Objective: In presurgical evaluation, positron emission tomog-raphy with fluorodeoxyglucose-F18 (FDG-PET) is an important tool in identifying epileptogenic area. The aim of this study was to evaluate glucose metabolism in FDG-PET in patients with temporal lobe epilepsy (TLE) showing ‘switch-of lateral-isation’ (SL) and ‘bilateral asynchrony’ (BA) in ictal scalp EEG and compare their results with patients with TLE and none of these patterns. Methods: Twenty-four patients with TLE showing SL and/or BA in at least one of their seizures in video-EEG monitoring and 38 patients with TLE and without these patterns who had epilepsy surgery and a follow-up at least 5-years were included. The clinical, electrophysiological and imaging features were evaluated and a statistical comparison was performed between the groups. Results: Bilateral hypometabolism was more frequent in patients with SL and/or BA (39%) than in patients without these patterns (0%, p=0.040) in parallel with bilateral interictal epileptiform discharges and bilateral abnormalities in MRI. The pres-ence of unilateral or bilateral hypometabolism was not related to postsurgical outcome in patients with SL and/or BA. Conclusion: The possibility of low accuracy in the lateralisation of hypometabolism in FDG-PET might be interpreted cautiously in TLE with bilateral independent ictal activity like SL and BA.
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Objectives: Epileptogenesis is still not clearly understood. Therefore, there is an inevitable need for research that investigates triggers for reflex seizures and neuropsychological activation (NPA) methods using electroencephalography (EEG) in different epileptic syndromes. In this regard, we aimed to examine the characteristics and frequency of triggers for reflex seizures as well as changes in the frequency of epilepti-form discharges (EDs), according to the stimulus in patients with generalized genetic epilepsy (GGE) and drug- resistant focal epilepsy (FE) by performing a comparative study with a survey and a neuropsychological EEG activation method, besides routine EEG.Methods: A detailed and structured survey questioning seizure triggers was applied to patients with FE and GGE. Afterward, the changes in EDs in juvenile myoclonic epilepsy (JME), absence epilepsy (AE), and resistant FE groups were examined using NPA methods with EEG.Results: The most frequently reported triggers in all patient groups (n=66) were sleep deprivation (68.2%), stress (65.3%), fatigue/physical stress (53%), awakening (42.4%), and light stimuli (25.8%). There was no significant difference between the JME (n=34), AE (n=16), and resistant FE (n=16) groups in terms of either the triggering or inhibition of EDs in EEG by conventional activation and NPA methods. While the triggering of EDs occurred in 24% of patients by hyperventilation and in 18.1% of patients by intermittent photic stimulation, a similar triggering rate was detected in 21.2% of patients by NPA methods. In addition, while the results of the conventional EEG activation methods were negative, a triggered ED was observed in six patients during NPA (11%). Only two patients showed an inhibition by the NPA methods. Four patients had EDs on their EEGs during the NPA methods associated with triggers reported in the questionnaire.Conclusion: In 11% of patients, while an ED was not seen in conventional methods, we observed that ED triggering occurred with the NPA methods. Planning the NPA methods for specific triggers during EEG recordings by prior questioning on the seizure triggers of the patients and applying NPA as an additional triggering method, especially for patients who do not have EDs in EEG with standard activation methods, may be beneficial in terms of the correct diagnosis.
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Introduction: The present study is an examination of possiblesubclinical involvement of lower motor neuron (LMN) in patients withprimary lateral sclerosis (PLS) and hereditary spastic paraparesis (HSP)electrophysiologically.Methods: Nine PLS patients and 5 HSP patients were prospectivelyanalyzed. Jitter measurement with concentric needle electrode (25mm, 30 G) (CN-jitter) recorded from right extensor digitorum muscleduring voluntary contraction with 1 kHz high-pass frequency filter set.European Myelopathy Score (EMS) was used to evaluate disability. Therelationship between disability score and jitter values was investigated.Results: HSP patients had suffered from the disease for longer periodof time (p<0.001). Mean jitter values of patients with PLS and HSP were26.5±12.1 μs and 30.8±34.8 μs, and the number of individual high jitters(>43 microseconds) observed in the PLS and HSP groups was 16/180and 9/100, respectively without a significant intergroup difference. Theratio of patients with an abnormal jitter study were higher in HSP group(60%) compared to PLS (22%) (p<0.05). Potential pairs with blockingwere present in HSP group (7 of 100 potential pairs) but not seen in PLSpatients. EMS values were significantly lower in patients having potentialpairs with high jitter and blocking compared to those without high jitterand blocking.Conclusion: The present study has demonstrated that early signs ofLMN dysfunction can be detected electrophysiologically by CN-jitterin patients with UMN involvement. These electrophysiological findingsin these patients with longer disease duration and lower clinical scoresmay be explained by spreading of the disease to LMNs or transsynapticdegeneration and its contribution in disease progression.
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Objective: To decompose a part of the nerve action potential (NAP), mainly originating from large-myelinated sensory fibers, from mixed NAPs by using a stimulus with long duration during surface recordings.Materials and Methods: Median and ulnar mixed NAPs were elicited using submaximal stimulus intensities with 0.5 and 1.0-ms stimulus duration, which were adjusted to just below the threshold to activate motor fibers as detected visually through muscle twitch in hand muscles, by stimulating the median and ulnar nerves at the wrist and elbow and recording from the median and ulnar nerves at both the elbow and axilla, respectively. Healthy controls and patients with demyelinating neuropathy and/or motor conduction block were included in the study.Results: Mixed NAPs were recorded in 24 healthy subjects and three patients who had multifocal motor neuropathy (MMN), acute motor axonal neuropathy (AMAN), and ulnar entrapment neuropathy (UEN). Reference values were calculated in the healthy subjects. In patients with AMAN and MMN, mixed NAPs were normal, whereas in UEN, ulnar mixed NAPs had prolonged latencies.Conclusion: Mixed NAPs elicited by stimuli with long duration and low strength in the upper limbs can be used to detect sensory involvement at segments where motor conduction block exists and might help to classify demyelinating neuropathies.
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Bazı solunum yolu virüslerinin nörolojik tutulum yapabildiği uzunyıllardır bilinmektedir. Ne yazık ki, Aralık 2019’da ortaya çıkan ve akut ağırsolunum yetersizliği sendromuna yol açan yeni tip koronavirüs 2 (SARSCoV-2), diğer adıyla koronavirüs hastalığı 19 (COVID-19) ile artık nörolojikenvazyon potansiyeli olan virüsler grubuna yeni bir üyenin katıldığıgörülmektedir. Önüne geçilemeyen bir hızla tüm dünyada yayılmayadevam eden ve şimdiden milyonlarca insanı enfekte eden SARSCoV-2 ile ilişkili nörolojik semptom ve bulgulara gün geçtikçe yenilerieklenmektedir. Başağrısı, “dizziness”, bilinç bulanıklığı, ataksi, epilepsi,iskemik inme, nöropatik ağrı ve miyopatinin özellikle enfeksiyonun ağırseyrettiği olgularda daha sık olarak görüldüğü bildirilmektedir. Ayrıcaikincil nörolojik semptom gelişmesinin kötü sonlanım ile ilişkili olduğuda ifade edilmektedir. Öte yandan, çok sayıda SARS-CoV-2 taşıyıcısındaise tek semptomun koku duyusunda azalma olduğu ve bu semptomunhastalık belirteci olarak kabul edilebileceği ileri sürülmüştür. Kısacasıhafif semptomu olan ya da hastalığın ağır seyrettiği geniş spektrumda,SARS-CoV-2’nin direkt ve dolaylı mekanizmalar aracılığıyla bu nörolojiksemptomlara yol açabileceği düşünülmektedir. Bununla birlikte, birensefalit hastasının beyin omurilik sıvısında virüsün gen sekanslamasıile gösterilebilmesinin ardından, virüsün nöro-envazyon yapabildiğineve merkezi sinir sistemini enfekte edebildiğine yüksek olasılık olarakbakılmaya başlanmıştır. Sonuçta, salgının yükselme dönemini yaşamaktaolduğumuz dönemde, pandemi süresince en fazla karşılaşacağımızhastalığın olası nörolojik bulguları ile ilgili bilgi sahibi olmak değerlidir.Bu amaçla, literatürde SARS-CoV-2 ile ilişkilendirilmiş nörolojik tablolaraek olarak, yeni koronavirüsün yüksek oranda homoloji gösterdiği SARSCoV veya Ortadoğu solunum sendromu (MERS)-CoV gibi insandaenfeksiyona yol açan diğer koronavirüslere ilişkin literatürün de gözdengeçirilmesi ve salgının uzun dönem komplikasyonlarıyla ilgili fikir sahibiolunması amaçlanmıştır
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Objective: To investigate the effect of voluntary contraction atlow frequency repetitive nerve stimulation (RNS) as a sign of presynapticcompensation in patients with Myasthenia Gravis (MG).Material and Method: Thirty-five patients with MG were included.RNS at 3 Hz, recorded from the abductor digiti minimi, trapezius,nasalis, and orbicularis oculi muscles were performed. Inmuscles with more than 10% decrement, RNS at 1 Hz with 20-90stimuli was applied after 10-second maximal isometric voluntarymuscle contraction (MIVMC). Progressive decremental patternwas considered when decrement values were increasing untilthe last response. Facilitation after MIVMC was determined bydividing the amplitude of motor response in resting state by theamplitude of the motor response recorded just after contraction.Results: Among 15 patients having RNS at 1 Hz, nine had facilitationafter MIVMC. In the muscle with facilitation, there wasa significant positive correlation between the increment ratioand the progressive decrement difference between responses1-4 and 1-9 (correlation coefficient 0.730, p=0.026). Although notstatistically significant, muscles showing facilitation followingdecrement tended to have a progressive decremental pattern.Conclusion: During RNS, facilitation after MIVMC followed byprogressive decremental pattern may be related to presynapticcompensation of neuromuscular transmission failure in MG.
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