Kinesigenic dyskinesias after ENT surgery misdiagnosed as focal epilepsy

We describe a man in his 30s who presented with paroxysmal right-sided dyskinesias of the arm and neck, misdiagnosed with drug-resistant focal epilepsy. Two months earlier he had undergone surgery for chronic sinusitis. Immediately after this procedure, he developed hemiparesis, hemiataxia, paresthesias and disturbances in verbal fluency. Cranial MRI revealed a disruption of the left lamina cribrosa and an intracerebral injury resembling a branch canal spanning to the left dorsal third of the thalamus. Single-photon emission tomography imaging demonstrated malperfusion of the left ventral thalamus, left-sided cortex and right cerebellar hemisphere. During continuous video-EEG monitoring, three dyskinetic episodes with tremor of the right arm and dystonia of the finger and shoulder could be recorded. The paroxysmal dyskinesias did not improve with carbamazepine, valproate and tiapride. This case demonstrates an unusual symptomatic cause of a thalamic movement disorder misdiagnosed as focal epilepsy and highlights the postoperative complications, diagnostic and treatment efforts.