Clinical Reasoning: A 5-year-Old Boy With Subacute and Refractory Myoclonus

We present a case of a 5-year-old, who developed refractory, multifocal myoclonus, which progressed over several weeks, leading to a profound functional decline. The diagnostic workup was complicated by a compelling genetic finding that suggested a possible primary epileptic encephalopathy. However, meticulous history-taking uncovered key details inconsistent with a purely genetic disorder, raising suspicion for an alternative, acquired condition. This case highlights the critical importance of a detailed clinical history and neurologic examination to guide the diagnostic process, particularly when a patient's evolving story does not fully align with initial genetic testing.