Abstracts

Rationale: Assessment of consciousness is integral to characterization of epileptic seizures. Generalized seizures have more than minimal involvement of bilateral hemispheres, are associated with unresponsiveness and lack of ictal subjective experience. We report a patient with prolonged secondarily generalized clonic-tonic-clonic seizure with retained consciousness. Methods: Continuous electrocardiography and video electroencephalography (EEG) were performed. Results: 58-year-old right-handed woman status-post partial resection of left parasagittal parietal meningioma (Fig. 1) presented with recurrent spells of mumbling speech, full body jerking, and maintained awareness and recall. Video EEG captured one 22 minutes, 6 seconds seizure (Fig. 2). EEG onset began 1 second prior to clinical onset with rhythmic 1 Hertz (Hz) sharp waves over left centroparietal region (P3, Pz) evolving to rhythmic 3.5 Hz sharp waves spreading to Fz, Cz. At clinical onset she had right hand, arm clonic activity progressing to superimposed tonic right arm flexion and facial posturing within 2 seconds, during which she answered complex questions appropriately, read and demonstrated good immediate and recent recall. As ictal pattern spread diffusely to both hemispheres (max P3, Pz) left arm tonic posture developed and she still conversed. Ictal pattern evolved to diffuse bilateral rhythmic spikes (max P3, Pz) associated with forceful tongue protrusion and generalized tonic-clonic activity, figure of four posturing. With continued generalized polyspike waves, tongue retracted, generalized tonic-clonic activity continued, and she followed commands including looking at the nurse and partially reading the sign until she became unresponsive at 5 minutes. Spontaneous clinical offset was 20:01 and EEG offset was 22:06. Conclusions: Our patient had seizures symptomatic of parasagittal meningioma. Parasagittal meningiomas present with seizures at a frequency of 27-62%, usually generalized. Surgery cured epilepsy in 62.7% of all meningiomas, but pre- and postoperative prevalence of epilepsy was unchanged in parasagittal meningiomas. Our case is unusual due to elements of retained consciousness demonstrated by following commands and reading during clinical and electrographic secondarily generalized seizure activity. There are few reported cases of generalized seizures with retained consciousness. Common to all is onset near sensorimotor cortex, right hemisphere (4 of 5), and 90 seconds duration. This contrasts to our patient with left sided onset and prolonged seizure that spontaneously resolved. During her generalized seizure, brain regions determining level and content of consciousness were relatively spared. After five minutes, ictal pattern likely spread to portions of subcortical structures, limbic region and/or frontoparietal association cortices associated with loss of awareness. Our patient was diagnosed with focal epilepsy characterized by simple and complex focal seizures that may secondarily generalize with clonic-tonic-clonic activity and retained consciousness.