A. Patients with neurologic problems present in the intensive care unit (ICU) as primary neurologic problems or as neurologic complications secondary to medical or surgical disorders. Only a few common neurologic situations occur in the ICU, although they can be caused by many diseases.

1. Depressed state of consciousness, coma.

2. Altered mental function.

3. Required support of respirations or other vital functions.

4. Monitoring: increased intracranial pressure (ICP), respirations, consciousness.

5. Determination of brain death.

6. Prevention of further damage to the central nervous system (CNS).

7. Management of seizures or status epilepticus.

8. Evaluation of a neurologic change occurring as a result of known medical disease.

9. Management of medical disease developing during neurologic illness.

10. Acquired weakness during an ICU stay.

B. Primary neurologic problems in the ICU include the following:

1. Stroke.

2. Guillain-Barré syndrome.

3. Status epilepticus.

4. Myasthenia gravis.

5. Head or spinal cord trauma.

C. Neurologic complications of medical disease are far more common than primary neurologic problems. They include:

1. Impaired consciousness following cardiac arrest and cardiopulmonary resuscitation.

2. Altered mental status from metabolic disorders.

3. Development of delirium.

4. Critical care neuromyopathy.

5. Focal neurologic deficits, or impaired consciousness, in a patient with multisystem disease.

1. Depressed state of consciousness. Depressed consciousness ranges from lethargy to coma and raises many questions:

a. Is there a focal brainstem lesion or diffuse cerebral involvement?

b. Is there an anatomic lesion or a metabolic disorder?

c. Have vital brainstem functions been impaired?

d. Is ICP increased?

2. The most common primary neurologic causes of depressed consciousness include:

a. Head trauma.

b. Intracranial hemorrhage.

c. Nonconvulsive seizures.

3. The secondary conditions seen most often are

a. Metabolic-anoxic disorders.

b. Drug intoxications.

c. Diabetic ketoacidosis.

4. It is crucial to establish whether depressed consciousness is the result of

a. Intrinsic brainstem damage.

b. Increased ICP.

c. Toxic substances.

d. Widespread anoxia/ischemia.

e. Other, less common causes.

A. In the patient with depressed consciousness, it is particularly important to identify as rapidly as possible the component(s) that may be treatable!

1. Neurologic examination of patients with stupor or coma. Examination of the patient with depressed consciousness includes evaluation of (a) mental status, (b) cranial nerve functions, (c) motor functions and coordination, (d) reflexes, (e) sensation, and (f) vascular integrity; supplemented by appropriate laboratory studies.

a. Mental status.

i. Detailed evaluation of memory and cognitive function is rarely possible in lethargic patients and is impossible when stupor or coma is present.

ii. Estimate the responsiveness of the patient, including vital functions, respiratory pattern, eye opening, response to painful stimuli, and speech.

b. Cranial nerve evaluations: Vision (e.g., blink to threat), pupils (size and response), corneal reflexes, “doll’s eyes” responses, and, if absent, ice water caloric response, cough, facial movements to pain, and gag reflex are tested.

c. Motor function: Evaluate by observing all limbs for spontaneous movement, symmetry, and adventitious movements. Pinch or other noxious stimulus may help evaluate purposeful defensive movements.