LAUSR

Opsoclonus–myoclonus syndrome (OMS) is a rare neuroinflammatory disease of paraneoplastic, parainfectious or idiopathic origin, characterized by opsoclonus, myoclonus, ataxia, as well as behavioral and sleep disorders. OMS is a rare disorder that appears in 1 in a million individuals worldwide. It usually affects infants and young children. In approximately 50% of affected children, a tumor of embryonic nerve cells (neuroblastoma) is responsible for the symptoms associated with OMS. In other cases, the disorder has been designated “idiopathic” or attributed to various— mostly—viral infections (Coxsackie virus B3 or St. Louis encephalitis virus) or bacterial infections (Streptococcus) [1, 2]. We present a case of a 22-year-old girl that was admitted to our hospital due to opsoclonus with rapid, involuntary, horizontal and vertical, conjugate fast eye movements, mild myoclonic jerks of eyelids, upper and lower limbs, and mild ataxia. Extensive diagnostic evaluation was performed. Her routine investigations of laboratory tests, including thyroid hormones were normal. Erythrocyte sedimentation rate, C-reactive protein and other immunological tests (antinuclear antibody, antineutrophil cytoplasmic antibodies, antidsDNA antibodies, C3 and C4-complement, serum immunoelectrophoresis) were negative, as well as oncomarkers, paraneoplastic and antiganglioside antibodies. Swab of the posterior pharynx revealed Streptococcus pyogenes (group A). Patient did not have signs of pharyngitis. Antistreptolysin O (ASO) titer was 653 IU/ml. Tests for detection of viral markers for cytomegalovirus, Epstein–Barr virus, herpes simplex viruses type 1 and 2, varicella-zoster virus, human immunodeficiency virus, hepatitis B and C virus were negative. Molecular-genetic analysis for spinocerebellar ataxia type 1, 2, 3, 6, and 7, MELAS (mitochondrial myopathy, encephalopathy lactic acidosis, and stroke-like) syndrome, myoclonic epilepsy with ragged red fibers, Unverricht–Lundborg disease (EPM1) and Lafora disease (EPM2A or EPM2B) was normal. Anti-neuroleukin antibodies, urinary vanillylmandelic acid and homovanillic acid were not determined in our patient. Anti-Ri and anti-Hu antibodies were negative. Cerebrospinal fluid analysis was within normal limits. Electroencephalogram showed right temporoparietal lateralisation and left focal abnormalities with occasional generalized spike-and-wave discharges. Brain magnetic resonance imaging 3-Tesla was normal. Positron emission tomography showed increased glucose metabolism in the tonsils and sublingual glands. Electromyoneurography found a mild sensory polyneuropathy. Following diagnostic evaluation, we have made the diagnosis of poststreptococcal OMS and administered intravenous immunoglobulin (IVIG) at doses of 0.4 g/kg given on 5 consecutive days, with oral penicillin V for 10 days and then intramuscular benzathine penicillin G, which resulted in clinical improvement and gradual normalization of neurological status. We have also started antiepileptic therapy with levetiracetam and clonazepam. The treatment of IVIG continued till today once a month, with remission of the disease. Intramuscular benzathine penicillin G was introduced every month for a year. 2 years since the beginning of the treatment, the ASO titer decreased (304 IU/ml). Five years since the beginning of the treatment, the disease is still in remission. The immunopathogenesis of OMS is poorly understood. There appears to be humoral and cell-mediated immune mechanisms involved both in paraneoplastic and idiopathic syndromes [3]. In many cases the symptoms are reversible * Ivana Cajic [email protected]