Purkinje Cell Cytoplasmic Antibody (PCA-2)-related Chorea–Dystonia Syndrome

Abstract

Ethics Statement: All patients that appear on video have provided written informed consent; authorization for the videotaping and for publication of the videotape was provided. There are several causes of adult-onset chorea, with Huntington's disease (HD) being the most common. We report a patient who developed a complex movement disorder consisting of chorea and dystonia associated with caudate atrophy on brain magnetic resonance imaging (MRI) because of a paraneoplastic etiology that can be easily confused with HD. He was found to have elevated titers of Purkinje cell cytoplasmic antibody (PCA-2) in the serum and cerebrospinal fluid (CSF). A 70-year-old Caucasian male with no pertinent past medical history was referred for complaints of unintentional weight loss, weakness, and involuntary movements. Over the past year, he had experienced progressive weakness in his legs such that he required a walker. As his weakness progressed, he developed bladder and bowel incontinence, further gait decline, and 60-pound (27-kg) weight loss. During the course of his weight loss and gait decline, he developed involuntary movements of the mouth, abnormal posturing of the hands, and dysarthria. His involuntary movements disappeared during sleep and while he was eating or drinking. The tongue did not push food out and he was able to eat and swallow without difficulty. There was no history of medication intake that could cause these involuntary (tardive) movements. The family history was negative for neurode-generative disorders. He had a 30 pack-year smoking history and prior history of heavy alcohol intake. Clonazepam was prescribed to help with the involuntary movements, which resulted in mild improvement as seen in the latter half of the video (Video 1). His general examination was significant for cachexia. On neurolo-gical examination, he was alert and oriented. Cranial nerves were intact with the exception of the involuntary movements discussed below. Ocular motor examination did not reveal any impairment in saccades or smooth pursuit. Strength and reflexes in the upper extremities were normal. Strength testing in the lower extremities showed bilateral hip flexors (Medical Research Council [MRC] grade 2/5), knee flexors (MRC grade 2/5), knee extensors (MRC grade 3/5), ankle dorsiflexors (MRC grade 4/5), and plantar flexors (MRC grade 4/5). Reflexes were increased in the lower extremities with clonus and bilateral extensor plantar responses. Sensory testing was normal. Coordination was found to be normal on finger-nose-finger testing. As far as his involuntary movements were concerned, overall they could be best described as a combination of dystonia and chorea. He had involuntary, irregular, continuous, and partially suppressible dystonic movements around the mouth leading to opening of the jaw and protrusion of the tongue. His left eye closure was suggestive of unilateral blepharospasm. His hands assumed dystonic posturing while holding a towel to clear oral secretions. His movements in the neck, upper limbs, and trunk appear to be choreiform in nature (Video 1). MRI of the brain showed bilateral caudate atrophy along with global parenchymal loss (Figure 1). MRI studies of the cervical, thoracic, and lumbar spine with and without contrast were normal. Electromyography and nerve conduction studies did not show evidence of neuropathy or motor neuron disease. A movement neuro-physiology study showed co-contraction of agonist and antagonist muscles in the upper extremities suggestive of dystonia. The following investigations were negative or normal: human immunodeficiency Freely available online Tremor and Other Hyperkinetic Movements