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 and the Risk of Relapse in Multiple Sclerosis Patients: A Fight with No Bystander Effect?

BACKGROUND: COVID-19 is speculated to increase the likelihood of relapsing-remitting multiple sclerosis (RRMS) exacerbation. OBJECTIVE: To investigate the association between contraction of COVID-19 and incidence of acute MS attacks in RRMS patients six months post-infection. METHODS: This retrospective cohort study compares the risk of relapse in RRMS patients with (n=56) and without COVID-19 (n=69). Incidence of relapse was recorded for six-month following contraction of COVID-19. Incidence of RRMS exacerbation in patients with COVID-19 was compared to patients without COVID-19 (the independent control group) and the same patients six months prior to the COVID-19 pandemic. RESULTS: A lower incidence rate of RRMS exacerbation was observed in patients that contracted COVID-19 than in patients who did not contract COVID-19 (incidence rate ratio: 0.275; p=0.026). Self-controlled analysis showed no significant difference in relapse rates before the COVID-19 pandemic and after contracting COVID-19 (p=0.222). The relapse risk was not different between patients who had been hospitalized due to COVID-19 severity and those who had not (p=0.710). CONCLUSION: COVID-19 contraction may not increase the risk of acute MS attacks shortly following contraction. We hypothesize that COVID-19-associated lymphopenia may partly preclude the autoreactive memory cells from expansion and initiating relapses through a so-called bystander effect of COVID-19 infection.

"NMDA receptor spectrum disorder" in the differential diagnosis of demyelinating disorders of the CNS: optic neuritis and myelitis.

OBJECTIVE: The aim of this study was to investigate the frequency of anti-N-methyl-D-aspartate receptor (anti-NMDAR) antibody positivity in patients presenting with transverse myelitis (TM) and/or optic neuritis (ON), to describe their neurologic and radiological characteristics, and to compare these characteristics with those reported in previous studies. MATERIAL AND METHODS: This study included 179 patients (ON: 96, TM: 74, ON and TM: 9) who visited Isfahan Multiple Sclerosis Center from January 2017 to September 2019, for approximately 32 months. The respective neurological examinations were performed. Demographic data of the patients, as well as findings from radiological and serological investigations were obtained. RESULTS: Frequencies of anti-NMDAR seropositivity in patients with TM, ON, and concurrent TM and ON were approximately 3.4%, 1.4%, and 11.1%, respectively. None exhibited any psychiatric symptoms. CONCLUSION: Based on the frequency of seropositivity for anti-NMDAR antibody in our patients, positivity for this antibody appears to be more frequent than previously anticipated in patients presenting with these conditions. We recommend that the anti-NMDAR antibody presence in CSF/serum be checked and considered in addition to the routine examinations performed upon confronting demyelinating conditions such as TM and ON. We suggest considering the term "NMDAR spectrum disorder" to more clearly distinguish the potentially overlapping conditions with different etiologies in patients with CNS disorders.

MRI signs of CNS demyelinating diseases.

The differential diagnosis of the central nervous system (CNS) demyelinating diseases can be greatly facilitated by visualization and appreciation of pathognomonic radiological signs, visualized on magnetic resonance imaging (MRI) sequences. Given the distinct therapeutic approaches for each of these diseases, a decisive and reliable diagnosis in patients presenting with demyelination-associated symptoms is of crucial value. Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are major examples of such conditions, each possessing a number of MRI signs, closely associated with the disorder. This pictorial review aims to describe seventeen pathognomonic MRI signs associated with several CNS demyelinating disorders including MS, NMOSD, myelin oligodendrocyte glycoprotein-associated disease, Baló's concentric sclerosis, metachromatic leukodystrophy, progressive multifocal leukoencephalopathy, and neurosarcoidosis.

The effect of fampridine on the risk of seizure in patients with multiple sclerosis.

BACKGROUND: Fampridine was first approved by the US Food and Drug Administration (FDA) to improve walking in multiple sclerosis (MS) patients, which was demonstrated by an increase in their walking speed. Nevertheless, the medication has been reported to possess an epileptogenic effect since it blocks the voltage-gated potassium channels in neural fibers. Several studies have indicated that the risk of seizure among fampridine consumers is not substantially higher than that in the general MS population, however. The objective of this study is to describe 97 MS patients for whom fampridine was prescribed and to assess the incidence of post-medication seizures. METHODS: This cohort study included 97 MS patients with gait problems who referred to the Isfahan Clinic of MS from August 2017 to September 2019. The exclusion criteria were a previous or family history of seizure or a history of renal impairment. Fampridine was prescribed for all the patients at a dose of 10 mg twice daily (12 hours apart). RESULTS: three patients (with an approximate incidence rate of 0.015 per 100 patient-years) presented with generalized tonic-clonic seizures, 7, 9, and 14 months after initiating fampridine consumption. The radiological findings revealed significant cortical and subcortical lesions in the three patients. Further, two of them consumed baclofen or fingolimod simultaneously with fampridine. CONCLUSION: The reported incidence rate is relatively higher than that in the general MS population. The extensive (sub) cortical lesions and the concomitant medications probably have an important role in the epileptogenesis, regardless of fampridine. However, the potential pro-convulsant properties of fampridine should not be overlooked.