Hypothyroidism-induced Reversible Encephalopathy as a Cause of Aggravation of Parkinsonism and Myoclonus in Parkinson’s Disease

Background: Myoclonus and encephalopathy are unusual in patients with Parkinson’s disease (PD). Case report: We describe the case of a 59-year-old male with PD who developed myoclonus and encephalopathy. Underlying hypothyroidism was revealed after admission and treated with levothyroxine. Myoclonus and encephalopathy were completely resolved following thyroid hormone replacement. Discussion: Hypothyroidism can cause reversible myoclonus and encephalopathy along with unusual aggravation of parkinsonism symptoms in patients with PD.