Neuromielitis óptica: asociación con espasmos tónicos paroxísticos dolorosos

Update on the diagnosis and treatment of neuromyelits optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part I: Diagnosis and differential diagnosis

The term 'neuromyelitis optica spectrum disorders' (NMOSD) is used as an umbrella term that refers to aquaporin-4 immunoglobulin G (AQP4-IgG)-positive neuromyelitis optica (NMO) and its formes frustes and to a number of closely related clinical syndromes without AQP4-IgG. NMOSD were originally considered subvariants of multiple sclerosis (MS) but are now widely recognized as disorders in their own right that are distinct from MS with regard to immunopathogenesis, clinical presentation, optimum treatment, and prognosis. In part 1 of this two-part article series, which ties in with our 2014 recommendations, the neuromyelitis optica study group (NEMOS) gives updated recommendations on the diagnosis and differential diagnosis of NMOSD. A key focus is on differentiating NMOSD from MS and from myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD), which shares significant similarity with NMOSD with regard to clinical and, partly, radiological presentation, but is a pathogenetically distinct disease. In part 2, we provide updated recommendations on the treatment of NMOSD, covering all newly approved drugs as well as established treatment options.

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.

Painful tonic spasms in a patient with neuromyelitis optica spectrum disorder: A case report

Painful tonic spasms initially described in association with multiple sclerosis are actually more common in patients with neuromyelitis optica spectrum disorder. Characterized by fierce pain and tonic posture of limbs, painful tonic spasms are common in patients during the recovery phase after the first episode of myelitis. A 68-year-old man presented with painful tonic spasm after 2 months of diagnosis of neuromyelitis optica spectrum disorder. Eventual use of eslicarbazepine resulted in significant control of spasms. Early recognition of painful tonic spasms and appropriate therapeutic medications can significantly decrease the impact it can have on the quality of life among neuromyelitis optica spectrum disorder patients.

Pain in neuromyelitis optic spectrum disorder

BACKGROUND

Pain is a common symptom of neuromyelitis optica spectrum disorder (NMOSD), but there are relatively few studies on NMOSD pain.

METHODS

We retrospectively reviewed the medical records of 145 patients with NMOSD admitted to our hospital between July 2016 and June 2019.

RESULTS

The clinical characteristics of pain and factors related to NMOSD were analyzed, revealing that the incidence of pain in NMOSD is high and can be used for disease localization.

CONCLUSION

Different types of pain occur at different stages of the disease, and serum aquaporin-4 antibody (AQP4-ab) positivity is an independent risk factor for NMOSD pain. Hormones and biological immune agents may also be effective in some cases.

Pain, depression, and quality of life in adults with MOG-antibody-associated disease

BACKGROUND AND PURPOSE

Myelin oligodendrocyte glycoprotein-antibody-associated disease (MOGAD) is an inflammatory autoimmune condition of the central nervous system. However, data on pain and depression have remained scarce. The aim of this study was to assess features of chronic pain and depression as well as their impact on health-related quality of life (hr-QoL) in MOGAD.

METHODS

Patients with MOGAD were identified in the Neuromyelitis Optica Study Group registry. Data were acquired by a questionnaire, including clinical, demographic, pain (PainDetect, Brief Pain Inventory-Short Form, McGill Pain Questionnaire-Short Form), depression (Beck Depression Inventory-II), and hr-QoL (Short Form-36 Health Survey) items.

RESULTS

Twenty-two of 43 patients suffered from MOGAD-related pain (11 nociceptive, eight definite neuropathic, three possible neuropathic) and 18 from depression. Patients with neuropathic pain had the highest pain intensity and most profound activities of daily living (ADL) impairment. Fifteen patients reported spasticity-associated pain, including four with short-lasting painful tonic spasms. Later disease onset, profound physical impairment, and depression were associated with chronic pain. Physical QoL was more affected in pain sufferers (p < 0.001) than in pain-free patients, being most severely reduced by neuropathic pain (p = 0.016). Pain severity, visual impairment, and gait impairment independently predicted lower physical QoL. Depression was the only factor reducing mental QoL. Twelve patients still suffering from moderate pain (pain severity 4.6 ± 2.3) received pain medication. Only four out of 10 patients with moderate to severe depression took antidepressants.

CONCLUSIONS

Being highly prevalent, pain and depression strongly affect QoL and ADL in MOGAD. Both conditions remain insufficiently controlled in real-life clinical practice.

Myelitis in inflammatory disorders associated with myelin oligodendrocyte glycoprotein antibody and aquaporin-4 antibody: A comparative study in Chinese Han patients

BACKGROUND AND PURPOSE

Myelitis is an important clinical component of myelin oligodendrocyte glycoprotein antibody (MOG-ab)-associated disease (MOGAD) and aquaporin-4 antibody (AQP4-ab)-positive neuromyelitis optica spectrum disorder (NMOSD). The aim of this work was to evaluate the differentiating features of myelitis between the two diseases.

METHODS

Myelitis-related clinical and radiologic data from 130 patients with MOGAD and 125 patients with AQP4-ab-positive NMOSD were retrospectively reviewed and compared. A scoring model was established to differentiate MOG-ab-associated myelitis from AQP4-ab-associated myelitis.

RESULTS

Overall, 29.2% (38/130) of patients with MOGAD and 66.4% (83/125) of patients with AQP4-ab-positive NMOSD had ever experienced myelitis. Compared with those with NMOSD, patients with MOGAD exhibited a lower frequency of myelitis, either during the first episode (p < 0.0001) or throughout the disease duration (p < 0.0001). Compared with AQP4-ab-associated myelitis, MOG-ab-associated myelitis manifested a higher male-to-female ratio (p < 0.0001), younger age at disease onset (p = 0.0004), more prodromic influenza-like symptoms (p = 0.030), more prodromic fever (p = 0.0003), more bowel and bladder dysfunction (p = 0.011), less painful tonic spasms (p < 0.0001), and lower Expanded Disability Status Scale scores after treatment (p < 0.0001). On magnetic resonance imaging, lower spinal cord lesions (p = 0.023), short-segment lesions (p = 0.021), conus involvement (p = 0.0001), and H sign (p < 0.0001) were more common in MOG-ab-associated myelitis. A scoring model with a cutoff value of 4 differentiated MOG-ab-associated myelitis from AQP4-ab-associated myelitis with a sensitivity of 87.9% and a specificity of 90.1%.

CONCLUSIONS

Myelitis was less commonly observed in MOGAD and exhibited distinct features compared to those of AQP4-ab-positive 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.

Pain and the immune system: emerging concepts of IgG-mediated autoimmune pain and immunotherapies

The immune system has long been recognised important in pain regulation through inflammatory cytokine modulation of peripheral nociceptive fibres. Recently, cytokine interactions in brain and spinal cord glia as well as dorsal root ganglia satellite glia have been identified important- in pain modulation. The result of these interactions is central and peripheral sensitisation of nociceptive processing. Additionally, new insights and the term 'autoimmune pain' have emerged through discovery of specific IgGs targeting the extracellular domains of antigens at nodal and synaptic structures, causing pain directly without inflammation by enhancing neuronal excitability. Other discovered IgGs heighten pain indirectly by T-cell-mediated inflammation or destruction of targets within the nociceptive pathways. Notable identified IgGs in pain include those against the components of channels and receptors involved in inhibitory or excitatory somatosensory synapses or their pathways: nodal and paranodal proteins (LGI1, CASPR1, CASPR2); glutamate detection (AMPA-R); GABA regulation and release (GAD65, amphiphysin); glycine receptors (GLY-R); water channels (AQP4). These disorders have other neurological manifestations of central/peripheral hyperexcitabability including seizures, encephalopathy, myoclonus, tremor and spasticity, with immunotherapy responsiveness. Other pain disorders, like complex regional pain disorder, have been associated with IgGs against β2-adrenergic receptor, muscarinic-2 receptors, AChR-nicotinic ganglionic α-3 receptors and calcium channels (N and P/Q types), but less consistently with immune treatment response. Here, we outline how the immune system contributes to development and regulation of pain, review specific IgG-mediated pain disorders and summarise recent development in therapy approaches. Biological agents to treat pain (anti-calcitonin gene-related peptide and anti-nerve growth factor) are also discussed.

The history of neuromyelitis optica. Part 2: 'Spinal amaurosis', or how it all began

Neuromyelitis optica (NMO) was long considered a clinical variant of multiple sclerosis (MS). However, the discovery of a novel and pathogenic anti-astrocytic serum autoantibody targeting aquaporin-4 (termed NMO-IgG or AQP4-Ab), the most abundant water channel protein in the central nervous system, led to the recognition of NMO as a distinct disease entity in its own right and generated strong and persisting interest in the condition. NMO is now studied as a prototypic autoimmune disorder, which differs from MS in terms of immunopathogenesis, clinicoradiological presentation, optimum treatment, and prognosis. While the history of classic MS has been extensively studied, relatively little is known about the history of NMO. In Part 1 of this series we focused on the late 19th century, when the term 'neuromyelitis optica' was first coined, traced the term's origins and followed its meandering evolution throughout the 20th and into the 21st century. Here, in Part 2, we demonstrate that the peculiar concurrence of acute optic nerve and spinal cord affliction characteristic for NMO caught the attention of physicians much earlier than previously thought by re-presenting a number of very early cases of possible NMO that date back to the late 18th and early 19th century. In addition, we comprehensively discuss the pioneering concept of 'spinal amaurosis', which was introduced into the medical literature by ophthalmologists in the first half of the 19th century.

Complexity and wide range of neuromyelitis optica spectrum disorders: more than typical manifestations

Neuromyelitis optica (NMO), considered to be mediated by autoantibodies, often cause severely disabling disorders of the central nervous system, and predominantly cause optic nerve damage and longitudinally extensive transverse myelitis. Remarkable progress has been made in deciphering NMO pathogenesis during the past decade. In 2015, the International Panel for NMO Diagnosis proposed the unifying term "NMO spectrum disorders" (NMOSD) and the updated NMOSD criteria reflects a wide range of disease and maintains reasonable specificity. Moreover, cumulative findings have indicated that NMOSD are frequently associated with multiple autoimmune diseases, thereby presenting complex clinical symptoms that make this disease more difficult to recognize. Notably, most neurologists do not heed these symptoms or comorbid conditions in patients with NMOSD. Whereas previous reviews have focused on pathogenesis, treatment, and prognosis in NMOSD, we summarize the present knowledge with particular emphasis on atypical manifestations and autoimmune comorbidities in patients with NMOSD. Furthermore, we emphasized the identification of these atypical characteristics to enable a broader and better understanding of NMOSD, and improve early accurate diagnosis and therapeutic decision making.

Treatment of Neuromyelitis Optica Spectrum Disorder: Acute, Preventive, and Symptomatic

OPINION STATEMENT

Neuromyelitis optica spectrum disorder (NMOSD) is a rare, autoimmune disease of the central nervous system that primarily attacks the optic nerves and spinal cord leading to blindness and paralysis. The spectrum of the disease has expanded based on the specificity of the autoimmune response to the aquaporin-4 water channel on astrocytes. With wider recognition of NMOSD, a standard of care for treatment of this condition has condition based on a growing series of retrospective and prospective studies. This review covers the present state of the field in the treatment of acute relapses, preventive approaches, and therapies for symptoms of NMOSD.