Abstracts

Rationale:
Epilepsy is a commonly prevalent condition and is seen in 1-3% of the population. Precuneus onset epilepsy is a rare subset of focal onset epilepsy and has been reported in a small number of cases only. We discuss a case of a patient who was suspected to have precuneus onset epilepsy based on her PET and MEG findings, with confirmation on intracranial EEG.
Method:
This 34 year old woman presented to our clinic for evaluation of her refractory epilepsy. She had uncontrolled seizures despite the use of 3 seizure medications at high doses. We subjected her to a comprehensive evaluation at our epilepsy center for further intervention for her refractory epilepsy.
Results:
MRI scans of her brain were unremarkable. Video EEG studies using scalp EEG in our epilepsy monitoring unit captured 3 seizures with right posterior quadrant onset and 1 seizure with left anterior quadrant onset. Quantitative PET scans showed diffuse reductions in metabolic activity with most prominent metabolic reductions seen in both precuneus regions, left greater than right. Magnetoencephalography (MEG) revealed prominent epileptogenic spike dipoles in both precuneus regions as well. She underwent a hybrid strip and stereo EEG survey with coverage of anterior and posterior regions bilaterally with prominent coverage of the precuneus regions. Intracranial EEG captured multiple seizures with electrographic lead at onset from the left precuneus. She is scheduled to undergo implantation of a responsive neurostimulator (RNS) targeting her precuneus regions bilaterally for management of her epilepsy. Resective surgery was not offered due to the high probability for cognitive deficits from resection in this region.
Conclusion:
Precuneus onset epilepsy represents a rare subset of focal epilepsy and is often missed or misdiagnosed. The precuneus shows high connectivity and seizure manifestations can be diverse and localization can often be incorrect using conventional means. The use of quantitative analysis of imaging, like PET scans, may help improve the detection rates for this condition. MEG and stereo EEG are more likely to enable better detection of such epilepsies and pinpoint their onset accurately. The use of RNS in such patients is expected to be efficient in disrupting their seizure networks. We are optimistic that findings from our patient will enable a better understanding of the diagnostic and therapeutic aspects of such cases. Additional research in future is essential to analyze and refine approaches to such patients.
Funding:
:None