Careful observation of the patient during the history may aid in evaluating his emotional status, memory, intelligence, powers of observation, character, and personality. Observe the general appearance, attitude, and behavior of the patient, including whether he looks tidy, neat, and clean
or slovenly, dirty, and rumpled. Note the patient’s manner, speech, and posture, and look for abnormalities of facial expression. There may be odd or unusual dress, gait, and mannerisms; prominent tattoos; excessive jewelry; or other evidence of eccentricity. Unkempt, disheveled patients or those dressed in multiple layers may have dementia, frontal lobe dysfunction, a confusional state, or schizophrenia. Depression, alcoholism, and substance abuse may lead to evidence of self-neglect. Flamboyant dress may suggest mania or hysteria. Patients with visuospatial disturbances or dressing apraxia due to a nondominant parietal lesion may not be able to get into their clothes properly.

The patient may show interest in the interview, understand the situation, and be in touch with the surroundings, or appear anxious, distracted, confused, absorbed, preoccupied, or inattentive. The patient may be engaged, cooperative, helpful, and pleasant or indifferent, irritable, hostile, or belligerent. He may be alert, even hypervigilant, or dull, somnolent, or stuporous. Patients who are disinhibited, aggressive, or overly familiar may have frontal lobe lesions. Patients who are jumpy
and hyperalert with autonomic hyperactivity (sweating, tachycardia) may be in drug withdrawal. Abnormal motor activity may include restlessness; repetitive, stereotypical movements; bizarre mannerisms; catatonia; and posturing. Inertia and psychomotor slowing suggest depression, dementia, or parkinsonism. Restlessness, agitation, and hyperactivity may occur with mania or drug ingestion. Note any tendency to emotional lability (pseudobulbar state) or apparent unconcern (la belle indifference). The ability to establish rapport with the patient may give insight into the personality of both the patient and the physician. It is sometimes informative to observe patients when they are not aware of being watched.

If there is any suggestion of abnormality from the interaction with the patient during the history taking phase of the encounter, then a more formal mental status examination (MSE) should be carried out. The formal MSE is a more structured process that expands on the information from the history. Detailed MSE should also be carried out if there is any complaint from the patient or family of memory difficulties, cognitive slippage, or a change in character, behavior, personality, or habits. For instance, formerly personable and affable patients who have become irascible and contentious may have early dementia. Other reasons to proceed further include symptoms that are vague and circumstantial, patients with known or suspected psychiatric disease or substance abuse, or when other aspects of the neurologic investigation indicate subtle or covert cognitive impairment could be present, such as anosmia suggesting a frontal lobe tumor.

A number of short screening mental status evaluation instruments have been developed for use at the bedside and in the clinic. The most widely used of these is the Folstein Mini-Mental State exam (MMSE), but there are others, including the Information-Memory-Concentration Test, Orientation-Memory-Concentration Test, Mental Status Questionnaire, Short Portable Mental Status Questionnaire (SPMSQ), Abbreviated Mental Test (AMT), Neurobehavioral Cognitive Status Examination, Short Test of Mental Status, Cambridge Cognitive Examination, and Cognistat (Table 5.3). The MMSE has a series of scored questions that provides a localization based overview of cognitive function, but does not assess any function in detail. The maximum score is 30. Minimum normal performance depends on age and educational level, but has been variously stated as between 24 and 27 (Table 5.4). The MMSE has limitations in both sensitivity and specificity, and should not be used as more than a screening instrument. It is affected not only by age and education, but by gender and cultural background. With a cutoff score of 24 the test is insensitive and will not detect mild cognitive impairment, especially in well educated or high functioning patients. A normal MMSE score does not reliably exclude dementia. There is also a relatively high false positive rate. A comparison of the MMSE, AMT, and SPMSQ showed sensitivities of 80%, 77%, and 70% and specificities of 98%, 90%, and 89%, respectively. In patients where there is a question of
cognitive impairment or a change in behavior and the MMSE or a similar instrument is normal, formal neuropsychological testing may provide more detail regarding the mental status.