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:
Whether and how a sleeping or seemingly unconscious patient can be aroused
Whether the patient requires repeated instructions
Whether the patient's abnormalities are continuous or intermittent.
If the patient is not awake, it is best to document the following:
What stimulus is needed to arouse the patient (eg, voice, tactile stimulation, noxious stimulation)
How the patient responds to the stimulus (eg, nonspecific movements, eye opening, verbalization, degree of cooperation)
How long the patient continues to function at the poststimulation level before returning to the unstimulated level
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 ), which involves testing multiple aspects of cognitive function, such as the following:
Orientation to time, place, and person
Attention and concentration
Verbal and mathematical abilities
Loss of orientation to person (ie, not knowing one’s own name) occurs only when obtundation, delirium Delirium Delirium is an acute, transient, usually reversible, fluctuating disturbance in attention, cognition, and consciousness level. Causes include almost any disorder or drug. Diagnosis is clinical... read more , or dementia Dementia Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is... read more 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 Overview of Mood Disorders Mood disorders are emotional disturbances consisting of prolonged periods of excessive sadness, excessive elevated mood, or both. Mood disorders can occur in adults, adolescents, or children... read more . Vocabulary usually correlates with educational level.
The patient is asked to do the following:
Follow a complex command that involves 3 body parts and discriminates between right and left (eg, “Put your right thumb in your left ear, and stick out your tongue”)
Name simple objects and parts of those objects (eg, glasses and lens, belt and belt buckle)
Spatial perception can be assessed by asking the patient to imitate simple and complex finger constructions and to draw a clock, cube, house, or interlocking pentagons; the effort expended is often as informative as the final product. This test may identify impersistence, perseveration, micrographia, and hemispatial neglect.
Praxis (cognitive ability to do complex motor movements) can be assessed by asking the patient to use a toothbrush or comb, light a match, or snap the fingers.
(See also Approach to the Patient With Mental Symptoms Routine Psychiatric Assessment Patients with mental complaints or concerns or disordered behavior present in a variety of clinical settings, including primary care and emergency treatment centers. Complaints or concerns may... read more and Introduction to the Neurologic Examination Introduction to the Neurologic Examination The purpose of the neurologic examination is to establish whether the patient’s brain, special senses, spinal cord, peripheral nerves, and muscle and skin receptors are functioning normally... read more .)