Dystonic and athetoid movements are usually caused by lesion of the basal ganglia, however the etiopathogenesis of involuntary movements could be also different. The 27-year-old female was admitted to the Neurological Department of the Kopernik Hospital in ŁódŸ, because of developing in two days writhing dystonic and athetoid movements of the hands and weakness with paresthesias of upper and lower limbs. The neurological examination also revealed the loss of abdominal reflexes, which could suggest demyelinating process. The laboratory tests of blood and composition of CSF were normal. No demyelinating lesions were disclosed in the brain MRI. The only one lesion was noticed in posterior cervical spine in the cervical MRI. The results of EVP and BEARs were normal. The involuntary movements diminished after treatment with intravenous infusions of amantadine, but the patient decided to discharge from the hospital before the end of therapy. In one week the patient was admitted to the hospital again because of the same complaints and appearance of pathological symptoms and Lhermitte’s sign. Repeated MRI of the brain and cervical spine showed only the lesion found earlier. The amplitude of F wave was extremely high in EMG examination. The involuntary movements as a clinical manifestation of the single cervical demyelinating lesion are described in literature rarely.