Reversible myoclonus in a patient undergoing transcervical hysteroscopic surgery

We describe a 58-year-old woman who underwent hysteroscopic myomectomy to treat a large submucosal leiomyoma. A hypotonic glycine solution was instilled to distend the uterus. At one hour after the distending medium infusion started for hysteroscopic resection an electrolytic imbalance developed. One hour later myoclonus developed predominantly involving the bilateral sternocleidomastoidei and abdominal muscles. The patient was alert and cooperative; jerks were spontaneous and triggered by sensory stimuli. The electroencephalographic and brain computed tomography was normal. The clinical characteristics of her myoclonus resemble reticular reflex myoclonus, a form of subcortical myoclonus originating from the lower brainstem reticular formation. Given her severe hyponatremia we conjecture that she had symptomatic metabolic myoclonus caused by electrolytic disturbance. The case report we present underlines the need to detect in time and promptly treat neurological symptoms such as myoclonus suggesting resorption syndrome, an uncommon event complicating transcervical hysteroscopic surgery and urologic procedures.