Unveiling paroxysmal kinesigenic dyskinesia: A case report of misdiagnosed epilepsy with premonitory behavioral symptoms and oculogyric crisis

Paroxysmal kinesigenic dyskinesia (PKD) is an autosomal, dominant, episodic, and brief type of involuntary dyskinesia that lasts for seconds to minutes and is induced by sudden movement, startle, or hyperventilation with intact awareness and no postictal phenomenon.[1] It mimics epilepsy due to its varied clinical presentation. In this communication, we present a genetically proven case of an 11-year-old boy with PKD who was exhibiting episodic behavioral symptoms and episodes of oculogyric crisis in addition to dyskinetic movements that were previously misdiagnosed as focal epilepsy. The patient presented with premonitory symptoms of pain, paresthesia, and a stretching-like sensation in the left limb, followed by episodes of involuntary dyskinetic movements of the left upper and lower limbs lasting for approximately 2–3 minutes with intact awareness and no postictal phenomenon [Video 1]. The onset of symptoms was around 6 years of age. The frequency gradually increased to 20–30 times per day. There were independent episodes of anger outbursts amounting to both verbal and physical aggression toward bystanders on trivial provocation that lasted from 30 minutes to 10–12 hours. On some occasions, the patient slashed his wrist to bleed. He felt guilty after the incident and no postictal amnesia was documented. These episodes of anger outbursts were often followed by dyskinetic movements within a few hours or sometimes the next day. In addition, he had discrete episodes of abnormal involuntary upward deviation of both eyes lasting from a few seconds to several minutes without any change in consciousness, limb movements, or any other symptoms, which resolved spontaneously [Video 2]. There was no exposure to antipsychotic or any other medications prior to the onset of these three different types of episodic symptoms, i.e., dyskinesia, oculogyric crisis, and behavioral changes. In primary care, he was diagnosed as a case of focal epilepsy with behavioral disorder and showed minimal response with levetiracetam and valproate for focal epilepsy and olanzapine for behavioral changes. The poor response with these medications led him to seek treatment with us. Detailed history and home-recorded videos of these episodes with normal ictal and postictal electroencephalogram, brain magnetic resonance imaging, and metabolic parameters pointed to PKD. The oculogyric crisis was considered an independent phenomenon, and no change in the frequency was documented with antipsychotic exposure. The PRRT2 gene mutation (Exon 3, c.971 del, p.Gly 324 Glu fsTer13) later confirmed our diagnosis. The patient showed marked reduction in the frequency of dyskinesia and oculogyric crisis as well as behavioral changes on administration of phenytoin and quetiapine. {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 1","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_ehjgxwso"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Video 2","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_xdzxifiq"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} In our case, the response of both oculogyric crisis and dyskinetic movements to antiepileptics connects PKD and epilepsy. The episodes of oculogyric crises can be a common manifestation of seizures arising from the frontal eye field.[2] Among other paroxysmal disorders, children with a confirmed CACNA1A gene mutation display eye movement disorder in early infancy, in conjunction with developmental delay with or without cerebellar atrophy on magnetic resonance imaging.[3] In our case, the most common identifiable gene of PKD, PRRT2, was positive.[4] However, the PRRT2 gene has also been linked to benign familial infantile epilepsy, infantile convulsion and choreoathetosis, episodic ataxia, and hemiplegic migraine, strengthening the link between epilepsy and movement disorders.[5] Therefore, electrophysiological studies using cortical and subcortical ictal recordings are required to evaluate the role of frontal lobe circuits to clarify whether PKD is purely an epileptic phenomenon, a movement disorder, or an amalgamation of both. Acknowledgement Nil. Author contribution Research Project: Conception: Govind Madhaw Organization: Suparna Kumar Execution: Govind Madhaw, Suparna Kumar Statistical Analysis Design: Suparna Kumar Execution: Govind Madhaw Review and Critique: Govind Madhaw, Suparna Kumar Manuscript Preparation Writing of the first draft: Suparna Kumar Review and Critique: Govind Madhaw. Ethical compliance statement We confirm that we have read the journal’s position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.