Vertigo

Definition:

Illusion of movement Disorder of orientation in space Disagreeable sensation of movement

Anatomy & physiology of balance

The balance depends on the three integrated inputs: 1- vision 70% 2- proprioceptive inputs / joints, skin & muscles. 15% 3- vestibular system 15%

Vestibular anatomybony & membranous labyrinths

Sensory epithelial cells
1. The sensory epithelium of the utricle, the utricular macula, 2. The sensory epithelium of saccule ,the saccular macula 3. s.c.c crista ampullaris

Macula &crista

Vestibular sensory cells

Vestibular physiology

Utricular macula signals position of head& linear acceleration Saccule / exact function is not known S.c.c. angular rotation


Movement of the cilia to kinocillium side results in a de polarization of the hair cell, a receptor potential that in turn releases a transmitter substance that finally depolarizes (the generator potential) the afferent fibers that contact it.

Positional vertigo Vertigo as an isolated symptom Vertigo with deafness & tinnitus Vertigo with other signs of neurological diseases


A- benign paroxysmal positional vertigo - brief, sudden attacks of vertigo precipitated by head movement - horizontal fatigable nystagmus after latent period - no other aural symptom - +ve positional test _ normal hearing assessment R, rest , avoid sudden movement & labrynthine sedatives

B- disequilibrium of ageing

Degenerative changes in the maculae & cristae cervical spondylosis can exacerbate the symptoms

c- Malignant positional vertigo

Coarse variable nystagmus ,no latent period nonfatigable e,g; disseminated sclerosis



Vestibular neuronitis * frequently preceded by viral infection * severe vertigo without deafness or tinnitus * caloric test >>canal paresis on the affected R, labr. Sedatives

B- drugs : 1) aminoglycosides e,g; streptomycin , gentamycin. 2) metronidazole 3) ethinyl oestrodiol

c- miscellaneous

Anaemia Hypotention D.M.


A- Meniere`s disease * unknown aetiology * theoretically , an expansion of the endolymphatic compartment >>> increasing endo. Pr. >>> decreasing the mobility of the basilar membrane>>>hearing difficulty & tinnitus . same changes are happened in the vestibular apparatus >>> vestibular dysfunction

Clinical features:

Episodes of vertigo + tinnitus & progressive sensorineural deafness 5th decade Last for 1-24h Nausea & vomiting Normal between attacks Vertiginous symptoms improve although hearing tends to deteriorate

Investigations :

Otoscopical ex ,>>> normal P.T.A >>> fluctuating SNHL Caloric test >>> canal pariesis

Treatment :

Medical : * reduce salt & fluid intake * reassurance * vestibular sedative / cinnirizine * vasodilator / betaserc

surgical

Decompression of the endolymphatic sac Vestibular n. section Labyrinthectomy

Neoplasm involving brain stem ,cerebellum, or mid brain Posterior inferior cerebellar artery thrombosis Vertibrobasilar insufficency