Novel ictal manifestations in Leucine rich Glioma Inactivated 1 Encephalitis - Transient, Alternating Hemi-body Paresthesias (P3-1.009)

Abstract

<h3>Objective:</h3> To describe transient, alternating hemi-body paresthesias as an ictal manifestation of LGI1-encephalitis. <h3>Background:</h3> LGI1 encephalitis is associated with multiple seizure types, as well as cognitive decline, behavioral changes, &amp; hyponatremia. There is marked heterogeneity in seizure subtypes associated with LGI1 encephalitis. <h3>Design/Methods:</h3> Case Report <h3>Results:</h3> A 54 years old patient began experiencing paroxysmal episodes of nausea, rising epigastric sensation (NRES), and three-months later he presented with cluster of two generalized tonic clonic (GTC) seizures. GTCs and NRES resolved with levetiracetam (LEV) and lacosamide (LCS) given in the ER. At 6-months symptom onset, he reported focal-aware seizures with transient, alternating hemi-body paresthesias (TAHP), spreading from head to right, left, or bilateral hemi-body. These increased in frequency &amp; duration. Cognitive difficulties followed soon after. <h3>Neuroimaging:</h3> At presentation MRI was normal. After his 4^th GTC, MRI showed expansile T2 hyperintense mass in right hippocampus. Serial MRIs first showed evolution to right mesial temporal sclerosis. <h3>Neurophysiology:</h3> At presentation EEGs were normal. Serial ambEEGs/vEEGs captured multiple paroxysmal episodes of NRES and TAHP – neither with electrographic correlate. Additionally, patient had numerous multifocal electrographic seizures but without clinical correlate nor awareness. <h3>Clinical Diagnosis and Prognosis:</h3> At 19 months after symptom onset, CSF showed LGI1 positive Antibodies. Systemic imaging was negative for occult malignancy. Steroids followed by IVIG and Rituximab were initiated. TAHP as well as electrographic seizures gradually resolved completely at 26-months after symptom onset. Repeat CSF analysis was negative for LGI-1. <h3>Conclusions:</h3> This patient demonstrated electroclinical dissociation in his ictal presentation. There were no electrographic correlates to reported NRESs and TAHPs, and no clinical correlate to numerous, multifocal electrographic-seizures. Yet, all these phenomena gradually resolved with immunotherapy. It is common to downplay or dismiss reported symptoms of TAHP, but this diagnostic inertia may lead to delayed diagnosis and treatment of inflammatory processes, such as LGI1-associated-encephalitis. <b>Disclosure:</b> Dr. Tripathi has nothing to disclose. Dr. Khan has nothing to disclose. Dr. Aydemir has nothing to disclose. The institution of Dr. Afra has received research support from LivaNova and UCB. Dr. Afra has a non-compensated relationship as a board member (representing AAN) with CoA-NDT that is relevant to AAN interests or activities.