Chapter 16 Patho

a patient is hit in the temporal portion of his skull. although initial loss of consciousness occurs, the patient soon awakens and is conversant. Three hours later vomiting, drowsiness, and confusion are noted. These symptoms are most likely related to which type of brain injury?

"epidural" - epidural hematoma: hit in the temporal area with damage to the middle meningeal artery. The patient will lose consciousness at the time of injury, but there may be a period where consciousness is regained. Patient then becomes more confused and drowsy.

which of the following statements is true regarding grading of the astrocytoma?

"grades III and IV are treated with surgery" - Grade 1: treated with surgery & follow up CT scans - Grade II: treated surgically if accessible and then radiation - Grade III & IV : treated with surgery - Grade III: well circumscribed

it is true that spinal shock

"involves all skeletal muscles below the level of injury"

a patient is experiencing pain that courses over the buttocks and into the calf and ankle. this is suggestive of a herniated disk at which vertebral level?

"lumbar" - lumbar area associated with pain that radiates along the sciatic nerve and courses over the butt and into the calf and ankle.

the most common cause of TBI is

"motor vehicle accidents" - car accidents: 50% - falls: 21% - sports-related events & violence: 10 & 12%

after a fall at home, an elderly patient experiences a hematoma located on the top of the brain. The hematoma is most likely:

"subdural" - subdural hematomas: bleeding between the dura mater and the brain. develop rapidly, commonly within hours and usually are located at the top of the skull

it is true that an acute cerebrovascular accident (CVA) is:

"the leading cause of disability in the united states" - CVAs are the leading cause of disability and the third leading cause of death. there are 500,000 stroke victims/year, 5-14% have a second stroke within 1 year

saccular aneurysms

(berry) result from congenital abnormalities in tunica media

fusiform aneurysms

(giant), less common - result of diffuse arteriosclerotic changes -act as space occupying lesions

two types of primary brain injury

1) focal 2) diffuse

what are the 6 classifications of stoke

1. ischemic stroke 2. transient ischemic attacks 3. chromatic strokes 4. embolic stroke 5. lacunar stroke 6. hypo perfusion

autonomic hyperreflexia (dysreflexia)

sudden massive reflex sympathetic discharge associated with spinal cord injury at level T6 or above.

premonitory migraine phase

symptoms hours to days before onset of aura or headache -tiredness, irritability, loss of concentration, stiff neck, food cravings

Moderate DAI

unconsciousness (coma) lasts days to weeks

compressed fracture

vertebral body compress anteriorly

comminuted (burst) fracture

vertebral body shattered into several fragments

thrombotic strokes

when the clot detaches, travel upstream and obstructs blood flow

How is an encapsulated CNS tumor different from a nonencapsulated CNS tumor?

Typically, nonencapsulated or invasive tumors invade and destroy adjacent normal CNS tissue, and more distal neural and vascular tissues are displaced and compressed, causing ischemia, edema, and increased intracranial pressure. Encapsulated tumors do not invade adjacent tissue; however, they displace and compress adjacent and distant tissues. Encapsulated tumors also produce ischemia, edema, and increased pressure.

simple fracture

a single break usually affecting transverse or spinous processes

what can trigger a migraine

altered sleep patterns, skipping meals, overexertion, weather change, stress, hormonal changes, chemicals

Migraine

an episodic neurologic disorder characterized by a headache lasting 4 to 72 hours. It is diagnosed when any two of the following features occur: unilateral head pain, throbbing pain, pain worsens with activity, moderate or severe pain intensity; and at least one of the following: nausea and/or vomiting, or photophobia and phonophobia. Age of onset is childhood, adolescence, or young adulthood, and they occur more frequently in women, and there is often a family history of headaches.

cluster headaches

are one of a group of disorders referred to as trigeminal autonomic cephalagias (headaches involving the autonomic division of the trigeminal nerve). They occur in one side of the head. The pain may alternate sides with each headache episode and is severe, stabbing, and throbbing. These uncommon headaches occur in clusters (up to 8 attacks per day) and last for minutes to hours for a period of days, followed by a long period of spontaneous remission. Age of onset is young adulthood or middle age, and they primarily occur in men. Family history of headaches is not necessarily a factor.

hypoperfusion

associated with systemic hypo perfusion resulting in inadequate blood supply to brain

migraine aura

aura symptoms last up to 1 hour. -visual, sensory, motor

subdural hematoma

bleeding between the dura mater and brain

epidural hematoma

bleeding between the dura mater and skull

hemorrhagic stroke

bleeding causes compressed brain tissue, leading to ischemia, edema, and increased ICP and necrosis

Intracerebral hematoma

bleeding within the brain

Subarachnoid hemorrhage (SAH)

blood escaping from injured vessel into subarachnoid space

Contusions

brain bruising from blood leaking from an injured vessel, causes 3 hematomas

Post traumatic seizures

can occur within days or up to 2-5 years post injury

cerebral infarction

caused by occlusion in the brain - loss of blood flow

mild DAI

coma lasts 6-24 hours

mild concussion

confusion for 1+ min, no loss of unconsciousness

Degenerative disk disorders (DDD)

continuous vertical compression of the spine - related to normal aging -spondylolysis -spondylolisthesis -spinal stenosis

spinal cord injury

damage to neural tissues by compressing tissue, pulling or exerting tension on tissue, or shearing tissues so that they slide into one another

spondylolisthesis

defects allow vertebrae to slide anteriorly in relation to vertebrae below (L5-S1) -pain in lower back and butt, muscle spasms in lower back and legs, tightened hamstrings

transient ischemic attacks (TIA)

episodes of neurologic dysfunction lasting no more than 1 week

migraine

episodic neurologic disorder, a headache lasting 4-72 hours

post concussion syndrome

headaches, dizziness, fatigue, anxiety etc -lasts for weeks or months post concussion

what is the third most common cause of a cerebrovascular accident

hemorrhagic stroke

focal brain injury

impacts on area of the brain -includes contusion, laceration, hematoma, open head trauma

secondary brain injury

indirect consequence of the primary injury; ex trauma and stroke

quadriplegia

injuries of cervical spinal cord - paralysis of all 4 extremities

paraplegia

injuries of thoracic spinal cord -paralysis of lower extremities including both legs

coup injury (closed head trauma)

injury directly below the point of impact

severe DAI

injury involves both hemispheres and brainstem. coma lasts months

contrecoup injury (closed head trauma)

injury on the side opposite of impact

embolic stroke

involves fragments that break from a thrombus formed outside of the brain

recovery phase

irritability, fatigue, depression may take hours to days to resolve

classic cerebral concussion

loss of consciousness for >6 hours. confusion for hours to days

arteriovenous malformation (AVM)

mass of dilated vessels between the arterial and venous systems; occurring in any part of the brain

diffuse brain injury (DAI)

results from shearing forces that result in axonal damage ranging from concussion to severe DAI state

intracranial aneurysms classifications (2)

saccular & fusiform

axonal damage

shearing, tearing, stretching of nerve fibers -reduces the speed of information processing and responding and disrupts persons attention span

what are some vertebral injuries

simple fracture compressed fracture comminuted (burst) fracture dislocation

risk factors for strokes

smoking, diabetes, thrombocythemia, high cholesterol

A trauma patient diagnosed with a brain contusion experiences changes in attention, memory, affect and emotion. In which region of the brain is the contusion most likely located?

"Frontal" - contusions commonly found in the frontal lobes, particularly at the poles and along the inferior orbital surfaces. Result in changes in attention, memory, and executive attentional functioning

kemig sign

straightening the knee with the hip and knee in flexed position produces pain in the back and neck

Which is accurate regarding subarachnoid hemorrhages? They are

"a particular risk for individuals with an intracranial aneurysms" - hypertension and trauma are also risk factors, mortality is over 50%

which is correct regarding hemorrhagic strokes? they

"are commonly caused by hypertension" - untreated hypertension is generally the cause of hemorrhagic stroke. It's the 3rd most common cause of CVA.

The person at highest risk for TBI is

"black and economically disadvantaged" - children 0-4 yrs - adolescents 15-19 yrs - adults 65 + - males - blacks - lower and median income families

spondylolysis

structural defect of the spine with displacement of the vertebrae -mostly L5 -lower back and limb pain

which is true regarding metastatic brain tumors?

"carcinomas are disseminated to the brain from the circulation" - 2/3 of metastatic tumors are located within the brain, 1/3 are located in the extradural spaces.

What are the major risk factors for TBI

Car accidents in children, falls in older adults

SAH can be classified as what?

Grade I, II, III, IV ,V

What are three types of spinal cord tumors?

The types of spinal cord tumors include intramedullary tumors that originate from the neural tissue, intradural tumors that arise from meninges or nerve roots, and extradural tumors that arise from epidural tissue or vertebral structures. Both intradural and extradural tumors are called extramedullary tumors. Metastatic spinal cord tumors are usually carcinomas, lymphomas, or myelomas.

It is correct to assume that Grade III and grade IV astrocytomas are:

" commonly found in the frontal lobe and cerebral hemisphere" - also found twice as often in men than women

a patient has a brain abscess with a decreased necrotic center and mature collagen. This is most consistent with which stage?

" early capsule formation"

which is true regarding meningitis?

" tubercular meningitis has a 90% recovery rate, if diagnosed early" - fungal meningitis is uncommon. - aseptic meningitis is most commonly caused by a virus - bacterial meningitis is caused by primary infection of pia mater and arachnoid

A patient experiences a vertebral fracture in which the C1 vertebrae is fractured into several fragments. This type of fracture can be described as:

"Comminuted fracture" - Also called burst fracture, the vertebral body is shattered into several fragments.

spinal shock

-cessation of all motor, sensory, reflex, and autonomic functions below the transected area. -loss of motor and sensory function depends on the level of injury -can be quadriplegia or paraplegia

migraine can be classified as

-migraine with aura (visual, sensory, language and motor disturbance) -migraine without aura

Closed head trauma

-more common -blunt: dura remains intact and brain tissues are not exposed to environment -can be coup or contrecoup

Why do extradural, subdural, and intracerebral hematomas act like expanding masses?

These three injuries all result in bleeding into a restricted space. Because the blood is unable to spread widely throughout the brain, it accumulates at the site of injury, increases in mass, and compresses adjacent tissue. It actually is an expanding mass. The issue with this is that pressure accumulates within the enclosed space of the skull, causing an increase in intracranial pressure that can be life-threatening.

what are the 4 phases of a migraine attack

-premonitory -migraine aura -headache phase - recovery phase

How can bacterial meningitis lead to an amputation?

Acute infectious purpura fulminans can sometimes occur with bacterial meningitis. It is a rare rapidly progressive syndrome of hemorrhagic infarction of the skin and disseminated intravascular coagulation that can lead to multiple organ failure, ischemic necrosis of digits and limbs with amputation required, and death. It is caused by bacterial endotoxin and inflammatory cytokines.

How is an AVM different from an aneurysm?

An AVM is a tangled mass of dilated blood vessels in the brain in which blood is shunted directly from the arterial to the venous system. Aneurysms are localized, abnormally dilated portions of blood vessels (usually arteries) caused by weakness of the vessel wall. Intracranial bleeding from an aneurysm is caused by rupture of the thin wall of the aneurysm.

Why is atherosclerosis a risk factor for thrombotic stroke?

Atherosclerosis narrows the arteries serving the brain and causes chronic inflammation and endothelial damage of the vessels. The endothelial damage stimulates clotting. When thrombi form in vessels already narrowed by atherosclerotic plaques, total occlusion and stroke can result. Clot formations in the veins when breaking off usually cause pulmonary issues or a pulmonary embolism. Clots that go to the aorta can result in myocardial infarction, if it lodges in the coronary arteries, or a stroke if it lodges in the cerebral arteries.

What are the autoimmune mechanisms that cause MS lesions?

Autoreactive T and B cells cross the blood-brain barrier and recognize myelin and oligodendrocyte autoantigens, triggering inflammation and loss of oligodendrocytes (myelin producing cells). Activation of microglia cells (brain macrophages) contributes to inflammation and injury with plaque formation and axonal degeneration. Loss of myelin disrupts nerve conduction with subsequent death of neurons and brain atrophy. Scar tissue that results from the damage is called a lesion.

How is a concussion different from a contusion?

Concussions and contusions are both primary injuries resulting from head trauma, usually blunt trauma. They share clinical manifestations of decreased level of consciousness, headache, decreased respirations, decreased heart rate and blood pressure, confusion, vomiting, and retrograde amnesia. However, a mild concussion is a less severe problem. It is a diffuse, transient injury causing no focal damage. Decreased level of consciousness usually lasts less than 5 minutes, and no abnormalities are seen on computed tomography (CT) scan. Classic cerebral concussion can cause loss of consciousness for as long as 6 hours, but symptoms usually do resolve. Contusion is a more serious injury, with focal bleeding and inflammation visible on CT scan. Intracranial pressure is increased, and alterations in level of consciousness generally last longer than 5 minutes.

What type of imaging is used to diagnose strokes

Ct, follow up with MRI, and carotid ultrasound

Why is head motion the principal causative mechanism of diffuse brain injury?

Diffuse axonal injury follows blunt head trauma or shaking that jars the brain against the skull. The mechanical shaking of the brain by acceleration, deceleration, or rotational forces shears and tears the nerve fibers, resulting in stripping the myelin from the axons.

Where in the peripheral nervous system can disease occur?

Disease processes may injure the axons traveling to and from the brainstem and spinal cord neuronal cell bodies. Injury may affect a distinct anatomic area on the axon, or the spinal nerves may be injured at the roots, at the plexus before peripheral nerve formation, or at the nerves themselves. The cranial nerves do not have roots or plexuses and are affected only within themselves. Autonomic nerve fibers may be injured as they travel in certain cranial nerves and emerge through the ventral root and plexuses to travel in the peripheral nerves of the body.

Why do lacunar strokes involve small infarcts?

Lacunar strokes are caused by atherosclerosis associated with hypertension and diabetes mellitus. This combination predisposes the small vessels of the basal ganglia, internal capsule, and pons to clot formation. The very small thrombi result in infarcts that are less than 1 cm in diameter.

Why do antibodies contribute to the development of myasthenia gravis?

Myasthenia gravis results from a defect in nerve impulse transmission at the neuromuscular junction. The postsynaptic acetylcholine receptors on the muscle cell's membrane are no longer recognized as "self" and therefore elicit the generation of IgG antibodies produced in opposition to the acetylcholine receptors; these antibodies attach to the receptor sites and block the binding of acetylcholine. Eventually, the antibody action destroys the receptor sites. This causes diminished transmission of the nerve impulse across the neuromuscular junction and a lack of muscle depolarization. Why this autosensitization occurs is not known.

complications of TBI

Post concussion syndrome post traumatic seizures chronic traumatic encephalopathy (CTE)

What are the two classifications of TBI

Primary and secondary

Why do TIA's signs and symptoms resolve completely?

TIAs are probably caused by platelet clumps and result in only intermittent occlusion of circulation or in spasm of a cerebral vessel. Because the period of insufficient perfusion is brief, death of cells and permanent damage to the brain do not occur. When perfusion is restored, symptoms resolve. However, TIAs are an indication of an impending cerebral issue, such as a stroke.

categories of DAI

mild concussion classic cerebral concussion mild DAI Moderate DAI Severe DAI

spinal stenosis

narrowing of the spinal canal, cause pressure on spinal nerves -produces pain, numbness, tingling in the neck hands arms legs

lacunar strokes

occlusion of single, deep, perforating artery causing ischemic lesions - rare

contralateral motor sensory deficits

occur on opposite side of the body from the location of brain lesion

conjugate ipsilateral eye deviation

occur on same side of body as brain lesion

ischemic stroke

occurs when there is obstruction to arterial blood flow

brudzinski sign

passive flexion of the neck produces neck pain and increased rigidity

open head trauma

penetrating trauma; skull fracture with exposure of the cranial vault to environment

chronic traumatic encephalopathy (CTE)

progressive dementing disease that develops with repeated brain injury associated with sports, blast trauma, work related head trauma

herniated intervertebral disk

protrusion of part of the nucleus pulposus -mostly at L5-S1 and L4-5 -extruded pulpous compresses the nerve root causing pain that radiates along the sciatic nerve course

headache phase

throbbing pain on one side of the head, spreads to entire head