Faciobrachial Dystonic Seizures in a patient without Limbic Encephalitis (P4.172)

OBJECTIVE: To report a case of faciobrachial dystonic seizures (FBDS) in a patient without limbic encephalitis BACKGROUND: The brief dystonic movements that predominantly affect the arm and ipsilateral face are termed faciobrachial dystonic seizures (FBDS). FBDS are pathognomonic for Leucine rich glioma inactivated protein 1 (LGI1) antibody limbic encephalitis. Recognition of FBDS should prompt testing for voltage gated potassium channel (VGKC/GLI1) antibodies. DESIGN/METHODS: Case report and literature review RESULTS: We would like to present a case of an 88 year old man who presented with spasms affecting right arm and face. He also noted mild cognitive decline and slower gait. The spasms were relapsing and remitting with no response to anticonvulsant therapy. During the initial presentation, MRI brain showed a small area of restricted diffusion in the subcortical left frontal lobe without abnormal enhancement. MRA brain and neck was normal. CSF studies were negative. CT chest/abdomen/pelvis as well as FDG PET revealed no malignancies. Serum paraneoplastic panel was negative including both voltage-gated potassium channel and LGI1 antibody. Routine and ambulatory EEG revealed no epileptiform discharges. The dystonic spasms responded only to corticosteroids. The patient9s overall course was one of gradual decline including cognitive decline with fluctuating mental status. Repeat MRI brain that included gradient echo images showed a small area of acute ischemia in the subcortical area and multiple microhemorrhages. 12 months after initial presentation he was admitted due to altered mental status. CT head and MRI brain at that time revealed multiple bihemispheric hyperdense lesions and a small amount of subarachnoid blood. The GRE images were suggestive of cerebral amyloid angiopathy (CAA). CONCLUSIONS: We believe that our patient had CAA manifesting with FDBS and that CAA should be considered in the differential diagnosis of FBDS. Study Supported by: N/A Disclosure: Dr. Bronstein has nothing to disclose. Dr. Danesh has nothing to disclose. Dr. Petrovic has nothing to disclose. Dr. Ashikian has nothing to disclose. Dr. Arbuckle has nothing to disclose.