CHAPTER 72 The Neurological Examination
OVERVIEW
Why does a psychiatrist need to know how to perform a good neurological examination?
By the late nineteenth century the elementary neurological examination was refined with objective, consistent, and reproducible findings.1 The practice of the examination is considered most effective when the clinician has formed a hypothesis that is based on observation and history and is prepared to fluidly adapt both examination and hypothesis as new information and findings appear. A well-rehearsed examination prevents omissions and ensures consistency of technique. A well-reasoned examination with an array of alternative techniques that verify findings ensures greater accuracy and confidence in those findings. The complexity of planning, performing, and interpreting the neurological examination is a challenge that persists throughout the entirety of a physician’s career.
The neurological examination is performed routinely on most psychiatric admissions but is uncommonly performed in outpatient psychiatric settings. In some circumstances, a careful history alone may establish a neurological diagnosis; however, this is often not the case. The examination is helpful for corroborating the history, establishing the severity of a condition, and directing treatment. The overall assessment approach should use a reproducible methodology for obtaining and interpreting the history, performing the examination, and analyzing both. A comprehensive neurological examination is unnecessary in every patient. The clinician must learn to focus, or expand, his or her examination as needed. A good examination can be instrumental in discerning primary psychiatric illness from secondary symptoms that result from diverse neurological conditions (such as stroke, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, and demyelinating disease). See Table 72-1 for a summary of major neurological findings and associated conditions that frequently have psychiatric symptoms. Malingering and conversion disorder also need to be distinguished from true neurologi-cal deficits.2 Medication side effects, such as parkinsonism and dystonia, need to be identified, treated, and followed clinically.
Table 72-1 Neurological Abnormalities That Suggest Diseases Associated with Psychiatric Symptoms
General principles include the following:
There is no clear consensus among experts as to the order of performing and presenting the neurological examination. However, there is little dispute about the mental status portion being performed first followed by examination of the cranial nerves. Thereafter, there are variations in the order, selected components of the examination, terminology used to describe findings, and the interpretation of findings. Clinicians should decide on a sequence, practice and become proficient at it, and then use it consistently. This improves performance and speed, provides a database of variations in responses, and reduces the likelihood of forgetting to perform aspects of the examination. A common approach and examination sequence will be offered along with some options for expanding the examination and validating findings with use of other maneuvers (Tables 72-2, 72-3, and 72-4).
Table 72-2 Components of Elemental Neurological Examination
Table 72-3 Elements of the Psychiatric Mental Status Examination
Table 72-4 Elements of the Neurological Mental Status Examination
THE EXAMINATION
The Psychiatric Portion of the Mental Status Examination
The separation of the mental status examination into psychiatric portions and neurological portions represents a historical difference in emphasis rather than purpose; this distinction will be continued for the purpose of clarity. See Table 72-3 for a summary of the components of the psychiatric portion of the mental status examination.
Initial Observations of the Patient
Behavioral Appearance.
Hygiene, body odor, posture, demeanor, cooperativeness, eye contact, speed of movement, the manner of dress, social graces, and attitude toward the examiner should be noted. A patient may be anxious, inattentive, engaged, cooperative, disinhibited, angry, hostile, or extremely courteous.
Speech.
Manifestations of speech include the speed, fluency, volume, and prosody. A person with a history of 4 days of speaking very quickly and being very hard to interrupt in conversation may be manic or be under the influence of drugs. Prosody describes the melodic patterns of intonation in language that convey shades of meaning. Impairment may be in the production of prosody,3 or in the comprehension of another person’s prosody. Testing prosody is uncommonly done. If clinically indicated, appreciation of prosody can be tested by situating oneself behind the patient and saying a short sentence, such as “I’m going home now,” with four different emotional tones (e.g., happy, sad, angry, and neutral). Being positioned behind the patient prevents the patient from interpreting the expression of your face. One should ask the patient to identify the emotional state of each of your theatrical renditions. Prosody production may be tested by asking the patient to repeat the same sentence in each of the emotional states previously listed. Listening for the patient’s spontaneous prosody is also essential.
Mood and Affect.
A patient with a stooped posture, slow speech, and flat affect could be manifesting signs of depression. If his stated mood is “sad” or “depressed,” his mood and affect are congruent. Some neurological conditions may be associated with a disassociation of mood and affect. A condition now known as involuntary emotional expressive disorder (IEED),4 previously named pseudobulbar affect or palsy, is characterized by episodes of involuntary or exaggerated emotional expression that results from brain disorders affecting structures of a neural network involving the frontal lobes, the limbic system, the brainstem, the cerebellum, or the interconnecting white matter tracts of this network. Extremes of emotional expression (from crying to, less often, laughing) occur without the patient actually feeling these emotions or without the patient feeling the concordant degree of the emotion expressed. IEED can occur in association with a number of neurolog-ical conditions including Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), stroke, and traumatic brain injury.
Thought Content.
Terms such as paranoia, thought blocking, and ideas of reference may be interpreted as involving perceptions, thought process, or content.5
The Neurological Portion of the Cognitive Mental Status Examination
A psychiatric mental status examination should include several major components. The following sequence affords the opportunity to evaluate cognition in a hierarchy of increasing complexity. Subsequent performance on complex tasks requires that more basic aspects of cognition are intact. See Table 72-4 for a more complete summary of the components of the neurological mental status examination.
Level of Consciousness
Consciousness is most commonly viewed as being a function of the level of arousal. The lowest level of consciousness has many descriptive terms, some of which imply a pathological state, such as coma. A patient might appear to be comatose yet actually be in nonconvulsive status epilepticus.6 An awareness of the nuances of descriptive terms will help avoid confusion in most circumstances. One common method is to describe arousability with respect to pain, loud noise, voice, and command. The relative ease or difficulty of arousability with these stimuli is also noted.
Attention
Other Tests.
Have the patient state the days of the week (or months) backward. Digit span also tests attention. It is a test during which a patient is presented with successively longer strings of random digits starting at two or three digits and with each rendition increasing the string by one digit until the patient reaches a string between five and seven digits. Performance, to some degree, depends on age; however, there is considered to be little decay in this ability with normal aging. This test may also be performed backward. Normal performance is seven digits forward and five digits backward. However, recalling six digits forward and four digits backward is probably acceptable. It is considered normal to have a difference of two between forward and backward testing.7,8
