Seizures in inflammatory demyelinating disorders of the central nervous system.

BACKGROUND: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may be associated with acute symptomatic seizures and chronic epilepsy as well. The clinical features of the seizures and/or accompanying epilepsy seen in each disease group may vary. In this study, we aimed to contribute to the existing literature by describing the clinical features of seizures and epilepsy in our demyelinating patient population. METHODS: We retrospectively analyzed patients who were followed up in our tertiary referral center neurology demyelinating diseases outpatient clinic between 2019 and 2024. Patients who had at least one seizure before, simultaneously, or after the diagnosis of demyelinating disease were included in the study. RESULTS: Among 1735 patients with MS, 40 had experienced at least one epileptic seizure (2.3 %). Thirty patients (1.7 %) had seizures that could not be explained by another factor than MS. When secondary progressive MS (SPMS) and relapsing-remitting MS (RRMS) were compared, the interval between MS-epilepsy diagnosis was longer and seizure recurrence was more in SPMS. However, the prognosis of epilepsy was good in both subtypes. There were 21 patients followed up with antibody-positive neuromyelitis optica spectrum disorder. No patient had a seizure during the follow-up. We identified 56 patients who fulfilled the criteria for MOGAD with high antibody titers. Seizures were observed in three of them (5.4 %). All of them had status epilepticus either at the onset or during the course of the disease. CONCLUSION: Even rare, seizures constitute one of the important clinical features of the inflammatory demyelinating disorders of the central nervous system. The pathophysiologic mechanism underlying seizures in MS is still not clear. Seizures may occur through different mechanisms in patients where seizures are the initial symptom or a sign of relapse and those that occur spontaneously during the progressive course of the disease. Prevalence of status epilepticus was common in MOGAD patients. Given the rarity of the seizures in CNS demyelinating disorders, it is difficult the define clinical and pathophysiological characteristics of accompanying seizures and epilepsy. Future studies conducted on large patient groups will contribute to the existing literature.

Clinical and demographic characteristics of late-onset multiple sclerosis: LOMS-TR study.

OBJECTIVES: Multiple sclerosis (MS), which is known as a young-adult age disease, is called late-onset MS (LOMS) when it occurs at the age of 50 and older. In our study, we aimed to analyse the clinical and demographic characteristics, comorbidities, diagnostic and treatment challenges and prognosis of LOMS. METHODS: In a retrospective analysis of 136 patients diagnosed with multiple sclerosis (MS) after the age of 50, based on the 2017 McDonald criteria, and who were under observation in eight distinct MS centers across Turkey; demographic information, clinical characteristics of the disease, oligoclonal band (OCB) status, initial and current Expanded Disability Status Scale (EDSS) values, administered treatments, and the existence of spinal lesions on magnetic resonance imaging (MRI) were investigated. RESULTS: The mean age of the 136 patients was 60.96±6.42 years (51-79), the mean age at diagnosis was 54.94±4.30 years, and 89 (65.4 %) of the patients were female. Most of the cases, 61.1 % (83) had at least one comorbidity. In 97 patients who underwent lumbar puncture (LP), OCB positivity was observed in 63.6 %. In 114 patients (83.8 %), spinal lesions were detected on MRI. Eighty-seven patients had relapsing-remitting MS (RRMS) (64 %), 27 patients had secondary progressive MS (SPMS) (19.9 %), and 22 patients had primary progressive MS (PPMS) (16.2 %). The mean EDSS at the time of diagnosis was 2.44±1.46, and the mean current EDSS was 3.15±2.14. CONCLUSIONS: In LOMS patients, the rates of delay in the diagnostic process, treatment disruption and progressive disease are higher than in the general MS population. The high rates of LP applying and OCB positivity of this study may indicate the habit of looking for clear evidences in advanged age in our country. This situation and comorbidities may cause a delay in diagnosis and eliminates the window of opportunity for early diagnosis. Although the high number of spinal lesions is a known marker for progressive disease, it is an issue that needs to be discussed whether the increased frequency of progressive course at older ages is due to the nature of the disease or immune aging itself.

Segmental Reflex, Long Latency Reflex, and Mixed Nerve Silent Period in Dystonia.

We hypothesized that "long latency reflexes" (LLRs), associated segmental reflex (SR), and mixed nerve silent periods (MnSPs) recorded on the distal upper extremity muscles would behave differently in patients with cervical dystonia and focal hand dystonia. We enrolled patients with cervical dystonia, generalized dystonia, focal hand dystonia, and healthy individuals. We recorded SR, LLRs, and MnSPs. The mean amplitude of SR on the affected side of focal hand dystonia was significantly lower (p = 0.010). The parameters related to LLRs and MnSPs were not different between groups. We suggest, using SR, LLRs, and MnSPs, we could not show an electrophysiological signature specific to dystonia.

Myoclonus and tremor in chronic inflammatory demyelinating polyneuropathy: a multichannel electromyography analysis.

BACKGROUND: Information regarding involuntary movements in chronic inflammatory polyneuropathy (CIDP) is gradually increasing. Our goal is to identify the types of involuntary movements in CIDP. METHODS: All patients who were followed with the diagnosis of CIDP were invited for clinical and electrophysiological evaluations. Demographic and clinical findings (age, gender, duration of illness, diagnosis, treatments) were noted. Clinical examination and multichannel surface electromyography were done. We also performed routine upper and lower extremity peripheral nerve conduction studies, F-waves, long latency reflexes, blink reflex, mixed nerve silent period and cutaneous silent period in all patients. RESULTS: Twenty-two patients accepted the invitation. Eleven patients with CIDP had involuntary movements. Ten (45.5%) patients with CIDP had tremor and seven (31.8%) had short-duration and high-amplitude myoclonus. Regarding demographic, clinical and electrophysiological features, there was no significant difference between patients with and without tremor. The latencies of R1, R2 and R2c components of BR were longer among CIDP patients without tremor compared to CIDP patients with tremor. Presence of myoclonus (p = 0.007) and delayed F-waves (p = 0.008) were associated with the presence of tremor. CONCLUSION: Tremor and myoclonus were frequent in CIDP. The fact that myoclonus was detected in the majority of patients only by multichannel surface EMG who were clinically evaluated as pure tremor suggests that a more detailed electrophysiological evaluation is required. There was no difference in the medications used or other clinical features between patients with and without tremor.