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 Examination of Mental Status), which involves testing multiple aspects of cognitive function, such as the following:
Orientation to time, place, and person
Attention and concentration
Memory
Verbal and mathematical abilities
Judgment
Reasoning
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.
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)
Name body parts and read, write, and repeat simple phrases (if deficits are noted, other tests of aphasia are needed)
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 and Introduction to the Neurologic Examination.)
Examination of Mental Status
The mental status examination is an assessment of current mental capacity through evaluation of general appearance, behavior, any unusual or bizarre beliefs and perceptions (eg, delusions, hallucinations), mood, and all aspects of cognition (eg, attention, orientation, memory). Examination of mental status is done in anyone with an altered mental status or evolving impairment of cognition whether acute or chronic. Many screening tools are available; the following are particularly useful:
Baseline results are recorded, and the examination is repeated yearly and whenever a change in mental status is suspected. Patients should be told that recording of mental status is routine and that they should not be embarrassed by its being done. The examination is done in a quiet room, and the examiner should make sure that patients can hear the questions clearly. Patients who do not speak English as their primary language should be questioned in the language they speak fluently. Mental status examination evaluates different areas of cognitive function. The examiner must first establish that patients are attentive—eg, by assessing their level of attention while the history is taken or by asking them to immediately repeat 3 words. Testing an inattentive patient further is not useful. The parameters of cognitive function to be tested and examples of how to test them include the following: | ||
Orientation | Test the 3 parameters of orientation:
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Short-term memory | Ask the patient to recall 3 objects after about 2 to 5 min. | |
Long-term memory | Ask the patient a question about the past, such as “What color suit did you wear at your wedding?” or “What was the make of your first car?” | |
Math | Use any simple mathematical test. Serial 7s are common: The patient is asked to start with 100 and to subtract 7, then 7 from 93, etc. Alternatively, ask how many nickels are in $1.35. | |
Word finding | Ask the patient to name as many objects in a single category, such as articles of clothing or animals, as possible in 1 min. | |
Attention and concentration | Ask the patient to spell a 5-letter word forward and backward. “World” is commonly used. | |
Naming objects | Present an object, such as a pen, book, or ruler, and ask the patient to name the object and a part of it. | |
Following commands | Start with a 1-step command, such as “Touch your nose with your right hand.” Then test a 3-step command, such as “Take this piece of paper in your right hand. Fold it in half. Put the paper on the floor.” | |
Writing | Ask the patient to write a sentence. The sentence should contain a subject and an object and should make sense. Spelling errors should be ignored. | |
Spatial orientation | Ask the patient to draw a house or a clock and mark the clock with a specific time. Or ask the patient to draw 2 intersecting pentagons. | |
Abstract reasoning | Ask the patient to identify a unifying theme between 3 or 4 objects (eg, all are fruit, all are vehicles of transportation, all are musical instruments). Ask the patient to interpret a moderately challenging proverb, such as “People who live in glass houses should not throw stones.” | |
Judgment | Ask the patient about a hypothetical situation requiring good judgment, such as “What would you do if you found a stamped letter on the sidewalk?” Placing it in the mailbox is the correct answer; opening the letter suggests a personality disorder. | |
