Multiple sclerosis (MS) is a complex and unpredictable neurological condition. It is the most commonly seen autoimmune disorder. The incidence of disease and its prevalence are growing worldwide. Early identification of the disease and accurate diagnosis is important to prevent further complications and disability. The etiology remains unclear, and it is believed that complex gene-environment interactions play an essential role. Genetic predisposition only describes a portion of the disease risk, whereas lifestyle and environmental factors are significant contributors. Smoking was identified as an important risk factor for MS. The main objectives of this review were to examine the underlying mechanisms of immune dysregulation in the development of MS, explore the association between smoking and MS, and identify other genetic and environmental factors that alter the risk of developing the disease. We searched PubMed for articles relevant to the study topic published between 2000 and 2020 using the search terms "multiple sclerosis," "cigarette smoking," "risk factors," and, "epigenetics." Studies reveal a marked association between smoking and the risk of MS. Unlike genetic risk factors, many lifestyles and environmental factors can be adjusted, with potential for prevention, particularly for people at the highest risk, such as families of individuals with MS.

COVID-19 disease has infected millions of people worldwide during the pandemic; hence, the need for an effective and safe vaccine was urgently required. A two-dose of the BNT162b2 mRNA COVID-19 vaccine was reported to have 95% efficacy in preventing COVID-19. The short-term safety profile recorded mild to moderate pain at the injection site, fatigue, and headache. The critical adverse effects were low and similar in the placebo group. However, we report the case of an 18-year-old male who developed acute central crushing chest pain four days following administration of the second dose of the BNT162b2 COVID-19 vaccine. After extensive cardiac workup, including coronary arteries diagnostic angiography, myocarditis was suspected and confirmed by a cardiac MRI. Fortunately, the patient's clinical condition gradually improved in the form of clinical symptoms and laboratory findings. He was discharged after one week of stay in hospital with regular follow-up in the cardiac clinic.

bCSF elicits a steep, transient Ca rise when administered to human astrocytes by activation of ATP-sensitive P2 receptors and subsequent inositol 1,4,5-trisphosphate-dependent Ca release from endoplasmic reticulum. This massive Ca overload leads to subsequent mitochondrial permeability transition pores opening and necrosis of the cells.

Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a type of smallvessel vasculitis. It is unusual for ANCA to involve aorta. However, multiple cases have been found where ANCA involved large vessels, particularly the aorta. Among vasculitides, aortic vasculitis is a part of Takayasu arteritis (TAK). In this review article, we tried to find the mechanism behind the aortic involvement in AAV. PubMed was used as a primary search engine, and all the available cases of aortic, as well as large-vessel involvement in ANCAassociated vasculitis, were thoroughly reviewed. Very limited data was available that could provide the mechanism behind this involvement. It is observed that ANCA-associated aortitis is more common in immunocompromised people; however, cases in previously healthy individuals have also been found. Pathogenesis of ANCA-related aortitis is different from Takayasu arteritis and is more close to ANCA-associated small vasculitis. ANCA-related aortitis involves the aorta through the same mechanism as it uses to involve small vessels. This rare manifestation of ANCA-associated vasculitis could be life-threatening but has a good prognosis if timely diagnosed and treated. ANCA-associated vasculitis must be considered as a differential diagnosis while treating a case of aortitis. We believe that there is a need to revise the classification of different types of vasculitides, and physicians should be aware of the possible overlap between different forms of vasculitides.

Inflammatory bowel disease (IBD) is an autoimmune inflammatory disorder that affects the gastrointestinal system with an annual increase in incidence and prevalence worldwide. While the precise cause behind IBD remains obscured, certain genetic susceptibilities, in addition to environmental factors, may trigger the stimulation of the immunoinflammatory system against the gastrointestinal system, eventually resulting in IBD. Furthermore, certain medications have been proposed to increase the risk of developing IBD, such as isotretinoin. IBD has been reported during the post-marketing phase of isotretinoin. Subsequently, IBD development was added as a potential gastrointestinal adverse effect of isotretinoin. This review article aims to evaluate the possible association between isotretinoin exposure and the development of inflammatory bowel disease. We enrolled 32 relevant studies, including case reports, case-control, and cohort studies. The results were critically analyzed and reviewed by independent authors to answer the research question and achieve the primary endpoint.

Encephalitis is one of the rare complications of coronavirus disease 2019 (COVID-19) that can be missed and confused with other causes of encephalitis. There was a 36-year-old male known to have glucose-6 phosphate dehydrogenase deficiency, who was brought to the emergency department with fever and confusion of one-week duration. Altered mental status work-up, including cerebrospinal fluid analysis, was done and turned out to be nondiagnostic. Multiple prolonged video-electroencephalographic recordings were done and showed different abnormalities suggestive of encephalitis. The diagnosis of COVID-19induced encephalitis was made by exclusion of other encephalitis-related etiologies in the presence of a positive COVID-19 polymerase chain reaction (PCR) test, and treatment was initiated accordingly. Over a period of three weeks, the patient showed progressive improvement and was discharged home with regular follow-up in the neurology clinic. Upon follow-up in the clinic, the patient was fully independent but with multiple abnormal electroencephalographic recordings showing generalized encephalopathy with no epileptic discharges.

Vascular complications of Behcet's disease, including intracardiac thrombus formation, are one of the significant causes of mortality and morbidity in this population. Similar to other vasculitic disorders, Behcet's disease is primarily treated with immunosuppressants. While the benefit of adding anticoagulants in Behcet's disease with thromboembolism remains debatable, some literature encourages its use with concomitant intracardiac thrombus. Herewith, we present the case of a young male who was diagnosed with bilateral pulmonary embolism in addition to right ventricle intracardiac thrombus upon his scheduled dose of infliximab infusion. He was managed by adding azathioprine to his regimen together with oral prednisolone and warfarin with a target international normalized ratio of 2-3. This case report addresses the importance and outcome of early identification of Behcet's disease's vascular complications and immediate initiation of anticoagulation accordingly.

Intermittent high-dose methylprednisolone therapy is widely used for various autoimmune conditions treatment. Common side effects are well known and monitored carefully during therapy. Although cardiovascular adverse events are uncommon, they have been increasingly reported in the literature. This is a case of a 30-year-old female who developed symptomatic sinus bradycardia after receiving three grams of intravenous methylprednisolone pulse therapy for multiple sclerosis flare-ups. Her pulse rate reached 40bpm, together with lightheadedness and chest tightness. An electrocardiogram confirmed sinus bradycardia, for which she was initially managed by splitting the methylprednisolone dose in half; however, 12 hours later, the heart rate decreased further to 35bpm, and her symptoms worsened.Subsequently, the medicine was omitted, and the patient shifted to the intensive care unit for close observation and monitoring. She was treated conservatively with close observation resulted in a gradual normalization of the heart rate. The diagnosis of methylprednisolone pulse-induced bradycardia was made after excluding other common etiologies of sinus bradycardia. This case report aims for careful cardiovascular monitoring in patients receiving high doses of methylprednisolone due to the dosedependent cardiovascular risks.