The mental status examination is used to evaluate the patient’s level of consciousness and the content of consciousness. Patients are considered alert if they are actively perceiving the world around them and anticipating the examiner's and their next actions. Patients are considered comatose if they do not respond to any stimuli.
For all other intermediate levels of consciousness, it is best to avoid relying solely on imprecisely defined descriptive words (eg, drowsy, lethargic, stuporous) because these words are subjective and do not help other examiners assess whether the patient is improving or worsening. Such descriptive terms should be supplemented by more detailed observation-based descriptions, such as the following:
If the patient is not awake, it is best to document the following:
The content of consciousness cannot be accurately characterized unless the patient is awake and alert; attempting to do so is usually not worth pursuing in detail because the results may not reflect the patient's underlying abilities. Thus, the patient’s attention span is assessed first; an inattentive patient cannot cooperate fully, limiting testing.
In the conscious patient, the mental status examination is intended to test specific parts of the brain. For example, language and calculation problems point to the dominant hemisphere, spatial neglect to the nondominant hemisphere, and apraxias to the contralateral sensorimotor areas in the contralateral cerebral hemisphere.
Any hint of cognitive decline requires examination of mental status (see sidebar Examination of Mental Status ), which involves testing multiple aspects of cognitive function, such as the following:
Loss of orientation to person (ie, not knowing one’s own name) occurs only when obtundation, delirium , or dementia is severe; when it occurs as an isolated symptom, it suggests malingering.
Insight into illness and fund of knowledge in relation to educational level are assessed, as are affect and mood . Vocabulary usually correlates with educational level.