Transcript The Dizzy patient

The Dizzy patient
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Vertigo
Presyncopal dizziness
hypoglycaemic dizziness
feeling drunk
sense of dysequilibrium
unsteadiness
loss of balance
light headedness
Dizziness - History
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Duration of symptoms
Onset -?sudden
Length of episode(s)
Other neurology?
?Fever, headache,
trauma
• Precipitating factors
• Previous episodes
• ? neck trauma
• ? ototoxic drugs
Dizziness - examination
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eye movements
hearing
Weber’s test
neck
Hallpike manoeuvre
finger-nose
heel-toe walking
Romberg’s
The semicircular canals - 1
• Posterior vertical canal is
transverse and causes most
BPV
• Ampulla at end of each canal
contains crista or cupola: hair
cells (each with kinocilium and
stereocilia)
• Endolymph in canals detects
angular acceleration by
movement of kinocilium
towards stereocilia
• vertical canals stimulated by
movement away from ampulla
Causes of vertigo
• Benign
positional
vertigo
• Migraine
• Viral labyrinthitis
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traumatic vestibular damage
Chronic vestibulopathy
Meniere’s diesase
Ischaemia
Vertebrobasilar insufficiency
Benign Positional Vertigo
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Many causes
Positional
Usually brief
Often turning in bed
Hallpike manoeuvre fatiguable torsional
vertical nystagmus
Vestibulo-ocular reflex
• Aim to keep image on
fovea by saccadic eye
movements (Saquer = to pull as
in the tug of a horses reins to turn head
or the flicking of a sail in a gust of
wind)
• Prolonged head
rotations use Smooth
pursuit movements,
which in man needs
VOR suppression
• Precise relationship
between individual
semicircular canals
and pulling direction
of extraocular muscles
• VORs keep eyes
stationary
VOR, turning head to left
• Fluid in left horizontal
canal moves towards
cupola
• Excitation in medial
vestibular nucleus
• Opposite VI and up
ipsilateral MLF to III
• Eyes move to right,
maintaining image on
fovea
• Extra information
from cerebellum and
proprioceptive stretch
receptors in neck
muscles via
vestibulospinal tract
Drug treatment of dizziness
• There is no rational
basis for using specific
drugs based on
understanding of
receptors and
neurotransmitters
• Glutamate, GABA and
ACh (Hist, 5HT,
peptides, DA, NA)
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Prochlorperazine(Stemetil)
Betahistine (Serc)
Cinnarazine (Stugeron)
Cyclizine
Hyoscine
promethazine (Phenergan)
Treatment of Vertigo
• Positional Manoeuvre
for BPV (Epley’s) BMJ
311: 489 (1995)
• Drugs
• vestibular
rehabilitation
• Other