What Is NMO Spectrum Disorder?
The neurological condition invoked by the aberrant functioning of immune cells is quoted as neuromyelitis optica spectrum disorder (NMOSD). NMO spectrum disorder with no prompt intervention could bring forth trouble in one’s life. Both morbidity and mortality could be brought out by neuromyelitis optica spectrum disorder. NMO spectrum disorder express a heightened inclination for the female population, particularly within 30 to 40 years of age. However, it is perceived to be an infrequent and rare condition with minimal incidence among the global population.
Neuromyelitis optica spectrum disorders are precipitated by overstated autoimmune expression. The immune cells are designated to strike and combat the pathogenic invasion. In autoimmune states, these immune cells express their fight against self-cells, mutilating their functions and prompting disabilities. The French neurologist, Mr. Eugene Devic, first elucidated and narrated the attributes of NMO spectrum disorder. This condition specifically strikes the nervous system, particularly the spinal cord and optic nerve, which are the key integrants of the nervous system.
In neuromyelitis optica spectrum disorder, the immune cells encounter the myelin sheath (natural protective sheath or envelope framed of fats and proteins which enwraps the major branching of the nerve cell called axon) as invader cells and elicit a fight with the myelin cells that structure the protective wrappings in certain nerve cells. It is through the axonal branching that the electrical signals are conveyed across, and the myelin wrappings in the nerve axon expedite their signal conveyance. In NMOSD, the immune cells inflict harm or mutilate the myelin cells, which instigates functional impairment of those nerve cells as the signal conveyance gets hindered and held up unintendedly. Autoimmune destruction inflicts inflammation in the spinal cord and optic nerve, which brings forth diverse manifestations.
How Is the NMO Spectrum Disorder Diagnosed?
Precise and timely diagnosis are prime integrants that could govern the recovery prospects of every disease. Diagnostic interventions are therefore formulated to expedite the diagnosis process. Neuromyelitis optica spectrum disorder is often wrongly perceived as multiple sclerosis (depicted by autoimmune invoked myelin harm), which is a discrete and independent disease entity. However, both ailments express similar and overlapping manifestations that upscale the propensity for misdiagnosis.
The below quoted are some of the routinely instituted diagnostic strategies for validating and substantiating the diagnosis of neuromyelitis optica spectrum disorder:
Clinical Evaluation: NMOSD brings out obvious manifestations, which aids in the diagnosis process by guiding the medical team. Eye pain, muscle pain, blurry vision, loss of eyesight, impaired bowel and urine control, muscle spasticity (abnormal muscle contraction), double vision, trouble keeping body balance, vertigo, frequent hiccups, aberrant and uncoordinated eye movements, hearing impairment, and daytime sleepiness are the manifestations confronted with NMOSD. However, it is not necessary to reflect all of these manifestations, and the clinical presentations might exhibit individual variances.
Neurological Evaluation: Neurological evaluation is instituted through simple tests that could precisely and accurately pin down irregularities or aberrations in neurological functions. Muscle movements, senses, walking patterns, body balance, reflexes, and facial expressions are checked out to weigh up the neurological functions.
Aquaporin-4 Antibody Test: The aquaporin-4 antibody test is instituted to shut out and exclude the possibility of multiple sclerosis. The suspected individual’s blood needs to be screened for aquaporin-4 (AQP4) antibody. AQP4 proteins are expressed over certain nerve cells. In certain subsets of NMOSD, these nerve cell proteins are mutilated, which is invoked by the aquaporin-4 antibodies.
Myelin Oligodendrocyte Glycoprotein Antibody Test: Blood tests are also advocated for disclosing the existence of myelin oligodendrocyte glycoprotein (MOG) antibodies. Myelin oligodendrocyte glycoproteins are integral and requisite for myelin sheath. The MOG antibodies mutilate the MOG proteins, thus impeding and unsettling the myelin envelope over the nerve axon. It also favors demyelination (uprooting of the myelin layer from the nerve axon).
Magnetic Resonance Imaging: Magnetic resonance imaging (MRI ) could demonstrate and underscore the demyelination and other neuronal harm inflicted by the NMOSD. MRI findings also aid in delineating the NMOSD and multiple sclerosis.
What Are the Treatment Strategies Advocated for NMO Spectrum Disorder?
Neuromyelitis optica spectrum disorder treatment ought to be strategically structured and effectuated. However, complete curation of NMOSD is unattainable owing to its autoimmune association. Prompt therapeutic interventions palliate and downturn the manifestations of NMOSD. Furthermore, it also mitigates the proclivity for disabilities or impairments, like vision loss or hearing loss.
NMOSD often mandates therapeutic interventions for a longer period. However, immediate intervention is also equally pertinent to attaining appreciable recovery and shutting out irrevocable disabilities. NMOSD tends to express a relapsing course with episodic NMOSD attacks. The exacerbation and NMOSD attacks could be downturned and delimited by medical interventions. Here are a few of the therapeutic strategies instituted for NMO spectrum disorder:
1. For Acute Attack of NMOSD:
Corticosteroids: The first line of intervention advocated during an acute attack is corticosteroids, which ought to be delivered through veins (intravenously). Methylprednisolone is the routinely advocated intravenous corticosteroid for NMOSD attacks at a daily dosage of one gram. The duration for which the intravenous corticosteroid therapy ought to be continued varies over three to five days and exhibits individual variances in the therapy duration.
Plasmapheresis: Plasmapheresis, otherwise called plasma exchange (PLEX), is advocated for acute NMOSD attack instances. During plasmapheresis, the blood’s liquid part, plasma, is withdrawn from the person’s circulation, which is then subjected to certain processing to extract and rub out the AQP4 and MOG antibodies that mediate the myelin and neuronal harm. Plasmapheresis heightens the recovery prospects in individuals who express intolerance or defense against corticosteroid therapy. In severe NMOSD attack cases, both intravenous methylprednisolone and plasma exchange could be teamed to bring out the best therapeutic outcome.
Intravenous Immunoglobulins: NMOSD patients with other medical comorbidities that delimit the applicability of other conventional treatment strategies are advocated for intravenous immunoglobulin therapy.
Immunoadsorption: Immunoadsorption also selectively filters out autoantibodies (like MOG and AQP4 antibodies inflicted by NMOSD) from the blood plasma. It is often advocated as a stand-by for plasma exchange. The therapeutic potency of immunoadsorption is perceived to be on par with plasma exchange.
2. Long Term Interventions:
Long-term interventions are formulated to mitigate relapse and recurrence prospects.
Intravenous Immunosuppressants: These agents palliate and downturn the functional attributes of immune cells. As NMOSD is mediated and piloted by autoimmunity, downgrading the immune functions could temper the prospect of relapse episodes.
B-Cell Depleting Agents: Medicaments that could down-regulate B-cells could bring out appreciable palliation in the relapses.
Conclusion
Neuromyelitis optica spectrum disorder, though rarely encountered, could bring out irreversible disabilities. Timely diagnosis and treatment could gear down the gravity for permanent impairments. The therapeutic strategies for tackling NMOSD attacks often entail both acute and long-term interventions. The wider therapeutic possibilities for NMOSD have augmented the prognostic attributes of the condition. Azathioprine therapy expressed appreciable preventative attributes in NMOSD cases. Many more investigations are ongoing to broaden the preventative aspects concerning NMOSD.
