head elevated for 5 to 10 days to allow healing to take place. The symptoms will often subside and come on only with forceful maneuvers such as straining or sneezing, or changes in pressure
in the inner ear. Persons with chronic or worsening symptoms may go on for surgical management.
CLINICAL EXAMINATION OF THE VESTIBULAR SYSTEM
The clinician begins a clinical or “bedside” examination of vestibular system function by achieving an accurate description of the patient’s complaints. Often, the term dizzy is used to describe a host of symptoms not related to vestibular system dysfunction, such as difficulty with walking, unsteadiness, headache, and lightheadedness. Symptoms of vertigo strongly indicate a vestibular system contribution to the patient’s complaints, while complaints of “lightheadedness” are suggestive of medication side effects, migraine, cardiac, and anxiety among other nonvestibular disorders as the source of the patient’s symptoms. Nausea and vomiting along with dizziness or vertigo is indicative of either central or peripheral vestibular lesions. The temporal nature, onset, and duration of symptoms of dizziness also guide the clinician’s differential assessment Review of systems A review of systems (ROS) is an important component of a comprehensive clinical examination. The ROS, in conjunction with the patient’s subjective report and medical history, gathers information that is vital to the process of differential assessment. In an ROS, the examiner performs a systematic screening of all body systems to identify the source of the patient’s symptoms. For the patient who presents with symptoms that implicate vestibular system dysfunction, it is of utmost importance to determine whether the cardiac system, vascular system, neurological system, psychological disorders, and polypharmacy are contributing factors to the patient’s chief complaint of dizziness and imbalance. When assessing the presence of neurological system impairment as the possible etiology of symptoms of dizziness and impaired postural control, the examiner should look for changes in muscle strength and coordination, muscle tone, sensation, vision, hearing, speech, and cognition. Cardiac and vascular disorders may cause dizziness upon exertion, postural hypotension, and dizziness provoked with cervical extension motions due to vertebral circulation insufficiency. For the patient with a history Oculomotor system Examination of the oculomotor system establishes baseline function of eye muscles and central oculomotor pathways. Since the vestibular system mediates head-eye coordination, it is important to determine whether full active ocular movement is present in order to accurately interpret findings on vestibular testing. Furthermore, abnormalities seen on oculomotor testing indicate the possibility of a centrally mediated disorder; these tests assess the function of central oculomotor pathways that are independent of the vestibular system. The components of the oculomotor examination are observation of ocular motility and alignment, presence of nystagmus, tests of smooth pursuit and saccade, and vergence. Ocular motility and alignment The examination should start with observation of ocular motility and alignment. The patient is asked to actively look up, down, side to side, and across the diagonal, with the head stationary, to assess motor function of the medial and lateral rectus, trochlear, and superior and inferior oblique ocular muscles. Any abnormalities in resting alignment of the eyes in the orbits should also be appreciated. Observation of differences in vertical alignment of the eyes is called skew deviation . Skew deviation is a vertical misalignment of the eyes. Although typically a sign of CNS lesion, vertical skew deviation at rest can be seen in acute unilateral vestibular loss. The loss of utricular inputs on the side of the lesion results in the ipsilateral eye resting lower in the orbit, and the contralesional eye appearing higher in the orbit
process. The clinician should establish whether the patient is experiencing an acute attack of dizziness, described as onset within the last 3 days, is experiencing chronic dizziness, lasting more than 3 days, or if the patient’s dizziness is episodic. Understanding whether the onset was abrupt or insidious as well as particular provoking factors or preceding illness events is also diagnostic. For episodic dizziness, the provoking factor and duration of symptoms in terms of seconds, minutes, or hours are important to elucidate for the purposes of differentiating the source of symptoms and vestibular system impairment. Clinical examination of vestibular function includes a review of systems, specific testing of the oculomotor and vestibular systems, assessment of postural control, and the use of standardized tools to measure the impact the disorder has on the patient’s life. of psychological disorders, the onset of psychogenic-related dizziness and balance dysfunction will have a situational trigger, be associated with palpitations, trembling, and shortness of breath, or be motivated by some aspect of secondary gain. A comprehensive review of the patient’s medications, both prescribed and over the counter, is essential to determine whether possible medication side effects or medication interactions are contributing to the patient’s primary complaints. Of particular importance is to determine whether the patient has been prescribed antihistamines (such as meclizine, Antivert) to dampen symptoms of dizziness, nausea, and vomiting; these medications will blunt the patient’s responses on vestibular testing, reducing the diagnostic value of findings on clinical examination. Furthermore, the patient with non-vestibular- related symptoms will demonstrate a pattern of clinical findings that do not characterize vestibular pathology. The differential assessment process should provide the clinician with enough evidence to determine whether to treat the patient or refer him or her to a more appropriate specialist for further diagnostic workup and management. due to the loss of inhibitory input from the opposite (lesioned) side. If this finding is associated with acute peripheral vestibular dysfunction, resolution of skew deviation alignment will occur within 3 to 14 days due to spontaneous rebalancing of the tonic firing rate (Herdman & Clendaniel, 2014). Most often, skew deviation is caused by a centrally mediated lesion, typically in the cerebellum or brainstem. Further assessment of underlying skew deviation is achieved through the Cross-Cover Test, also called the Cover-Uncover or Alternate Cover Test . The examiner alternately covers one eye and then the other, looking for changes in ocular position. In most cases of skew deviation, the covered eye will migrate either up or down, and when rapidly uncovered a vertical correction (corrective saccade) will be observed. This correction repositions the eye in the center of the orbit as aided by visual fixation once the eye is uncovered. The skew is named for the side that is elevated (migrates downward with visual fixation), with the other side being the side of the CNS lesion. Nystagmus Assessing the presence of nystagmus is another important component of the oculomotor examination. Nystagmus is a rapid repetitive involuntary movement of the eyes that occurs under both normal and pathological conditions. Under normal conditions, nystagmus is elicited through vestibular or visual stimuli. It is seen in central or peripheral vestibular pathology due to an imbalance in vestibular outputs caused by a unilateral
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