Chapter 44: Acute Disorders of Brain Function

Question 1

Glasgow Coma Scale

Answer 1

• Standardized tool for assessing LOC in acutely brain-injured persons
• Numeric scores given to arousal-directed responses of eye opening, verbal utterances, and motor reactions (Mild (>12), moderate (9 to 12), to severe (

Question 2

Pupil Reflex

Answer 2

• Indicates the function of the brainstem and cranial nerves (CN) II and III
• Changes in size, shape, and reactivity of the pupil early indicator of ICP and possible brain herniation
• Eye movements controlled by CN III, IV, and VI may be impaired with increased ICP
• Nystagmus, dysconjugate movement, and ocular palsies may be present

Question 3

Oculovestibular Reflex

Answer 3

• Impaired reflex implies brainstem dysfunction
• Doll’s-eyes maneuver entails rotating the patient’s head from side to side (Normally eyes turn in opposite direction of the head rotation)
• Cold calorics: inject cold water into ear (Normal response: tonic deviation of both eyes toward the side that is irrigated)
• Both tests have many contraindications

Question 4

Corneal Reflex

Answer 4

• Wisp of cotton touches cornea of the eye to elicit a blink response
• Absence of blink response: indictor of severely impaired brain function

Question 5

Epidemiology of Cerebrovascular disease and stroke

Answer 5

• Cause abnormalities of cerebral perfusion (Transient ischemic attacks (TIA), ischemic stroke, and hemorrhagic stroke)
• Stroke is a sudden onset of neurologic dysfunction due to cardiovascular disease that results in an area of brain infarction
• Stroke is the third leading cause of death in the United States
• Most common form of stroke is ischemic
• Females affected more often than males
• Risk factors are similar to those for other atherosclerotic vascular diseases (hypertension, DM, hyperlipidemia, smoking, advancing age, family history)

Question 6

Ischemic stroke

Answer 6

• Results from sudden occlusion of cerebral artery secondary to thrombus formation or emboli
• Thrombotic strokes associated with atherosclerosis and coagulopathies
• Embolic strokes associated with cardiac dysfunction or dysrhythmias (atrial fibrillation)

Question 7

Clinical Manifestations and Treatment of Ischemic Stroke

Answer 7

• Clinical manifestations include contralateral hemiplegia, hemisensory loss, and contralateral visual field blindness
• treatment: salvaging the penumbra is the aim of early thrombotic therapy; however, treatment must be instituted within 3 hours of symptom onset to be maximally effective

Question 8

Transient Ischemic Attack (TIA)

Answer 8

• Neurologic symptoms typically last only minutes, but they may last as long as 24 hours
• Symptoms resolve completely without evidence of neurologic dysfunction
• TIAs are important warning signs of thrombotic disease and carry a significant risk for subsequent stroke
• Treatment: daily aspirin; carotid endarterectomy or angioplasty if 70% occluded

Question 9

Hemorrhagic Stroke

Answer 9

• Hemorrhage within the brain parenchyma
• Usually occurs secondary to severe, chronic hypertension
• Most occur in basal ganglia or thalamus
• Degree of secondary injury and associated morbidity and mortality is much higher in hemorrhagic stroke than ischemic stroke

Question 10

Treatment of Stroke

Answer 10

• Cardiovascular stabilization
• Brain CT determines type and location
• ICP monitoring and management
• Ischemic stroke: treatment aimed at minimizing infarct size and preserving neurologic function (Thrombolytics, anticoagulant, antiplatelet, endarterectomy, angioplasty, stents)
• Hemorrhagic stroke: blood pressure management (keep mildly hypertensive at first)

Question 11

Stroke: Motor Deficits

Answer 11

• Initially motor deficits occur as flaccidity or paralysis; recovery of motor function occurs with onset of spasticity
• Contralateral to the side of the brain where the stroke occurred
• Active/passive range of motion exercises should be started in acute phase of recovery
• Elevate edematous limbs, use elastic stockings, and maintain body alignment
• Aggressive rehabilitation commonly required

Question 12

Stroke: Sensory Deficits

Answer 12

• Sensory disturbances occur in same locations as motor paralysis and may involve neglect or visual impairment
• Loss of visual field on the paralyzed side also contributes to neglect
• Contralateral field blindness: homonymous hemianopsia, the same side of the retina in each eye is blinded
• Assess fall risk

Question 13

Stroke: Language Deficits

Answer 13

• Aphasia occurs with brain damage to the dominant cerebral hemisphere and can involve all language modalities
• Broca aphasia (verbal motor/expressive) consists of poor articulation and sparse vocabulary
• Wernicke aphasia (sensory, acoustic, receptive) characterized by impaired auditory comprehension and speech that is fluent but does not make sense

Question 14

Stroke: Cognitive Deficits

Answer 14

• Area of brain affected dictates presence and severity of cognitive impairments
• Evidenced as language impairment, impaired spatial relationship skills and short-term memory, and poor judgment
• Concentration, memory, and reasoning may be impaired
• May require rehabilitative services

Question 15

Meningitis

Answer 15

• Bacteria usually reach the CNS via the bloodstream or extension from cranial structures like sinuses or ears
• Most common bacteria are Streptococcus pneumoniae
• Bacteria invade leptomeninges; accumulation of inflammatory exudate can result in obstructive hydrocephalus
• Clinical manifestations: Headache, fever, nuchal rigidity, photosensitivity
• Tx: Depends on the organism causing infection