Endocrine Abstracts

Case history: A 26-year-old lady presented with a two-week history of weakness associated with pins and needles affecting the lateral calf and dorsomedial aspect of her left foot. The patient denied any trauma or symptoms including weight loss. She had no drug allergies and was taking no regular medications. She had a vegan diet supplemented with multivitamins. Her past medical and family history was unremarkable. On examination, she had a narrow-based high-steppage-gait. Lower limb exam revealed normal tone and full power except for left ankle dorsiflexion (MRC Grade 4/5) and left hallux dorsiflexion (MRC Grade 3/5). Inversion and eversion were normal. Reflexes were present with reinforcement and symmetrical with downgoing plantars. Sensation was intact and Romberg’s sign was negative. Examination of all other systems was normal.

Investigations: A CT brain scan demonstrated no abnormalities. Initial laboratory investigations revealed a venous glucose level of 49.9 mmol/l, blood ketones of 2.2 mmol/l (normal <0.6 mmol/l), normal pH and HCO3^-. Her HbA1c was 142 mmol/mol (15.1%). The remainder of her work-up including full blood count, renal, thyroid and liver function, cortisol, vitamin B12 and folate levels was unremarkable.

Results and treatment: Anti-islet cells and anti-GAD antibodies were positive, confirming Type 1 diabetes mellitus (T1DM). She was treated with intravenous insulin, fluids and potassium replacement. She was discharged on a basal-bolus insulin regimen. Her foot drop resolved within three weeks with no recurrence at 12 months follow-up.

Conclusions and points for discussion: Symptoms of hyperglycaemia represent the most common presentation in patients with newly diagnosed T1DM. Some subjects may present with vague complaints such as weight loss and fatigue. Cases of T1DM presenting with neurological manifestations including cerebral infarction, extrapontine myelinosis and ataxia have been described in the paediatric population but they are extremely rare in adults. Hyperglycaemia-induced hemiballismus in adults with type 2 diabetes has been previously reported. Here we describe for the first time a new onset T1DM presenting with right foot drop and no symptoms attributable to hyperglycaemia. In our case no history of weight loss or osmotic symptoms was elicited and the identification of hyperglycaemia, thought to be responsible for the peroneal nerve conduction block, was merely incidental. Our case confirms that new onset diabetes can be associated with neurologic manifestations and reiterates the importance of including diabetes mellitus in the differential diagnosis of an otherwise healthy patient presenting with peripheral neuropathy.