The care of patients in all specialties has been enhanced by the use of an increasingly sophisticated array of biomarkers, genetic tests, and imaging modalities. Yet even in the setting of these critical advancements, the physical examination remains of utmost importance in Neurology. We glean valuable information from listening to the manner in which concerns are expressed, observing how patients walk into the clinic or lie in a hospital bed, and performing maneuvers designed to interrogate the functional integrity of nervous system components. Ultimately, the examination is a tool we use to pinpoint the nature and origin of abnormalities. The resultant picture can narrow the list of possible diagnoses and guide further investigation.

PRINCIPLES

1.It is useful to conduct a complete examination at least once for every Neurology patient. The neurologic examination may be unique in its length, but it is worthwhile to complete a thorough assessment at least once with each Neurology patient for several reasons. First, that examination provides a baseline assessment of neurologic status—which can be particularly valuable in the hospital, where examinations can evolve in important and sometimes unforeseen ways. Second, a full examination may uncover unexpected abnormalities. One might be tempted to skip a full mental status examination for a patient who can exchange pleasantries normally—only to be surprised when the patient identifies the year as 1962. Because neurologic problems can present with discrete deficits, formal testing in each domain is sensible. Third, abnormalities on basic tests can point out the need for more in-depth, specialized evaluations. For example, the emergence of diplopia on testing extraocular movements might prompt a search for fatigable eyelid weakness that can raise concern for myasthenia gravis. In this way, the neurologic examination becomes tailored for each individual patient. Fourth, the examination allows one to directly confirm or refute hypotheses about contributory problems suggested by the history. Foot drop is more likely to result from a lumbosacral radiculopathy if accompanied by back pain; a positive straight leg raise test can help corroborate this explanation. Finally, the examination can show a pattern of abnormalities that provides a clue as to where in the nervous system the problem lies.

2.The goal is to localize the problem. The nervous system is extensive. Broadly, we can characterize elements as central or peripheral. The central nervous system includes the brain and spinal cord. The peripheral nervous system (PNS) incorporates nerve roots, plexi, peripheral nerves, neuromuscular junctions, and muscles. Dysfunction originating from each of these locations can translate into distinctive examination findings (Table 1-1); recognizing characteristic patterns is often the key to localizing a deficit. Using this approach, the exam can help determine whether left hand weakness stems from carpal tunnel syndrome, a brachial plexus injury, cervical radiculopathy, or a middle cerebral artery stroke. These distinctions are important because the diagnostic steps, prognoses, and therapies differ for each of these conditions.

3.Findings should be interpreted in the context of the history. In performing a comprehensive neurologic examination, it is not uncommon to detect incidental abnormalities. Particularly at the start of one’s career, it can be difficult to discern whether certain abnormalities are important. One should assign greater weight to findings related to the presenting symptoms or a patient’s medical history. For instance, abnormal sensation in a football-shaped region over the anterolateral thigh may be a key finding in an obese person who developed burning in this area after wearing tight-fitting pants, but an unimportant (or untrustworthy) discovery in an individual who presents with an acute change in mental status.

The details of the neurologic examination (Table 1-2) should be tailored to fit the patient’s presenting symptoms and identified abnormalities on a basic exam.

MENTAL STATUS

The mental status exam is performed to identify cognitive deficits related to specific regions in the brain. The first step is to assess level of consciousness, which can range from awake and alert to unarousable even with noxious stimulation. Rather than using medical terms such as stuporous or obtunded in the latter setting, it is more helpful to describe what external stimuli are required to arouse a patient or maintain wakefulness. The level of consciousness frames further testing of cognitive function. Attention is tested, typically by asking patients to recite spans of numbers, months, or words such as “world,” forward and backward. A specific form of inattention is referred to as neglect. Patients with dense neglect may fail to describe items on one side of a picture or of their surroundings or fail to bisect a line properly. Subtle neglect may manifest as extinction to double simultaneous stimulation; in this scenario, a patient can sense a single visual or sensory stimulus on either side of the body but reports it on the nonneglected side alone when bilateral stimuli are presented. In some cases, it is not possible to perform formal tests of attention because patients become focused on one detail or task and keep repeating it (“perseveration”). Deficits in attention are important to recognize because they can compromise the ability to complete other tasks in the mental status examination. Orientation is tested by asking a patient to identify his or her name and location as well as the day, date, month, year, and current situation.

Memory is assessed by asking patients to repeat several words immediately and again after intervals (e.g., 30 seconds and 3 minutes). The examiner should make note of whether the patient is aware of current events. Language is assessed in several ways: by listening to the fluency and prosody of spontaneous speech, identifying word substitutions (i.e., paraphasic errors), and assessing the ability to repeat phrases, read, write, and name common and uncommon objects. Furthermore, the examiner can ask the patient to name as many words as possible starting with the letter “F,” “A,” or “S” in 1 minute, paying attention not only to the number of words generated but also to the manner in which they are named. For example, does the patient recognize whether she or he repeated words? Were words volunteered in identifiable categories? In addition to insight into language function, these details provide insight into how well patients can plan and organize information (i.e., frontal lobe executive function). To assess verbal comprehension, check to see if patients can follow spoken midline, appendicular, and cross-body commands.

Calculation ability can be tested by asking patients to perform simple arithmetic (e.g., the number of quarters in $1.50). One can check for apraxia by asking patients to pantomime a learned motor task—optimally one that requires use of both hands, for example, cutting a loaf of bread. Visuospatial function and nonverbal learning can be tested in a variety of ways. Patients can be asked to draw numbers in a circle to form a clock; alternatively, they can be asked to copy a complex figure drawn by the examiner (Fig. 1-1).

FIGURE 1-1. Example of a complex figure to be copied by the patient as test of visuospatial function.

Other tests of frontal lobe function include learning and then repeating a simple motor sequence of hand postures (i.e., the Luria manual sequencing task). Another test of appropriate inhibition, the go/no go test, comprises tapping the table when only one letter (e.g., “B”) is said aloud in a string of letters. Perseveration is also considered a frontal deficit. If cognitive impairment emerges as a concern, the examiner should consider looking for the presence of primitive reflexes, which are signs of “frontal release” or disinhibition. Examples include the palmo-mental, snout, and rooting reflexes; of note, the examiner should be careful not to overinterpret these reflexes, because they can occur in normal subjects with age or may not be relevant to the presenting problem.

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