Spinal Movement Disorders in Neuromyelitis Optica: An Under-recognized Phenomenon

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

Paroxysmal painful tonic spasms in neuromyelitis optica spectrum disorder

Background

Recently, an association between painful tonic spasms (PTS) and Neuromyelitis Optica Spectrum Disorder (NMOSD) was established.

Objective

To describe the clinical characteristics of PTS in NMOSD based on a video recording and to provide a literature review on the topic.

Methods

We report a case of a 38 years-old woman with a diagnosis of NMOSD and positive aquaporin-4 IgG antibody status who developed PTS five weeks after an episode of longitudinal extensive transverse myelitis (LETM).

Results

Repetitive, brief, and painful episodes of muscle contraction were observed on the patient's left hand, spreading to the left arm, and then extending to the four limbs. While pregabalin and topiramate had no influence on these episodes, the patient responded to carbamazepine (CBZ), without symptom recurrence after one year.

Conclusions

PTS in association with LETM can be considered typical for NMOSD. Although the exact mechanism is unknown, ephaptic transmission after spinal cord damage and excitatory soluble factors released during acute inflammation responses are sought to be involved. Symptomatic treatment with CBZ achieved remission of spams in our case.

Paroxysmal spinal hemidystonia in neuromyelitis optica

Paroxysmal dystonia occurs because of genetic or structural lesion in the basal ganglia or thalamus, and there is paucity of reporting in spinal pathology. We report a patient with paroxysmal hemidystonia admitted to a tertiary care hospital, India, and review the literature on spinal dystonia in neuromyelitis optica (NMO). A 19-year-old woman presented with recurrent visual loss and quadriparesis. She developed paroxysmal hemidystonia after 18 days of a second episode of quadriplegia, during which her muscle power improved to Grade 3. Magnetic resonance imaging (MRI) of her spine showed central T2 hyperintensity extending from C2 to C7 vertebral level, and a cranial MRI was normal. Tibial somatosensory evoked potentials were unrecordable. Aquaporin-4 antibody was positive in serum, confirming the diagnosis of NMO. Paroxysmal hemidystonia responded to carbamazepine 200 mg thrice daily. Paroxysmal dystonia may occur in a patient with myelitis and may respond to carbamazepine.

A comparison between subjective and objective measurements of spasticity in neuromyelitis optica spectrum disorder patients

BACKGROUND

Spasticity is a common and disabling problem in multiple sclerosis (MS), but its effect in other CNS inflammatory demyelinating diseases (CNSIDDs), such as neuromyelitis optica spectrum disorder (NMOSD) is not widely studied. This study aims to compare subjective and objective measurements of spasticity in NMOSD patients and determine associated factors.

METHODS

A prospective cross-sectional study was performed on CNSIDD patients attending the Multiple Sclerosis and Related Disorders Clinic at Siriraj Hospital, a tertiary hospital in Thailand, from June to November 2020 was performed. MS, NMOSD, and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) patients were included. Patients' self-rated Numeric Rating Scale (NRS) for spasticity and clinician-evaluated Modified Ashworth Scale (MAS) scores on the same visit were compared and assessed for correlations. Data on characteristics of patients including demographics, number of transverse myelitis (TM) attacks, disease duration, and Expanded Disability Status Scale (EDSS) score were collected.

RESULTS

Seventy-nine CNSIDD patients were included with 25 MS, 53 NMOSD, and 1 MOGAD. There was a statistically significant correlation between NRS and MAS scores (r = 0.934, p < 0.001). Spasticity was more commonly observed in NMOSD patients compared to MS (34% vs 8%, p = 0.016). Clinical characteristics strongly associated with spasticity were higher number of TM attacks (p < 0.001), severe TM attacks (p < 0.001), longitudinally extensive transverse myelitis attacks (p < 0.001), longer disease duration (p = 0.025), higher EDSS (p < 0.001), and pyramidal Functional System Scale scores (p = 0.001).

CONCLUSIONS

Patients' self-reported NRS score had a good correlation with clinician-evaluated MAS score for spasticity assessment in NMOSD and CNSIDD patients overall. Number and severity of TM attacks were associated with spasticity. Spastic patients had more disability measured by EDSS.

Movement Disorder in Demyelinating Disease: Tracing the Charcot's Foot Print

Movement disorders may be one of the neurological manifestations of demyelinating disorders. They can manifest in Parkinsonism or a wide spectrum of hyperkinetic movement disorders including tremor, paroxysmal dyskinesia, dystonia, chorea, and ballism. Some of these disorders occur during an acute episode of demyelination, whereas others can develop later or even may precede the onset of the demyelinating disorders. The pathophysiology of movement disorders in demyelination is complex and the current evidence indicates a wide involvement of different brain networks and spinal cord. Treatment is mainly symptomatic and oral pharmacological agents are the mainstay of the management. Botulinum toxin and neurosurgical interventions may be required in selected patients.

Movement Disorders in Multiple Sclerosis and Other Demyelinating Diseases: A Retrospective Review From a Tertiary Academic Center

BACKGROUND

Movement disorders (MDs) have been described in demyelinating diseases (DDs). However, data is lacking in the effective treatment of these MD as well as in a potential correlation between DD lesions localization and the phenomenology of the MD and its response to treatment.

METHODS

Retrospective review of 185 patients with MD and DD seen at our center over a period of 7 years. Clinical imaging, medications, and therapeutic responses to both MD and DD treatments were reviewed.

RESULTS

Of the 185 patients, 62 were excluded because of a diagnosis of spasticity without any other MD. One hundred twenty three patients with DD (75% female, age 48.8±12.8 y) had one or more MD. The most common MD was ataxia followed by isolated tremor. Forty-two patients (34%) received any treatment for MD, 29 (69%) of which responded at least partially to a first MD agent and 78.6% responded at least partially to a second or third agent. Responders to the first MD therapy were more likely to have a lesion in the basal ganglia or the cerebellum, and less likely to have a lesion in the brainstem or the spinal cord, but these results could be biased by a lower-than-expected frequency of tonic spasms in our series. No correlation between DD lesions localization and the phenomenology of the MD was discovered.

CONCLUSIONS

MD are common in DD and are frequently overlooked or undertreated. MD in this sample have a 69% therapeutic response to a first trial. Greater awareness of potential therapeutic options is needed to decrease disability.

Symptomatic and restorative therapies in neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorders (NMOSD) are a group of autoimmune inflammatory conditions that primarily target the optic nerves, spinal cord, brainstem, and occasionally the cerebrum. NMOSD is characterized by recurrent attacks of visual, motor, and/or sensory dysfunction that often result in severe neurological deficits. In recent years, there has been a significant progress in relapse treatment and prevention but the residual disability per attack remains high. Although symptomatic and restorative research has been limited in NMOSD, some therapeutic approaches can be inferred from published case series and evidence from multiple sclerosis literature. In this review, we will discuss established and emerging therapeutic options for symptomatic treatment and restoration of function in NMOSD. We highlight NMOSD-specific considerations and identify potential areas for future research. The review covers pharmacologic, non-pharmacologic, and neuromodulatory approaches to neuropathic pain, tonic spasms, muscle tone abnormalities, sphincter dysfunction, motor and visual impairment, fatigue, sleep disorders, and neuropsychological symptoms. In addition, we briefly discuss remyelinating agents and mesenchymal stem cell transplantation in NMOSD.

Pain in NMOSD and MOGAD: A Systematic Literature Review of Pathophysiology, Symptoms, and Current Treatment Strategies

Neuromyelitis optica spectrum disorders (NMOSDs) and myelin oligodendrocyte glycoprotein-antibody-associated disease (MOGAD) are autoimmune inflammatory disorders of the central nervous system (CNS). Pain is highly prevalent and debilitating in NMOSD and MOGAD with a severe impact on quality of life, and there is a critical need for further studies to successfully treat and manage pain in these rare disorders. In NMOSD, pain has a prevalence of over 80%, and pain syndromes include neuropathic, nociceptive, and mixed pain, which can emerge in acute relapse or become chronic during the disease course. The impact of pain in MOGAD has only recently received increased attention, with an estimated prevalence of over 70%. These patients typically experience not only severe headache, retrobulbar pain, and/or pain on eye movement in optic neuritis but also neuropathic and nociceptive pain. Given the high relevance of pain in MOGAD and NMOSD, this article provides a systematic review of the current literature pertaining to pain in both disorders, focusing on the etiology of their respective pain syndromes and their pathophysiological background. Acknowledging the challenge and complexity of diagnosing pain, we also provide a mechanism-based classification of NMOSD- and MOGAD-related pain syndromes and summarize current treatment strategies.

Painful tonic spasm in Chinese patients with neuromyelitis optica spectrum disorder: Prevalence, subtype, and features

OBJECTIVES

Painful tonic spasm (PTS) is a common symptom in patients with neuromyelitis optica spectrum disorder (NMOSD). We herein aimed to explore the prevalence, subtype, and features of PTS in Chinese Han patients with NMOSD.

METHODS

We retrospectively reviewed medical records and interviewed patients with NMOSD who were admitted to Huashan Hospital and the Jing'an District Center Hospital of Fudan University in Shanghai, China, from February 2017 to May 2019. The primary questionnaires included a Numerical Rating Scale (NRS), Spinal Cord Injury Health Questionnaire (SCI-HQ), Penn Spasm Frequency Scale (PSFS), and Patient Global Impression of Improvement (PGI-I).

RESULTS

Sixty-seven of 153 (43.79%) patients with NMOSD showed PTS, only when spinal cord was involved. PTS had a negative impact on daily life in 97.01% (65/67) of the patients, and 92.54% (62/67) of the patients needed symptomatic treatment. Pain intensity and frequency of PTS were significantly different (P = 0.018 with NRS, P = 0.045 with PSFS) among flexor tonic spasm, extensor tonic spasm, isometric tonic spasm and complex tonic spasm subtype. Forty patients (59.71%) manifested complex tonic spasms, which indicated more severe pain and frequent spasms comparing to other subtypes. The locations of PTS were significantly different among the 5 subtypes (P<0.001), i.e.,77.78% (7/9) of flexor tonic spasms appeared in the upper extremity, 100% (9/9) of extensor tonic spasm occurred in the lower extremity, and isometric tonic spasms principally occurred in the trunk (87.5%). Forty-one patients (66.13%) demonstrated good responses to the symptomatic treatments, and there were no statistical differences with respect to the therapeutic responses among the 5 PTS subtypes (P = 0.509).

CONCLUSIONS

PTS was associated with myelitis, and was a common symptom in NMOSD. Intensity, frequency and location were different among the PTS subtypes. Complex tonic spasm was the most common and serious subtype.

Defining the spectrum of spasticity-associated involuntary movements

BACKGROUND

Spasticity can be associated with several hyperkinetic involuntary movements generally referred to as "spasms" despite different phenomenology and clinical characteristics.

OBJECTIVE

To better characterize the phenomenology and clinical characteristics of spasticity-associated involuntary movements.

METHODS

We performed a cross-sectional study of a consecutive patient sample from the spasticity clinic. Each patient was interviewed by a movement-disorder neurologist who conducted a standardized movement-disorder survey and a focused exam. Patients with involuntary movements were video-recorded and videos were independently rated by a separate blinded movement-disorder neurologist.

RESULTS

Sixty-one patients were included (54% female, mean age 49.7 ± 13.9 years). Of the entire cohort, 11.5% had spinal, 44.3% had cerebral, and 44.3% had mixed-origin spasticity. Fifty-eight patients (95%) reported one or more involuntary movements: 75% tonic spasms (63% extensor, 58% isometric, 41% flexor/adductor), 52% spontaneous clonus, 34% myoclonus, 33% focal dystonia, and 28% action tremor. One third of the involuntary movements were painful. Only 53% of patients reported that their involuntary movements were much or very-much improved with their current anti-spasticity management. Patients treated with intrathecal baclofen therapy were more likely to report much or very-much improvement compared to patients receiving oral and/or botulinum therapy (P = 0.0061 and 0.0069 respectively).

CONCLUSION

Most spastic patients experience spasticity-associated involuntary movements of variable phenomenology and impact. However, only half of these patients experience significant improvement with the current management strategies. More research is needed to explore better treatment options for spasticity-associated involuntary movements with focus on phenomenology-specific approaches.

Movement disorders in early MS and related diseases: A prospective observational study

BACKGROUND

Little is known about the true prevalence and clinical characteristics of movement disorders in early multiple sclerosis (MS) and related demyelinating diseases. We conducted a prospective study to fill this knowledge gap.

METHODS

A consecutive patient sample was recruited from the MS clinic within a 1-year-period. Patients diagnosed over 5 years before the study start date were excluded. Each eligible patient was interviewed by a movement disorder neurologist who conducted a standardized movement disorder survey and a focused examination. Each patient was followed prospectively for 1-4 follow-up visits. Movement disorders identified on examination were video-recorded and videos were independently rated by a separate blinded movement expert.

RESULTS

Sixty patients were included (56.6% female, mean age 38.3 ± 12.7 years). Eighty percent reported one or more movement disorders on the survey and 38.3% had positive findings on examination. After excluding incidental movement disorders (e.g., essential tremor), 58.3% were thought to have demyelination-related movement disorders. The most common movement disorders in a descending order were restless legs syndrome, tremor, tonic spasms, myoclonus, focal dystonia, spontaneous clonus, fasciculations, pseudoathetosis, hyperekplexia, and hemifacial spasm. The movement disorder started 5 months following a relapse on average but in 8 patients it was the presenting symptom of a new relapse or the disease itself. The majority of movement disorders occurred secondary to spinal (85.7%) or cerebellar/brainstem lesions (34.2%). Spinal cord demyelination was the only statistically significant predictor of demyelination-related movement disorders.

CONCLUSION

Movement disorders are more common than previously thought even in early MS. They typically begin a few months after spinal or brainstem/cerebellar relapses but may occasionally be the presenting symptom of a relapse.