Epilepsy

Etiology:  The gerbil displays spontaneous epileptiform seizures (see photo).  These seizures may be precipitated by sudden stress, handling, or introduction to a novel environment.  The condition is inherited, and both seizure-resistant and seizure-sensitive strains have been developed by selective breeding.

Incidence:  Incidence of this syndrome is about 20% in natural populations.  Inbred animals can have up to 100% incidence.

Clinical Signs:  Seizures vary in severity from mild hypnotic episodes characterized by cessation of activity and twitching of the pinnae and vibrissae, to severe myoclonic convulsions followed by tonic extensor rigidity.  Post-seizure fatality occurs in less than 1% of affected animals.

Pathology:  Gerbils with this condition have decreased inhibition of neurotransmitter release and increased numbers of dendritic boutons.  Onset occurs at two to three months of age with seizure incidence and severity increasing with age until the animal reaches six months of age.  A refractory period of up to five days can follow more severe seizures.