Unit 5 - Neurological Alterations - Unit 17 - Neurologic Clinical Assessment and Diagnostic Procedures

31. Which of the following patients may need sedation before having an MRI scan? a. Claustrophobic patient b. Comatose patient c. Elderly patient d. Patient with a spinal cord injury

ANS: A The magnetic resonance imaging procedure is lengthy and requires the patient to lie motionless in a tight, enclosed space. Mild sedation, a blindfold, or both may be necessary for claustrophobic patients.

1. A score of 6 on the Glasgow Coma Scale (GCS) indicates a. a vegetative state. b. paraplegia. c. coma. d. obtundation.

ANS: C The best possible score on the Glasgow Coma Scale (GCS) is 15, and the lowest score is 3. Generally, a score of 7 or less on the GCS indicates coma. Originally, the scoring system was developed to assist in general communication concerning the severity of neurologic injury.

29. The most serious complication of lumbar puncture in a critically ill patient is a. bacterial meningitis. b. dural tear. c. brainstem herniation. d. spinal cord trauma.

ANS: C Two life-threatening risks associated with lumbar puncture include possible brainstem herniation, if intracranial pressure is elevated, and respiratory arrest associated with neurologic deterioration.

36. The most clinically significant ICP waveform is a. A waves. b. B waves. c. C waves. d. D waves.

ANS: A A waves are the most clinically significant of the three types. They usually occur in an already elevated baseline intracranial pressure (ICP) (>20 mm Hg) and are characterized by sharp increases in ICP of 30 to 69 mm Hg, which plateau for 2 to 20 minutes and then return to baseline. B waves appear to reflect fluctuations in cerebral blood. C waves are small, rhythmic waves that occur every 4 to 8 minutes at normal levels of ICP. They are related to normal fluctuations in respiration and systemic arterial pressure.

32. An important intervention before and after a cerebral angiogram is a. ensuring that the patient is adequately hydrated. b. maintaining the patient on an NPO status. c. administering antibiotics to the patient. d. keeping the patient flat in bed for 24 hours.

ANS: A After the cerebral angiogram, adequate hydration is necessary to assist the kidneys in clearing the heavy dye load. Inadequate hydration may lead to renal dysfunction and renal shutdown.

21. A patient is admitted to the critical care unit with a subdural hematoma. The GCS is used to assess his level of consciousness. In assessing the patient's best motor response, the movement that receives the lowest score is a. decerebrate posturing. b. localizing pain. c. withdrawing from pain. d. decorticate posturing.

ANS: A Extension, or decerebrate posturing, to noxious stimuli receives a score of 2 on the Glasgow Coma Scale. The only lower score is 1, which is a flaccid response.

37. A critical care patient is diagnosed with massive head trauma. The patient is receiving brain tissue oxygen pressure (PbtO2) monitoring. The nurse recognized that the goal of this treatment is to maintain PbtO2 a. greater than 20 mm Hg. b. less than 15 mm Hg. c. between 15 and 20 mm Hg. d. between 10 and 20 mm Hg.

ANS: A In a patient with head injury, the goal of treatment is to maintain the PbtO2 greater than 20 mm Hg. Factors that decrease PbtO2 include tissue hypoxia, hypocapnia, hypovolemia, decreased blood pressure, low hemoglobin levels, intracranial hypertension, and hyperthermia. Treatment is directed at the underlying cause.

14. Before performing the doll's eye or oculocephalic reflex, the nurse must verify a. the absence of cervical injury. b. the depth and rate of respiration. c. a physician's order to perform the maneuver. d. the patient's ability to follow a verbal command.

ANS: A In an unconscious patient, assessment of ocular function and innervation of the medial longitudinal fasciculus (MLF) is performed by eliciting the doll's eyes reflex. If the patient is unconscious as a result of trauma, the nurse must ascertain the absence of cervical injury before performing this examination.

28. Results from which two procedures complement each other in the preoperative evaluation of the carotid arteries? a. Ultrasound Doppler and magnetic resonance angiography b. Conventional angiography and evoked potential c. CT and magnetic resonance angiography d. Transcranial Doppler and extracranial Doppler

ANS: A Magnetic resonance angiography of the carotid arteries has become an established complement to preoperative ultrasound evaluation. It helps determine the area of salvageable tissue (or penumbra) after acute stroke and head injury.

5. How much of a size difference between the two pupils is still considered normal? a. 1 mm b. 1.5 mm c. 2 mm d. 2.5 mm

ANS: A Pupil size should be documented in millimeters with the use of a pupil gauge to reduce the subjectivity of description. Most people have pupils of equal size, between 2 and 5 mm. A discrepancy up to 1 mm between the two pupils is normal.

20. A patient is admitted to the critical care unit with a subdural hematoma. The GCS is used to assess his level of consciousness. Which statement is true concerning the GCS? a. It provides data about level of consciousness only. b. It is considered equivalent to a complete neurologic examination. c. It is a sensitive tool for evaluation of an altered sensorium. d. It is the most critical assessment parameter to account for possible aphasia.

ANS: A Several points should be kept in mind when the Glasgow Coma Scale is used for serial assessment. It provides data about level of consciousness only, and it should never be considered a complete neurologic examination. Additionally, it is not a sensitive tool for evaluation of an altered sensorium, and it does not account for possible aphasia or mechanical intubation. It is also a poor indicator of lateralization of neurologic deterioration.

19. The clinical manifestations of the Cushing reflex are a. bradycardia, systolic hypertension, and widening pulse pressure. b. tachycardia, systolic hypotension, and tachypnea. c. headache, nuchal rigidity, and hyperthermia. d. bradycardia, aphasia, and visual field disturbances.

ANS: A The Cushing reflex is a set of three clinical manifestations (bradycardia, systolic hypertension, and widening pulse pressure) related to pressure on the medullary area of the brainstem.

22. Considering anatomic location, which cranial nerve will be affected first by downward pressure onto the infratentorial structures? a. III b. VI c. IX d. X

ANS: A With the location of the oculomotor nerve (cranial nerve [CN] III) at the notch of the tentorium, pupil size and reactivity play a key role in the physical assessment of intracranial pressure changes and herniation syndromes. In addition to CN III compression, changes in pupil size occur for other reasons. Large pupils can result from the instillation of cycloplegic agents, such as atropine or scopolamine, or can indicate extreme stress. Extremely small pupils can indicate narcotic overdose, lower brainstem compression, or bilateral damage to the pons.

1. Indications for the use of EEG include (Select all that apply.) a. cerebral infarct. b. metabolic encephalopathy. c. confirmation of brain death. d. altered consciousness. e. all head injuries.

ANS: A, B, C, D Indications for the use of electroencephalography include suspected seizure activity, cerebral infarct, metabolic encephalopathies, altered consciousness, infectious disease, some head injuries, and confirmation of brain death.

4. Identify the sites for monitoring ICP. (Select all that apply.) a. Intraventricular space b. Epidural space c. Jugular veins d. Subdural space e. Parenchyma

ANS: A, B, D, E The five sites for monitoring intracranial pressure are (1) the intraventricular space, (2) the subarachnoid space, (3) the epidural space, (4) the subdural space, and (5) the parenchyma.

2. When assessing motor function, which of the following are correct? (Select all that apply.) a. The presence of a Babinski reflex is an abnormal finding in an adult. b. Lower extremity muscle tone is assessed by asking the patient to push or pull his or her foot against resistance. c. When using noxious stimuli to elicit a motor response, each limb is tested separately. d. Abnormal extension, or decerebrate posturing, indicates a less positive outcome than abnormal flexion. e. Evaluation of deep tendon reflexes is an essential part of the nursing assessment.

ANS: A, C, D The presence of a Babinski response in an adult is indicative of neurologic dysfunction, pushing or pulling against resistance tests muscle strength, and deep tendon reflexes are not routinely checked by the critical care nurse during assessment.

26. Successful completion of digital subtraction angiography requires what participation on the part of the patient? a. Responding appropriately to various commands b. Repositioning at appropriate intervals c. Remaining motionless d. Holding inspiration during imaging

ANS: C The major disadvantage of digital subtraction angiography involves the patient's ability to remain motionless during the entire procedure. Even swallowing significantly interferes with the imaging process.

10. Which of the following statements best describes assessment of arousal? a. It measures content of consciousness and is a higher level function. b. It is an evaluation of the reticular activating system and its connection with the thalamus and the cerebral cortex. c. It becomes a valid parameter when the patient is able to respond to verbal stimuli, such as squeezing the hands on command. d. Noxious stimuli are not to be used as an assessment parameter.

ANS: B Assessment of the arousal component of consciousness is an evaluation of the reticular activating system and its connection with the thalamus and the cerebral cortex. Arousal is the lowest level of consciousness, and observation centers on the patient's ability to respond to verbal or noxious stimuli in an appropriate manner.

18. Symptoms of late stages of intracranial hypertension include a. decreased perfusion of cerebral tissue. b. widening pulse pressure values. c. increased perfusion pressure across the blood-brain barrier. d. decreased intracranial pressure.

ANS: B Attention must also be paid to the pulse pressure because widening of this value may occur in the late stages of intracranial hypertension. With the loss of autoregulation as blood pressure increases, cerebral blood flow (CBF) and cerebral blood volume increase and intracranial pressure (ICP) therefore increases. The mean arterial pressure must be maintained at a level sufficient to produce adequate CBF in the presence of elevated ICP.

24. Which of the following procedures is the diagnostic study of choice for acute head injury? a. Magnetic resonance imaging b. Computed tomography c. Transcranial Doppler d. Electroencephalography

ANS: B Computed tomography offers rapid, convenient, noninvasive visualization of structures and is the diagnostic study of choice for an acute head injury.

13. Testing of extraocular eye movements assesses a. pupillary response to light. b. function of the three cranial nerves of the eye. c. the ability of the eyes to accommodate to a closer moving object. d. the oculocephalic reflex.

ANS: B Control of eye movements occurs with interaction of three cranial nerves: oculomotor (III), trochlear (IV), and abducens (VI).

30. The patient is ordered a CT scan with contrast. Which question should the nurse ask the conscious patient before the procedure? a. Are you allergic to penicillin? b. Are you allergic to iodine-based dye? c. Are you allergic to latex? d. Are you allergic to eggs?

ANS: B If the patient is scheduled to receive contrast for computed tomography (CT) scanning, questions about possible sensitivity to iodine-based dye must be asked beforehand, if possible. During infusion of the dye and for 10 to 30 minutes afterward, the patient is observed closely for an anaphylactic reaction. Fewer than 1% of all patients undergoing contrast-enhanced CT have severe anaphylactic reactions, shock, or cardiac arrest.

25. MRI is superior to CT for which of the following? a. Brain death determination b. Detection of central nervous system infection c. Estimation of intracranial pressure d. Identification of subarachnoid hemorrhage

ANS: B Magnetic resonance imaging (MRI) produces images with greater detail than computed tomography (CT) and provides views of several planes (sagittal, coronal, axial, and oblique) that are not possible with CT. MRI with contrast is the preferred study for detection of infectious and inflammatory processes of the central nervous system (CNS). MRI can detect areas of cerebral infarct within a few hours of the incident and can identify small areas of plaque in patients with multiple sclerosis. MRI with contrast is the preferred study for detection of infectious and inflammatory processes of the CNS, malignancy, and metastatic lesions; cervical spine imaging; and postoperative evaluation of tumor recurrence. MRI also is the diagnostic study of choice in the evaluation of spinal cord injury.

3. Which of the following choices is an acceptable and recommended method of noxious stimulation? a. Nipple pinch b. Nail bed pressure c. Supraorbital pressure d. Sternal rub

ANS: B Nail bed pressure and trapezius pinch are acceptable methods of noxious stimulation. Nail bed pressure allows evaluation of individual extremity function. Trapezius pinch is difficult to perform on large or obese adults. Repeated sternal rub can cause the sternum to become excoriated, open, and infected. Supraorbital pressure must be avoided in patients with head injuries, frontal craniotomies, or facial surgery. Nipple and testicle pinching are inappropriate and unnecessary.

4. Which of the following denotes the most serious prognosis? a. Decorticate posturing b. Decerebrate posturing c. Absence of Babinski reflex d. GCS score of 14

ANS: B Outcome studies indicate that abnormal flexion or decorticate posturing has a less serious prognosis than does extension, or decerebrate posturing. Onset of posturing or a change from abnormal flexion to abnormal extension requires immediate physician notification. The Babinski reflex is a pathologic finding; absence of this reflex is a normal neurologic finding in adults. The range of scores for the Glasgow Coma Scale is 3 to 15. A score of 14 denotes a minimal deficit.

6. An oval pupil is indicative of a. cortical dysfunction. b. intracranial hypertension. c. hydrocephalus. d. metabolic coma.

ANS: B Pupil shape is also noted in the assessment of pupils. Although the pupil is normally round, an irregularly shaped or oval pupil may be noted in patients with eye surgery. Initial stages of cranial nerve III compression from elevated intracranial pressure can also cause the pupil to have an oval shape.

8. The initial history for the neurologically impaired patient needs to be a. limited to the chief complaint. b. comprehensive, including events preceding hospitalization. c. directed to level of consciousness and pupillary reaction. d. information that only the patient can provide.

ANS: B The one factor common to all neurologic assessment is the need to obtain a comprehensive history of events preceding hospitalization.

15. With an intact oculocephalic reflex, the a. patient's eyes move in the same direction the head is turned. b. patient's eyes move in the opposite direction to the movement of the patient's head. c. patient's eyes remain midline. d. doll's eye reflex is absent.

ANS: B To assess the oculocephalic reflex, the nurse holds the patient's eyelids open and briskly turns the head to one side while observing the eye movements and then briskly turns the head to the other side and observes. If the eyes deviate to the opposite direction in which the head is turned, doll's eyes are present, and the oculocephalic reflex arc is intact. If the oculocephalic reflex arc is not intact, the reflex is absent.

38. The patient's ICP reading has gradually climbed from 15 to 23 mm Hg. The nurse's primary action is to: a. drain off 7 mm of CSF from the catheter. b. notify the physician. c. place the patient in a high Fowler position to decrease the pressure. d. check level of consciousness.

ANS: B Under normal physiologic conditions, mean intracranial pressure (ICP) is maintained below 15 mm Hg. An increase in ICP can decrease blood flow to the brain, causing brain damage. Persistent ICP elevation above 20 mm Hg remains the most significant factor associated with a fatal outcome.

3. Identify the drawbacks to using continuous electroencephalography (cEEG) in a critical care unit. (Select all that apply.) a. Size of machine b. Expensive c. Labor-intensive program d. Requires expertise for interpretation e. Artifacts from ICU environment

ANS: B, C, D, E The drawbacks to the use of cEEG are that it is an expensive, labor-intensive program that requires expertise for interpretation, and is subject to artifacts from the intensive care unit environment. More research on cEEG is needed to determine its cost-saving potential and impact on outcome.

34. Which type of ICP monitoring device has the most accurate ICP measurement and provides access to CSF for sampling? a. Subarachnoid bolt or screw b. Subdural or epidural catheter c. Intraventricular catheter d. Fiberoptic transducer tipped catheter

ANS: C An intraventricular catheter allows accurate intracranial pressure (ICP) measurement and provides access to cerebrospinal fluid (CSF) for drainage or sampling. A subarachnoid bolt or screw is less accurate to measure high ICP elevations and provides no access for CSF sampling. A subdural or epidural catheter may have baseline drift over time causing possible loss of reliability or accuracy and provides no access for CSF drainage or sampling. A fiberoptic transducer tipped catheter cannot be recalibrated after placement and provides no access for CSF sampling or drainage.

9. The most important aspect of the neurologic examination is a. medical history. b. physical examination. c. level of consciousness. d. pupillary responses.

ANS: C Assessment of the level of consciousness is the most important aspect of the neurologic examination.

33. Postprocedural care of a patient undergoing a water-based contrast myelogram should include which of the following interventions? a. Maintain the patient flat in bed for 4 to 6 hours. b. Observe the puncture sight every 15 minutes for 2 hours for signs of bleeding. c. Keep the patient's head elevated 30 to 45 degrees for 8 hours. d. Administer a sedative to keep the patient from moving around.

ANS: C Postprocedure care includes keeping the patient's head elevated 30 to 45 degrees for 8 hours, monitoring neurologic status, and encouraging oral fluids.

11. A critically injured patient can be aroused only by vigorous and continuous external stimuli. The patient's level of consciousness is considered a. lethargic. b. obtunded. c. stuporous. d. comatose.

ANS: C Stuporous means the patient can be aroused only by vigorous and continuous external stimuli. Motor response is often withdrawal or localizing to stimulus. Obtunded means the patient displays dull indifference to external stimuli, and response is minimally maintained. Questions are answered with a minimal response. Lethargic means the patient displays a state of drowsiness or inaction in which the patient needs an increased stimulus to be awakened. Comatose means vigorous stimulation fails to produce any voluntary neural response in the patient.

39. According to the 2007 Brain Trauma Foundation guidelines, the recommended CPP range is a. 10 to 30 mm Hg. b. 30 to 50 mm Hg. c. 50 to 70 mm Hg. d. 70 to 85 mm Hg.

ANS: C The 2007 Brain Trauma Foundation guidelines now recommend a cerebral perfusion pressure (CPP) in the range of 50 to 70 mm Hg and consideration of cerebral autoregulation status when selecting a CPP target in a specific patient.

7. Decerebrate posturing (abnormal extension) indicates dysfunction in which area of the central nervous system? a. Cerebral cortex b. Thalamus c. Cerebellum d. Brainstem

ANS: D Abnormal flexion occurs with lesions above the midbrain in the region of the thalamus or cerebral hemispheres. Abnormal extension occurs with lesions in the area of the brainstem.

23. Which of the following is an abnormal finding in the analysis of the cerebrospinal fluid? a. Clear and colorless b. Glucose of 60 mg/dL c. Protein of 20 mg/dL d. 30 red blood cells

ANS: D Cerebrospinal fluid is normally a clear, colorless, odorless solution that contains 50 to 75 mg/dL of glucose, 5 to 25 mg/dL of protein, and no red blood cells.

17. The respiratory pattern with rhythmic increase and decrease of rate and depth of respiration, then brief periods of apnea, is known as a. central neurogenic hyperventilation. b. apneustic breathing. c. ataxic respirations. d. Cheyne-Stokes respirations.

ANS: D Cheyne-Stokes respirations have a rhythmic crescendo and decrescendo of rate and depth of respiration, including brief periods of apnea. These respirations are usually seen with bilateral deep cerebral lesions or some cerebellar lesions. Central neurogenic hyperventilations are very deep, very rapid respirations with no apneic periods. They are usually seen with lesions of the midbrain and upper pons. Apneustic breathing includes clusters of irregular, gasping respirations separated by long periods of apnea. They are usually seen in lesions of the lower pons or upper medulla. Ataxic respirations are irregular, random patterns of deep and shallow respirations with irregular apneic periods. They are usually seen in lesions of the medulla.

27. Cerebral infarction is a serious complication of which procedure? a. Extracranial Doppler b. Evoked potential testing c. Myelography d. Conventional angiography

ANS: D Complications associated with cerebral angiography include cerebral embolus caused by the catheter dislodging a segment of atherosclerotic plaque in the vessel, hemorrhage or hematoma formation at the insertion site, vasospasm caused by the irritation of catheter placement, thrombosis of the extremity distal to the injection site, and allergic or adverse reaction to the contrast medium.

12. While starting an intravenous line on the right hand of an unconscious patient, the patient reaches over with his left hand and tries to remove the noxious stimuli. This response is called a. decorticate posturing. b. decerebrate posturing. c. withdrawal. d. localization.

ANS: D Localization occurs when the extremity opposite to the extremity receiving pain crosses the midline of the body in an attempt to remove the noxious stimulus from the affected limb.

2. The GCS is an invalid measure for the patient with a. hemiplegia. b. Parkinson disease. c. mental retardation. d. intoxication.

ANS: D Several points should be kept in mind when the Glasgow Coma Scale is used for serial assessment. It provides data about level of consciousness only, and it should never be considered a complete neurologic examination. Additionally, it is not a sensitive tool for evaluation of an altered sensorium, and it does not account for possible aphasia or mechanical intubation. It is also a poor indicator of lateralization of neurologic deterioration

35. Studies have shown that the intraparenchymal catheter has a better result than the intraventricular catheter. Identify the answer that supports this statement. a. The intraparenchymal catheter allows for CSF drainage. b. The intraparenchymal catheter has increased monitoring time. c. The intraparenchymal catheter has a longer insertion time for monitoring ICP. d. The intraparenchymal catheter has decreased device-related complications.

ANS: D The intraventricular space is considered the gold standard for monitoring of intracranial pressure because it is the most accurate of all methods. However, a recent study found that an intraparenchymal catheter was better than an intraventricular catheter unless cerebrospinal fluid drainage was required. The intraparenchymal catheter was associated with decreased monitoring time, decreased length of stay, and decreased device-related complications.

16. The oculovestibular reflex, or cold caloric test, a. should not be performed on an unconscious patient because of the risk of aspiration. b. has an abnormal response of rapid nystagmus-like deviation to the side of the body that is tested. c. is a routine test of the nursing neurologic examination. d. is one of the final clinical assessments of brainstem function.

ANS: D The oculovestibular reflex is one of the final clinical assessments of brainstem function. After confirmation that the tympanic membrane is intact, the head is raised to a 30-degree angle. Then 20 to 100 mL of ice water is injected into the external auditory canal. In a normal response, eye movement is in the direction of the injection site. An abnormal response is dysconjugate eye movement, which indicates a brainstem lesion, or no response, which indicates little to no brainstem function.