Transient attenuation of visual evoked potentials during focal status epilepticus in a patient with occipital lobe epilepsy.
OBJECTIVE
Seizures originating in the occipital areas are relatively uncommon. They are usually characterized by visual hallucinations and illusions or other symptoms related to the eyes and vision.


METHODS
In a 54-year-old woman with occipital lobe epilepsy, complex visual hallucinations, illusions, and migraine-like headache constitute the major clinical manifestations. During focal status epilepticus, ictal electroencephalography revealed rhythmic focal spikes in the right occipital region, rapidly propagating to the right parietal and contralateral occipital areas. Ictal brain single-photon emission computed topography revealed hyperperfusion of the right occipital region. Using a full-field pattern-shift visual evoked potential (VEP) study, we found that the P100 responses on both sides were markedly attenuated in amplitude during occipital focal status epilepticus, whereas the latencies of the VEPs were normal. The amplitude and morphology of P100 responses on both sides, however, returned to the normal range 7 days after cessation of the seizures.


CONCLUSIONS
In addition to clinical seizure semiology, scalp EEG, SPECT and neuroimaging studies, VEP studies may be used as a supplementary examination tool to provide further information in the patients with occipital lobe seizures or epilepsies.
Tsai
Meng-Han
MH
Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Hsu
Shih-Pin
SP
Huang
Chi-Ren
CR
Chang
Chen-Sheng
CS
Chuang
Yao-Chung
YC
D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000503:physiopathology*; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008875:Middle Aged; D013226:Status Epilepticus / Q000503:physiopathology*