Focal epilepsy presenting as tongue tremor: A case report

Plenty of etiologies are reported to cause tongue tremor. Focal epilepsy presenting as isolated tongue tremor is a rare condition, suggesting how variable the focal seizure presentation may be. This paper reports a case of focal epilepsy due to presence of a cavernous angioma in the region of cortical motor area related to tongue movements. It is an clinical example of pathological conditions affecting the tongue area in motor homunculus.

Atherosclerosis and multiple sclerosis: An overview on the prevalence of risk factors

BACKGROUND

Atherosclerosis is the leading cause of ischemic heart disease and coronary artery disease. The process of atherosclerosis develops over a period of years and is mainly immune-mediated. Data regarding the prevalence of vascular disease and atherosclerosis among people with multiple sclerosis (pwMS) is inconsistent, therefore, we aimed to provide an overview of the prevalence of atherosclerotic risk factors in pwMS.

METHODS

This is a cross-sectional study over a period of one year among pwMS visiting the Isfahan MS center. Study data have been extracted using participants' files and a checklist that was completed by the observers. Only people with relapsing-remitting (RRMS) and secondary progressive (SPMS) forms of MS were included in the study. Participants with primary progressive (PPMS) disease are only described and have been excluded from analyses.

RESULTS

Of the 396 pwMS (343 with RRMS and 53 with SPMS), in descending order, the reported risk factors were tobacco smoking (18.4%), dyslipidemia (10%), hypertension (8.8%), and diabetes mellitus (4.5%). In people with RRMS, 17.4% were smokers, 9.9% had dyslipidemia, 8.1% had hypertension, and 4.3% had diabetes mellitus. In SPMS patients 24.5% reported a history of smoking, 13.2% had hypertension, 9.4% had dyslipidemia, and 3.7% had diabetes mellitus. Smoking was insignificantly associated with higher expanded disability status scale (Z: 1.70, p-value = 0.090). Male sex (RR [95%CI]: 1.628 [1.172, 2.261], p-value = 0.004) and increasing age (RR [95%CI]: 1.024 [1.008, 1.040], p-value = 0.003) were associated with a higher number of risk factors.

CONCLUSION

The highest observed atherosclerosis risk factor among pwMS was smoking. Diabetes mellitus was the least reported risk factor in our population as a whole. Overall, and in participants with RRMS, dyslipidemia and hypertension were the second and third most commonly reported risk factors, however, hypertension exceeded dyslipidemia in participants with SPMS. Male sex and increasing age were associated with a higher number of atherosclerosis risk factors.

Deep brain stimulation of anteromedial globus pallidus internus improved OCD rather than tics in a Gilles de la Tourette syndrome patient

A 32-year-old gentleman with refractory Gilles de la Tourette syndrome went on a DBS procedure on anteromedial globus pallidus internus. At the most suitable adjustment, the OCD component of his disease improved almost completely while his tics remained unchanged which was in contrast with other previous studies. Moreover, variations in symptoms were seen in response to different adjustments. We discuss that these variations and fluctuations in the therapeutic outcomes may be due to differences in physiological conditions of tic- or OCD-specified pathways and areas including distinct stimulation threshold and occurrence of neuroplasticity in neural circuits which may determine the responsiveness of each pathway or circuit to a specific stimulus. At last, we suggest that pathways and circuits should be targeted for DBS rather than single components; as these components may be involved in multiple pathways, related to different pathophysiological states.

Successful seroconversion following mild COVID-19 contraction in a double-vaccinated B-cell-depleted person with multiple sclerosis: A hint towards booster efficacy?

Background

While early booster administration has been started in many regions to tackle failure of seroconversion among people with multiple sclerosis (pwMS) on anti-CD20 therapies (aCD20), its efficacy is still doubted in presence of B-cell depletion.

Case presentation

We report the case of a rituximab-treated person with MS who contracted COVID-19 after being double-vaccinated. While hypothesizing that COVID-19 contraction itself could mimic a vaccination booster, we investigated anti-SARS-CoV-2-Spike serology and B-cell counts in this case. The results showed successful seroconversion despite low relative counts of CD19+ and CD20+ cells.

Conclusion

Until further population-based data becomes available, further administration of early boosters among pwMS on aCD20 is highly encouraged.

Cutaneous adverse events related to COVID-19 vaccines: A cross-sectional questionnaire-based study of 867 patients

Considering the emergency approval of the Food and Drug Administration for widespread use of coronavirus disease 2019 (COVID-19) vaccines, evaluating potential vaccine-related adverse effects is critical as it will allow physicians to diagnose and manage these complications properly. In this descriptive cross-sectional questionnaire-based study, we evaluated the possible side effects of the COVID-19 vaccine from June 1, 2021 to June 21, 2021. The Iranian population is generally vaccinated with AstraZeneca, Sputnik V, Sinopharm, and Bharat vaccines. The continuous and categorical variables were described and data analyzed by the SPSS software version 25. Cutaneous reactions occurred in 30% of individuals vaccinated against COVID-19. The most common cutaneous complications were focal injection site reaction, exanthematous rash, and urticaria. There were infrequent cutaneous adverse events that included vesicular eruption, pernio-like lesions, angioedema, erythema multiforme-like eruption, and zoster. Acquainting physicians with COVID-19 vaccine-related cutaneous complications will assist them in detection and management. In addition, introducing these complications to individuals might improve acceptance of vaccine-related adverse effects in the general population.

SARS-CoV-2 serology among people with multiple sclerosis on disease-modifying therapies after BBIBP-CorV (Sinopharm) inactivated virus vaccination: Same story, different vaccine

Background

Various studies indicated blunted humoral responses to COVID-19 mRNA and viral vector vaccines among people with multiple sclerosis (pwMS) on sphingosine 1-phosphate receptor (S1PR) modulators and anti-CD20 therapies (aCD20); however, limited evidence was found regarding SARS-CoV-2 serology after inactivated virus vaccination.

Objective

To provide evidence regarding humoral response to COVID-19 inactivated virus vaccination among pwMS on disease-modifying therapies (DMTs).

Methods

A cohort study was carried out in Isfahan, Iran, enrolling DMT-exposed pwMS and unexposed (UX) healthy participants. Post-vaccination anti-SARS-CoV-2 Spike IgG serology testing was carried out among the participants and compared between participants based on their DMT exposure, using proper statistical tests. A multivariable logistic regression model was used to control for confounding. Association between the second vaccine dose-to-phlebotomy (vac2phleb) and the humoral response was investigated in each DMT-exposed cohort, using linear regression. Among the aCD20 cohort, the association of the last aCD20 infusion-to-first vaccine dose period with serostatus was investigated using an unpaired t-test.

Results

After enrolling 358 participants (144 pwMS and 214 healthy), blunted humoral responses were only observed in fingolimod (Log₁₀ mean diff. [SE]: 0.72 [0.18], P = 0.001) and aCD20 (Log₁₀ mean diff. [SE]: 0.75 [0.15], P < 0.001) cohorts compared to the UX cohort. Multivariable analysis confirmed the results. The study did not achieve enough statistical power to detect a significant association between the vac2phleb period and humoral responses. The last aCD20 infusion to first vaccination dose period was longer in the seroconverted pwMS on aCD20 (mean diff. [SE]: 8.43 weeks [2.57], P = 0.005).

Conclusion

The results of this study mirrored the results of previous studies among mRNA- or viral vector-vaccinated pwMS on DMTs. Therefore, it can be concluded that mode of action contributes less than timing, to the efficiency of vaccination strategies among pwMS on DMTs – especially the ones on S1PR modulators and aCD20. Meanwhile, the mentioned pwMS should be advised to receive early boosters and remain vigilant until further data becomes available and more efficient vaccination strategies are crafted.

Outcome of COVID-19 infection in multiple sclerosis patients receiving disease-modifying therapies

Background

With the spread of COVID-19, treatment of diseases such as multiple sclerosis (MS) should be resumed with caution due to the disease-modifying therapies (DMTs) used in this subset of patients and the immunoregulatory effects of these drugs. We aim to assess the outcome of COVID-19 infection in MS patients receiving DMTs.

Materials and Methods

This is a cross-sectional study involving 45 COVID-19-infected patients previously diagnosed with MS. The data regarding their MS status and the type of DMT taken by the patients were extracted from the Isfahan MS Institute registry and were summarized. Diagnosis of MS was based on the 2017 McDonald Criteria, and the diagnosis of COVID-19 was based on computed tomography scan and polymerase chain reaction of nasopharyngeal swabs.

Results

Out of the 45 MS patients infected with COVID-19, 5 had unfavorable outcomes. Two patients deceased and the other three had persistent respiratory complications on the 4-week follow-up visit. Hypertension, diabetes, seizures, and rheumatoid arthritis were among the comorbidities that the patients reported. Both patients who died received rituximab as part of their MS treatment. All other patients recovered completely.

Conclusion

Each different drug category may possess a distinct risk for infection, therefore until robust evidence are available, the safest drug should be utilized or the therapy should be postponed, if possible, to minimize patient risk. Disease-modifying therapy use in MS patients should be cautiously applied as their effect on COVID-19 infection prognosis is not yet studied.

Movement Disorders Associated with COVID-19

As neurological complications associated with COVID-19 keep unfolding, the number of cases with COVID-19-associated de novo movement disorders is rising. Although no clear pathomechanistic explanation is provided yet, the growing number of these cases is somewhat alarming. This review gathers information from 64 reports of de novo movement disorders developing after/during infection with SARS-CoV-2. Three new cases with myoclonus occurring shortly after a COVID-19 infection are also presented. Treatment resulted in partial to complete recovery in all three cases. Although the overall percentage of COVID-19 patients who develop movement disorders is marginal, explanations on a probable causal link have been suggested by numerous reports; most commonly involving immune-mediated and postinfectious and less frequently hypoxic-associated and ischemic-related pathways. The current body of evidence points myoclonus and ataxia out as the most frequent movement disorders occurring in COVID-19 patients. Some cases of tremor, chorea, and hypokinetic-rigid syndrome have also been observed in association with COVID-19. In particular, parkinsonism may be of dual concern in the setting of COVID-19; some have linked viral infections with Parkinson's disease (PD) based on results from cerebrospinal fluid analyses, and PD is speculated to impact the outcome of COVID-19 in patients negatively. In conclusion, the present paper reviewed the demographic, clinical, and treatment-associated information on de novo movement disorders in COVID-19 patients in detail; it also underlined the higher incidence of myoclonus and ataxia associated with COVID-19 than other movement disorders.

Risk factors of severe COVID-19 in people with multiple sclerosis : A systematic review and meta-analysis

Objectives

To gather, synthesize, and meta-analyze data regarding the risk factors associated with a severe course of COVID-19 among patients with multiple sclerosis (pwMS).

Methods

MEDLINE, Embase, Scopus, and WoS were searched in May 2021. Briefly, the eligibility criteria included: 1) studies assessing COVID-19 severity among adult pwMS; 2) definitive diagnoses or high clinical suspicion of COVID-19; 3) a categorization of COVID-19 severity into at least two categories; 4) quantitative effect size and precision measurements; and 5) English language; and 6) clear effect size/precision measures. internal validity of studies was assessed using the NIH Quality Assessment Tools. A list of possible risk factors was created based on the search results and was later used in extraction, synthesis, and meta-analysis of the data.

Results

Thirteen studies were included in the syntheses. Outcome measures were either extracted from the papers, obtained from the primary researchers or calculated manually. The meta-analyses showed a significantly (P < 0.05) increased odds of a severe COVID-19 in pwMS with all of the assessed risk factors, except smoking and most DMTs.

Conclusion

This study facilitates evidence-based risk/benefit assessments in practice. Older men with progressive MS on anti-CD20 therapies are more at risk of an unfortunate COVID-19 outcome.

Atypical parkinsonism and self-mutilation: A new lens on the old concept

We report a case of atypical parkinsonism and self-mutilation.

Epidemiological and clinical features of pediatric-onset multiple sclerosis: A population-based study in Isfahan, Iran, between 1997-2020

Background: Pediatric-onset multiple sclerosis (POMS) is an autoimmune demyelinating disorder of the central nervous system (CNS), affecting individuals younger than 18 years of age. We sought to characterize the epidemiological and clinical features of patients with POMS in Isfahan, Iran, from April 1997 to March 2020. Methods: The medical records of patients with POMS in the databases of Isfahan Department of Public Health and Isfahan Multiple Sclerosis Society (IMSS) were retrospectively reviewed. The 2006 and 2016 Isfahan Province population censuses were used as reference values for assessing the temporal trend of POMS. Results: From April 1997 to March 2020, 509 individuals under18 years of age were diagnosed with POMS in Isfahan. 404 of these patients (79.4%) were girls, and 105 patients (20.6%) were boys (a female to male ratio of 3.85:1). Most of the patients (83%) were monosymptomatic at onset, with optic neuritis and brainstem-cerebellar disorders being the most frequent initial presentations. Mean ± standard deviation (SD) of age at disease diagnosis was 15.8 ± 2.5 years (ranging from 3 to 18, mode = 18). From April 2019 to March 2020, the crude prevalence and the crude incidence rate of the POMS were 5.42 per 100000 and 1.86 per 100000, respectively. Poisson regression analysis revealed a 3.4% increase in the incidence rate of POMS from April 1997 to March 2020 [relative rate:1.034, 95% confidence interval (CI): 1.021-1.048]. Conclusion: The female to male ratio in our cohort was significantly higher than any other studies conducted previously. The high female to male ratio and increasing incidence of the disease suggest increasing regionalization of care.

Frequency of diencephalic syndrome in NMOSD

BACKGROUND

Diencephalic region of the brain harbors sites with a considerable amount of aquaporin-4 expression. Neuromyelitis optica spectrum disorder (NMOSD) primarily involves autoimmune processes against this molecule. However, little is known about the frequency of symptoms of diencephalic involvement in NMOSD patients.

OBJECTIVE

To investigate the frequency of symptoms of diencephalic involvement in NMOSD patients and describe the associated characteristics in patients presenting such symptoms.

MATERIALS AND METHODS

This retrospective cohort included 145 NMOSD patients (39 males and 106 females) who visited Isfahan Multiple Sclerosis Center from January 2013 to February 2020 for approximately 61 months. Demographic and clinical information of patients and findings from radiological and serological investigations were retrieved.

RESULTS

The frequency of diencephalic involvement in NMOSD patients was 3.4% (five cases). Diencephalic syndrome-associated symptoms observed in this cohort consisted of narcolepsy (n = 2; 40%), hypotension (n = 1; 20%), amenorrhea (n = 1; 20%), and syndrome of inappropriate antidiuretic hormone secretion (n = 1; 20%). These manifestations responded well to NMOSD-associated treatments, i.e., rituximab and azathioprine.

CONCLUSION

Although rarely manifested through symptoms suggestive of diencephalic involvement, NMOSD should be considered when encountering patients with the diencephalic syndrome to identify the primary cause of these manifestations.

Covid-19 in Parkinson's Disease treated by drugs or brain stimulation

PURPOSE

Covid-19 has affected all people, especially those with chronic diseases, including Parkinson's Disease (PD). Covid-19 may affect both motor and neuropsychiatric symptoms of PD patients. We intend to evaluate different aspects of Covid-19 impact on PD patients.

METHODS

647 PD patients were evaluated in terms of PD-related and Covid-19-related clinical presentations in addition to past medical history during the pandemic through an online questioner. They were compared with an age-matched control group consist of 673 individuals and a sample of the normal population consist of 1215 individuals.

RESULTS

The prevalence of Covid-19 in PD patients was 11.28%. The mortality was 1.23% among PD patients. The prevalence of Covid-19 in PD patients who undergone Deep Brain Stimulation (DBS) was 18.18%. No significant association was found between the duration of disease and the prevalence of Covid-19. A statistically significant higher prevalence of Covid-19 in PD patients who had direct contact with SARS-CoV-19 infected individuals was found. No statistically significant association has been found between the worsening of motor symptoms and Covid-19. PD patients and the normal population may differ in the prevalence of some psychological disorders, including anxiety and sleeping disorders, and Covid-19 may affect the psychological status.

CONCLUSION

PD patients possibly follow tighter preventive protocols, which lead to lower prevalence and severity of Covid-19 and its consequences in these patients. Although it seems Covid-19 does not affect motor and psychological aspects of PD as much as it was expected, more accurate evaluations are suggested in order to clarify such effects.

Case series: New-onset freezing of gait in combined use of deep brain stimulation and Levodopa

Concurrent use of DBS and levodopa in Parkinson's disease patients can lead to freezing of gait. This phenomenon may be due to an inverted-U-Shaped function of dopamine.

Irreversible extreme freezing of gait after dopamine agonist withdrawal

Dopamine agonist withdrawal can cause freezing of gait in PD patients.

Autoimmune encephalitis: the first observational study from Iran

BACKGROUND

Even within the most populous countries in the Middle East, such as Iran, autoimmune encephalitis cases have been rarely reported.

OBJECTIVE

We aimed to describe the demographic, clinical, and paraclinical characteristics of Iranian patients with autoimmune encephalitis positive for anti-neuronal autoantibodies.

METHODS

This cross-sectional study included all patients diagnosed with autoimmune encephalitis and referred to our hospital, in Isfahan, Iran, from March 2016 to May 2020. Patients' demographic, clinical, laboratory, radiological, and electroencephalographic features were obtained from their medical records.

RESULTS

We identified a total of 39 (21 females, 53.8%) patients with autoimmune encephalitis (mean age = 34.9 ± 12.8 years). The most commonly detected antibody was anti-NMDAR (n = 26, 66.7%), followed by anti-GABA_BR (n = 8, 20.5%), anti-Zic4 (n = 4, 10.3%), and anti-GAD65 (n = 1, 2.6%) antibodies, in descending order of frequency. Two anti-NMDAR-positive patients had a history of systemic lupus erythematosus (SLE), and four had a prior history of herpes simplex encephalitis. Clinical presentations in patients positive for anti-Zic4 antibodies included cognitive decline (n = 4, 100%), seizures (n = 3, 75%), parkinsonism (n = 1, 25%), and stiff-person syndrome (n = 1, 25%).

CONCLUSION

This was the first case series of Iranian patients with autoimmune encephalitis with some interesting observations, including SLE-associated anti-NMDAR encephalitis, as well as an unusual concurrence of anti-Zic4 antibody positivity and cognitive problems, seizures, parkinsonism, and stiff-person syndrome.

Parkinson's disease patients may have higher rates of Covid-19 mortality in Iran

Background

Parkinson's disease (PD) patients may be at increased risk of Covid-19 mortality due to the nature of their disease or underlying conditions.

Method

The information of 12,909 Covid-19 patients who were hospitalized during the last eleven months were collected from the data depository of two referral university hospitals. Eighty-seven of these patients were diagnosed with PD, and thirty-one of these PD patients died because of Covid-19. 2132 other deaths occurred in these centers, related to Covid-19 of non-PD patients. Fisher exact test, Chi-square test, and Principle component analysis were used for statistical analysis.

Results

The mortality among PD patients and other hospitalized patients was 35.6% and 19.8%, respectively, and the difference between the mortality of these two groups was found to be statistically significant (p-value<0.01). The mean age of PD patients who passed away was 77.06 ± 7.46, and it was not significantly different from that of alive PD patients (p-value>0.05). Alzheimer's disease as an underlying condition was more frequent in deceased PD patients in comparison to survived PD patients, and this difference was found to be statistically significant (p-value<0.01).

Conclusion

PD patients possess a higher rate of Covid-19 mortality in comparison with other patients hospitalized for Covid-19. PD pathophysiology, advanced age, underlying conditions, and health systems’ efficacy may play an essential role in such an outcome.

Myasthenia gravis and coronavirus disease 2019: A report from Iran

Background: Coronavirus disease 2019 (COVID-19) is spreading rapidly and has affected millions of people worldwide. Comorbid diseases have complicated the course of infection and increased mortality. Myasthenia gravis (MG) affects the neuromuscular junctions (NMJs) and can compromise respiratory muscle action, leading to worse clinical outcomes in individuals infected with the COVID-19 theoretically. In this study, the aim is to assess the pattern of COVID-19 infection in patients with MG based on several factors. Methods: This was a prospective cohort study following 150 patients with MG over a six-month period. The patients were monitored for the development of signs and symptoms of the COVID-19 infection. Results: Comparison of the patients infected with COVID-19 with MG and those not infected was performed independently based on age, duration since MG diagnosis, status of thymectomy, and current clinical status of MG disease. Data analysis did not reveal increased susceptibility or increased severity of COVID-19 illness based the criteria assessed. Conclusion: COVID-19 related deaths and susceptibility were not related to age, thymectomy status, and disease duration in patients with MG.

Prevalence of coronavirus disease 2019 in patients with neuromyelitis optica in Isfahan, Iran, and a review on recent reports and literature

Background: Despite many studies, it is still unclear how patients with neuromyelitis optica spectrum disorder (NMOSD) would respond to coronavirus disease 2019 (COVID-19). We conducted a research on prevalence of COVID-19 in patients with NMOSD in Isfahan, Iran. We have also reviewed the recent publications on this issue. Methods: 149 patients with NMOSD who were under medications were monitored for confirmed cases of COVID-19. Prevalence of COVID-19 in addition to mean age, mean duration of disease, and mean age of onset of infected patients and uninfected patients were calculated via Microsoft Excel software. Results: The prevalence of COVID-19 in studied patients with NMOSD was 5.37%. Mean age, mean duration of disease, and mean age of onset of eight patients (male to female ratio: 1:3) diagnosed with COVID-19 were 33.62 ± 5.20 years, 6.87 ± 6.05 years, and 26.75 ± 6.94 years, respectively, while they were 39.97 ± 11.37 years, 7.50 ± 3.91 years, and 32.46 ± 11.29 years for uninfected patients with NMOSD (n = 141). No significant association was observed between the type of medications and prevalence of COVID-19 (P > 0.05). Conclusion: There is not a consensus in the literature on the prevalence of COVID-19 in patients with NMOSD and the effect of NMOSD medications on susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The prevalence of COVID-19 in our sample was 5.37%. The impact of the kind of NMOSD medication on the prevalence of COVID-19 in patients with NMOSD was found to be insignificant. Moreover, the infected patients were relatively younger, and their disease started earlier in comparison to uninfected patients.

Conus medullaris involvement in demyelinating disorders of the CNS: A comparative study

BACKGROUND

Differentiation of the demyelinating disorders of the CNS seems challenging in practice. Conus medullaris, the cone-shaped end of the spinal cord, is more involved in anti-MOG patients based on preliminary studies, a possibly helpful detail in its differentiation. Nevertheless, the evidence is still limited and the underlying cause is unclear and undiscussed in previous studies.

OBJECTIVE

To contribute to preliminary studies by comparing conus involvement among patients with MS, anti-AQP4, and anti-MOG diseases using larger sample size.

METHODS

More than a thousand MS, anti-AQP4, and anti-MOG patients were followed up for a maximum of five years, scanned for conus medullaris involvement. Data regarding each cohort were then analyzed and compared using statistical methods.

RESULTS

The rate of conus medullaris involvement was significantly higher in anti-MOG patietns (OR = 27.109, P < 0.001), followed by anti-AQP4 (OR = 4.944, P = 0.004), and MS patients (OR = reference). Survival analysis showed higher pace and cumulative incidence of conus attacks in anti-MOG patients. Conus-involved patients, showed no significant difference regarding age, sex, concurrent brain lesions, and their partial recovery. Predictive values show that the probability of being diagnosed with anti-MOG is roughly 13 times higher in conus-involved patients (25.93% vs. 1.97%), although this probability was still higher for MS, as it has a much higher incidence.

CONCLUSION

Despite minor differences, the results were in line with previous studies, confirming the higher rate of conus medullaris involvement among anti-MOG patients. Potential underlying causes are proposed and remain to be investigated in future studies.

Atypical parkinsonism and self-mutilation: A new lens on the old concept

We report a case of atypical parkinsonism and self-mutilation.

Can COVID-19 accelerate neurodegeneration?

COVID-19 may accelerate neurodegeneration in patients with neurodegenerative disease.

Rituximab induced cytokine release syndrome in an MS patient: A case report

Cytokine release syndrome with rituximab has been reported in certain diseases, however, it is rarely reported in MS patients treated with rituximab. The treating physician should suspect the syndrome when typical signs and symptoms appear.

Multiple sclerosis epidemiology in Asia and Oceania; A systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) is an inflammatory demyelinating CNS disease and the most common neurological immune-mediated disorder. Due to its progressive format, it affects patients' quality of life (QoL) significantly. This study aimed to evaluate epidemiologic parameters of MS in the Asia and Oceania continents.

METHODS

A comprehensive literature search on October 1st, 2020, was performed in PubMed, Scopus, and Web of Science to retrieve original population-based studies on MS epidemiology in the Asian and Oceanian countries, published between January 1st, 1985 and October 1st, 2020. The designed search strategy was repeated for each country, and the relevant referenced articles were added to our database. A random-effect model was used to combine the epidemiological estimates, and subgroup analysis was also performed by continent, region, and country, when possible. Meta-regression analysis was done to evaluate the effects of Human Developmental Index (HDI), latitude, and study period on the epidemiologic parameters.

RESULTS

A total of 3,109 publications were found, of which 89 articles met the eligibility criteria and were included for data extraction. These articles provided data on prevalence, incidence, and mean age at disease onset in 18 countries in Asia and Oceania, including Iran, Turkey, Cyprus, Kuwait, Saudi Arabia, Qatar, UAE, Jordan, Israel, India, Malaysia, China, Hong Kong, Taiwan, Republic of Korea, Japan, Australia, and New Zealand. The pooled total prevalence, incidence, and mean age of onset in Asia and Oceania were 37.89/100000 (95% CI: 35.65 - 40.142), 2.40/100000 (95% CI: 2.22 - 2.58), and 28.21 (95% CI: 27.55 - 28.88), respectively. MS prevalence and incidence in the female gender (68.7/100000 and 4.42/100000, respectively) were infinitely higher than in the male gender (24.52/100000 and 2.06/100000, respectively). Our subgroup analysis showed that MS was much more prevalent in Australia and West Asia among the studied area. The meta-regression showed that the total incidence decreased with an increase in the HDI, and the total prevalence in Asia increased with increasing latitude gradients. Also, the study period had a positive effect on the total prevalence and incidence in Asia and Oceania.

CONCLUSION

MS prevalence and incidence have increased in recent decades. This study highlights the need for further studies to elucidate MS's geographical and temporal variations' exact etiologies.