Myoclonus as a neurologic manifestation of hypoglycemia in dogs.

BACKGROUND

Myoclonus consists of brief, shock-like jerks and is not reported in dogs as a neurological manifestation of hypoglycemia.

HYPOTHESIS/

OBJECTIVES

To describe hypoglycemia-associated myoclonus in dogs and report diagnostic findings, treatment, and outcome.

ANIMALS: Ten dogs presenting myoclonus and concurrent hypoglycemia.

METHODS

Multicenter, retrospective study of dogs presenting hypoglycemia-related myoclonus.

RESULTS

All dogs presented with myoclonus. Neurological examination was abnormal in 5/10 (50%). Myoclonus was generalized in 8/10 (80%) dogs and focal (head) in 2/10 (20%), with progression to generalized tonic-clonic epileptic seizures in 5/10 (50%). Hypoglycemia (<3.3 mmol/L) was observed in all dogs (median, 2.07 mmol/L) during the myoclonic episodes. Insulinoma was a suspected (n = 1), presumptive (n = 5), or definitive (n = 3) diagnosis in 9/10 (90%) dogs. One dog (10%) developed iatrogenic hypoglycemia after IV administration of fast-acting human insulin and myoclonic episodes resolved after dose reduction. Among dogs with suspected, presumptive or confirmed insulinoma, 5/9 (56%) received medical treatment alone, 3/9 (33%) combined medical and surgical treatment, and 1/9 (11%) was not treated. Medical treatment included, prednisolone (n = 6), diazoxide (n = 3) and therapeutic diet (n = 6). Surgical treatment consisted of pancreatic mass resection. Medical or surgical treatment resulted in short-term improvement in myoclonus frequency in all dogs, however, four were later euthanized due to recurrence of hypoglycemia and myoclonus.

CONCLUSIONS AND CLINICAL

IMPORTANCE

Myoclonus might represent an underrecognized neurological manifestation of hypoglycemia in dogs. Measurement of blood glucose concentrations is a fundamental diagnostic approach for identifying hypoglycemia-related myoclonus. Treatment can lead to clinical improvement, but prognosis is dependent on the underlying cause.