No abstract

Ruptured aneurysms of the distal anterior cerebral artery (ACA) are relatively rare and surgical management provides some unique technical challenges. This retrospective analysis of 20 patients with distal ACA aneurysms evaluated the clinical features and surgical strategies. The characteristic findings were small and common concurrent aneurysms, and frequent intracerebral hematoma (ICH). Aneurysms were divided by location on the genu (n ＝ 13), infracallosal (n ＝ 5), and supracallosal portions (n ＝ 2). All patients except one underwent surgery via an interhemispheric route. Unilateral craniotomy was performed for aneurysms on the genu portions without massive ICH. Bilateral craniotomies were selected for aneurysm located on the infracallosal portion or combined with massive ICH. No intraoperative rupture was observed. Favorable outcomes were achieved in 15 of 20 patients, and only one patient died. The preoperative Hunt and Kosnik grade was closely correlated with the outcome.

Summary: Purpose: 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.Methods: 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).Results: 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 IPSinduced generalized convulsive seizure was transformed into a secondarily generalized seizure arising from the nonlesioned right hemisphere.Conclusions: 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.

Kindling of the cingulate cortex in the Senegalese baboon Papio papio led to a protracted nonconvulsive seizure state characterized by immobile staring with (anterior cingulate, AC) or without (posterior cingulate, PC) widening of eyelids and neck flexion, followed by postictal visual searching behavior. Despite early bilateral spread of EEG discharges, ictal and interictal patterns remained persistently asymmetric. Secondary generalization was rapid and predictable once contralateral lower facial twitching associated with sustained adversion developed. After the primary site had been kindled, stimulation of the contralateral homotopic posterior cingulate cortex readily produced afterdischarge. However, it remained localized and kindling growth did not occur. The findings suggest that (a) the cingulate cortex can support nonconvulsive seizures; (b) cingulate seizures are accompanied by asymmetric convexity EEG discharges indicating its lateralized onset; (c) further evolution to convulsive seizures after kindling of cingulate cortex requires access to the ipsilateral frontocentral cortex responsible for facial twitching; and (d) the development of focal epileptogenesis at one cingulate site interferes with clinical seizure development at the homotopic contralateral site.