Abstracts

RATIONALE: Temporal resection is usually ineffective in patients with occipital seizures. When seizures are unilateral occipital resection are now at times considered. When bilateral seizures and field defect exist occipital resection can not be considered. When temporal seizure onset can be shown in such patients palliative temporal resection may be justified.
METHODS: We report two patients with medically refractory bilateral occipital lobe seizures. Clinical and electrophysiological patterns suggested spread to temporal lobe structures. Long-term EEG video monitoring was followed by stereoencephalography to assess involvement of temporal and occipital regions symmetrically.
RESULTS: Both patients had non-lateralized elementary visual aura followed by loss of contact, automatism and occasionally secondary generalization. The MRIs of the brain revealed bilateral parieto-occipital ischemic lesions without concomittant temporal volumetric abnormalities. They had bilateral or unilateral altitudinal field defects. Scalp EEGs showed independent bilateral temporal or temporo-occipital interictal epileptic abnormalities. Scalp ictal recording in one patient revealed bilateral temporal seizure onset. The second patient had bilateral occipital or left parieto-occipital onsets. Intracranial EEG recordings showed multifocal interictal epileptic abnormalities. In both, all disabling seizures originated in, or rapidly spread to the right hippocampus. Since occipital resections were unadvisable both patients underwent selective amygdalo-hippocampectomy. Seizures continued in both (2 year follow-up) but were much less severe, not associated with falling, shorter, less frequent, not followed by fatigue or headache and with faster recovery.
CONCLUSIONS: When occipital resection is unadvisable because of bilateral or diffuse visual problems palliative temporal resection may be considered in patients with lesional bilateral occipital lobe epilepsy and rapid seizure spread to mesial temporal structures.