Spinal myoclonus in a patient with hepatic encephalopathy.

Abstract

Spinal myoclonus can be classified into spinal segmental myoclonus and propriospinal myoclonus, in which myoclonic activities spread up and down the spinal cord via propriospinal pathways [1], and can be idiopathic or may be associated with spinal cord disorders. It occurs rarely during drug and toxin exposure, or can be associated with malignancy or infection. [2] Spinal myoclonus associated with metabolic encephalopathy is exceptional or even questionable for the etiology. We experienced a patient with fulminant hepatitis A and spinal myoclonus. A 22-year-old woman was referred from the hepatology department with jerky, jackknife truncal movement 1 day in duration. The patient suffered from right upper quadrant abdominal pain, anorexia, and nausea due to fulminant hepatitis A. She was neither exposed to neuroleptics, nor did she have a history of movement disorders. Abnormal physical findings included mild icterus of the sclera and skin, abdominal tenderness, hepatomegaly, and palpable spleen. On neurologic examination, the patient presented with myoclonic movement that involved the trunk. The involuntary movements were forceful, jerky, irregular, large-amplitude movements with a frequency of 1–1.5 Hz, and were aggravated in the supine position (video 1), and caused a lurching gait, but did not occur during sleep. The patient’s mental status was normal and cranial, motor and sensory nerve examinations revealed no other abnormalities. Laboratory testing of hepatic function yielded aspartate aminotransferase and alanine aminotransferase over 1,000 U/L, respectively, and anti HAV-IgM antibody was positive. Magnetic resonance imaging (MRI) of the brain demonstrated high signal intensity on both of the basal ganglia on T1-weighted images without gadolinium enhancement (Fig. 1). Whole-spine MRI and electroencephalogram were normal; somatosensory evoked potential was also normal. The patient was diagnosed with hepatitis A with fulminant hepatic failure and symptomatic myoclonus. On hospital day 10, she began showing symptomatic and laboratory improvement and, without treatment for myoclonus, spinal myoclonus resolved completely. Negative myoclonus of the hands occurs commonly in patients with hepatic encephalopathy, who also present with bilateral pallidal hyperintensities in T1-weighted MRI, which may be accompanied by similar changes in the substantia nigra and the dentate cerebellar nucleus [3]. In our patient, spinal myoclonus appeared during the manifestation of fulminant hepatitis. The occurrence of spinal myoclonus with hepatitis and neither evidence of spinal cord lesion nor a history of neuroleptic medication suggests a possible association between the two conditions. Although we cannot be entirely sure of the role of the basal ganglia lesion in the patient’s neurologic symptoms, the temporal relationship suggests that spinal myoclonus was caused by viral infection with hepatitis A. Transverse Electronic supplementary material The online version of this article (doi:10.1007/s10072-014-1948-5) contains supplementary material, which is available to authorized users.