An assessment and evaluation of the structures and functions of the nervous system. Typically, a neurological examination covers cognitive function, motor function, and sensory function. Though all physicians have had some training in performing neurological examinations, neurologists are the most expert at performing them and interpreting their results. Often, the physician overlaps these areas during the examination to expedite the proceedings and also to help the person feel less self-conscious. The extent to which the examination probes these functions depends on whether the purpose is diagnostic or follow-up.
The neurologist assesses basic cognitive function by asking simple questions such as “What is today’s date?” and “Who is the president?” These kinds of questions aim to establish whether the person is oriented to current time and events. The neurologist then may ask the person to repeat a sequence of letters, words, or numbers. These questions evaluate memory and recall, as well as attention span and concentration. The doctor may conduct a mini mental status examination (MMSE) or administer a more comprehensive cognitive assessment. This portion of the neurological examination also typically includes questions about sleeping and waking patterns, particularly SLEEP DISTURBANCES and DAYTIME SLEEPINESS. The doctor may ask the person to complete an epworth sleepiness scale (ESS) self-assessment. As well, the doctor should ask about his or her concerns or noticeable problems.
The motor function assessment begins before the person knows the examination is under way, when the doctor observes posture, balance, and movement. When extending a handshake for greeting, the doctor notices whether there is tremor or hesitation, full extension of the arm, and strength and firmness in the grip. More focused examination or motor function includes instructed movements such as walking down a corridor, which allow the doctor to evaluate gaIt and gait disturbances suggestive of Parkinson’s disease such as reduced arm swing, slumping or stooped shoulders and upper posture, and short-ened leg stride and step. Other kinds of gait disturbances, such as swinging one leg in an arclike pattern during forward stepping or dragging the heels, suggest neurological or neuromuscular disorders other than Parkinson’s disease. A wide stumbling gait may suggest cerebellar problems rather than Parkinson’s. Other gait and balance problems might suggest normal pressure hydro-cephalus, neuropathy, or other disorders. The doctor watches for whether symptoms are asymmetrical (one-sided) or symmetrical (affect both sides); Parkinson’s is nearly always asymmetrical until its later stages.
The doctor will instruct the person to squeeze his or her hand or fingers to determine whether strength is appropriate and even on both sides and to push and pull against the doctor’s hands to test strength. The doctor puts the wrists, elbows, knees, and ankles through a series of passive movements to check for rigidity, a classic sign of Parkinson’s. During this part of the examination, the doctor also looks for other patterns of stiffness suggestive of disorders other than Parkinson’s. The doctor checks the standard tendon tap reflexes, alteration of which may suggest a different or additional disorder in people suspected to have Parkinson’s. Often the doctor tells the person to stand and push and pull the person at the shoulders to test balance and postural righting reflex. This is always done in such a way that the person cannot fall. It is normal to take a step forward or back to recover balance; a person with Parkinson’s typically takes three or more steps before recovering.
Some motor function tests seem silly, such as wiggling the fingers and rapidly tapping heel-toe. But these activities challenge the brain’s motor functions and draw out disturbances that might otherwise remain undetected. The doctor engages the person in conversation during the motor function examination and listens closely to the person’s voice modulation and speech patterns. Soft, slow speech suggests Parkinson’s disease and may be present without the person’s awareness. The conversation additionally helps the doctor to assess cognitive function. During conversation the doctor observes the person’s face for changes in facial expression, smiling, blinking, and eye movements. Reduced facial expression and slowed blinking are common early signs of Parkinson’s.
Sensory functions are those related to the five senses: vision, hearing, smell, taste, and touch. In most people with Parkinson’s sensory perceptions are normal with the exception of smell. More than half of people with Parkinson’s have an altered sense of smell or cannot detect smells. Parkinson’s can cause visual disturbances when it affects the muscles that control eye movements; the doctor explores this function by asking the person to move the eyes to follow a moving object. There also seems to be some decrease in visual acuity from retinal changes in Parkinson’s as well; the retina also needs dopamine (from dopaminergic cells on the retinal surface) to function properly. Disturbances of touch may suggest peripheral neuropathy (damage to the peripheral nerves); the doctor tests for this by touching the feet, legs, hands, arms, face, and sometimes back with a soft object such as a cotton swab and a hard object such as a tongue depressor or the stick end of the swab. Tests of sensory function help to establish whether the cranial nerves are functioning properly; sensory disturbances can suggest cranial nerve lesions or damage.
Most people have a neurological examination because they have symptoms. The doctor should ask about these symptoms throughout the examination and may conduct focused tests to evaluate those that appear prominent or significant further. For example, the doctor may ask a person who is experiencing coordination and dexterity difficulties to perform a number of exercises such as touching the finger to the nose, rapidly tapping the fingers, reaching for a moving object, matching movements with the doctor, picking up small objects such as coins from a smooth surface, and writing a sentence or drawing (copying) a geometric figure. These kinds of exercises tell the doctor as much about the conditions the person does not have as about those he or she may have.
The physician may want the person to have magnetic resonance imaging (MRI) studies, laboratory testing of blood or other samples, functional IMAGING STUDIES, ELECTROPHYSIOLOGIC STUDIES, or other tests to narrow the diagnosis further, assess the progression of the disease, or evaluate the effectiveness of a treatment regimen. As there are no conclusive diagnostic markers for Parkinson’s disease, diagnostic testing is primarily used to rule out other causes of symptoms. lesions such as tumors or scars and injuries such as those from trauma or stroke that affect the basal ganglia or the brainstem can cause tremors and dyskine-sias, for example, and typically are detected on FUNCTIONAL IMAGING STUDIES such as COMPUTED tomography (CT) scan or magnetic resonance imaging (MRI). None of these tests is necessary when the cardinal symptoms of Parkinson’s resting tremor, bradykinesia, postural instability, and rigidity are present. The fewer of the cardinal symptoms that are present or younger the person is the more likely the doctor is to want additional diagnostic information.