Objective: To evaluate the frequency, consequences, and treatment outcomes of misdiagnosis in myoclonic epilepsies (MEs), with emphasis on inappropriate antiseizure medication (ASM) use, unnecessary surgical interventions, psychosocial harms, and ASM optimization outcomes.

Methods: A prospective observational-interventional study of 100 patients with confirmed MEs was conducted at a specialized epilepsy clinic. Inadequate management of ASM was characterized by the misuse of ASM or incorrect classification continuing for one year or more. Demographic, clinical, EEG, treatment, and outcome information were gathered, and ASM treatment plans were adjusted based on the accurate identification of the underlying syndrome.

Results: Out of 100 patients, twenty-four (24%) were misdiagnosed, and of those 11 patients underwent prolonged mismanagement that persisted for 1-3 decades. The EEG patterns included generalized epileptiform discharges in 65%, mixed focal-generalized in 20%, pure focal in 10%, and normal in 5%. All twenty-four misdiagnosed patients had been maintained on narrow-spectrum ASMs that worsened the seizures. Two patients underwent unnecessary surgical interventions: one vagus nerve stimulation (VNS) implantation and one planned corpus callosotomy. The psychosocial consequences included unemployment, repeated injuries, divorce, one suicide attempt, and two epilepsy-related deaths. Every time the appropriate ASM was used, myoclonic jerks and falls were near completely resolved, and led to a 90% decrease in the attacks of generalized tonic-clonic seizures, improved EEG readings and psychosocial functioning.

Significance: Misdiagnosis of MEs can persist for decades, leading to avoidable surgical procedures and substantial psychosocial burden. Improved EEG interpretation, accurate syndromic classification, and evidence-based ASM selection are essential to prevent long-term harm.

Keywords: juvenile myoclonic epilepsy, misdiagnosis, antiseizure medications, psychosocial outcomes

Segvan Kucher is a Neurologist from University of Zakho, Iraq.