Endocrine Abstracts

Introduction: Diabetic striatopathy is a rare neurological complication of diabetes presenting in most cases with an acute/subacute hemichorea associated with contralateral putamen T1 hyperintensity on MRI. It is associated with significant hyperglycaemia, high HbA1c and osmolality. It resolves within few days to 10 months in 74% of cases. Recurrence is seen in 13% of cases, mostly within the first two months. Hypoglycaemia induced chorea is extremely rare.

Case report: 68-year-old male with a history of transient ischaemic attack and well controlled type 2 diabetes on oral therapies was admitted with fall and long lie. He was swaying when stood, had shuffling gait and his speech was difficult to understand. On admission had significant hyperglycaemia (33.6 mmol/l), raised osmolality (311 mosmol/kg) and dramatic HbA1c increase to 181 mmol/mol from 58 mmol/mol five months previously, likely precipitated by metabolic sequalae of severe Covid illness a year prior. He was described as ‘restless, grabbing at things, picking at clothes’ and was noted to have involuntary movements progressing to severe generalised and orofacial choreoathetosis. Interestingly, he was not distressed by these movements and appeared unaware. Brain MRI showed high T1 signal the putamina bilaterally and excluded a stroke. Thyroid, autoimmune, paraneoplastic and infection screen were negative. Diagnosis of hyperglycaemia induced chorea was made. Glucose control was achieved with a variable insulin infusion and basal insulin. His choreoathetosis worsened initially after achievement of euglycemia preventing patient’s ability to glucose monitor and insulin self-administer, but improved with stable glucose control allowing discharge 12 days after admission. He was readmitted 16 days later with chorea recurrence, this time in association with hypoglycaemia (glucose 2.7 mmol/l). He was discharged 6 days later and remained symptom free 2.5 years later.

Discussion: Diabetic striatopathy should be considered in a differential diagnosis of choreoathetosis of an acute or subacute onset together with a stroke, bleed, autoimmune disease, paraneoplastic syndrome, cocaine and HIV. Our case highlights several unique aspects including occurrence in a middle-aged Caucasian male, deterioration of symptoms after initial glucose normalisation, bilateral symptoms, bilateral putamina radiological changes and a recurrence precipitated by hypoglycaemia, which is to our knowledge very rare. Proposed mechanisms of hyperglycaemia induced choreoathetosis include an induction of mild ischaemia in the putamen via osmotic shift induced hypoperfusion leading to anaerobic metabolism and gamma-aminobutyric acid (GABA) depletion. Hypoglycaemia probably induces cell oedema and hypoperfusion and utilisation of GABA and acetylcysteine as alternative sources of energy.