S1 component, became tense as it was stretched across the protruding disc, increasing the compression. For those who receive relief in this position, it is assumed that the nerve is pulled in a way that decreases the impact of the herniating mass on the nerve roots.
A father takes his 12-year-old daughter across the country to visit her 75-year-old grandmother, whom neither has seen for several years. The son is shocked to see how much his mother has "aged." She has a markedly decreased stature and is "stooped over" to the point of appearing "humpbacked." She seems unsteady on her feet. At her son's insistence, she visits her physician for the first time in years. History: The patient had a hysterectomy soon after her only pregnancy. She did not nurse her baby. She was told as a child that she had a "milk allergy" and so has avoided dairy products most of her life. She is a smoker and admits to having "an alcoholic drink or two" daily. She reports that she has never taken female hormones and that her mother took on a similar appearance in her advanced years. She says she has had headaches and vision problems. She has stopped wearing her glasses (bifocals) because they seem to make her headaches worse. Physical Examination: Excess thoracic kyphosis with compensating cervical extension. She has had a decrease in her weight as well as a marked decrease in height (nearly 3 inches shorter than reported on her driver's license, which expired 5 years ago). Radiology Report: Excess thoracic kyphosis due to several wedged, flattened and biconcave thoracic vertebrae. The decrease in her bone mass is apparent radiographically. Diagnosis: Osteoporosis, markedly affecting the thoracic vertebrae. Explain the loss of height and radiographic findings
In osteoporosis, the rate of bone resorption exceeds that of bone formation, resulting in a net loss in bone mass that makes bones weak and vulnerable to fracture. Women may eventually lose up to half of their bone mass. The proximal femur, distal radius, and vertebral column are especially affected. In the vertebral bodies, the horizontal trabeculae are most affected, leaving the vertical trabeculae unsupported. The vertebral bodies undergo a series of microfractures that eventually cause them to collapse, becoming shortened or wedge-shaped, thus increasing the thoracic kyphosis and reducing the individual's height, producing a so-called dowager's hump in severe cases.
A 62-year-old man who was a heavy drinker and smoker consulted his physician about feeling a strong pulse in his abdomen. He said it felt like a second heart. He also complained about pain in his abdomen, back, and groin. The physician arranged for radiographic studies, including CT scans. Radiology Report: The plain radiographs showed calcium deposits in the wall of the abdominal aorta and an apparent aneurysm. The CT scans revealed an abdominal aortic aneurysm that was 11 cm in diameter. Before he could be admitted to the hospital for repair of the aneurysm, the patient passed out on his way home and was involved in a car accident. He was rushed to the hospital and admitted to surgery for repair of a ruptured aneurysm. During surgery, extensive mobilization of the aorta was necessary, so several segmental arteries were ligated and divided. Although the aorta was successfully repaired using a Dacron graft, the patient was paraplegic and impotent following the surgery, and his bladder and bowel functions were no longer under voluntary control. Diagnosis: Paraplegia and other neurological deficits resulting in sphincter paralysis in the urinary bladder and anal canal. Based on the symptoms, which arteries were ligated and divided during surgery?
In this patient, the segmental artery giving rise to the great anterior segmental medullary artery and perhaps others supplying segmental medullary arteries to the lumbosacral enlargement were ligated. The longitudinal arteries were not able to provide adequate collateral circulation, and at least a complete segment of the cord must have been deprived of blood. This would have the same effect as a transection of the cord.
A 62-year-old man who was a heavy drinker and smoker consulted his physician about feeling a strong pulse in his abdomen. He said it felt like a second heart. He also complained about pain in his abdomen, back, and groin. The physician arranged for radiographic studies, including CT scans. Radiology Report: The plain radiographs showed calcium deposits in the wall of the abdominal aorta and an apparent aneurysm. The CT scans revealed an abdominal aortic aneurysm that was 11 cm in diameter. Before he could be admitted to the hospital for repair of the aneurysm, the patient passed out on his way home and was involved in a car accident. He was rushed to the hospital and admitted to surgery for repair of a ruptured aneurysm. During surgery, extensive mobilization of the aorta was necessary, so several segmental arteries were ligated and divided. Although the aorta was successfully repaired using a Dacron graft, the patient was paraplegic and impotent following the surgery, and his bladder and bowel functions were no longer under voluntary control. Diagnosis: Paraplegia and other neurological deficits resulting in sphincter paralysis in the urinary bladder and anal canal. What is the most likely anatomical basis for the patient's paraplegia, sphincter dysfunctions, and impotence?
It appears that in this patient, the lumbosacral portion of the spinal cord became nonfunctional as a result of a spinal cord infarction. Paraplegia, impotence, and loss of sensation and motor function in lower limb and pelvic and perineal regions supplied by spinal nerves arising from the cord inferior to the lesion would result from such an infarct.
Concerned friends took a female college student to the student infirmary because she suffered a sudden onset of fever, nausea, and vomiting. She told the admitting nurse that she had "a massive headache" that is worse when she is upright and walking and that it hurts to turn her head. The campus has not been experiencing episodes of flu, and the physician on call suspected meningitis. What is meningitis?
Meningitis is an inflammation of the meninges, which can result from viral, bacterial or fungal, or parasitic infections. The infection involves the cerebrospinal fluid (CSF), and so, usually both cranial and spinal meninges become involved. Viral meningitis is often benign and of limited duration, but other forms have serious consequences and are often fatal.
A father takes his 12-year-old daughter across the country to visit her 75-year-old grandmother, whom neither has seen for several years. The son is shocked to see how much his mother has "aged." She has a markedly decreased stature and is "stooped over" to the point of appearing "humpbacked." She seems unsteady on her feet. At her son's insistence, she visits her physician for the first time in years. History: The patient had a hysterectomy soon after her only pregnancy. She did not nurse her baby. She was told as a child that she had a "milk allergy" and so has avoided dairy products most of her life. She is a smoker and admits to having "an alcoholic drink or two" daily. She reports that she has never taken female hormones and that her mother took on a similar appearance in her advanced years. She says she has had headaches and vision problems. She has stopped wearing her glasses (bifocals) because they seem to make her headaches worse. Physical Examination: Excess thoracic kyphosis with compensating cervical extension. She has had a decrease in her weight as well as a marked decrease in height (nearly 3 inches shorter than reported on her driver's license, which expired 5 years ago). Radiology Report: Excess thoracic kyphosis due to several wedged, flattened and biconcave thoracic vertebrae. The decrease in her bone mass is apparent radiographically. Diagnosis: Osteoporosis, markedly affecting the thoracic vertebrae. What facts in the patient's history are likely to have contributed to her condition?
Nearly all the elements of this patient's history describe factors that increase the likelihood of developing osteoporosis. Osteoporosis is two and a half times more common in women than in men. In women, its occurrence is directly related to decreased availability of estrogen. Her early hysterectomy and noninvolvement in nursing her baby both contributed to reduced estrogen levels. Reduced intake of calcium during the formative years, two or more alcoholic drinks per day, cigarette smoking, and a family history of osteoporosis are all contributing factors.
A physician prepares to perform a lumbar puncture to establish the diagnosis in a patient with suspected intracranial bleeding. Are these levels safe in infants?
No. The L3/4 level has potential risk in infants. The spinal cord usually ends at the L3 level at birth, and there is variation. Thus, in infants and young children, the L4/5 level should be used, or CSF should be withdrawn from the posterior cerebellomedullary cistern (L., cisterna magna) by inserting the needle through the posterior atlanto-occipital membrane and foramen magnum.
A physician prepares to perform a lumbar puncture to establish the diagnosis in a patient with suspected intracranial bleeding. Explain why a lumbar puncture is contraindicated when there is a potential for increased intracranial pressure.
One should proceed with caution in performing a lumbar puncture when there is a possibility of increased intracranial pressure. If the pressure suddenly drops in the extracranial subarachnoid space when the canal is entered, all or part of the cerebellum may herniate into the vertebral canal. Increased intracranial pressure can usually be detected by examining the back of the eyeball through the pupil with an ophthalmoscope.
A 13-year-old competitive gymnast who practiced 18-20 hours a week on her routines complained of low back pain. A physical examination and radiographs revealed that she had a stress fracture of L5 vertebra. What other activities do you think might produce this type of stress fracture?
Persons involved in diving, gymnastics, wrestling, and weight lifting are especially vulnerable to these bony defects. Overhead lifting and repetitive activities performed by painters, carpenters, and electricians can also produce spondylolysis.
A weight lifter was preparing for competition by lifting increasingly heavy weights. During extension of his vertebral column, he suddenly felt a severe pain in his lower back. Following a physical examination, a physician decided that the patient was experiencing acute back pain. What do you think might prevent this type of back injury?
Poor posture and improper lifting mechanics cause most acute back pain. Proper sitting and lifting techniques would be advisable, such as lifting with the lower limbs instead of the back.
An 18-year-old woman was thrown from a horse and sustained a spinal cord injury as the result of severe hyperextension of her neck. Although she was rushed to the hospital, she died after approximately 5 minutes. An autopsy was performed. Autopsy Report: The C1 and C2 vertebrae were fractured as a result of the hyperextension. The spinal cord was severely damaged at the level of articulation of the C2 and C3 vertebrae, with extensive bleeding into the soft tissues of the neck. Diagnosis: Transection of the superior end of the spinal cord resulting from multiple fractures of the cervical vertebrae. Describe fractures of the C1 and C2 vertebrae most likely to have occurred as a result of hyperextension.
Severe hyperextension of the neck often causes a fracture of the C1 vertebra at one or both grooves for the vertebral arteries, resulting in separation of the posterior arch. The vertebral arch of C2 is most vulnerable to fracture at the isthmus (interarticular part) between the superior and the inferior articular processes (a "hangman's fracture") as a result of hyperextension.
A physician examined a 68-year-old man with back and leg pain. After viewing the MRIs, the physician told the patient that his discomfort is the result of spinal stenosis. What are the causes of spinal stenosis?
Spinal stenosis may be congenital (a malformed vertebra) or acquired (caused by degeneration of structures related to the exit of the spinal nerves). Examples include buckling or calcification of the ligamentum flavum, the development of osteophytes around the zygapophysial joints or IV discs, or IV disc bulging or herniation.
A 67-year-old man who has been a smoker for most of his life complains of a "stiff neck." On physical examination, his range of neck motion is markedly limited. He experiences only mild discomfort in his neck, especially in the mornings, but recently has had episodes of "pins and needles" (numbness and tingling) and some weakness in his right shoulder and arm. His history reveals that his right hip was replaced 5 years ago due to chronic pain when walking and standing. Plain film radiographs reveal a hyperextension deformity of the neck, with narrowed IV disc spaces especially at the C3/4 and C4/5 levels, with osteophytes at the margins of the vertebral bodies and articular processes. The physician diagnoses the patient with spondylosis and osteoarthritis. What might relieve pain produced by cervical disc degeneration?
Superior traction of the head may relieve the pain and numbness caused by narrowing of the IV foramina and pressure on the zygapophysial joint capsules.
A 51-year-old man was waiting for a traffic light to turn green when his car was "rear-ended." His body was pushed forward and his head thrown violently backward. He suffered a slight concussion and felt shaky. When he talked to the man who had hit his car and to the traffic officer, he informed them that he was not badly hurt. The officer noted that the head restraint in his car was not raised to the level that would prevent hyperextension of his neck. The next morning the man's neck was stiff and painful, and he felt pain on the left side of his neck and in his left arm. Movement of his head aggravated the neck pain. He decided to visit his physician. Physical Examination: The physician observed that the man held his head rigidly and tilted it to the right. She also observed that his chin was pointed to the left and that his neck was slightly flexed. Palpation of the posterior aspect of his neck revealed some tenderness over the spinous processes of his inferior cervical vertebrae. His biceps reflex was also weak on the left side. She ordered a radiographical study of the cervical region of his vertebral column. Radiology Report: The IV discs between vertebra C5 and C6 and between C6 and C7 were thin, and there were small fringes of bone on the opposing edges of the bodies of vertebrae C5, C6, and C7. Diagnosis: Hyperextension injury of the neck. What is the anatomical basis for the patient's concussion, stiff neck, and pain in his neck and arm?
The association of rear-end automobile collisions and hyperextension injuries of the soft tissues of the cervical region of the vertebral column is well known. Head restraints (not "headrests") and bucket seats have been designed to minimize these injuries. However, a head restraint is useless if it is not raised so that the head will hit it if a rear-end collision occurs. The mechanism of injury in the present case was primarily one of rapid hyperextension of the neck. Because the head restraint was not in the correct position, there was nothing to restrict posterior movement of the head and neck. This would likely have occurred because the muscles of the patient's neck, the chief stabilizers of the cervical region of the vertebral column, would be relatively relaxed when the patient was caught off guard. A hyperextension injury of the neck is popularly called a whiplash injury. Many doctors consider this term an unacceptable medical designation because no well-defined clinical syndrome or fixed pathological condition is associated with the injury. A hyperflexion injury of the neck also may have occurred when the head was secondarily flung forward onto his chest. This occurs especially when a rear-end collision pushes a nonmoving vehicle forward into another car. During severe hyperextension of the neck, the anterior longitudinal ligament and neck muscles would be severely stretched, and some of its fibers were probably torn, leading to small hemorrhages. The resulting muscle spasms would account for the patient's stiff and painful neck. The concussion probably resulted from the sudden impact of the frontal and sphenoid bones against the frontal and temporal poles of his brain.
A weight lifter was preparing for competition by lifting increasingly heavy weights. During extension of his vertebral column, he suddenly felt a severe pain in his lower back. Following a physical examination, a physician decided that the patient was experiencing acute back pain. Which back muscles are commonly affected?
The back muscles that are usually involved are the intermediate and deep layers of intrinsic (deep) muscles (e.g., the erector spinae or its subdivisions and the lumbosacral portion of the multifidus).
A physician prepares to perform a lumbar puncture to establish the diagnosis in a patient with suspected intracranial bleeding. Why is the patient's back flexed as much as possible when performing a lumbar puncture?
The backs of patients are flexed when performing a lumbar puncture to separate the spinous processes and laminae as widely as possible to allow the needle to pass into the lumbar cistern containing CSF.
During a routine radiograph of a young man's back, a common congenital defect of the vertebral arch was observed. No signs of back pain were detected. Does this common defect usually cause back pain?
The defect is usually asymptomatic. If more than one lumbar vertebra is affected, the frequency of back pain may be greater.
A 62-year-old man who was a heavy drinker and smoker consulted his physician about feeling a strong pulse in his abdomen. He said it felt like a second heart. He also complained about pain in his abdomen, back, and groin. The physician arranged for radiographic studies, including CT scans. Radiology Report: The plain radiographs showed calcium deposits in the wall of the abdominal aorta and an apparent aneurysm. The CT scans revealed an abdominal aortic aneurysm that was 11 cm in diameter. Before he could be admitted to the hospital for repair of the aneurysm, the patient passed out on his way home and was involved in a car accident. He was rushed to the hospital and admitted to surgery for repair of a ruptured aneurysm. During surgery, extensive mobilization of the aorta was necessary, so several segmental arteries were ligated and divided. Although the aorta was successfully repaired using a Dacron graft, the patient was paraplegic and impotent following the surgery, and his bladder and bowel functions were no longer under voluntary control. Diagnosis: Paraplegia and other neurological deficits resulting in sphincter paralysis in the urinary bladder and anal canal. What are the risk factors known to be associated with the development of aneurysms?
The development of an aneurysm is accelerated by smoking; aneurysms occur three times more frequently in smokers than in nonsmokers.
An asymptomatic 10-year-old female visits her pediatrician for a school physical. The patient's gait is normal. When asked to "stand straight with your weight on both legs," the patient's vertebral column appears straight, but her waist seems slightly high on the left (as if she were standing with her weight on the left limb), and her right shoulder is somewhat higher than the left. When asked, the patient says she writes using her left hand. What condition do these findings suggest?
The findings suggest an idiopathic scoliosis.
An 18-year-old woman was thrown from a horse and sustained a spinal cord injury as the result of severe hyperextension of her neck. Although she was rushed to the hospital, she died after approximately 5 minutes. An autopsy was performed. Autopsy Report: The C1 and C2 vertebrae were fractured as a result of the hyperextension. The spinal cord was severely damaged at the level of articulation of the C2 and C3 vertebrae, with extensive bleeding into the soft tissues of the neck. Diagnosis: Transection of the superior end of the spinal cord resulting from multiple fractures of the cervical vertebrae. Do cervical fractures usually cause death?
The fractures were probably not the cause of the cord injury, since both of these fractures have the effect of enlarging the vertebral canal. Few fatalities are caused by neck fractures, and not all neck fractures result in paralysis. Improper transport techniques, however, can convert a minor injury into a much more serious one.
A father takes his 12-year-old daughter across the country to visit her 75-year-old grandmother, whom neither has seen for several years. The son is shocked to see how much his mother has "aged." She has a markedly decreased stature and is "stooped over" to the point of appearing "humpbacked." She seems unsteady on her feet. At her son's insistence, she visits her physician for the first time in years. History: The patient had a hysterectomy soon after her only pregnancy. She did not nurse her baby. She was told as a child that she had a "milk allergy" and so has avoided dairy products most of her life. She is a smoker and admits to having "an alcoholic drink or two" daily. She reports that she has never taken female hormones and that her mother took on a similar appearance in her advanced years. She says she has had headaches and vision problems. She has stopped wearing her glasses (bifocals) because they seem to make her headaches worse. Physical Examination: Excess thoracic kyphosis with compensating cervical extension. She has had a decrease in her weight as well as a marked decrease in height (nearly 3 inches shorter than reported on her driver's license, which expired 5 years ago). Radiology Report: Excess thoracic kyphosis due to several wedged, flattened and biconcave thoracic vertebrae. The decrease in her bone mass is apparent radiographically. Diagnosis: Osteoporosis, markedly affecting the thoracic vertebrae. What counseling should the granddaughter receive from the physician?
The granddaughter should be counseled regarding her risks for developing osteoporosis and educated about the importance of diet (particularly calcium intake) during the formative years and the risks of smoking.
A 13-year-old competitive gymnast who practiced 18-20 hours a week on her routines complained of low back pain. A physical examination and radiographs revealed that she had a stress fracture of L5 vertebra. What part of the vertebra is usually involved?
The interarticular parts of the lamina of L5 vertebra are usually involved, especially in persons whose vertebral columns are immature.
While carrying a heavy box of books, a 45-year-old man suddenly experienced severe pain in his lower back. Later, he developed a dull ache in the posterolateral aspect of his left thigh that extended along the calf of his leg into his foot. Lateral deviation of the lumbar region of his vertebral column was also observed. He limped when he walked because he could not fully extend his thigh. His family physician recommended backrest and referred the patient to a back specialist. Physical Examination: The orthopedist observed that the man's back muscles were in spasm. When asked to indicate the site of the most severe pain, the man pointed to his lower lumbar region. During the examination, no ankle reflex was observed on the left side. He experienced increased pain when the physician raised his extended lower limb on that side. The orthopedist arranged for a radiographical study and MRIs of the man's lower back. Radiology Report: The radiographs showed a slight narrowing of the space between the vertebral bodies of L5 and S1. MRI showed that the nucleus pulposus of the L5/S1 IV disc was protruding. Diagnosis: Posterolateral herniation of the nucleus pulposus of the IV disc between L5 and S1. What produced the lumbar deviation?
The lumbar deviation of the patient's vertebral column was produced by spasm of the intrinsic back muscles.
An asymptomatic 10-year-old female visits her pediatrician for a school physical. The patient's gait is normal. When asked to "stand straight with your weight on both legs," the patient's vertebral column appears straight, but her waist seems slightly high on the left (as if she were standing with her weight on the left limb), and her right shoulder is somewhat higher than the left. When asked, the patient says she writes using her left hand. If gait is normal, the vertebral column appears generally straight, and the patient is asymptomatic, is concern, or treatment justified?
The most common form of scoliosis involves an idiopathic (cause unknown) onset in females at 8-10 years of age, progressing throughout adolescence. Spinal growth is usually complete in females 18-24 months after menarche (onset of menses), and thus preventive treatment is no longer possible. Idiopathic scoliosis not only is potentially disfiguring but may cause life-long problems with backache and possible disc degeneration and may also affect lifestyle, career choices (e.g., military eligibility), etc. Early detection may enable treatment with only exercise and posture instruction. Traditionally, treatment has involved the wearing of a supportive (Milwaukee) brace up to 23 hours per day for several years. Transcutaneous electrical stimulation of muscles has been used more recently. Late detection or failure of more conservative treatments requires surgical intervention.
Concerned friends took a female college student to the student infirmary because she suffered a sudden onset of fever, nausea, and vomiting. She told the admitting nurse that she had "a massive headache" that is worse when she is upright and walking and that it hurts to turn her head. The campus has not been experiencing episodes of flu, and the physician on call suspected meningitis. Which symptom, in combination with the others, is most suggestive of meningitis?
The most pathognomonic (disease-specific) symptom for meningitis is the stiff neck (in combination with the other symptoms) due to the meningeal inflammation
A 51-year-old man was waiting for a traffic light to turn green when his car was "rear-ended." His body was pushed forward and his head thrown violently backward. He suffered a slight concussion and felt shaky. When he talked to the man who had hit his car and to the traffic officer, he informed them that he was not badly hurt. The officer noted that the head restraint in his car was not raised to the level that would prevent hyperextension of his neck. The next morning the man's neck was stiff and painful, and he felt pain on the left side of his neck and in his left arm. Movement of his head aggravated the neck pain. He decided to visit his physician. Physical Examination: The physician observed that the man held his head rigidly and tilted it to the right. She also observed that his chin was pointed to the left and that his neck was slightly flexed. Palpation of the posterior aspect of his neck revealed some tenderness over the spinous processes of his inferior cervical vertebrae. His biceps reflex was also weak on the left side. She ordered a radiographical study of the cervical region of his vertebral column. Radiology Report: The IV discs between vertebra C5 and C6 and between C6 and C7 were thin, and there were small fringes of bone on the opposing edges of the bodies of vertebrae C5, C6, and C7. What muscles were probably affected?
The musculocutaneous nerve (derived from spinal segments/nerves C5 and C6) supplies the biceps (brachii) muscle, and the biceps reflex is also mediated through spinal segments/nerves C5 and C6.
A 51-year-old man was waiting for a traffic light to turn green when his car was "rear-ended." His body was pushed forward and his head thrown violently backward. He suffered a slight concussion and felt shaky. When he talked to the man who had hit his car and to the traffic officer, he informed them that he was not badly hurt. The officer noted that the head restraint in his car was not raised to the level that would prevent hyperextension of his neck. The next morning the man's neck was stiff and painful, and he felt pain on the left side of his neck and in his left arm. Movement of his head aggravated the neck pain. He decided to visit his physician. Physical Examination: The physician observed that the man held his head rigidly and tilted it to the right. She also observed that his chin was pointed to the left and that his neck was slightly flexed. Palpation of the posterior aspect of his neck revealed some tenderness over the spinous processes of his inferior cervical vertebrae. His biceps reflex was also weak on the left side. She ordered a radiographical study of the cervical region of his vertebral column. Radiology Report: The IV discs between vertebra C5 and C6 and between C6 and C7 were thin, and there were small fringes of bone on the opposing edges of the bodies of vertebrae C5, C6, and C7. What spinal nerve root was probably compressed?
The pain in the patient's left shoulder and the weakness of his biceps reflex on the left likely resulted from compression of the left C6 spinal nerve root, possibly by a posterolateral herniation of the IV disc between vertebrae C5 and C6.
An 18-year-old woman was thrown from a horse and sustained a spinal cord injury as the result of severe hyperextension of her neck. Although she was rushed to the hospital, she died after approximately 5 minutes. An autopsy was performed. Autopsy Report: The C1 and C2 vertebrae were fractured as a result of the hyperextension. The spinal cord was severely damaged at the level of articulation of the C2 and C3 vertebrae, with extensive bleeding into the soft tissues of the neck. Diagnosis: Transection of the superior end of the spinal cord resulting from multiple fractures of the cervical vertebrae. What associated structures of the vertebral column were probably also ruptured?
The patient's anterior longitudinal ligament and the IV disc between vertebrae C2 and C3 were probably also ruptured. As the patient hit the ground, hyperextending her neck, her cranium and vertebrae C1 and C2 were probably separated from the rest of her vertebral column. As a result, the dislocation most likely sheared her spinal cord at the C2 and C3 vertebral level. The violent dislocation at this level is likely to have ruptured one or both vertebral arteries, accounting for the extensive bleeding.
While carrying a heavy box of books, a 45-year-old man suddenly experienced severe pain in his lower back. Later, he developed a dull ache in the posterolateral aspect of his left thigh that extended along the calf of his leg into his foot. Lateral deviation of the lumbar region of his vertebral column was also observed. He limped when he walked because he could not fully extend his thigh. His family physician recommended backrest and referred the patient to a back specialist. Physical Examination: The orthopedist observed that the man's back muscles were in spasm. When asked to indicate the site of the most severe pain, the man pointed to his lower lumbar region. During the examination, no ankle reflex was observed on the left side. He experienced increased pain when the physician raised his extended lower limb on that side. The orthopedist arranged for a radiographical study and MRIs of the man's lower back. Radiology Report: The radiographs showed a slight narrowing of the space between the vertebral bodies of L5 and S1. MRI showed that the nucleus pulposus of the L5/S1 IV disc was protruding. Diagnosis: Posterolateral herniation of the nucleus pulposus of the IV disc between L5 and S1. What is the anatomical basis for herniation (protrusion) of an IV disc and the resulting low back pain?
The patient's low back pain and muscle spasm, sometimes called lumbago, was probably caused by a sudden increase in the pressure on the nucleus pulposus of the IV disc between vertebrae L5 and S1 in the presence of a worn and torn and therefore vulnerable anulus fibrosis. The increased pressure on the IV disc ruptured the anulus fibrosus, enabling protrusion of the nucleus pulposus. The nucleus is located eccentrically, posterior to the center of the disc. Consequently, the anulus is thinner posteriorly. The posterolateral part of the anulus is not supported by either the posterior or anterior longitudinal ligaments; therefore, a herniated nucleus pulposus from the IV disc usually protrudes posterolaterally. The sudden rupture of the anulus and impingement upon the posterior longitudinal ligament—both provided with pain receptors innervated by (recurrent) meningeal nerves—is the likely cause of the initial acute lower back pain, followed by pain associated with hemorrhage, muscle spasm, and edema (swelling). Muscle spasm is a reflexive response to the pain that has a protective, splinting effect on the vertebral column, although it can be very painful in itself.
A 21-year-old man was involved in a head-on collision. When removed from his sports car, he complained of loss of sensation and voluntary movements in his lower limbs. Upper limb movements were also impaired, particularly in his hands. The patient was kept warm and immobilized until the ambulance arrived. Using a proper transport technique (spine board with the head and neck stabilized), the patient was taken to the emergency department. After examination at the hospital, radiographs of his vertebral column were taken. Radiology Report: Radiographs showed severe dislocation of C6 vertebra on C7 and a chip fracture of the anterosuperior corner of the body of C7. Diagnosis: Dislocation of C6 and C7 vertebrae. Surgical Treatment: Open reduction was carried out, and the spinous processes of C6 and C7 vertebrae were wired together to hold them in normal relation to each other. The reduction was maintained by immobilization of the neck in a plastic collar. Which ligaments binding the vertebrae together were probably strained and/or torn?
The posterior longitudinal and interspinous ligaments, and the anulus fibrosus, ligamenta flava, and articular capsules of the zygapophysial joints would have been severely injured. Because dislocation occurred in this case, the posterior longitudinal ligament and the ligamenta flava were severely stretched and were probably torn. As the anulus fibrosus of the IV disc attaches to the compact bony rims on the articular surfaces of the vertebral discs, its posterior part would also have been stretched and torn at the C6 and C7 level. It is possible that protrusion of the nucleus pulposus of the IV disc between these vertebrae also occurred because these nuclei are semifluid in young adults.
While carrying a heavy box of books, a 45-year-old man suddenly experienced severe pain in his lower back. Later, he developed a dull ache in the posterolateral aspect of his left thigh that extended along the calf of his leg into his foot. Lateral deviation of the lumbar region of his vertebral column was also observed. He limped when he walked because he could not fully extend his thigh. His family physician recommended backrest and referred the patient to a back specialist. Physical Examination: The orthopedist observed that the man's back muscles were in spasm. When asked to indicate the site of the most severe pain, the man pointed to his lower lumbar region. During the examination, no ankle reflex was observed on the left side. He experienced increased pain when the physician raised his extended lower limb on that side. The orthopedist arranged for a radiographical study and MRIs of the man's lower back. Radiology Report: The radiographs showed a slight narrowing of the space between the vertebral bodies of L5 and S1. MRI showed that the nucleus pulposus of the L5/S1 IV disc was protruding. Diagnosis: Posterolateral herniation of the nucleus pulposus of the IV disc between L5 and S1. Why did the patient experience pain in the posterolateral aspect of his thigh, leg, and foot?
The protruding nucleus pulposus often affects one or more spinal nerve roots. A posterolateral herniation of the nucleus pulposus through a degenerated anulus fibrosus compresses the spinal nerve roots passing inferiorly, posterior to the IV disc, on its way to the IV foramen one level below the level of the herniation. In this case, the compressed nerve roots were most likely those of spinal nerve S1. Compression of the roots of this nerve would cause pain in the S1 dermatome that extends from the sacroiliac and buttock regions to the posterior aspect of the thigh, leg, and lateral foot. Extrusion of disc material can also cause inflammation of the roots due to chemical irritation from substances released from the nucleus pulposus. Paresthesia ("pins and needles" sensation) also occurs in the dermatome.
During a routine radiograph of a young man's back, a common congenital defect of the vertebral arch was observed. No signs of back pain were detected. Are the spinal cord and meninges usually normal in people with spina bifida occulta?
The spinal cord and meninges are usually normal in people with spina bifida occulta.
A 62-year-old man who was a heavy drinker and smoker consulted his physician about feeling a strong pulse in his abdomen. He said it felt like a second heart. He also complained about pain in his abdomen, back, and groin. The physician arranged for radiographic studies, including CT scans. Radiology Report: The plain radiographs showed calcium deposits in the wall of the abdominal aorta and an apparent aneurysm. The CT scans revealed an abdominal aortic aneurysm that was 11 cm in diameter. Before he could be admitted to the hospital for repair of the aneurysm, the patient passed out on his way home and was involved in a car accident. He was rushed to the hospital and admitted to surgery for repair of a ruptured aneurysm. During surgery, extensive mobilization of the aorta was necessary, so several segmental arteries were ligated and divided. Although the aorta was successfully repaired using a Dacron graft, the patient was paraplegic and impotent following the surgery, and his bladder and bowel functions were no longer under voluntary control. Diagnosis: Paraplegia and other neurological deficits resulting in sphincter paralysis in the urinary bladder and anal canal.A 62-year-old man who was a heavy drinker and smoker consulted his physician about feeling a strong pulse in his abdomen. He said it felt like a second heart. He also complained about pain in his abdomen, back, and groin. The physician arranged for radiographic studies, including CT scans. Identify the arteries that supply the spinal cord.
The spinal cord receives its blood supply from two sources: the vertebral arteries and segmental medullary arteries. At the superior end of the cord, the vertebral arteries give rise to three longitudinal arteries (two posterior and one anterior) that run the length of the cord. Eight to ten segmental medullary arteries occur at irregular intervals, arising from the spinal branches of the vertebral arteries or from the segmental arteries, to reinforce the blood supply to the longitudinal arteries.
During a violent altercation at a local park, a 16-year-old youth was stabbed with a knife in the posterior aspect of the neck. As he ducked to avoid his attacker, he flexed his neck. Much to the surprise of his assailants, the youth fell to the ground and was completely immobilized from the neck down. How was it possible for the knife to reach a site where it could cause such serious injury?
The spinous processes and laminae of the vertebral arches usually protect the spinal cord during injuries to the posterior aspect of the neck, even those resulting from stab wounds. When the neck is flexed, the spaces between these spinous processes and laminae of the vertebral arches increase, permitting a knife to pass between them, enter the vertebral canal, and sever the cervical region of the spinal cord. Verify this movement of the cervical vertebrae during flexion by placing your hand on the back of your neck with the tip of your little finger on the external occipital protuberance and your thumb on the spinous process of C7 (vertebra prominens), then flexing your neck as much as possible. Note that the space between your fingers widens, reflecting the widening of the spaces between the spinous processes of vertebrae C2-C7. Had the youth been stabbed in the same place when his head was erect, he probably would not have been severely injured. The knife likely would have struck the spinous processes and/or laminae of the cervical vertebrae and glanced off without damaging the spinal cord.
A 51-year-old man was waiting for a traffic light to turn green when his car was "rear-ended." His body was pushed forward and his head thrown violently backward. He suffered a slight concussion and felt shaky. When he talked to the man who had hit his car and to the traffic officer, he informed them that he was not badly hurt. The officer noted that the head restraint in his car was not raised to the level that would prevent hyperextension of his neck. The next morning the man's neck was stiff and painful, and he felt pain on the left side of his neck and in his left arm. Movement of his head aggravated the neck pain. He decided to visit his physician. Physical Examination: The physician observed that the man held his head rigidly and tilted it to the right. She also observed that his chin was pointed to the left and that his neck was slightly flexed. Palpation of the posterior aspect of his neck revealed some tenderness over the spinous processes of his inferior cervical vertebrae. His biceps reflex was also weak on the left side. She ordered a radiographical study of the cervical region of his vertebral column. Radiology Report: The IV discs between vertebra C5 and C6 and between C6 and C7 were thin, and there were small fringes of bone on the opposing edges of the bodies of vertebrae C5, C6, and C7. Diagnosis: Hyperextension injury of the neck. What probably caused the thinning of the patient's IV discs and the formation of the bony fringes on the edges of his cervical vertebral bodies?
The thinning of the IV discs in the cervical region probably resulted from desiccation (loss or removal of fluid) of the nuclei pulposi of the IV discs. Degenerative disc disease often occurs with advancing age and may result in bulging of the anuli fibrosi of the IV discs. Formation of fringes of subperiosteal new bone (osteophytes) on the edges of the vertebral bodies occurs in older persons. These fringes of bone can also compress the spinal nerve roots.
A weight lifter was preparing for competition by lifting increasingly heavy weights. During extension of his vertebral column, he suddenly felt a severe pain in his lower back. Following a physical examination, a physician decided that the patient was experiencing acute back pain. What symptoms and signs would you anticipate in persons with this condition?
The usual symptom of muscular spasm is a constant, dull ache in the lower back. The obvious sign is a limited range of motion of the vertebral column and large areas of tenderness.
A weight lifter was preparing for competition by lifting increasingly heavy weights. During extension of his vertebral column, he suddenly felt a severe pain in his lower back. Following a physical examination, a physician decided that the patient was experiencing acute back pain. What was the likely cause of the man's acute back pain?
The weight lifter probably experienced a severe back spasm.
An asymptomatic 10-year-old female visits her pediatrician for a school physical. The patient's gait is normal. When asked to "stand straight with your weight on both legs," the patient's vertebral column appears straight, but her waist seems slightly high on the left (as if she were standing with her weight on the left limb), and her right shoulder is somewhat higher than the left. When asked, the patient says she writes using her left hand. What is the significance of knowing whether the patient is right- or left-handed?
There may be a slight but normal lateral convexity toward an individual's dominant side. In this case, however, the curvature was to the right, and the patient indicated she was left-handed.
A physician prepares to perform a lumbar puncture to establish the diagnosis in a patient with suspected intracranial bleeding. Why are these vertebral levels used?
These vertebral levels are safe for teenagers and adults because the spinal cord usually ends at L2/L3 vertebral level in teenagers and at the L1/L2 level in most adults. Hence, the inferior end of the dural sac contains the cauda equina and no spinal cord.
A 13-year-old competitive gymnast who practiced 18-20 hours a week on her routines complained of low back pain. A physical examination and radiographs revealed that she had a stress fracture of L5 vertebra. What is the clinical name given to this bony defect?
This defect, called spondylolysis, may result in anterior movement of the body of L5 vertebra on the sacrum (spondylolisthesis).