The neurologic examination is a systematic process that includes a variety of clinical tests, observations, and assessments designed to evaluate a complex system. Although the neurologic examination is often limited to a simple screening, the examiner must be able to conduct a thorough neurologic assessment when the patient’s history or other physical findings warrant it..
The brain and spinal cord cannot be examined as directly as other systems of the body. Thus, much of the neurologic exami-nation is an indirect evaluation that assesses the function of the specific body part or parts controlled or innervated by the ner-vous system. A neurologic assessment is divided into five compo-nents: cerebral function, cranial nerves, motor system, sensory system, and reflexes. As in other parts of the physical assessment, the neurologic examination follows a logical sequence and pro-gresses from higher levels of cortical function such as abstract thinking to lower levels of function such as the determination of the integrity of peripheral nerves.
Cerebral abnormalities may cause disturbances in mental status, intellectual functioning, and thought content and in patterns of emotional behavior. There may also be alterations in perception, motor and language abilities, as well as lifestyle.
An assessment of mental status begins by observing the patient’s appearance and behavior, noting dress, grooming, and personal hygiene. Posture, gestures, movements, facial expressions, and motor activity often provide important information about the pa-tient. The patient’s manner of speech and level of consciousness are also assessed. Is the patient’s speech clear and coherent? Is the patient alert and responsive, or drowsy and stuporous?
Assessing orientation to time, place, and person assists in eval-uating mental status. Does the patient know what day it is, what year it is, and the name of the president of the United States? Is the patient aware of where he or she is? Is the patient aware of who the examiner is and of his or her purpose for being in the room? Is the capacity for immediate memory intact?
A person with an average IQ can repeat seven digits without fal-tering and can recite five digits backward. The examiner might ask the patient to count backward from 100 or to subtract 7 from 100, then 7 from that, and so forth (called serial 7s) ( Johnson, 2001). The capacity to interpret well-known proverbs tests ab-stract reasoning, which is a higher intellectual function; for ex-ample, does the patient know what is meant by “the early bird catches the worm”? Patients with damage to the frontal cortex appear superficially normal until one or more tests of integrative capacity are performed. Questions designed to assess this capac-ity might include the ability to recognize similarities: how are a mouse and dog or pen and pencil alike? Can the patient make judgements about situations—for instance, if the patient arrived home without a house key, what alternatives are there?
During the interview, it is important to assess the patient’s thought content. Are the patient’s thoughts spontaneous, natural, clear, relevant, and coherent? Does the patient have any fixed ideas, illusions, or preoccupations? What are his or her insights into these thoughts? Preoccupation with death or morbid events, hallucinations, and paranoid ideation are examples of unusual thoughts or perceptions that require further evaluation.
An assessment of cerebral functioning also includes the patient’s emotional status. Is the patient’s affect (external manifestation of mood) natural and even, or irritable and angry, anxious, apathetic or flat, or euphoric? Does his or her mood fluctuate normally, or does the patient unpredictably swing from joy to sadness during the interview? Is affect appropriate to words and thought content? Are verbal communications consistent with nonverbal cues?
The examiner may now consider more specific areas of higher cortical function. Agnosia is the inability to interpret or recog-nize objects seen through the special senses. The patient may see a pencil but not know what it is called or what to do with it. The patient may even be able to describe it but not to interpret its function. The patient may experience auditory or tactile agnosia as well as visual agnosia. Each of the dysfunctions implicates a dif-ferent part of the cortex (Chart 60-1).
Screening for visual and tactile agnosia provides insight into the patient’s cortical interpretation ability. The patient is shown a familiar object and asked to identify it by name. Placing a fa-miliar object (eg, key, coin) in the patient’s hand and having him or her identify it with both eyes closed is an easy way to assess tac-tile interpretation.
Assessment of cortical motor integration is carried out by asking the patient to perform a skilled act (throw a ball, move a chair). Successful performance requires the ability to understand the ac-tivity desired and normal motor strength. Failure signals cerebral dysfunction.
The person with normal neurologic function can understand and communicate in spoken and written language. Does the patient answer questions appropriately? Can he or she read a sentence from a newspaper and explain its meaning? Can the patient write his or her name or copy a simple figure that the examiner has drawn? A deficiency in language function is called aphasia. Dif-ferent types of aphasia result from injury to different parts of the brain (Chart 60-2).
The nurse assesses the impact the neurologic impairment has on the patient’s lifestyle. Issues to consider include the limitations imposed on the patient by any deficit and the patient’s role in so-ciety, including family and community roles. The plan of care that the nurse develops needs to address and support adaptation to the neurologic deficit and continued function to the extent possible within the patient’s support system.
Interpretation and documentation of neurologic abnormalities, particularly mental status abnormalities, should be specific and nonjudgmental. Lengthy descriptions and the use of terms such as “inappropriate” or “demented” should be avoided. Terms such as these often mean different things to different people and are therefore not useful when describing behavior. The examiner records and reports specific observations regarding orientation, level of consciousness, emotional state, or thought content, all of which permit comparison by others over time. Analysis and the conclusions that may be drawn from these findings usually de-pend on the examiner’s knowledge of neuroanatomy, neuro-physiology, and neuropathology.
Table 60-5 describes how to assess the cranial nerves. Opposite sides of the face and neck are compared throughout the examination.
A thorough examination of the motor system includes an assess-ment of muscle size, tone, and strength, coordination, and balance. The patient is instructed to walk across the room while the exam-iner observes posture and gait. The muscles are inspected, and pal-pated if necessary, for their size and symmetry. Any evidence of atrophy or involuntary movements (tremors, tics) is noted. Mus-cle tone (the tension present in a muscle at rest) is evaluated by pal-pating various muscle groups at rest and during passive movement. Resistance to these movements is assessed and documented. Abnormalities in tone include spasticity (increased muscle tone), rigidity (resistance to passive stretch), and flaccidity.
Assessing the patient’s ability to flex or extend the extremities against resistance tests muscle strength. The function of an in-dividual muscle or group of muscles is evaluated by placing the muscle at a disadvantage. The quadriceps, for example, is a pow-erful muscle responsible for straightening the leg. Once the leg is straightened, it is exceedingly difficult for the examiner to flex the knee. Conversely, if the knee is flexed and the patient is asked to straighten the leg against resistance, a more subtle disability can be elicited. The evaluation of muscle strength compares the sides of the body to each other. For example, the right upper ex-tremity is compared to the left upper extremity. In this way, sub-tle differences in muscle strength can be more easily detected and accurately described.
Clinicians use a five-point scale to rate muscle strength (O’Hanlon-Nichols, 1999). A 5 indicates full power of contrac-tion against gravity and resistance or normal muscle strength; 4 indicates fair but not full strength against gravity and a moderate amount of resistance or slight weakness; 3 indicates just sufficient strength to overcome the force of gravity or moderate weakness; 2 indicates the ability to move but not to overcome the force of gravity or severe weakness; 1 indicates minimal contractile power—weak muscle contraction can be palpated but no movement is noted—or very severe weakness; and 0 indicates complete paralysis. A stick figure may be used to record muscle strength and is a precise form of documenting findings. Distal and proximal strength in both upper and lower extremities is recorded using the five-point scale (Fig. 60-14).
Assessment of muscle strength can be as detailed as necessary. One may quickly test the strength of the proximal muscles of the upper and lower extremities, always comparing both sides. The strength of the finer muscles that control the function of the hand (hand grasp) and the foot (dorsiflexion and plantar flexion) can then be assessed.
Cerebellar influence on the motor system is reflected in balance control and coordination. Coordination in the hands and upper extremities is tested by having the patient perform rapid, alternat-ing movements and point-to-point testing. First, the patient is in-structed to pat his or her thigh as fast as possible with each hand separately. Then the patient is instructed to alternately pronate and supinate the hand as rapidly as possible. Lastly, the patient is asked to touch each of the fingers with the thumb in a consecutive motion. Speed, symmetry, and degree of difficulty are noted.
Point-to-point testing is accomplished by having the patient touch the examiner’s extended finger and then his or her own nose. This is repeated several times. This assessment is then car-ried out with the patient’s eyes closed.
Coordination in the lower extremities is tested by having the patient run the heel down the anterior surface of the tibia of the other leg. Each leg is tested in turn. Ataxia is defined as incoor-dination of voluntary muscle action, particularly of the muscle groups used in activities such as walking or reaching for objects. The presence of ataxia or tremors (rhythmic, involuntary move-ments) during these movements suggests cerebellar disease.
It is not necessary to carry out each of these assessments for co-ordination. During a routine examination, it is advisable to per-form a simple screening of the upper and lower extremities by having the patient perform either rapid, alternating movements or point-to-point testing. When abnormalities are observed, a more thorough examination is indicated.
The Romberg test is a screening test for balance. The patient stands with feet together and arms at the side, first with eyes open and then with both eyes closed for 20 to 30 seconds. The exam-iner stands close to reassure the patient of support if he or she be-gins to fall. Slight swaying is normal, but a loss of balance is abnormal and is considered a positive Romberg test. Additional cerebellar tests for balance in the ambulatory patient include hop-ping in place, alternating knee bends, and heel-to-toe walking (both forward and backward).
The motor reflexes are involuntary contractions of muscles or muscle groups in response to abrupt stretching near the site of the muscle’s insertion. The tendon is struck directly with a reflex hammer or indirectly by striking the examiner’s thumb, which is placed firmly against the tendon. Testing these reflexes enables the examiner to assess involuntary reflex arcs that depend on the presence of afferent stretch receptors, spinal synapses, efferent motor fibers, and a variety of modifying influences from higher levels. Common reflexes that may be tested include the deep ten-don reflexes (biceps, brachioradialis, triceps, patellar, and ankle reflexes) and superficial or cutaneous reflexes (abdominal reflexes and plantar or Babinski response) (Fig. 60-15).
A reflex hammer is used to elicit a deep tendon reflex. The han-dle of the hammer is held loosely between the thumb and index finger, allowing a full swinging motion. The wrist motion is sim-ilar to that used during percussion. The extremity is positioned so that the tendon is slightly stretched. This requires a sound knowledge of the location of muscles and their tendon attach-ments. The tendon is then struck briskly, and the response is compared with that on the opposite side of the body. A wide vari-ation in reflex response may be considered normal; it is more im-portant, however, that the reflexes be symmetrically equivalent. When the comparison is made, both sides should be equivalently relaxed and each tendon struck with equal force.
Valid findings depend on several factors: proper use of the re-flex hammer, proper positioning of the extremity, and a relaxed patient. If the reflexes are symmetrically diminished or absent, the examiner may use reinforcement to increase reflex activity. This involves the isometric contraction of other muscle groups. If lower extremity reflexes are diminished or absent, the patient is instructed to lock the fingers together and pull in opposite direc-tions. Having the patient clench the jaw or press the heels against the floor or examining table may similarly elicit more reliable bi-ceps, triceps, and brachioradialis reflexes.
The absence of reflexes is significant, although ankle jerks (Achilles reflex) may be normally absent in older people. Deep tendon re-flex responses are often graded on a scale of 0 to 4+. A 4+ indicates a hyperactive reflex, often indicating pathology; 3+ indicates a re-sponse that is more brisk than average but may be normal or in-dicative of disease; 2+ indicates an average or normal response; 1+ indicates a hypoactive or diminished response; and 0 indicates no response. As stated previously, scale ratings are highly subjective. Findings can be recorded as a fraction, indicating the scale range (eg, 2/4). Some examiners prefer to use the terms present, absent, and diminished when describing reflexes. As with muscle strength recording, a stick figure such as the one shown in Chart 60-3 may also be used to record numerical findings.
The biceps reflex is elicited by striking the biceps tendon of the flexed elbow. The examiner supports the forearm with one arm while placing the thumb against the tendon and striking the thumb with the reflex hammer. The normal response is flexion at the elbow and contraction of the biceps (see Fig. 60-15A).
To elicit a triceps reflex, the patient’s arm is flexed at the elbow and positioned in front of the chest. The examiner supports the patient’s arm and identifies the triceps tendon by palpating 2.5 to 5 cm (1 to 2 in) above the elbow. A direct blow on the tendon normally produces contraction of the triceps muscle and exten-sion of the elbow (see Fig. 60-15B).
With the patient’s forearm resting on the lap or across the ab-domen, the brachioradialis reflex is assessed. A gentle strike of the hammer 2.5 to 5 cm (1 to 2 in) above the wrist results in flexion and supination of the forearm.
The patellar reflex is elicited by striking the patellar tendon just below the patella. The patient may be in a sitting or a lying position. If the patient is supine, the examiner supports the legs to fa-cilitate relaxation of the muscles. Contractions of the quadriceps and knee extension are normal responses (see Fig. 60-15C ).
To elicit an ankle (Achilles) reflex, the foot is dorsiflexed at the ankle and the hammer strikes the stretched Achilles tendon (see Fig. 60-15D). This reflex normally produces plantar flexion. If the examiner cannot elicit the ankle reflex and suspects that the patient cannot relax, the patient is instructed to kneel on a chair or similar elevated, flat surface. This position places the ankles in dorsiflexion and reduces any muscle tension in the gastroc-nemius. The Achilles tendons are struck in turn, and plantar flex-ion is usually demonstrated.
When reflexes are very hyperactive, a phenomenon called clonus may be elicited. If the foot is abruptly dorsiflexed, it may continue to “beat” two or three times before it settles into a position of rest. Occasionally with central nervous system disease this activity per-sists and the foot does not come to rest while the tendon is being stretched but persists in repetitive activity. The unsustained clonus associated with normal but hyperactive reflexes is not considered pathologic. Sustained clonus always indicates the presence of cen-tral nervous system disease and requires further evaluation.
The major superficial reflexes include corneal, gag or swallowing, upper/lower abdominal, cremasteric (men only), plantar, and perianal.
These reflexes are graded differently than the motor re-flexes and are noted to be present (+) or absent (-). Of these, only three are tested commonly. The corneal reflex is tested carefully using a clean wisp of cotton and lightly touching the outer cor-ner of each eye on the sclera. The reflex is present if the action elicits a blink. Conditions such as a cerebrovascular accident or coma might result in loss of this reflex, either unilaterally or bi-laterally. Loss of this reflex indicates the need for eye protection and possible lubrication to prevent corneal damage.
The gag reflex is elicited by gently touching the posterior phar-ynx with a cotton-tipped applicator; first on one side of the uvula and then the other. Positive response is an equal elevation of the uvula and “gag” with stimulation. Absent response on one or both sides can be seen following a cerebrovascular accident and requires careful evaluation and treatment of the resultant swal-lowing dysfunction to prevent aspiration of food and fluids into the lungs.
The plantar reflex is elicited by stroking the lateral side of the foot with a tongue blade or the handle of a reflex hammer. Stimulation normally causes toe flexion. Toe fanning (positive Babinski) is an abnormal response and is discussed below (O’Hanlon-Nichols, 1999).
A well-known reflex indicative of central nervous system disease affecting the corticospinal tract is the Babinski reflex. In some-one with an intact central nervous system, if the lateral aspect of the sole of the foot is stroked, the toes contract and are drawn to-gether (see Fig. 60-15E ). In patients who have central nervous system disease of the motor system, however, the toes fan out and are drawn back. This is normal in newborns but represents a se-rious abnormality in adults. Several other reflexes convey similar information. Many of them are interesting but not particularly informative.
The sensory system is even more complex than the motor system because sensory modalities are carried in different tracts located in different portions of the spinal cord. The sensory examination is largely subjective and requires the cooperation of the patient. The examiner should be familiar with dermatomes that represent the distribution of the peripheral nerves that arise from the spinalcord (see Fig. 60-11). Most sensory deficits result from periph-eral neuropathy and follow anatomic dermatomes. Exceptions to this include major destructive lesions of the brain; loss of sen-sation, which may affect an entire side of the body; and the neuropathies associated with alcoholism, which occur in a glove-and-stocking distribution or over the entire hand or foot in areas traditionally covered by a glove or sock.
Assessment of the sensory system involves tests for tactile sen-sation, superficial pain, vibration, and position sense (proprio-ception). During the sensory assessment, the patient’s eyes are closed. Simple directions and reassurance that the examiner will not hurt or startle the patient encourage the cooperation of the patient.
Tactile sensation is assessed by lightly touching a cotton wisp to corresponding areas on each side of the body. The sensitivity of proximal parts of the extremities is compared with that of distal parts.
Pain and temperature sensations are transmitted together in the lateral part of the spinal cord, so it is unnecessary to test for temperature sense in most circumstances. Determining the patient’s sensitivity to a sharp object can assess superficial pain perception. The patient is asked to differentiate between the sharp and dull ends of a broken wooden cotton swab or tongue blade; using a safety pin is inadvisable because it breaks the integrity of the skin. Both the sharp and dull sides of the object are applied with equal intensity at all times, and as with the motor evaluation the two sides are compared.
Vibration and proprioception are transmitted together in the posterior part of the cord. Vibration may be evaluated through the use of a low-frequency (128- or 256-Hz) tuning fork. The handle of the vibrating fork is placed against a bony prominence, and the patient is asked whether he or she feels a sensation and is instructed to signal the examiner when the sensation ceases. Common locations used to test for vibratory sense include the distal joint of the great toe and the proximal thumb joint. If the patient does not perceive the vibrations at the distal bony promi-nences, the examiner progresses upward with the tuning fork until the patient perceives the vibrations. As with all measure-ments of sensation, a side-to-side comparison is made.
Position sense or proprioception may be determined by ask-ing the patient to close both eyes and indicate, as the great toe is alternately moved up and down, in which direction movement has taken place. Vibration and position sense are often lost together, frequently in circumstances in which all others remain intact.
Integration of sensation in the brain is evaluated next. This may be performed by testing two-point discrimination—when the patient is touched with two sharp objects simultaneously, are they perceived as two or as one? If touched simultaneously on op-posite sides of the body, the patient should normally report being touched in two places. If only one site is reported, the one not being recognized is said to demonstrate extinction. Another test of higher cortical sensory ability is stereognosis. The patient is in-structed to close both eyes and identify a variety of objects (eg, keys, coins) that are placed in one hand by the examiner.
The nervous system undergoes many changes during the normal aging process and is extremely vulnerable to general systemic ill-ness. Changes throughout the nervous system vary in degree as the person ages. Nerve fibers that connect directly to muscles show little decline in function with age, as do simple neurologic functions that involve a number of connections in the spinal cord. Disease in the elderly often makes it difficult to distinguish normal from abnormal changes. However, it is important for clinicians not to attribute abnormality or dysfunction to aging without appropriate investigation (Kaye & Quinn, 2000).
There are a number of alterations that occurwith increasing age. Brain weight decreases, as does the number of synapses. A loss of neurons occurs in select regions of the brain. There is a reduction in cerebral blood flow and metabolism. Temperature regulation becomes less efficient. In the peripheral nervous system, myelin is lost, resulting in a decrease in conduc-tion velocity in some nerves. There is an overall reduction in muscle bulk and the electrical activity within muscles. Taste buds atrophy and nerve cell fibers in the olfactory bulb degenerate. Nerve cells in the vestibular system of the inner ear, cerebellum, and proprioceptive pathways also degenerate. Deep tendon re-flexes can be decreased or in some cases absent. Hypothalamic function is modified such that stage IV sleep is reduced. There is an overall slowing of autonomic nervous system responses. Pupil-lary responses are reduced or may not appear at all in the presence of cataracts (Kaye & Quinn, 2000).
There is an overall reduction in muscle bulk,with atrophy most easily noted in the hands (Kaye & Quinn, 2000). Changes in motor function often result in a flexed posture, shuffling gait, and rigidity of movement. These changes can create difficulties for the older person in maintaining or recovering bal-ance. Strength and agility are diminished, and reaction time and movement time are decreased. Repetitive movements and mild tremors may be noted during an examination and may be of con-cern to the individual. Observation of gait may reveal a wide-based gait with balance difficulties.
Sensory isolation due to visual and hearingloss can cause confusion, anxiety, disorientation, misinterpretation of the environment, and feelings of inadequacy. Sensory alter-ations may require modification of the home environment, such as large-print reading materials or sound enhancement for the telephone, as well as extra orientation to new surroundings. Simple explanations of routines, the location of the bathroom, and how to operate the call bell are just a few examples of infor-mation the elderly patient needs when hospitalized.
Other manifesta-tions of neurologic changes are related to temperature regulation and pain. The elderly patient may feel cold more readily than heat and may require extra covering when in bed; a room temperature somewhat higher than usual may be desirable. Reaction to painful stimuli may be decreased with age. Because pain is an important warning signal, caution must be used when hot or cold packs are used. The older patient may be burned or suffer frostbite before being aware of any discomfort. Complaints of pain, such as ab-dominal discomfort or chest pain, may be more serious than the patient’s perception might indicate and thus require careful evaluation.
The acuity of the taste buds de-creases with age; along with an altered olfactory sense, this may cause a decreased appetite and subsequent weight loss. Extra sea-soning often increases food intake as long as it does not cause gastric irritation. A decreased sense of smell due to atrophy of olfactory organs may present a safety hazard, because elderly people living alone may be unable to detect household gas leaks or fires. Smoke and carbon monoxide detectors, important for all, are critical for the elderly.
Another neurologic alteration inthe elderly patient is the dulling of tactile sensation due to a de-crease in the number of areas of the body responding to all stimuli and in the number and sensitivity of sensory receptors. There may be difficulty in identifying objects by touch, and because fewer tactile cues are received from the bottom of the feet, the person may get confused as to body position and location.
These factors, combined with sensitivity to glare, decreased peripheral vision, and a constricted visual field, may result in dis-orientation, especially at night when there is little or no light in the room. Because the elderly person takes longer to recover visual sensitivity when moving from a light to dark area, night-lights and a safe and familiar arrangement of furniture are essential.
Mental status is evaluated while the history is ob-tained, and areas of judgment, intelligence, memory, affect, mood, orientation, speech, and grooming are assessed. Family members who bring the patient to the attention of the health care provider may have noticed changes in the patient’s mental status. Drug toxicity should always be suspected as a causative factor when the patient has a change in mental status. Delirium (mental confu-sion, usually with delusions and hallucinations) is seen in elderly patients who have underlying central nervous system damage or are experiencing an acute condition such as infection, adverse medication reaction, or dehydration. About 25% of patients over the age of 70 admitted to the hospital have delirium ( Johnson, 2001). The cause is often reversible and treatable (as in drug toxi-city, vitamin B deficiency, or thyroid disease). Depression may produce impairment of attention and memory. For elderly pa-tients, delirium, which is an acute change in mental status attrib-utable to a treatable medical problem, must be differentiated from dementia, which is a chronic and irreversible deterioration of cognitive status.
Nursing care for patients with age-relatedchanges to the nervous system and for patients with long-term neurologic disability who are aging should include the modifica-tions previously described. In addition, the consequences of any neurologic deficit and its impact on overall function such as ac-tivities of daily living, use of assistive devices, and individual coping need to be assessed and considered in planning care for patients.
Patient teaching is also affected because the nurse must un-derstand the altered responses and the changing needs of the el-derly patient before beginning to teach. When caring for the elderly patient, the nurse adapts activities such as preoperative teaching, diet therapy, and instruction about new medications, their timing, and doses to the patient’s needs and capabilities. The nurse considers the presence of decline in fine motor move-ment and failing vision. When using visual materials for teaching or menu selection, adequate lighting without glare, contrasting colors, and large print are used to offset visual difficulties caused by rigidity and opacity of the lens in the eye and slower pupillary reaction.
Procedures and preparations needed for diagnostic tests are ex-plained, taking into account the possibility of impaired hearing and slowed responses in the elderly. Even with hearing loss, the elderly patient often hears adequately if the speaker uses a low-pitched, clear voice; shouting only makes it harder for the patient to understand the speaker. Providing auditory and visual cues aids understanding; if the patient has a significant hearing or vi-sual loss, assistive devices, a signer, or a translator may be needed.
Teaching at an unrushed pace and using reinforcement en-hance learning and retention. Material should be short, concise, and concrete. Vocabulary is matched to the patient’s ability, and terms are clearly defined. The elderly patient requires adequate time to receive and respond to stimuli, to learn, and to react. These measures allow comprehension, memory, and formation of association and concepts.
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