The Nervous System

Headache

Headache is the most common neurologic symptom. It has been estimated that more than 35 million individuals in the United States suffer from recurrent headaches. Most of these patients have headaches that are related to migraine, muscle contraction, or tension. A headache pattern that is unchanged and has been present for several years is unlikely to be related to present illness of the patient. Several points must be clarified for any patient complaining of a recent change in the frequency or severity of headaches. Ask the following questions:

• “How long have you been having headaches?”

• “When did you notice a change in the pattern or severity of your headaches?”

• “How has the pattern of your headaches changed?”

• “How often do your headaches occur?”

• “How long does each headache last?”

• “Which part of your head aches?”

• “What does the headache feel like?”

• “How quickly does the headache reach its maximum?”

• “When you get headaches, do you have any other symptoms?”

• “Are you aware of anything that produces the headaches?”

• “Are there any warning signs?”

• “Does anything make the headaches worse?”

• “What makes the headaches better?”

Patients complaining of a sudden onset of headache usually have more serious illnesses than patients with headaches of chronic duration. A continuous headache can be related to muscle spasm, whereas a recurrent headache may be a migraine or cluster headache. A throbbing headache often has a vascular cause. Certain headaches are associated with visual phenomena, nausea, or vomiting. In patients with increased intracranial pressure, any maneuver that increases the pressure, such as coughing or bending, may worsen the headache. In any patient who experiences a severe, sudden headache, stroke should be suspected.

Migraine is a biphasic type of headache associated with a prodromal phase, called the aura, followed by the headache phase. During the aura, one or more physiologic events may occur. These include transient experiences of autonomic, visual, motor, or sensory phenomena. Common visual symptoms are photophobia, blurred vision, and scotomata. As the aura fades, the headache begins. It is usually unilateral and is often described as pulsating; it can last for hours to days. Migraine headaches are often triggered by stress, anxiety, the use of birth control pills, and hormonal changes. Many patients experience migraine headaches after a period of excitement. Other important triggers are hunger and the ingestion of certain foods such as chocolate, cheese, cured meats, and highly spiced foods. There is often a family history of migraine.

Cluster headaches are associated with oculosympathetic disturbances. The typical patient is a middle-aged man complaining of recurrent episodes of pain around the eye that last for up to 1 hour. Classically, cluster headaches awaken the patient from sleep on successive nights for 2 to 4 weeks. There is ipsilateral miosis, ptosis, conjunctival edema, tearing, and nasal stuffiness during the headache. It is thought that alcohol may precipitate such attacks.

Headache may be the result of referred pain from sinus infections, ocular disease, or dental disease. Systemic conditions such as viral infections, chronic obstructive pulmonary disease, and poisoning may produce headaches. Determine whether the patient is taking any medications that may be producing the head pain. (See Table 21.2 at the end of this chapter, which provides an approach to patients with the symptom of headache.)

Loss of Consciousness

Loss of consciousness—syncope—may result from cardiovascular or neurologic causes. The cardiovascular causes are discussed in Chapter 14 , The Heart, and Chapter 15 , The Peripheral Vascular System. The term blackout is commonly used, but it may mean different conditions to the patient and the interviewer. Any patient who uses this term should be asked to clarify its meaning. The patient may be referring to an actual loss of consciousness, a dimming of vision, or a decreased awareness of the environment without an actual loss of consciousness.

A useful way to clarify the symptom of loss of consciousness is to ask the patient, “Have you ever lost consciousness, fainted, or felt that you were not aware of your surroundings?” If the patient answers in the affirmative, identify the cause of the loss of consciousness. Ask the following questions:

• “Can you describe the attack to me—every event as it occurred until you lost consciousness?”

• “Did anyone witness the attack?” ⁶

  6 Document a history with an observer, if possible.

• “Were there any symptoms that preceded the attack?”

• “Were you told that there were body movements?”

• “Can you describe everything you remember after the attack until you felt completely normal?”

• “Was there a period of sleepiness that followed?” If yes, “For how long did this period last?”

• “How did you feel after the attack? Were you confused?”

• “Did you notice afterward that you had urinated or had a bowel movement during the attack?”

Epileptic seizures may produce a loss of consciousness and are caused by the sudden, excessive, disorderly discharge of neurons. The first step in approaching the symptom of seizure is to identify its type. If the discharge is focal, the clinical seizure reflects the effect of the excessive discharge in that area of the body. For example, if the discharge occurs in the inferior precentral gyrus, involved with hand and arm motion, the seizure is characterized by involuntary motion of the hand and arm. A generalized seizure results from a discharge in the subcortical structures, such as the thalamocortical radiations. These have widespread bilateral cortical connections. There are three main types of generalized seizures:

• Petit mal (absence seizure)

• Grand mal (generalized tonic-clonic)

• Myoclonic

A petit mal seizure is characterized by a sudden attack of unconsciousness lasting only about 10 seconds, usually without any warning. During the petit mal seizure, the patient appears to be staring or daydreaming. There is no associated falling or involuntary limb motion. The patient rapidly returns to normal activity without being aware of the attack. These seizures are most common in children 5 to 15 years of age. On occasion, they may persist into adulthood.

A grand mal seizure is a generalized major motor convulsion. Affected patients lose consciousness, and many fall down rigidly. In 50% of patients with grand mal seizures, there is an aura of giddiness, involuntary twitching, change in mood, confusion, or epigastric discomfort as the seizure begins. Some patients may cry out initially. During this tonic phase, there is an increase in muscle tone, resulting in a rigid, flexed posture and then a rigid, extended posture. The patient may become apneic and cyanotic. The eyes may open and stare or may be deviated to one side. The clonic phase follows, with involuntary movements of the body. These are often associated with salivation, eye rolling, and incontinence. Biting the tongue is common. After the clonic phase, the individual passes into a phase resembling sleep from which she or he cannot be easily awakened. Postictally, or after the seizure, the patient may be confused and often falls into a deep sleep that lasts for hours. Accompanying muscle pain and headache are common.

A myoclonic seizure is a minor motor seizure characterized by sudden muscle contractions of the face and upper extremities. The eyelids and forearms are commonly affected. There is no detectable loss of consciousness.

Febrile convulsions are common in children from 6 months to 6 years of age and are similar to grand mal seizures. When a child has a high fever, a seizure lasting less than 10 minutes may occur. The younger the child is at the time of the first febrile seizure, the greater is the likelihood that seizures will recur.

“Dizziness”

Dizziness is a term used frequently by patients and should be avoided by the interviewer. “Dizziness” may be the patient's description of vertigo, ataxia, or lightheadedness. Any time the patient uses this term, it must be clarified by additional questioning, because different pathophysiologic mechanisms may be responsible. The interviewer needs to differentiate vertigo from ataxia. If the patient complains of “dizziness,” it is important to ask these questions:

• “Would you describe the dizziness as a strange spinning sensation in your head?”

• “Did the room spin, or did it feel as if you were spinning?”

• “Were you unsteady while walking?”

Vertigo is partially discussed in Chapter 11 , The Ear and Nose. Vertigo is the hallucination of movement. Acute vertigo may be associated with nausea, vomiting, perspiration, and a sense of anxiety. Ask patients whether they have the sensation that objects are moving around them or that they are spinning or moving. In addition to the questions in Chapter 11 , ask the following:

• “During the attack, did you experience any nausea or vomiting?”

• “Have you noticed any problem with your hearing or ringing in your ears?”

• “Have you ever been given an antibiotic called gentamicin?”

Ménière disease can result in protracted attacks of severe vertigo associated with vomiting. Many patients with Ménière disease also have the symptoms of tinnitus and hearing loss. During the attack, the patient is unsteady, with horizontal nystagmus directed away from the affected ear. Certain drugs (such as gentamicin) are associated with changes in the labyrinth of the ear and can cause vertigo and deafness.

Dizziness and stumbling are commonly associated with a stroke.

Ataxia

Disruption of the vestibular-ocular-cerebellar control mechanism produces ataxia. Ataxia is persistent unsteadiness in the upright position. Any patient complaining of dizziness must be evaluated for abnormal function of the vestibular, visual, proprioceptive, and cerebellar systems. Equilibrium requires the integration of sensory input and motor output, acting primarily at a reflex level for the maintenance of balance. The ears and eyes and their central connections in the brain stem and the cerebellum are intimately involved in balance. Any patient with ataxia should be asked the following questions:

• “Are you unsteady when you walk?”

• “Have you noticed that the dizziness is worse when your eyes are open or closed?”

• “What does your diet consist of? What did you eat yesterday?”

• “Have you ever had syphilis?”

Abnormal proprioceptive input from the lower extremities can cause ataxia. Severe posterior column damage from syphilis, vitamin B ₁₂ deficiency, or multiple sclerosis may produce a “sensory” ataxia, resulting in a wide-based, high-stepping gait. The gait is worsened by having the patient close the eyes and is improved by having the patient observe the feet. Vitamin B ₁₂ deficiency may result from pernicious anemia or from inadequate intake, although poor nutrition is a rare cause. “Motor” ataxia results from an abnormality in the cerebellum and central vestibular pathways. It is characterized by wide-based, irregular placement of the feet and poor placement of the center of gravity, with a lurching to either side.

Changes in Consciousness

Changes in consciousness may be related to changes in attention span, perception, arousal, or a combination. In confusional states, the patient can receive information normally, but the processing is disturbed. In delirium, the individual perceives the information abnormally. Any patient, or member of the patient's family, who indicates that a change in consciousness has occurred should be asked the following:

• “Did the change occur suddenly?”

• “Have there been other symptoms associated with the change in consciousness?”

• “Do you use any medications? Depressants? Insulin? Alcohol? Recreational drugs?”

• “Is there a history of psychiatric illness?”

• “Is there a history of kidney disease? Liver disease? Thyroid disease?”

• “Have you ever had an injury to your head?”

Many factors can produce changes in consciousness. The acuteness of the change in consciousness is often helpful in making a diagnosis. Hemiparesis, paresthesia, hemianopsia, garbled speech, and arm and leg weakness are common associated symptoms of supratentorial lesions. Brainstem lesions are often associated with changes in consciousness and with nystagmus, vomiting, double vision, nausea, and excessive yawning. Drugs of any type can produce acute changes in consciousness. A history of earlier psychiatric illness is important. Toxic and metabolic changes are frequently associated with changes in consciousness. Liver or kidney failure, myxedema, and diabetic ketoacidosis are common causes of metabolic abnormalities. A history of head trauma may result in a subdural hematoma and produce a gradual change in consciousness.

Visual Disturbance

Visual disturbances are common neurologic presenting symptoms. The most important symptoms are acute visual loss, chronic visual loss, and double vision. Ask any patient complaining of visual disturbances the following questions:

• “How long have you noticed these visual changes?”

• “Is the visual loss associated with pain?”

• “Did it occur suddenly?”

• “Do you have a history of glaucoma?”

• “Have you ever been told that you had a thyroid problem?”

• “Do you have diabetes?”

Acute painless visual loss is caused by either a vascular accident or a retinal detachment. Painless loss of vision over a longer period occurs with compression of the optic nerve or tract or radiation. Glaucoma is often the cause of chronic, insidious, painless loss of vision. Acute narrow-angle glaucoma, however, may be responsible for transient loss of vision in association with intense ocular pain. Episodes of migraine may produce transient episodes of visual loss before the development of the headache. Amaurosis fugax is transient visual loss lasting up to 3 minutes and is a feature of internal carotid artery disease.

Double vision, or diplopia, is discussed in Chapter 10 , The Eye. Ocular motor palsies, thyroid abnormalities, myasthenia gravis, and brainstem lesions are well-known causes of diplopia. Ocular motor palsies can occur in trauma, multiple sclerosis, myasthenia gravis, aneurysms of the circle of Willis, diabetes, and tumors. Ask the following questions of any patient complaining of diplopia:

• “Are you diabetic?”

• “In which field of gaze do you have double vision?”

• “Did the double vision occur suddenly?”

• “Was there any pain associated with the double vision?”

• “Has there been any injury to your head or eye?”

• “Have you ever been told that your blood pressure was elevated?”

• “Does the double vision get worse when you are tired?”

• “Have you been exposed to the AIDS (acquired immune deficiency syndrome) virus?”

When a cranial nerve is affected, resulting in an extraocular muscle palsy, the patient may complain of diplopia in one field of gaze when the affected eye is unable to move conjugately with the other. Ocular palsies involve the third, fourth, and sixth cranial nerves. A complete third (oculomotor) nerve palsy causes ptosis, mydriasis, and loss of all extraocular movements except abduction. Trauma, multiple sclerosis, tumors, and aneurysms are the most frequent causes. Aneurysms of the posterior communicating artery can involve the third nerve, which passes near the artery on its way to the cavernous sinus. Cavernous sinus thrombosis, not infrequently seen in patients with AIDS, may also produce a complete third nerve palsy. Pupil-sparing third nerve, fourth (trochlear) nerve, and sixth (abducens) nerve palsies are seen in diabetic patients and in patients with long-standing hypertension. Patients with myasthenia gravis often have diplopia in the later part of the day as the muscles tire and weaken.

Visual disturbances, including blocked vision or loss of vision in one eye, blurry vision, or “graying out” are seen frequently in patients suffering a stroke.

Dysphasia

Speech abnormalities, or dysphasia, may be either nonfluent (expressive) or fluent (receptive). In expressive aphasia, the speech pattern is hesitant and labored, with poor articulation. The patient has no problem with comprehension. When asked to say, “no ifs, ands, or buts,” the patient has great difficulty. In receptive aphasia, the speech is rapid and appears fluent but is full of syntax errors, with the omission of many words. Handwriting changes are nonspecific but indicate an impairment of neuromuscular control. Ask the following questions:

• “Have you noticed any recent change in your speech pattern, such as slurring of your words?”

• “Do you have trouble understanding things that are said to you?”

• “Have you had any difficulty finding the right word in conversation?”

• “Has your handwriting changed recently?”

Language problems, as well as slurred speech, are found commonly in patients suffering a stroke.

Dementia

An important symptom of neurologic disease is failing memory. Dementia can be defined as the progressive impairment of orientation, memory, judgment, and other aspects of intellectual function. Dementia is a symptom rather than a specific disease entity. The most common cause of dementia is Alzheimer disease . Other causes include Parkinson disease, vascular disorders, metabolic disorders, drugs, tumors, vitamin B ₁₂ deficiency, tertiary syphilis, and normal-pressure hydrocephalus. It is common for patients with early dementia to recognize an increasing inability to comprehend written material. They are aware also of their cognitive impairment but fail to acknowledge it with friends and family. It is often so insidious that individuals with dementia may live with their family for years without the family recognizing the problem. In addition, family members and friends may not wish to acknowledge the failing mental capacities.

Ask the patient and his or her friends and family the following:

• “Have you noticed any change in your memory lately?”

• “Do you have difficulty reading or understanding what you have read?”

• “What was the patient's personality like a few years ago?”

• “When was the last time the patient seemed normal?”

• “What does the patient's diet consist of? Does he or she eat well?”

• “Can the patient live alone?”

Cerebrovascular Accident

Strokes, or cerebrovascular accidents, are common. Most are thromboembolic (80%), but some are hemorrhagic (20%). Thirty percent of patients who sustain a stroke die within the first month. Most patients with strokes have paresis of at least one limb. Transient ischemic attacks (TIAs) are short episodes manifested by focal neurologic dysfunction. They usually last only a few minutes, after which complete recovery occurs. The importance of TIAs is that, in 30% of affected patients, a stroke occurs within 4 to 5 years.

Gait Disturbance

Gait disturbances may occur for a variety of reasons. Gait may be changed by local pain in the foot, pain in a joint, claudication of the hip or leg, bone disease, vestibular problems, and extrapyramidal disorders. Interruption of the corticospinal tracts in the cerebrum after a stroke produces a spastic weakness in the contralateral leg. The foot is dragged, and the whole leg appears stiff and extended. Lesions in the spinal cord may produce a spastic paralysis affecting both legs. The gait is slow and stiff, with small steps. Patients with Parkinson disease walk stooped over, with short, quick, shuffling steps. Any patient with a gait disturbance should be asked the following:

• “Do you have pain in your leg or hip when you walk?”

• “Do you have diabetes?”

• “Have you ever had syphilis?”

• “What do you eat? Tell me everything you ate yesterday.”

Patients with vascular occlusive disease of the hip or leg may experience pain while walking and may alter their gait. Diabetes, syphilis, and pernicious anemia may produce a sensory loss, and each condition can result in gait abnormalities.

Tremor

A tremor is a rhythmic motion of the distal parts of the limbs or head. A physiologic tremor has an oscillation of 10 to 12 cycles per second and is more obvious after exercise. A pathologic tremor is slower. Parkinson disease is the most frequently encountered extrapyramidal movement disorder. In this condition, the tremor is present at rest and is decreased with action. It has a frequency of 3 to 6 cycles per second and is worsened by anxiety. An intention, or ataxic, tremor is slow (2 to 4 cycles per second) and worsens on attempted movement. Multiple sclerosis is one of the many causes of intention tremor. Metabolic problems from liver or kidney failure are frequently responsible. Withdrawal from alcohol or caffeine is often a precipitating factor. Any patient with the symptom of tremor should be asked these questions:

• “Does the tremor worsen when you try to do something?”

• “Is there a history of thyroid disease?”

• “Have you ever been told about any problems with your liver or kidneys?”

• “What is your daily consumption of alcoholic beverages?”

• “How much coffee or tea do you drink?”

• “How much chocolate do you eat?”

Chorea is involuntary jerky motions of the face and limbs. A common cause is Huntington disease, in which chorea is accompanied by personality changes and progressive mental deterioration terminating in dementia.

“Numbness”

Numbness is another term used by patients to indicate a variety of problems. “Numbness” can be used by patients to describe a “pins-and-needles” sensation, coolness, pain, or clumsiness. The interviewer should be sure to clarify the meaning. The examiner must be careful during the physical examination to palpate the distal pulses in any patient complaining of numbness, because arterial insufficiency is a possible cause. Diabetes mellitus is a common cause of lower extremity numbness. Multiple sclerosis may cause numbness in any extremity.

“Weakness”

Weakness may be a symptom of the motor system. A patient with a proximal arm motor weakness complains of difficulty brushing hair, shaving, or reaching up to shelves. A patient with distal arm motor weakness complains of difficulty putting a button through a buttonhole, using keys, or writing with a pen or pencil. Proximal leg motor weakness is characterized by difficulty climbing stairs or getting into bed or the bathtub. Foot drop is a classic sign of distal leg motor weakness. Chapter 20 , The Musculoskeletal System, reviews some of the important questions related to weakness.

Face droop and weakness are common signs of a stroke, as is the presence of numbness or clumsiness in one arm or hand.

Pain

Pain is an infrequent symptom of neurologic disease, but it merits mention. Trigeminal neuralgia, also known as tic douloureux, is the occurrence of severe, jabbing pain lasting only seconds in the distribution of the maxillary or mandibular divisions of the trigeminal nerve ( Fig. 21.10 ). It is frequently provoked by motion, touch, eating, or exposure to cold temperatures. Another cause of facial pain is the cluster headache, already discussed. Herpes zoster infection of a sensory nerve root, also known as shingles, manifests with intense pain along the distribution of that nerve root. The classic linear, vesicular skin eruption develops 3 to 4 days later along the distribution of the nerve. Fig. 8.70 shows the classic dermatologic manifestations of herpes zoster infection of spinal nerve T3.

Sciatica is intense pain shooting down the leg in the distribution of the sciatic nerve. In this condition, there is impingement of portions of the sciatic nerve by the vertebrae. Arthritis of the lumbosacral spine is frequently the cause.

Sometimes the paresthesias associated with demyelinating diseases are so intense that the patient may describe them as pain.

Patients with inflammation of the meninges often complain of pain in the neck and a resistance to flexion of the neck. If meningitis is suspected, have the patient lie on his or her back. Place your hand behind the patient's neck and flex it until the chin touches the sternum. In patients with meningitis, there is neck pain and resistance to motion. This is called Brudzinski sign. There may also be flexion of the patient's hips and knees. Jósef Brudzinski described at least five different physical signs indicative of meningeal irritation. This sign is the best known and most reliable sign. Another sign of meningeal irritation can be elicited while the patient lies on the back and you flex one of the patient's legs at the hip and knee. If pain or resistance is elicited as the knee is extended, a positive Kernig sign is present.

Mental Status

See Video 21.1 .

During the interview, the examiner has already gained much insight into the mental status of the patient. The interviewer may have already been able to assess the patient's remote memory, affect, and judgment. The formal mental status portion of the neurologic examination is introduced by saying to the patient, “I would like to ask you a few routine questions. Some of them you will find very easy. Others will be more difficult. Do the best you can.”

The mental status examination consists of evaluation of the following:

• Level of consciousness

• Speech

• Orientation

• Knowledge of current events

• Judgment

• Abstraction

• Vocabulary

• Emotional responses

• Memory

• Calculation ability

• Object recognition

• Praxis

Cranial Nerves

The examination of the cranial nerves should be carried out in an orderly manner. Several of the cranial nerves have already been evaluated. Table 21.1 lists the cranial nerves, their functions, and the clinical findings when a lesion exists.