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 & duration. Cognitive difficulties followed soon after.
Neuroimaging: At presentation MRI was normal. After his 4th GTC, MRI showed expansile T2 hyperintense mass in right hippocampus. Serial MRIs first showed evolution to right mesial temporal sclerosis.
Neurophysiology: 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.
Clinical Diagnosis and Prognosis: 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.
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.