Multifocal myoclonus as a heralding manifestation of Wilson disease

Abstract

Wilson disease (WD) is one of the few curable movement disorders that manifests with varied presentations so that WD needs to be considered in any patient with a movement disorder under the age of 50 years. Although WD is one of the causes of myoclonus, it is rarely seen in WD and usually as an associated finding. We report a case of an adolescent female patient of WD who presented with cortical multifocal myoclonus of 6-month duration with later development of generalized dystonia, extrapyramidal syndrome, and cognitive decline. Kayser–Fleischer ring was present on slit lamp examination. Serum copper, urine copper, serum ceruloplasmin, and magnetic resonance imaging brain were consistent with the diagnosis of WD. Copper chelation was started along with other symptomatic treatments and diet modifications. Myoclonus had resolved by 3-month follow-up with the improvement of other symptoms. This case report emphasizes that myoclonus can be the main and presenting feature of WD.

Myoclonic Jerks, Exposure to Many Cats, and Neurotoxoplasmosis in an Immunocompetent Male

“…Central nervous system (CNS) toxoplasmosis can cause multiple movement disorders and seizures including multifocal myoclonic jerks, even with normal EEG and magnetic resonance imaging/magnetic resonance angiography scans of the brain. [1][2][3] Myoclonic jerks because of neurotoxoplasmosis in immunocompetent individuals are rare and we found no other similar reports in the literature. Recent studies have also implicated chronic or latent toxoplasmosis as a possible cause of cryptogenic seizures and/or epilepsy in the immunocompetent individual, which gives added relevance to this case.…”

“…Myoclonus may also be present in multiple sclerosis, Parkinson's disease, Alzheimer's disease, opsoclonus myoclonus syndrome, Creutzfeldt-Jacob disease, Lyme disease, systemic lupus erythematosus, Tourette syndrome, and mitochondrial encephalomyopathy. [1][2][3] Clinical, video-imaging, laboratory and serological examination, radiological studies, and electrophysiological analysis should be performed to identify the underlying cause; however, electrophysiology was not performed in our patient. Analysis of the differential diagnoses showed no other disease that could explain our patient's reversible encephalopathy (Table 3).…”

“…Owing to the severity of encephalitis caused by these atypical genotypes that can cause latent or subclinical infections worldwide, suspicion, early diagnosis, and appropriate treatment are essential even in settings with limited resources. [1][2][3] Multifocal myoclonic jerks are characterized by sudden, isolated, arrhythmic, asynchronous and asymmetric involuntary brief twitches, and jerks of muscles or muscle fibers involving various body areas, Video 1. Demonstration of Myoclonic Jerks in our Patient.…”

“…In cortical myoclonus, the electroencephalogram may be normal as seen in our patient, and this point was recently emphasized in a description of myoclonus in Wilson's disease. 2 Also, typical classification of physiological, hypnic, or hypnagogic jerks describes generalized jerks noted on falling asleep. The jerks observed in our patient presented within the first hour after sleep and they were multifocal.…”

“…3 The hypothesized mechanism of the neurotoxicity in the pathogenesis of myoclonus is inhibition of gamma-aminobutyric acid receptors and activation of excitatory N-methyl-D-aspartate receptors, leading to a toxic encephalopathy. [1][2][3]…”