The single most important assessment

Evaluation of level of consciousness (LOC) and mentation are the most important parts of the neuro exam. A change in either is usually the first clue to a deteriorating condition.

The following terms are commonly used to describe a decreased LOC, so it helps to be familiar with them:

Full consciousness. The patient is alert, attentive, and follows commands. If asleep, she responds promptly to external stimulation and, once awake, remains attentive.¹

Lethargy. The patient is drowsy but awakens—although not fully—to stimulation. She will answer questions and follow commands, but will do so slowly and inattentively.¹

Obtundation. The patient is difficult to arouse and needs constant stimulation in order to follow a simple command. She may respond verbally with one or two words, but will drift back to sleep between stimulation.

Stupor. The patient arouses to vigorous and continuous stimulation; typically, a painful stimulus is required.¹ She may moan briefly but does not follow commands. Her only response may be an attempt to withdraw from or remove the painful stimulus.

Coma. The patient does not respond to continuous or painful stimulation. She does not move—except, possibly, reflexively—and does not make any verbal sounds.