Primary Antiphospholipid Antibody Syndrome Manifesting As Refractory Partial Status Epilepticus Unrelated To A Structural Brain Abnormality

Objective: Case: A 61-year-old man with hypertension and hypereosinophilia presented with transient left leg myoclonus followed by paralysis. A head MRI showed a remote left anterior and middle cerebral arteries watershed area infarct. Cerebrospinal fluid examination was normal. Rheumatological evaluation revealed persistently elevated antiphospholipid antibodies (aPL) (lupus anticoagulant, anticardiolipin and anti-β2 glycoprotein-I antibodies). Primary antiphospholipid antibody syndrome (APS) was diagnosed and anticoagulation was started. During the admission he experienced episodic left arm and leg myoclonus with head turning to the left. Intravenous lorazepam and phenytoin limited the myoclonus to his left leg, however the myoclonus became persistent. Video/EEG monitoring showed right posterior quadrant semi-periodic spike and slow waves occurring every one to two seconds. Partial status epilepticus (PSE) was diagnosed. In the following three days, levetiracetam, valproic acid and phenobarbital were added respectively without aborting the seizures. He was intubated and started on midazolam infusion that aborted the clinical and electrographical seizures within two days. A repeat head MRI was unchanged. He was transferred to a rehabilitation facility with a residual left-sided weakness on phenytoin, levetiracetam and warfarin. Discussion: APS is an autoimune disease that usually affects young adults and is characterized by vascular thrombosis, pregnancy morbidity and persistent aPL. It is either a primary condition or is associated with a connective tissue disease. Neurological manifestations include stroke, seizures and chorea among others. Seizures are often precipitated by an acute ischemic event, but occasionally, structural abnormalities are absent. In these cases, it is hypothesized that seizures occur secondary to microvascular ischemia which increases blood-brain-barrier permeability, leading to neurotoxicity from influx of autoantibodies and cytokines. In our patient, the ischemic abnormalities were not acute and topographically unrelated to the seizures, thus supporting a non-thrombotic etiology of the status epilepticus. Conclusion: APS might present with PSE that is unrelated to a structural brain lesion. Disclosure: Dr. Maalouf has nothing to disclose. Dr. Hinduja has nothing to disclose. Dr. Shihabuddin has nothing to disclose.