Reversible cerebellar ataxia with thyrotoxicosis: An autoimmune brain disease in remission due to Graves’ disease
A 41-year-old male patient was admitted for evaluation of progressive imbalance of gait and difficulty in walking for two months. He was unable to sit in the bed without steadying himself. He has noticed a weight loss of 10 kg in the previous six months. Past medical history was significant for anti-epileptic medications for ten years for seizure disorder, which included carbamazepine 1000 mg / day in divided doses and clobazam 10 mg once daily. His seizures were under good control and the last episode was five years back. He was nonethanolic.\nGeneral physical examination showed diffuse goiter and tachycardia. His body weight was 54 kg with a BMI of 20.6 kg/m2. His blood pressure was 150/60 mm of Hg. Central nervous system (CNS) examination showed dysarthria and there were no cranial nerve deficits. Proximal muscle weakness was noted in the lower limbs bilaterally with a power of 4/5. Examination of sensory system was unremarkable. Cerebellar functions showed bilateral nystagmus on eccentric gaze and in-coordination of both upper and lower limbs (LL > UL). Tandem walking was not possible and the gait was ataxic. Outstretched hands showed fine tremors bilaterally. Clinical impression was thyrotoxicosis with cerebellar syndrome.\nOn investigations, complete blood count, ESR, blood sugar, serum electrolytes, calcium, magnesium, renal and liver function tests were normal. Thyroid function tests initially on 2/10/2008 showed T3: 8 ng/ml; T4: 27.4 μg/dl; TSH: 0.1 μIU/ml suggestive of primary hyperthyroidism. Ultrasound neck showed diffuse hypoechogenicity in both the thyroid lobes with increased vascularity. Radionuclide thyroid scan showed diffuse increase in uptake suggestive of Graves’ disease. ECG and echocardiography was normal. MRI brain was normal. Serum carbamazepine levels were also normal. Patient was started on tablet Carbimazole 10 mg thrice daily and tablet Propranalol 40 mg twice daily. On subsequent follow-up after 2 months, patient was feeling better symptomatically. After 7 months of starting antithyroid drugs, he showed remarkable improvement with no gait difficulty and in-coordination. During the subsequent follow-ups he showed sustained maintenance of near normal thyroid hormonal levels without any recurrence of initial symptoms. He was maintained on a dose of 20 mg of Carbimazole per day [].