Vestibular Hyperreflexia and Opsoclonus in Acute Hepatitis A Virus Infection

Abstract

Dear sir, Opsoclonus refers to a burst of involuntary, arrhythmic, toand-fro saccadic oscillations in multiple planes without an intersaccadic pause [1, 2]. Opsoclonus usually results from autoimmunity from preceding infections or dormant neoplasm [3, 4]. Opsoclonus often presents with other neurological symptoms and signs such as dizziness, myoclonus, ataxia, and mental confusion [3, 4]. In this study, we report vestibular hyperreflexia in a patient with opsoclonus-myoclonus syndrome as a rare complication of acute hepatitis A virus (HAV) infection. A previously healthy, 52-year-old woman presented with fever, myalgia, and general weakness for a week. The patient was febrile with a body temperature at 38.6 °C. The initial serologic tests revealed 1390 IU of aspartate transaminase (reference range [RR] = 0–40), 1090 IU of alanine transaminase (RR = 0–40), and 586 IU of r-glutamyl transpeptidase (RR = 8–35). Viral hepatitis was diagnosed with the anti-hepatitis A IgM antibody in the serum (4.41, RR = negative). Two days after hospitalization, the patient reported vertigo, oscillopsia, and unsteadiness. The neurological examination at that time revealed ocular flutter and marked truncal and limb ataxia. Head impulse tests (HITs) were unavailable due to frequent fixation losses. Bithermal caloric tests revealed hyperactive responses in both ears (477°/s of summated slow phase velocities induced by warm and cold stimulations in both ears, Fig. 1a). One day later, the patient lapsed into confusion and started to show intermittent myoclonic jerks in all extremities. Meanwhile, the ocular flutter evolved into opsoclonus by additionally involving the vertical and torsional planes (Fig. 1b and Video). Brain MRIs showed no responsible lesion, and cerebrospinal fluid examination showed an albuminocytologic dissociation (1/mm of WBCs and 87.5 mg/dL of protein). Whole body and brain fluorodeoxyglucose-positron emission tomography and serologic tests for the paraneoplastic antibodies and tumor markers were all negative. After administration of 1 g per day of intravenous methylprednisolone and 0.4 mg/kg per day of immunoglobulin for 5 consecutive days, the patient gradually regained alertness. The myoclonus also improved over 2 weeks, and opsoclonus and ataxia disappeared 1 month after the initial presentation. Based on the clinical presentation, laboratory results, and response to the immune-modulating treatments, the patient was finally diagnosed with opsoclonus-myoclonus syndrome due to HAV-associated autoimmune encephalitis. Until now, diverse parainfectious causes have been described in relation to opsoclonus, including herpes simplex, Epstein-Barr, varicella-zoster, human immunodeficiency, mumps, and Zika viruses [1, 2]. Along with those, HAVassociated opsoclonus was also reported once [7]. Of interest, our patient showed vestibular hyperreflexia on caloric tests. Previously, vestibular hyperreflexia was once described with HITs (hyperactive head impulse sign) in a patient with ocular flutter [8]. To the best of our knowledge, however, vestibular hyperreflexia on caloric tests has not been reported in patients with opsoclonus or ocular flutter. Vestibular Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12311-019-01043-3) contains supplementary material, which is available to authorized users.