The%20Dizzy%20patient

1
The Dizzy patient

• Vertigo
• Presyncopal dizziness
• hypoglycaemic dizziness
• feeling drunk
• sense of dysequilibrium
• unsteadiness
• loss of balance
• light headedness

2
Dizziness - History

• Duration of symptoms
• Onset -?sudden
• Length of episode(s)
• Other neurology?
• ?Fever, headache, trauma
• Precipitating factors
• Previous episodes

• ? neck trauma
• ? ototoxic drugs

3
Dizziness - examination

• eye movements
• hearing
• Webers test
• neck
• Hallpike manoeuvre
• finger-nose
• heel-toe walking
• Rombergs

4
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

5
Causes of vertigo

• Benign positional vertigo
• Migraine
• Viral labyrinthitis
• traumatic vestibular damage
• Chronic vestibulopathy
• Menieres diesase
• Ischaemia
• Vertebrobasilar insufficiency

6
Benign Positional Vertigo

• Many causes
• Positional
• Usually brief
• Often turning in bed
• Hallpike manoeuvre - fatiguable torsional
  vertical nystagmus

7
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

8
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

9
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)

• Prochlorperazine(Stemetil)
• Betahistine (Serc)
• Cinnarazine (Stugeron)
• Cyclizine
• Hyoscine
• promethazine (Phenergan)

10
Treatment of Vertigo

• Positional Manoeuvre for BPV (Epleys) BMJ 311
  489 (1995)
• Drugs
• vestibular rehabilitation
• Other