Principles of Mental Status Testing

Goals and Levels

Mental status testing aims for the practical evaluation for cognitive problems along a medical model. The overriding goal is to screen for cognitive deficits in the clinic or at the bedside with readily available stimulus materials. Within this goal, a rapid MSX can occur with brief screening of key cognitive domains when time and circumstances are limited, such as on an inpatient service. With somewhat more time, mental status scales and inventories allow for a semiquantitative assessment of general cognition. Alternatively, the screening may use targeted tests or scales for special situations, such as delirium (see Chapter 3). For all three of these approaches, brief MSX screening, mental status scales or inventories, and targeted MSX, clinicians must be able to recognize abnormalities requiring further testing. A more extensive and comprehensive neurobehavioral status examination (NBSE) is part of a subspecialty clinical assessment for neurocognitive disorders and is a major focus of this book. NBSE is indicated when time is not an issue and the clinician can devote time to a thorough assessment of the different cognitive domains. Finally, referral for neuropsychological testing should be a consideration under certain situations, to be described later.

Brief MSX Screen

(see Chapter 5)

The initial aspects of the brief assessment are observation, interaction, and orientation. The briefest assessment involves pausing to observe the patient’s general behavior, such as state of alertness and wakefulness, interaction with others, and coherence of verbal output and physical movements. Clinicians often overlook the importance of just observing patients, yet this can be a very informative “MSX.” If possible, engage the patient in conversation and note the quality and quantity of the interaction, including use of language and any clues to memory for recent events. Orientation, which involves asking patients to state the current date and place, is not an actual “cognitive domain,” but it is a sensitive measure of either attentional or memory impairment. In the absence of a watch or other obvious display of the time, the patient’s knowledge of the exact time of day can be a further extension of the assessment for temporal orientation.

Beyond observation, interaction, and orientation, clinicians can perform a brief MSX screen in approximately 5 minutes. Most clinicians can quickly examine one or two representative tasks in critical mental status areas, including awareness (arousal and attention), language (naming by confrontation), declarative episodic memory (delayed recall of a few words), and perception (three-dimensional visuospatial construction) ( Table 2.1 ).

Mental Status Scales and Inventories

(see Chapters 15 and 16)

When 5 to 15 minutes are available, short instruments containing a number of heterogeneous items are useful in evaluating memory plus other cognitive domains and deriving a general cognitive score. Usually, there are guidelines for administration and cutoff scores for impaired cognition. These cutoff scores may have age- and education-dependent adjustments. These instruments are useful for screening for referral for more extensive evaluation; they are less informative for assessing specific brain-behavior impairments or localization.

There are many cognitive and behavioral rating scales. Although the choice of rating scale may vary with the specific goals of the evaluation, the clinician should gain familiarity with a limited number of widely used scales, such as the Mini-Mental State Examination (MMSE) (5–10 minutes) or the Montreal Cognitive Assessment (MoCA) (10–15 minutes). Some scales are shorter and more quickly administered (e.g., the Mini-Cog or the Six-Item Screen) and others are longer and more extensive (e.g., Addenbrooke Cognitive Examination). Scales have different levels of difficulty, for example, the MMSE is easier than the MoCA, and there are differential floor and ceiling effects, for example, the MMSE shows more variance in more impaired ranges, and the MoCA shows more variance at higher levels of functioning.