General Examination

Every patient with a disorder of equilibration or true vertigo should have a screening general physical examination. Patients who exhibit symptoms suggesting presyncope or actual syncope must have particular attention paid to their cardiovascular system. Not only should patients have their blood pressure measured in the resting, sitting, and standing position, but they also should have their blood pressure measured at 1 minute intervals up to 5 minutes after assuming the upright position, as delayed postural hypotension is not uncommon. Exercise-induced hypotension is an important observation and should lead to consideration of conditions such as the Shy-Drager syndrome, diabetic autonomic neuropathy, and cardiac defects such as aortic stenosis and obstructive cardiomyopathy. Whenever episodic symptomatology is associated with a question of alteration of consciousness or lightheadedness, particular attention should be paid to the possibility of cardiac dysrhythmia. Most patients with cardiac dysrhythmias do not report associated sensations of irregular heartbeat, thumping in the chest, or fluttering, however, examination may reveal an irregular cardiac rhythm or cardiac murmur.

During the general examination, attention should be paid to systemic conditions that could give rise to a general feeling of malaise or weakness interpreted by the patient as a disorder of balance. Conditions leading to sudden syncope may be revealed on the general physical examination. Patients with suspected extracranial vascular disease not only should have the head and neck auscultated for bruits, but also should have a general examination of the peripheral vascular system, including the cranial and carotid pulses and evaluation for signficant varicose veins that may lead to venous pooling and hypotensive episodes.

The neurological examination should be directed by the patient's history. In patients with clear-cut episodic vertigo, the neurological examination will usually be normal with the exception of the ocular motor findings to be described. However, when the patient's symptom complex is more vaguely defined and includes disequilibration or unsteadiness, particular attention must be paid to examination of the motor system, reflexes, sensation, and cerebellar function.

All patients with undiagnosed disorders of equilibration, however described, should have a complete neurological examination. Portions of the neurological examination will be described briefly, followed by suggestions of which entities might cause abnormality.

Mental Status Examination 

Signs of diffuse alteration in consciousness may suggest overmedication, metabolic encephalopathy, or an acquired dementing process. Focal disturbances in intellectual function, such as a subtle aphasia, may lead to the consideration of multi-infarct dementia with accompanying brainstem infarctions, or of a mass lesion in the dominant hemisphere.

Cranial Nerve Examination

Alterations in visual sensory function can be a primary or exacerbating cause of disequilibration. Even the recent addition of a new refractive correction, particularly lenses for presbyopia, may be an added or primary cause of imbalance. Visual field defects such as unsuspected bitemporal or homonymous field defects from infarcts or tumors may cause patients to run into objects or feel disoriented in space. The presence of papilledema or absent venous pulsations on fundoscopy should be an immediate clue to raised intracranial pressure. Altered corneal sensation can be the clue to a previously unsuspected cerebellopontine angle mass. Simple auditory screening tests may reveal a previously unsuspected hearing loss and should always lead to formal audiological testing. Abnormalities on examination of cranial nerves IX through XII raise the differential diagnosis of multiple cranial neuropathies caused by collagen vascular disease, tumors of the base of the skull, or nasopharyngeal carcinoma.

Ocular Motor Examination 

The presence of spontaneous or induced nystagmus is of critical importance in the diagnosis of peripheral, central, or systemic causes of imbalance. Nystagmus types of particular note are described in the section on the directed neuro-otologic examination. Defective downward gaze is often the first sign of progressive supranuclear palsy a condition often accompanied by disequilibration. The presence of asymmetrical slowing of the adducting eye indicating an internuclear ophthalmopleglia is a subtle but important clue to the presence of brainstem multiple sclerosis, brainstem infarction, or mass lesion of the posterior fossa.

Motor System Examination 

The examination of motor function can reveal focal or diffuse weakness indicative of CNS or neuromuscular disorders. A subtle hemiparesis may be the true cause of the patient's balance complaint. Diffuse hyperreflexia reflects cerebral or spinal cord dysfunction and, in combination with cerebellar abnormality, might lead to the diagnosis of a spinocerebellar degeneration.

Sensory System Examination 

Examination of sensation can reveal a significant peripheral neuropathy leading to a diagnosis of diabetes or toxic neuropathy. Selective loss of sensory modalities conveyed by the posterior column such as proprioception and vibration, may indicate that the patient has vitamin B12 deficiency or early tabes dorsalis. Such patients are relatively steady during the Romberg test with eyes open, but rapidly lose balance and fall in any direction when visual compensation is eliminated by eye closure.

Cerebellar System Examination 

Obvious limb or body ataxia should be an immediate clue to the CNS abnormality as the cause for the patient's imbalance. Unsteadiness during Romberg testing with eyes open and only slight exaggeration on eye closure indicates a cerebellar abnormality. Cerebeller dysfunction is usually accompanied by abnormality during gait testing or even difficulty maintaining balance while seated. Patients with symptomatic peripheral vestibulopathy tend to fall toward the side of the abnormality during eye closure with the head straight ahead. Unilateral limb ataxia is almost always an indicator of focal posterior fossa abnormality, such as infarct, demyelination, abscess, or tumor.

Directed Neuro-otologic Examination 

A directed neuro-otologic examination should be performed, particularly when there are abnormalities of the auditory, ocular motor and vestibular systems. Audiological testing is discussed later. During the neurological examination, there may be subtle signs of peripheral vestibular dysfunction indicated by nystagmus. On external examination the nystagmus fast phase is away from the ear with the vestibular abnormality. During the funduscopic examination, particular attention should be paid to the movement of the optic disc. A rhythmical subtle horizontal slow and fast component nystagmus is frequently present in patients with new peripheral vestibular dysfunction. The nystagmus is brought out by reducing fixation during the funduscopic examination. For example, with the patient staring at a dimly lit target in the distance, the presence of a slow ocular drift to the left and a fast phase to the right of the optic disc should indicate to the examiner that the patient has a subtle left beating nystagmus in the primary position. The findings indicate a right peripheral vestibular abnormality. Fast upward rhythmic vertical movement of the optic disc seen during funduscopic examination signifies the presence of downbeat nystagmus. The examiner should then search carefully for the presence of downbeat nystagmus during examination of oblique and downward gaze. The need to search for presence of any type of nystagmus during the directed neuro-otologic examination cannot be overemphasized. The directed neuro-otologic examination should include a detailed otoscopic examination of the external auditory canal and the tympanic membrane. The presence of a retracted or scarred eardrum suggests prior middle ear infection. The presence of a blue mass behind the tympanic membrane points to a glomus jugular tumor.

The patient should be tested for balance during standing, walking, and turning, and for the presence of past-pointing. Past-pointing is a tendency for the repetitively elevated and lowered outstretched fingers to drift unidirectionally. Past-pointing is a clear indication of tonic imbalance in the vestibular system. If during Romberg testing the patient tends to fall in a certain direction, can this direction be altered by changing head position? The ability to alter the direction of the fall during Romberg testing by head turning indicates a peripheral vestibular abnormality. For example, a patient with an acute left peripheral vestibulopathy will tend to fall to the left during eye closure with the head straight ahead, but will fall backwards (toward the abnormal ear) with the head turned left, and will fall forward during eye closure when the head is turned to the right.

The physician should test for the presence of an intact vestibulo-ocular reflex (VOR), and observe whether the patient is able to maintain steady ocular fixation during funduscopic examination as the head is gently rotated from side to side. The patient with an intact VOR can still maintain fixation on distance objects during head turn. The absence of this ability produces an apparent nystagmus, most easily observed during funduscopic examination, which is good evidence for a defective VOR. A different test of vestibulo-ocular control is for the patient to fix on his or her own thumb while rotating the head in the same direction. During this maneuver, the patient must suppress the vestibulo-ocular response in order to permit combined head and eye tracking. The loss of this ability may be a subtle clue to cerebellar system dysfunction. The patient should also be examined for the presence of nystagmus when visual fixation is reduced by wearing of Frenzel glasses, which blur the patient's vision. The lenses also magnify the eye allowing better detection of low amplitude nystagmus.

If the patient has no cervical problems, a head-shaking test can be performed. The patients are asked to shake their head rapidly twenty times back and forth while wearing Frenzel glasses. Then the patient is observed to determine whether there is any primary position horizontal nystagmus. The maneuver may bring out a latent nystagmus indicating vestibular imbalance. The fast phase of the nystagmus would be away from the ear with the peripheral vestibulopathy.