# Super refractory status epilepticus as an atypical presentation of Hashimoto’s encephalopathy

## TL;DR

A rare case shows that severe seizures can be the first sign of an autoimmune brain condition linked to thyroid disease, and treatment with steroids and immunoglobulin can lead to full recovery.

## Contribution

This case highlights SRSE as a rare initial presentation of Hashimoto’s encephalopathy and the effectiveness of combined corticosteroids and IVIG.

## Key findings

- SRSE can be an atypical initial sign of Hashimoto’s encephalopathy.
- Combined corticosteroids and IVIG treatment led to full neurological recovery.
- Elevated antithyroid antibodies support the diagnosis despite negative other tests.

## Abstract

•Super refractory status epilepticus may be an initial presentation of SREAT.•Elevated antithyroid antibodies support the diagnosis of Hashimoto’s encephalopathy.•Seizures in SREAT may be resistant to antiepileptic drugs and steroids alone.•Combined corticosteroids and IVIG can lead to full neurological recovery.

Super refractory status epilepticus may be an initial presentation of SREAT.

Elevated antithyroid antibodies support the diagnosis of Hashimoto’s encephalopathy.

Seizures in SREAT may be resistant to antiepileptic drugs and steroids alone.

Combined corticosteroids and IVIG can lead to full neurological recovery.

Hashimoto’s encephalopathy (HE), also known as steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is a rare autoimmune disorder characterized by neuropsychiatric manifestations and a favorable response to corticosteroids. Seizures occur in nearly half of patients; however, super refractory status epilepticus (SRSE) is an uncommon initial presentation. We describe a young adult woman with Hashimoto’s thyroiditis who developed SRSE after a brief prodrome of headache, confusion, and paranoia. Extensive infectious, metabolic, and autoimmune workup was negative, but anti-thyroid peroxidase and anti-thyroglobulin antibodies were markedly elevated. Brain MRI showed nonspecific subcortical T2/FLAIR hyperintensities. The patient was diagnosed with HE and treated with high dose intravenous methylprednisolone followed by intravenous immunoglobulin, resulting in full neurological recovery and sustained seizure freedom at three-month follow up. This case illustrates the importance of considering HE in patients with unexplained SRSE, as prompt recognition and immunotherapy can be lifesaving.