The Neurological Examination

Overview

Proficiency in performing a neurological examination is advantageous to the psychiatrist. All behavior and perception occurs as a result of neural activity. Neural activity arises from brain circuitry that is developmentally sculpted through the interaction of environmental factors with human genetic potential. Neural circuitry is susceptible to malfunction and damage in a host of ways; this results in many recognizable patterns of cognitive and behavioral impairments. The neurological examination is of tremendous utility for identifying these patterns and thereby allowing for recognition of neurological processes that may be treated. Neurological conditions are frequently co-morbid with psychiatric symptoms. Such symptoms may stem from the stress of illness, be a direct function of brain pathology, or result from a combination of the two. Psychiatric symptoms and behavioral changes may precede other key physical manifestations of the disorder or occur at any time during the disease course. An effective and reliable neurological examination may afford opportunities for earlier detection of treatable conditions, anticipation of psychiatric manifestations, and avoidance of adverse events (e.g., neuroleptic sensitivity of patients with Lewy body dementia) in persons who are at particular risk.

By the late nineteenth century the elementary neurological examination was refined with objective, consistent, and reproducible findings. 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 the examination and the 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 for 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 the examination as needed. A good examination can be instrumental in discerning primary psychiatric illness from secondary symptoms that occur in association with a multitude of neurological conditions (such as stroke, Alzheimer's disease, Huntington's disease, Parkinson's disease, and demyelinating disease). (See Box 73-1 for a summary of major neurological findings and associated conditions that frequently manifest by psychiatric symptoms.) Malingering and conversion disorder need to be distinguished from deficits that localize to specific neuroanatomy. Medication side effects, such as parkinsonism and dystonia, need to be identified, treated, and followed clinically.

General principles include:

• Assess for side-to-side symmetry during the neurological examination. One side of the body serves as a control for the other. Determine if there is focal asymmetry.

• Determine if dysfunction originates from the central nervous system (CNS), peripheral nervous system (PNS), or both.

• Consider if the finding (or findings) can be explained by a single lesion or whether a multi-focal process is required.

• Establish the lesion's location. If the process involves the CNS, clarify if it is cortical, subcortical, or multi-focal. If subcortical, clarify if it is in the white matter, basal ganglia, brainstem, cerebellum, or spinal cord.

• If the process involves the PNS, determine if it localizes to the nerve root, plexus, peripheral nerve, neuromuscular junction, muscle, skin, or if it is multi-focal.

Some of this localization, particularly to the PNS, will exceed the expertise of most psychiatrists. These principles are presented as tools to organize thinking.

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 sequence, selected components of the examination, methods of performance, terminology used to describe findings, and the interpretation of various 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 ( Boxes 73-2, 73-3, and 73-4 ).

The Examination

Patient well-being and examiner safety are important concerns from the outset. To safeguard these, assessment of the patient's receptiveness to evaluation, ability to cooperate, cultural sensitivities, and mental state should be accomplished at the earliest time. If one anticipates that the evaluation will agitate the patient or that conditions are deemed unsafe, then the evaluation should be discontinued or delayed until such a time when conditions are more favorable. The patient should be forewarned about any elements of the examination that might produce discomfort. In some cases the patient may have a heightened sensitivity to an examiner of the same or opposite gender. In such circumstances, a chaperone can provide useful reassurance during the interview and examination. Vital signs should be reviewed to assess for factors that may contribute to behavioral changes, such as very elevated blood pressure, fever, and hypoxia. Changes in blood pressure, pulse, and respirations may occur in a variety of contexts, such as with agitation, psychosis, alcohol withdrawal, complex partial seizures, and medical conditions, to name only a few. The examination begins when entering a patient's room or encountering the patient in the hallway. Initial observations are made wherever the patient is found, be it walking down the hall to meet you or lying in bed. Whether the patient is aware of being observed can be important since behavior may change when out of the physician's view.

Textbooks have been dedicated to various aspects of cognitive assessment. This section will introduce the fundamental aspects of the cognitive examination; some helpful anatomical and neuropsychiatric considerations will also be presented.