Strength-Duration Time Constant in Peripheral Nerve: No Abnormality in Multiple Sclerosis

Objectives. To investigate the properties of the strength-duration time constant (SDTC) in multiple sclerosis (MS) patients. Methods. The SDTC and rheobase in 16 MS patients and 19 healthy controls were obtained following stimulation of the right median nerve at the wrist. Results. SDTC and rheobase values were 408.3 ± 60.0 μs and 4.0 ± 1.8 mA in MS patients, versus 408.0 ± 62.4 μs and 3.8 ± 2.1 mA in controls. The differences were not significant in SDTC or rheobase values between the patients and controls (P = 0.988 for SDTC and P = 0.722 for rheobase). Conclusion. Our study showed no abnormality in relapsing remitting MS patients in terms of SDTC, which gives some indirect information about peripheral Na+ channel function. This may indicate that alterations in the Na+ channel pattern in central nervous system (CNS) couldnot be shown in the peripheral nervous system (PNS) in the MS patients by SDTC. The opinion that MS can be a kind of channelopathy might be proven by performing other axonal excitability tests or SDTC in progressive forms of MS

Effects of obstructive sleep apnea on retinal microvasculature

AIM: To detect retinal microvascular variations in obstructive sleep apnea syndrome patients. METHODS: This prospective, observational case-control study included healthy controls and patients with mild, moderate, and severe obstructive sleep apnea syndrome. Vascular parameters, foveal avascular area, and flow areas in macula-centered, 6.00×6.00 mm2 scan size optical coherence tomography angiography images were compared. RESULTS: The control group had the highest whole image, parafoveal, and perifoveal vessel density among the groups in both superficial and the deep capillary plexus (all P<0.05). Rapid eye movement sleep apnoea-hypopnoea index was reversely correlated with whole (Rho=-0.195, P=0.034), parafoveal (Rho=-0.242, P=0.008), perifoveal (Rho=-0.187, P=0.045) vessel density in the superficial capillary plexus, and whole (Rho=-0.186, P=0.046), parafoveal (Rho=-0.260, P=0.004), perifoveal (Rho=-0.189, P=0.043) vessel density in the deep capillary plexus, though the mean and non-rapid eye movement sleep apnoea-hypopnoea index related with only parafoveal vessel density in the superficial capillary plexus (Rho=-0.213, P=0.020; Rho=-0.191, P=0.038) and the deep capillary plexus (Rho=-0.254, P=0.005; Rho=-0.194, P=0.035). CONCLUSION: This study shows decreased vessel density and its reverse correlation with the apnoea-hypopnoea index in patients with obstructive sleep apnea syndrome

Gama amino butirik asit (GABA) reseptörlerinin genetik polimorfizmleri ile idiyopatik jeneralize epilepsi arasındaki ilişkinin araştırılması

TÜBİTAK TBAG Proje01.03.2012Epilepsy is one of the most common neurological diseases worldwide. Gamma amino butyric acid (GABA), the most important inhibitory neurotransmitter of the central nervous system, and its receptors are commonly mentioned in the pathophysiology of epilepsies. Some of the single nucleotide polymorphisms in the genes encoding GABA receptors have been reported to increase susceptibility to temporal lobe epilepsy. There are a limited number of studies analyzing the relationship of GABA receptors and idiopathic epilepsy, which is the most widespread (65%) when etiologically classified. In Turkish population, genetic polymorphisms of GABAA, GABAB1 and GABAB2 receptors have not been studied before. For these reasons, in this study we aimed to determine the frequencies of genetic polymorphisms of GABA receptors A, B1 and B2 in Turkish population by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method, and to investigate the correlation between these polymorphisms and idiopathic generalized epilepsy (IGE). A second aim of this study was to analzye the role of GABA receptor polymorphisms in differential diagnosis of pschogenic non-epileptic seizure (PNES). In this context, 196 IGE patients, 107 PNES subjects and 109 controls were inculded in this study. Polymorphic allele frequencies were very close to each other in the three groups (0.457 in IGE patients, 0.453 in PNES patients and 0.427 in controls) for the GABAA α1 rs2279020 polymorphism. A statistically significant relationship was not found between this polymorphism and IGE. We did not observe polymorphic alleles in Turkish population for GABAA 2 rs17852044, GABAA 3 rs79829085 and GABAB1 G1465A. For GABAB1 C59T polymorphism, when IGE patients and PNES subjects were compared, C59T polymorphism was found to increase IGE risk 1,5 times, but this result was not significant (P=0.164). The frequency of C59T polymorphism in control population was found as 0.110 in this study. We observed that four polymorphisms found on GABAB2 gene (rs3780428-rs1999501- rs967932-rs94688) did not constitute a significant risk for IGE when considered alone. When the genotype combinations were taken into account, we concluded that having polymorphic homozygote genotype for rs944688 and wild type genotype for rs967932 and rs1999501 had 15 times protective effect against IGE for PNES subjects (P=0.001). The same genotype combination constituted 12 times protective effect against IGE in control subjects (P=0.009). This triple combined genotype can be used to differentiate subjects who have psychogenic seizures (PNES) from those having epileptic seizures. All of the studied polymoprhisms were studied for the first time in Turkish populatio

Diagnosis of comorbid migraine without aura in patients with idiopathic/genetic epilepsy based on the gray zone approach to the International Classification of Headache Disorders 3 criteria

BackgroundMigraine without aura (MwoA) is a very frequent and remarkable comorbidity in patients with idiopathic/genetic epilepsy (I/GE). Frequently in clinical practice, diagnosis of MwoA may be challenging despite the guidance of current diagnostic criteria of the International Classification of Headache Disorders 3 (ICHD-3). In this study, we aimed to disclose the diagnostic gaps in the diagnosis of comorbid MwoA, using a zone concept, in patients with I/GEs with headaches who were diagnosed by an experienced headache expert.MethodsIn this multicenter study including 809 consecutive patients with a diagnosis of I/GE with or without headache, 163 patients who were diagnosed by an experienced headache expert as having a comorbid MwoA were reevaluated. Eligible patients were divided into three subgroups, namely, full diagnosis, zone I, and zone II according to their status of fulfilling the ICHD-3 criteria. A Classification and Regression Tree (CART) analysis was performed to bring out the meaningful predictors when evaluating patients with I/GEs for MwoA comorbidity, using the variables that were significant in the univariate analysis.ResultsLonger headache duration (&lt;4 h) followed by throbbing pain, higher visual analog scale (VAS) scores, increase of pain by physical activity, nausea/vomiting, and photophobia and/or phonophobia are the main distinguishing clinical characteristics of comorbid MwoA in patients with I/GE, for being classified in the full diagnosis group. Despite being not a part of the main ICHD-3 criteria, the presence of associated symptoms mainly osmophobia and also vertigo/dizziness had the distinguishing capability of being classified into zone subgroups. The most common epilepsy syndromes fulfilling full diagnosis criteria (n = 62) in the CART analysis were 48.39% Juvenile myoclonic epilepsy followed by 25.81% epilepsy with generalized tonic-clonic seizures alone.ConclusionLonger headache duration, throbbing pain, increase of pain by physical activity, photophobia and/or phonophobia, presence of vertigo/dizziness, osmophobia, and higher VAS scores are the main supportive associated factors when applying the ICHD-3 criteria for the comorbid MwoA diagnosis in patients with I/GEs. Evaluating these characteristics could be helpful to close the diagnostic gaps in everyday clinical practice and fasten the diagnostic process of comorbid MwoA in patients with I/GEs

Vagal Nerve Stimulation and Patient Selection

Vagal nerve stimulation (VNS) is a technique applied in patients with intractable epilepsy. Patients who are not eligible to epilepsy surgery and those who are accepted as failure after surgery are candidates for VNS. A meta analysis revealed that 50% of the patients have a > 50% seizure reduction, 24% of them have < 50% seizure reduction and 24% have no change (or even increase) in their baseline seizure frequencies. In this paper, indications for VNS and outcome and follow up the patients are discussed

Epilepsy and Military Service

The prevalence of epilepsy in Turkey was found to be 7 to 12.2 in 1000. If a mean prevalence of 10/1000 is accepted, according to the 2016 Turkish population census, there are about 134,000 epilepsy patients among men of military service age. Suitability for military service of epilepsy patients who are obliged to serve is determined by the Turkish Armed Forces, the Turkish Gendarmerie, and the Turkish Coast Guard Command Health Capability Ordinance (HCO). Men without disease or sequelae; or with disease or sequelae included in the “A” category of a list of diseases and sequelae are considered “fit for service.” Men with diseases or sequelae in the “B” and “D” categories are deemed “not fit for service.” Epilepsy disorders are reviewed in the 12th article of the HCO. In August 2016, military hospitals were assigned to the Ministry of Health. The authorization and responsibility to determine whether or not epilepsy patients and those with other disorders are fit for service now belongs to authorized hospitals affiliated with the Ministry of Health. The aim of this review was to offer some example templates as guidance to our colleagues performing this task