Abstracts

Rationale:
Occipital Lobe Epilepsy (OLE) is an uncommon focal epilepsy syndrome, semiology involves a wide range of visual manifestations i.e. frequent eye blinking, tonic gaze deviation, aura and hallucinations. It is a debilitating form of epilepsy due to heterogeneous visual phenomenon during ictal period. Epilepsia Partialis Continua (EPC) is a state of sustained repetitive seizure activity with paroxysmal neurologic deficits. It is a term commonly used in clinical practice to delineate status epilepticus of focal onset. Persistent epileptic visual defect such as homonymous hemianopsia (HH) is rare presentation of EPC. We report a patient who exhibited primary symptom of HH as harbinger of impending super refractory status epilepticus (SE).
Method:
A 58 year old male brought to emergency room with complaints of episodic right sided visual symptoms; described as flashing lights, floaters and scotomas, as well as waxing/waning confusion. Neurological examination revealed right HH with subtle right lower facial weakness. Computed topography of head was unremarkable. Magnetic Resonance Imaging (MRI) Brain with/without contrast showed diffusion restriction in cortical layers of left medial occipital lobe, associated with FLAIR hyperintensity and mild gyriform enhancement (Figure #1). Over span of few hours, patient developed recurrent transient episodes characterized by sudden behavioral arrest with right gaze deviation and rhythmic conjugate horizontal nystagmus. He had no response to voice, touch or noxious stimulation during the episode and appeared transiently drowsy afterwards. Given concern for symptomatic partial epilepsy, anti-epileptic drugs (AEDs) were administered along with electroencephalography (EEG) monitoring.
Results:
Initial EEG showed 5 seizures; rhythmic 10-13 hertz activity lasting 30-40 seconds in duration, originating from the left occipital and spreading to temporal lobe (Figure #2). Despite adequate dosage of 2nd line AEDs, frequent left occipitotemporal simple partial seizures associated with episodes of right gaze deviation, eyelid fluttering and behavioral arrest were recorded on continuous video EEG (vEEG). This sustained repetition of seizure fragments along with clinical correlation was consistent with EPC. Even with maximal midazolam dose, EEG revealed recurrent electrographic seizures with an average of 4 seizures every 2 hours. Due to super refractory SE, Ketamine drip was added to treatment regimen. At a high Ketamine dose (5 mg/kg/hr) patient became seizure free and EEG showed suppression burst pattern. Sedatives were successfully weaned off without recurrence of seizures. After 5 days patient was discharged without any residual deficit.
Conclusion:
A variety of clinical symptoms have been associated with SE, however HH is an uncommon presentation. It should be taken into consideration should a patient develops fluctuating course of complex and atypical visual symptoms which cannot be attributed to other conditions i.e. stroke and trauma. In our patient, the association of HH and restricted diffusion on imaging led to an initial diagnosis of acute ischemic stroke. Given super refractory SE, it is possible that the MRI findings are secondary to the epileptic abnormalities and not vice versa. Continuous vEEG is an important tool in establishing prompt diagnosis and prevent unnecessary intervention or additional work up. Appropriate AED therapy is warranted as it can hasten recovery and provide favorable outcome, with aggressive therapy initiated early in the course our patient has no neurological deficit at time of discharge.
Funding:
:We did not receive funding or any specific grant.