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新光醫院 神經科新光醫院 神經科許維志 醫師

Balance and Equilibrium Equilibrium

The ability to maintain orientation of the body and its parts in relation to external space.

Interaction between self and environment. Sensory input from visual, vestibular, and

proprioceptive information. Integration in the brain stem and cerebell

um.

Disorders of Equilibrium Diseases affect

Central or peripheral vestibular pathways Cerebellum Proprioceptive sensation

Mismatch of input signals and disintegration

Symptoms Vertigo Ataxia

Vertigo and Dizziness Vertigo 眩暈

Illusion of movement of the body or the environment.

Impulsion, oscillopsia, nausea, vomiting, cold sweating, or unsteadiness

Dizziness 頭昏 No association of illusion of movement Light-headedness, faintness, giddiness, swimmi

ng

Vestibular System Semicircular canal

Sense angular acceleration Head rotation

Otolith organs Sense linear acceleration Head translation and uprightness

The Vestibules

The Vestibule

The Ampulla

Functions of Semicircular Canals, Saccule and Utricle

Vertigo

Cerebellar System Archicerebellum

Flocculonodular lobe vestibulocerebellum

Paleocerebellum Anterior lobe Spinocerebellum

Neocerebellum Posterior lobe Pontocerebellum

The oldest cerebellum Caudal part Eye/head movement

The next oldest Midline Neck/trunk movement

The newest cerebellum Hemsiphere Limb movement

Origin and Classification of Vertigo

The Saccades, Pursuit, and Vestibular Control of Eye Movements

Dizziness

History

VertigoDisequilibrium without vertigo

Near-faint Psychological dizziness

Physiological dizziness

Central origin Peripheral origin

Distinguishing Vestibular From Nonvestibular Dizziness

Vestibular Nonvestibular

Description Spinning, falling, drunkenness, motion sickness, tilting

Floating, near-fainting, fatigue, head fullness, out-of body sensation

Precipitating factors Head movements, position changes

Standing after sitting or lying, cardiac disease, agoraphobia

Associated features Nausea, vomiting, unilateral tinnitus or hearing loss, imbalance, oscillopsia

Palpitation, diaphoresis, syncope, loss of concentration, dyspnea

Physiological VertigoType Provocative stimulus Mechanism

Motion sickness Prolonged passive head movement or movement of the environment

Vestibular-visual conflict

Visual vertigo Excessive visual stimulation

Vestibular-visual conflict

Mal de debarquement Long voyage on ship or plane

Maladaptation to chronic vestibular stimulation

Height vertigo Standing in a high place looking out

Lack of nearby stationary objects in peripheral vision

Space sickness Zero gravity Canal-otolith conflict

Causes of Pathological Vertigo

Peripheral vertigo Vestibular end organs: inner ear, labyrithi

ne apparatus Vestibular nerve

Central vertigo Brainstem: vestibular nucleus Archicerebellum (flocculonodular lobe)

Peripheral Causes of Vertigo Benign paroxysmal positional vertigo Meniere’s disease Acute peripheral vestibulopathy (vesti

bular neuritis) Head trauma Cerebellopontine angle tumor Toxic vestibulopathies

Disorders of the Semicircular Canal

Vertigo (spinning of the environment or the self)

Nystagmus Past-pointing of the li

mbs Ataxia Positive Romberg sign Turning during steppa

ge test

Tilt, a false sense of linear motion

Vertical diplopia Skew deviation Ataxia Positive Romberg sign Translation on the ste

ppage test

Disorders of the Otolith Organs

Central Causes of Vertigo Vertebrobasilar ischemia & infarction Cerebellar hemorrhage Alcoholic cerebellar degeneration Multiple sclerosis Posterior fossa tumors Paraneoplastic cerebellar degeneration Spinocerebellar degneration

Differentiating Peripheral From Central Vertigo

Peripheral Central

Nausea/vomiting Severe Variable, mild

Imbalance Mild-moderate Severe

Hearing loss Common Rare

Neurological symptoms

Rare Common

Nystagmus Unidirectional in all gaze; inhibit with fixation

Direction-changing in different gaze; not inhibited with fixation

Compensation Rapid Slow

Systemic Causes of Vertigo

Drugs: anticonvulsants, sedatives, antihypertensives

Hypotension, presyncope: heart diseases, postural hypotension

Infectious diseases: syphilis, meningitis Endocrine diseases: DM, hypothyroidism Vasculitis: collagen vascular disease, giant-cell ar

teritis Others: anemia, polycythemia, systemic toxins

Causes of Dysequilibrium without Vertigo

Disorders of afferent senses Bilateral vestibular loss Sensory ataxia Multisensory disequilibrium

Disorders of central processing and motor responses Cerebellar degeneration Frontal lobe syndrome Extrapyramidal syndrome

Approach to Vertigo and Dizziness

General examination BP in the lying and standing Look for cardiac arrhythmia Examination of extracranial and peripher

al vasculature

Approach to Vertigo and Dizziness

Neurological examination (1) Consciousness and mental status Visual acuity and visual field Fundus Screening for hearing impairment Ocular motor examination

Nystagmus Ocular motor palsy Slow or ataxic ocular movement

assessing current history Ask the patient to describe the symptoms without using the wor

d dizzy. Have the patient differentiate vertigo from presyncope or near-syncope.

Determine if the patient has a sense of being pushed down or pushed to one side (pulsion). A peculiar sense of movement of objects viewed when the patient moves is termed oscillopsia.

Ascertain whether the symptoms are related to an anxiety attack; patients with agoraphobia may describe their symptoms as dizziness.

Determine if the sensation is continuous or episodic (ie, attacks); if episodic, find out if the sensation is fleeting or prolonged.

Ascertain whether the onset and progression of symptoms were slow and insidious or acute.

Ask the patient about head trauma and other illnesses to determine the setting of the initial symptoms. Trauma resulting in damage to an ear often manifests as unilateral hearing loss, which may be the cause of episodic vertigo even years later (posttraumatic hydrops).

Determine if the attacks are associated with turning the head, lying supine, or sitting upright.

Determine if symptoms of an upper respiratory infection or flu-like illness preceded the onset of vertigo.

Inquire about associated symptoms such as hearing loss or tinnitus (ringing in the ears), aural fullness, diaphoresis, nausea, or emesis.

Determine if the patient has an aura or warning before the symptoms start. If hearing loss is evident, find out if hearing fluctuates. Determine if the patient has a headache or visual symptoms such as scintilla

ting scotoma. Ask the patient about brainstem symptoms such as diplopia, dysarthria, fac

ial paresthesia, or extremity numbness or weakness. Ascertain the degree of impairment during an attack

Examination of Vestibulo-ocular Reflexes

Spontaneous nystagmus Elicit slow phases with slow head

rotation, in yaw (horizontal), pitch (vertical), and roll (torsion), and with high accelerations in yaw and pitch (head thrust)

Caloric test Head-shaking nystagmus

Vestibulospinal Testing

Past-pointing with arms, with eyes closed Romberg: feet apposed, in tandem, in

tandem on toes, on one foot at a time, standing on compliant foam rubber

Fukuda stepping test or walking around a circle

Tandem gait, forward and backward

Approach to Vertigo and Dizziness

Neurological examination (2) Motor system examination

Focal or diffuse weakness Reflex changes

Sensory examination Stock-and-gloving sensation loss: polyneuro

pathy Loss of vibratory and proprioceptive sensatio

n: Vit B12 deficiency or tabes dorsalis Romberg’s sign

Approach to Vertigo and Dizziness

Neurological examination (3) Cerebellar examination

Observation of sitting and standing and walking

Bending backward Tandem gait Walking around a chair Finger-nose-finger Heel-knee-shin

Approach to Vertigo and Dizziness

Neurological examination (3) Cerebellar examination

Pronation-supination Knee-patting Rapid touching of each finger to the thumb Arm deviation Arm tapping Rebound test

The Most Common Causes of Vertigo Syndromes Seen in a Neurological Clinic

Benign paroxysmal positioning vertigo

Phobic postural vertigo Basilar migraine Meninere’s disease Vestibular neuritis

(T. Brandt, “Vertigo, its multisensory syndrome”)

Benign Paroxysmal Positioning Vertigo

The Vertical Vestibulo-ocular Projections

Excitatory afferents

Inhibitory afferents

Characteristic Nystagmus of BPPV

Benign Paroxysmal Positional Vertigo (BPPV) – Symptoms & Signs

Brief attacks of rotational vertigo and concomitant rotatory nystagmus precipitated by rapid head tilt, turning or extension.

The symptoms can be induced by Hallpike maneuver.

Typical peripheral vestibular nystagmus, short latency, limited duration, reversal on returning to the upright position, and fatigability on repeated provocation.

Benign Paroxysmal Positional Vertigo (BPPV) – Pathogenesis & Treatment

Otolith debris floats freely within the endolymph of the semicircular canal: canalolithiasis.

Heavy debris settles on the cupula transforming it as a transducer of angular acceleration into a transducer of linear acceleration: cupulolithiasis.

Treatment by canal repositioning or libratory maneuvers.

Brandt-Daroff vestibular exercise

Meriere’s Disease

Meriere’s Disease

Meniere’s Syndrome – Symptoms & Signs Fluctuating hearing loss, tinnitus,

episodic vertigo and a sensation of fullness or pressure in the ear.

Attacks lasted for hours but dizziness and unsteadiness remain for a few days.

Repeated attacks lead to progressive tinnitus, hearing loss, and impaired vestibular function.

Usual in the fourth to sixth decades.

Endolymphatic hydrops: increase of volume of endolymph associated with distension of entire endolymph system.

The attacks are caused by rupture of membranous labyrinth leading to paralysis of the surrounding vestibular or cochlear hair cells and neural structures.

Symptomatic treatment of acute spells. Salt restriction and diuretics. Intratympnic treatment with ototoxic antibiotics. Labyrinthectomy or vestibular neurectomy.

Meniere’s Syndrome – Pathogenesis & Treatment

Basilar Migraine – Symptoms & Signs

Vertigo may occur in about one-fourth of migraine patients, and can occur without headache.

Other symptoms of basilar migraine include ataxia, dysarthria, diplopia, visual symptoms, tinnitus, decreased hearing, bilateral pareses or paresthesia and decreased level of consciousness.

Benign paroxysmal vertigo of childhood. Benign recurrent vertigo of adulthood. Motion sensitivity with frequent bouts of motion si

ckness occurs in at least one-half of patients with migraine.

Basilar Migraine – Pathogenesis & Treatment Vasoconstriction (?). Neuronal depression (?). Genetic. Channelopathy. Symptomatic treatment of acute attack

Antivertiginous medications. Antiemetics. Sumatriptans and ergotamines often are ineffective and e

ven aggravate vertigo. Prophylactic treatment of attacks

Beta-blockers. Calcium channel blockers. Valproic acid. Tricyclics.

Vestibular Neuritis

Vestibular Neuritis – Symptoms & Signs

Vertigo, nausea, and vomiting developed over several hours, reach a peak within 24 h, and resolve gradually over several weeks.

Generally without hearing symptoms. Diagnosis is based on acute unilateral peripheral v

estibular loss and exclusion of other inner ear diseases.

Ramsay Hunt syndrome by varicella-zoster infection may causes facial paresis, tinnitus, hearing loss, and a vestibular defect.

Presumed of viral origin. Similar to Bell’s palsy caused by reactivation of d

ormant herpes infection in the Scarpa’s ganglion within the vestibular nerve.

Treatment is symptomatic. Antivertiginous medication should not be given as long as nausea and vomiting subsides. These drugs suppress central compensation.

Corticosteroid may shorten the clinical course. Vestibular rehabilitation exercise.

Vestibular Neuritis – Pathogenesis & Treatment

Drugs That Can Cause Dizziness or Be Harmful to the Dizzy Patient

Drug Drugs that causes dizziness

Drug that interfere with vestibular compensation

Ototoxic

Anti-arrythmics amiodarone, quinine +

Anticonvulsants barbiturates, CBZ, PHT +

Antidpressant amitiptyline, imipramine +

Antihypertensives +

Diuretics hydrochlorothiazide, furosemid +

Antiinflammatory Drugs ibuprofen, indomethacin, ASA + +

Antibiotics aminoglycosides +

Chemotherapeutics cisplatin +

Hypnotics +

Muscle relaxants +

Tranquilizers BZD + +

Vestibular suppressants meclizine, scapolamine + +

The End

Thank You.

The Supranuclear Control of Eye Movements

The Optokinetic nystagmus (OKN)

The Internuclear Ophthalmoplegia (INO)