Endocrine Abstracts

Introduction: Hashimoto’s encephalopathy or SREAT (steroid-responsive encephalopathy associated with auto-immune thyroiditis) is a rare autoimmune disorder that is particularly corticosensitive and whose pathogenesis remains poorly understood. It is associated with high levels of antithyroid antibodies in plasma and/or CSF. Clinical manifestations are deceptive and may include cognitive and behavioral disturbances, seizures or abnormal movements.

Case report: We report the case of a 54-year-old female patient who presented with progressive abnormal movements with balance disorders. The clinical examination revealed a cerebellar syndrome, a cerebellar dysarthria with an abolition of the osteotendinous reflexes. Brain MRI was without abnormalities. The electroencephalogram showed a diffuse slowing of the background rhythm without paroxysmal figure. Lumbar puncture revealed a clear cerebrospinal fluid without pleocytosis with hyperproteinorachy at 1.01 g/l. Antithyroglobulin and antithyroperoxidase antibodies were positive (anti-TPO antibody: 493 IU/ml and anti-TG antibody: 20 IU/ml) with a normal TSH. The diagnosis of Hashimoto’s encephalopathy was retained after ruling out other causes, including metabolic, vascular, toxic, infectious and neoplastic. Intravenous corticosteroid therapy at a dose of 1 g of methylprednisolone per day was started for 3 days, followed by oral corticosteroid therapy at a dose of 1 mg/kg for one month and then gradually tapered off over 2 months. The patient was controlled with prednisone 2.5 mg per day with good improvement of her neurological symptomatology.

Discussion and conclusion: Hashimoto’s encephalopathy is often underdiagnosed. The revealing neurological signs are polymorphic. Its pathophysiology is controversial, an autoimmune cerebral vasculitis is evoked. It should be systematically investigated in cases of unexplained encephalopathy, by looking for anti-TPO antibodies in the CSF even in cases of euthyroidism. This case highlights the different and often confusing clinical presentations of Hashimoto’s encephalopathy but also its particular corticosensitivity.

References: S. Bannier, F. Taithe, C. Solmon, P. Thieblot, P. Clavelou. Corticosensitive encephalopathy associated with autoimmune thyroiditis: current data. Annals of Endocrinology. Volume 68, Issues 2-3. 2007. Pages 167-172. H. Tibar, W. Regragui, E. Aitbenhaddou, A. Benomar, M. Yahyaoui. Hashimoto’s encephalopathy: a rare cause of status epilepticus. Revue Neurologique. Volume 171, Supplement 1. 2015. Page A105. I. Oueslati, A. Melki, N. Ben Ali, N. Mchirgui, I. Ben Nacef, K. Khiari, N. Ben Abdallah. Hashimoto’s encephalopathy: about a case. Annals of Endocrinology (2015) 412-453.