DEFINITIONVertigo is a medical condition that characterized by a sense of
dizziness and feeling motion when one is stationary or spinning movement.
PATHOGENESISVertigo is not a
desease, but a symptom.
Spatia orientation is depend on three points, they are:
- adequate sensation input (from sensoric organs: vision, balance and sensibility)
- central integration
- proper motor response
If information or sensor by eye (vision) is not match with information from
labirin (ear), that makes vertigo.
ETIOLOGY- Vestibulum
- Ear nerve
- Reticulus from brain branch
- Tabes dorsalis
- Imagination
- Generilized Illnes
- Ophtalmic desease
CLASSIFICATIONVertigo is classified into either peripheral or central depending on the
location of the dysfunction of the vestibular pathway
A. Peripheral
Also called
Otologic or Vestibular. Its mean that Vertigo which caused by problems with the inner ear or vestibular system. Motion sickness is
sometimes classified as a cause of peripheral vertigo.
B. Central
If Vertigo arises arises from the balance centers of the brain. it is usually milder, and has accompanying
neurologic deficits, such as slurred speech, double vision or
pathologic nystagmus. Brain pathology can cause a sensation of disequilibrium which is an off-balance sensation
PATOPHYSIOLOGY The
neurochemistry of vertigo includes primary
neurotransmitters that have been identified between the 3-neuron arc that drives the
vestibulo-
occular reflex (
VOR). many others play more minor roles.
Three neurotransmitters that work peripherally and centrally include: - Glutamate
- Acetylcholine
- GABA.
Three other neurotransmitters work centrally- Dopamine
- Nor epinephrine
- Histamine
Glutamate maintains the resting discharge of the central vestibular neurons, and may modulate synaptic transmission in all 3 neurons of the
VOR arc.
Acetylcholine appears to function as an
excitatory neurotransmitter in both the peripheral an central synapses.
GABA is thought to be inhibitory for
commisures of the medial vestibular nucleus, and the vertical
VOR.
Dopamine may accelerate vestibular compensation.
Norepinrphrine modulates the intensity of central reactions to vestibular stimulation and facilitates compensation.
Histamin is present only centrally, but its role is unclear. It is known that centrally acting
antihistamins modulate the symptoms of motion sickness.
The
neurochemistry of
emesis overlaps with the
neurochemistry of motion sickness and vertigo.
Acetylcholine, histamine, and dopamine are
excitatory neurotransmitters, working centrally on the control of
emesis.
GABA inhibits central
emesis reflexes. Serotonin is involved in central an peripheral control
of emesis but has little influence on vertigo and motion sickness