Helium Optically Pumped Magnetometers Can Detect Epileptic Abnormalities as Well as SQUIDs as Shown by Intracerebral Recordings.

Magnetoencephalography based on superconducting quantum interference devices (SQUIDs) has been shown to improve the diagnosis and surgical treatment decision for presurgical evaluation of drug-resistant epilepsy. Still, its use remains limited because of several constraints such as cost, fixed helmet size, and the obligation of immobility. A new generation of sensors, optically pumped magnetometers (OPMs), could overcome these limitations. In this study, we validate the ability of helium-based OPM (4He-OPM) sensors to record epileptic brain activity thanks to simultaneous recordings with intracerebral EEG [stereotactic EEG (SEEG)]. We recorded simultaneous SQUIDs-SEEG and 4He-OPM-SEEG signals in one patient during two sessions. We show that epileptic activities on intracerebral EEG can be recorded by OPMs with a better signal-to noise ratio than classical SQUIDs. The OPM sensors open new venues for the widespread application of magnetoencephalography in the management of epilepsy and other neurologic diseases and fundamental neuroscience.

A Rare Cause of Thoracic Spinal Cord Compression by Multiple Large Tarlov Cysts / 대한신경손상학회지

Spinal extradural arachnoid cyst (SEAC) is a rare cause of spinal cord compression. Bifocal location of thoracic and sacral SEACs is rarely reported in the literature. We report a case of thoracic spinal cord compression by SEAC associated with asymptomatic multiple sacral Tarlov cysts (TC). The surgical management and postoperative outcome of the patient are discussed. A 34-year-old woman was referred to the hospital for acute thoracic pain with a history of chronic long-standing back pain. She complained of walking difficulties. Neurological examination demonstrated incomplete spastic paraplegia with sensory level in T9. Magnetic resonance imaging revealed a large cystic formation from T7-11 and at the level of the sacrum. We performed laminectomies at the level of interest from T7-11. The cysts were dissected from the underlying dura after removal of the cerebrospinal fluid. We found nerve tissue in the cysts. We excised the cyst and preserved the nerve roots. Subsequently, a duraplasty was performed with autologous grafts from the lumbar fascia. The condition of the patient improved after surgery and he was recovering well at follow-up. Although the surgical treatment of TC is controversial, especially at the sacral lumbar level, decompression at the dorsal level in this case is indisputable.