Abstract:
Vigabatrin is an antiepileptic drug that has demonstrated significant
efficacy as adjunctive therapy for patients with poorly controlled partial
epilepsy, refractory to other antiepileptic drugs. It is the drug of choice for
infantile spasms.
In the present study, Vigabatrin was administered to albino rats in mild,
moderate and high doses. Vacuolation was a significant finding in all treated
groups and in all regions of the central nervous system that were studied, with
severity increasing with increasing doses. IME secondary to elevated levels of
GABA may underlie the pathogenesis. Demyelination was found at a few
selected sites suggesting that different parts of the brain have different affinity
for this feature after treatment with Vigabatrin. In the cerebellum and retina,
significant degenerative and atrophic changes were seen even in mild dose
treated group.. Focal neuronal and neuroglial loss was mainly evident in these
two parts suggesting that they are the main targets of toxic damage by
Vigabatrin. Congested blood vessels and dilated perivascular spaces, found in
all regions under study, were signs of edema. The involvement of retina
explains the high incidence of visual field defects associated with the use of
this drug. Present study has also demonstrated histopathological involvement
90
of the cerebellum which suggests that further extended studies should be done
and should be correlated with the cerebellar functions.
