Role of the claustrum in convulsive evolution of visual afferent and partial nonconvulsive seizure in primates

We tested cross-species validity of the role of the claustrum in the convulsive evolution of the visual afferent and amygdaloid seizure and the specificity of the claustral lesioning effect.

In 7 Senegalese baboons, we examined the effect of unilateral claustral lesioning on generalized convulsive seizures either kindled from the amygdaloid nucleus (AM) and cingulate cortex (CG) or induced by intermittent photic stimulation (IPS) after systemic administration of D,L-allylglycine (AG).

A lesioned area common to all animals was the anterior half of the left claustrum. Postoperative restimulation of the kindled left AM or CG evoked only nonconvulsive seizures. When few convulsive seizures emerged in 1 CG-kindled animal, they were mirror image of the kindled seizure and arose from the nonlesioned right hemisphere. Restimulation of the kindled right AM or CG reactivated kindled seizures. An IPS-induced generalized convulsive seizure was transformed into a secondarily generalized seizure arising from the nonlesioned right hemisphere.

The primate claustrum regulates the convulsive evolution of partial seizures originating from nonmotor structures such as the AM and CG and also regulates the convulsive development that follows IPS. Our findings suggest that predisposed susceptibility expressed at the claustrum may be involved in the clinical variation with respect to convulsive evolution of nonmotor partial seizures and convulsive susceptibility to IPS in human primates.