Spinal segmental myoclonus as an unusual presentation of multiple sclerosis

Spinal Segmental Myoclonus in Primary Progressive Multiple Sclerosis

Background

A wide variety of associated movement disorders has been described in multiple sclerosis.

Phenomenology Shown

A 57-year-old woman with primary progressive multiple sclerosis developed spinal segmental myoclonus associated with focal myelitis.

Educational Value

Movement disorders in multiple sclerosis are phenomenologically diverse and have varied pathophysiological mechanisms, making it essential to identify them to initiate appropriate treatment.

Spinal muscular atrophy-like phenotype in a mouse model of acid ceramidase deficiency

Mutations in ASAH1 have been linked to two allegedly distinct disorders: Farber disease (FD) and spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME). We have previously reported FD-like phenotypes in mice harboring a single amino acid substitution in acid ceramidase (ACDase), P361R, known to be pathogenic in humans (P361R-Farber). Here we describe a mouse model with an SMA-PME-like phenotype (P361R-SMA). P361R-SMA mice live 2-3-times longer than P361R-Farber mice and have different phenotypes including progressive ataxia and bladder dysfunction, which suggests neurological dysfunction. We found profound demyelination, loss of axons, and altered sphingolipid levels in P361R-SMA spinal cords; severe pathology was restricted to the white matter. Our model can serve as a tool to study the pathological effects of ACDase deficiency on the central nervous system and to evaluate potential therapies for SMA-PME.

[Telerehabilitation of Subjects with Neurodevelopmental Disorders During Confinement due to COVID-19]

Introduction

Social distancing measures due to the COVID-19 pandemic prevented many children with neurodevelopmental disorders from accessing face-to-face treatments. Telerehabilitation grew at this time as an alternative therapeutic tool. In this study we analysed remote cognitive rehabilitation in neurodevelopmental disorders.

Methods

This was a prospective, quasi-experimental (before-after) study that included 22 patients (mean age 9.41 years) with neurodevelopmental disorders who had telerehabilitation for over six months.

Results

After six months of telerehabilitation, a statistically significant improvement was found with a large effect size in these areas: attention (sustained, selective and divided), executive functions (verbal and visual working memory, categorisation, processing speed), visuospatial skills (spatial orientation, perceptual integration, perception, simultanagnosia) and language (comprehensive and expressive). On the Weiss Functional Impairment Scale, all areas (family, learning and school, self-concept, activities of daily living, risk activities) improved with statistical significance. We found a positive correlation between the number of sessions and the improvement observed in executive functions (visual working memory, processing speed), attention (sustained attention, divided attention) and visuospatial skills (spatial orientation, perceptual integration, perception, simultanagnosia). We did not find statistical significance between the family structure and the number of sessions carried out. A high degree of perception of improvement and satisfaction was observed in the parents.

Conclusions

Telerehabilitation is a safe alternative tool which, although it does not replace face-to-face therapy, can achieve significant cognitive and functional improvements in children with neurodevelopmental disorders.

Movement Disorders in Multiple Sclerosis: An Update

Background:

Multiple sclerosis (MS), a subset of chronic primary inflammatory demyelinating disorders of the central nervous system, is closely associated with various movement disorders. These disorders may be due to MS pathophysiology or be coincidental. This review describes the full spectrum of movement disorders in MS with their possible mechanistic pathways and therapeutic modalities.

Methods:

The authors conducted a narrative literature review by searching for ‘multiple sclerosis’ and the specific movement disorder on PubMed until October 2021. Relevant articles were screened, selected, and included in the review according to groups of movement disorders.

Results:

The most prevalent movement disorders described in MS include restless leg syndrome, tremor, ataxia, parkinsonism, paroxysmal dyskinesias, chorea and ballism, facial myokymia, including hemifacial spasm and spastic paretic hemifacial contracture, tics, and tourettism. The anatomical basis of some of these disorders is poorly understood; however, the link between them and MS is supported by clinical and neuroimaging evidence. Treatment options are disorder-specific and often multidisciplinary, including pharmacological, surgical, and physical therapies.

Discussion:

Movements disorders in MS involve multiple pathophysiological processes and anatomical pathways. Since these disorders can be the presenting symptoms, they may aid in early diagnosis and managing the patient, including monitoring disease progression. Treatment of these disorders is a challenge. Further work needs to be done to understand the prevalence and the pathophysiological mechanisms responsible for movement disorders in MS.

Prolonged-release fampridine for the treatment of myoclonus after cervical myelitis: a case report

Prolonged-release fampridine (PR-FAM), a potassium channel blocker, is approved for improving walking ability in patients with multiple sclerosis (MS). Beyond this, positive effects on other MS symptoms like fatigue, cognition, and tremor have been described. To our knowledge, a positive effect of PR-FAM on spinal myoclonus has not been described so far. Here, we report a 32-year-old female with myoclonus after cervical myelitis affecting both hands which markedly improved after administration of PR-FAM. Treatments used before such as carbamazepine or levetiracetam had to be withdrawn because of intolerable side effects or lack of efficacy. The positive effect of PR-FAM could be confirmed by transient suspension. PR-FAM may be considered as a treatment option in refractory spinal myoclonus after myelitis in selected cases.

Assessment and Treatment of Myoclonus: A Review

Myoclonus is defined as sudden, brief, shock-like contractions of muscles, and it can be a challenging diagnosis for the clinician to face. The number of aetiologies can make it difficult to determine the appropriate diagnostic workup for each individual patient without ordering a broad array of diagnostic studies from the start. As with other neurological conditions, a comprehensive history and physical examination are paramount in generating and ordering the initial differential diagnosis. Neurophysiological classification of myoclonus, using both electroencephalogram and electromyography, can be very helpful in elucidating the underlying aetiology. Treatment of myoclonus is often symptomatic, unless a clear treatable underlying cause can be found. This article aims to help providers navigate the assessment and treatment of myoclonus, focusing on neurophysiological classification as a guide. By the end of this article, providers should have a good understanding of how to approach the workup and treatment of myoclonus of various aetiologies.

Spinal myoclonus: a rare presentation of cervical myelopathy

Myoclonus describes a movement disorder characterised by brief, abrupt and involuntary contractions of muscles or groups of muscles, usually associated with intracranial lesions, with limited evidence linking it to spinal pathologies. The pathophysiology of spinal myoclonus is extensive and multifactorial. Infection, intramedullary and extramedullary space-occupying lesions, trauma, vascular abnormalities, degenerative processes and cervical spondylosis have been implicated with the disease, the latter been associated with cervical stenosis with no reported cases linking it to an underlying cervical disc herniation. Although medical therapy with clonazepam, levetiracetam, valproate, tetrabenazine hydrochloride and spinal block injections has been equivocal, spinal myoclonus secondary to disc herniation requires surgical intervention. This report describes a case of segmental spinal myoclonus, secondary to a herniated cervical intervertebral disc. After corpectomy and a cage-augmented fusion technique, the myoclonic symptoms resolved. To our knowledge, this was the first report to describe the successful management of discogenic spinal myoclonus with spinal surgery.

Spinal-generated movement disorders: a clinical review

Spinal-generated movement disorders (SGMDs) include spinal segmental myoclonus, propriospinal myoclonus, orthostatic tremor, secondary paroxysmal dyskinesias, stiff person syndrome and its variants, movements in brain death, and painful legs-moving toes syndrome. In this paper, we review the relevant anatomy and physiology of SGMDs, characterize and demonstrate their clinical features, and present a practical approach to the diagnosis and management of these unusual disorders.