Complex visual hallucinations as post-ictal cortical release phenomena.

Visual hallucinations can be elementary or complex and appear in a wide variety of neurological disorders. Hallucinations associated with seizures can either be ictal or part of a post-ictal cortical release phenomenon, and their features may help distinguish their etiology. We describe two patients with suspected ictal occipital lobe lesions with elementary hallucinations that were followed by post-ictal complex hallucinations.The pathophysiologies of elementary and complex hallucinations are reviewed. The sequential occurrence of these two distinct types of hallucinations in these patients emphasizes the observation that hallucinations associated with seizures can result from both irritative and cortical release mechanisms.