Subacute sclerosing panencephalitis presenting as repeated extension of the neck: A case report

Dear Editor, Subacute sclerosing panencephalitis (SSPE) is a devastating, slow-progressing viral infection of the central nervous system, triggered by a defective form of the measles virus. It typically begins during childhood and reveals itself through symptoms such as deteriorating school performance, behavioral changes, visual disturbances, and myoclonus. Periodic epileptiform discharges are observed on encephalography. The diagnosis is confirmed by high concentrations of anti-measles antibodies in the cerebrospinal fluid.[1,2] We report a case of SSPE with unusual periodic myoclonus involving neck muscles. A 14-year-old boy with a 6-month history of worsening school performance, social withdrawal, behavioral changes, and involuntary neck movements was evaluated. The neck movements were periodic and had a slow relaxation phase, which disappeared during sleep. He had a childhood history of measles with unclear vaccination records. On examination, he was attentive but easily distracted, with noticeable neck jerks that were slow to relax [Video 1]. His neurological examination was largely normal, except for brisk deep tendon reflexes. Blood tests and brain magnetic resonance imaging were normal, but electroencephalography (EEG) showed periodic large-amplitude complexes, and cerebrospinal fluid showed high anti-measles antibodies. Treatment with clonazepam was ineffective. {"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_wmqxlh2p"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Our patient presented with periodic neck movements. In SSPE, myoclonus exhibits a distinct pattern, occurring periodically and affecting the face, axial musculature, and limbs. While generally widespread and consistent, there are instances when myoclonus can be localized. The pathogenesis of myoclonus in SSPE involves viral-induced neuronal damage and neuroinflammation, disrupting neurotransmitter balance and neuronal excitability. This leads to hyperexcitability, especially in motor areas, and disrupts cortical and subcortical networks, causing myoclonic jerks. Electrophysiological changes, such as EEG abnormalities, also contribute, reflecting underlying brain dysfunction in this complex and a fatal disorder. A specific association between EEG findings and myoclonus could not be demonstrated.[3,4] In conclusion, periodic neck movements may be observed as an early manifestation of SSPE in combination with other typical features. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Acknowledgement A help of ChatGPT was taken to improve grammar and English only. Authors' contributions Each author contributed to the patient's clinical treatment, the composition and writing of the manuscript, and provided critical revisions of the text. Ethical compliance statement This work was conducted in compliance with ethical standards, and institutional review board approval was not required. We have secured informed consent from the subject for the publication of this material. The authors have reviewed the journal's ethical publication guidelines and attest that this submission adheres to them. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.