Chapter 022. Dizziness and Vertigo (Part 5) pptx

Dizziness and Vertigo Part 5 Evaluation of Patients with Pathologic Vestibular Vertigo The evaluation depends on whether a central etiology is suspected Table 22-2.. Such an examinatio

Chapter 022 Dizziness and Vertigo

(Part 5)

Evaluation of Patients with Pathologic Vestibular Vertigo

The evaluation depends on whether a central etiology is suspected (Table 22-2) If so, MRI of the head is mandatory Such an examination is rarely helpful

in cases of recurrent monosymptomatic vertigo with a normal neurologic examination Typical BPPV requires no investigation after the diagnosis is made (Table 22-1)

Vestibular function tests serve to (1) demonstrate an abnormality when the distinction between organic and psychogenic is uncertain, (2) establish the side of the abnormality, and (3) distinguish between peripheral and central etiologies The standard test is electronystagmography (calorics), where warm and cold water (or air) are applied, in a prescribed fashion, to the tympanic membranes, and the slow-phase velocities of the resultant nystagmus from the two are compared A velocity decrease from one side indicates hypofunction ("canal paresis") An inability to

induce nystagmus with ice water denotes a "dead labyrinth." Some institutions have the capability of quantitatively determining various aspects of the VOR using computer-driven rotational chairs and precise oculographic recording of the eye movements

CNS disease can produce dizzy sensations of all types Consequently, a neurologic examination is always required even if the history or provocative tests suggest a cardiac, peripheral vestibular, or psychogenic etiology Any abnormality

on the neurologic examination should prompt appropriate neurodiagnostic studies.Vertigo: Treatment

Treatment of acute vertigo consists of bed rest (1–2 days maximum) and vestibular suppressant drugs such as antihistaminics (meclizine, dimenhydrinate, promethazine), tranquilizers with GABA-ergic effects (diazepam, clonazepam), phenothiazines (prochlorperazine), or glucocorticoids (Table 22-3) If the vertigo persists beyond a few days, most authorities advise ambulation in an attempt to induce central compensatory mechanisms, despite the short-term discomfort to the patient Chronic vertigo of labyrinthine origin may be treated with a systematized vestibular rehabilitation program to facilitate central compensation

Table 22-3 Treatment of Vertigo

Agenta Doseb

Antihistamines

Meclizine 25–

50 mg 3 times/day

Dimenhydrinate 50

mg 1–2 times/day

Promethazinec 25–

50-mg suppository

or IM

Benzodiazepines

Diazepam 2.5

mg 1–3

Clonazepam 0.25

mg 1–3 times/day

Phenothiazines

Prochlorperazinec 5 mg

IM or 25 mg suppository

Anticholinergicd

Scopolamine

transdermal

Patch

Sympathomimeticsd

Ephedrine 25

mg/d

Combination

preparationsd

Ephedrine and

promethazine

25 mg/d of each

Exercise therapy

Repositioning

maneuverse

Vestibular

rehabilitationf

Other

Diuretics or

low-salt (1 g/d) dietg

Antimigrainous

drugsh

Inner ear surgeryi

Glucocorticoidsc 100

mg/d for 3 days,

tapered by

20 mg every

3 days