Publications by authors named "Barıs İsak"

Objective: Recent evidence indicated that amyotrophic lateral sclerosis (ALS) also impairs spinal circuits, including those mediating cutaneous silent period (CSP). However, most studies utilised surface electromyography (sEMG), which needs more resolution to pinpoint changes at the single motoneuron level. We aimed to investigate CSP properties using single motor unit discharges in ALS.

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Article Synopsis
  • - The study investigates the presence of axonal spheroids in motor axons and C-fibers of patients with amyotrophic lateral sclerosis (ALS) using corneal confocal microscopy and skin biopsies.
  • - It involved 31 ALS patients and 20 healthy subjects, measuring various nerve fiber metrics and dendritic cell density, revealing that ALS patients had more axonal spheroids and higher dendritic cell density compared to controls.
  • - The findings suggest that analyzing dendritic cells and axonal structures in ALS patients may help understand the disease's mechanisms and identify potential biomarkers for diagnosis or monitoring.
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Objective: Previous studies have identified autonomic dysfunction in amyotrophic lateral sclerosis (ALS) using mostly neurophysiological techniques. In this study, stereological evaluation of autonomic fibers and sweat glands has been performed to identify structural evidence of autonomic denervation in patients with ALS.

Methods: In this study, 29 ALS patients were compared to 29 controls using COMPASS-31 questionnaire, sympathetic skin response (SSR), and heart rate variability (HRV) at rest.

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Objective: In patients with chemotherapy-induced peripheral neuropathy (CIPN), demonstration of small fibre (SF) damage is important to understand chronic late effects.

Methods: Thirty patients having complaints compatible with possible CIPN following treatment with oxaliplatin or docetaxel were compared with 27 healthy subjects. All subjects were evaluated with quantitative sensory testing (QST) assessing SF function and laser evoked potentials (LEP).

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Background: The pattern of lower motor neuron (LMN) degeneration in amyotrophic lateral sclerosis (ALS), i.e., dying-back (from the nerve ending to cell body) or dying-forward (from the cell body to nerve ending), has been widely discussed.

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Objectives: Amyotrophic lateral sclerosis (ALS) disrupts motoneurons that control movement and some vital functions, however, exact details of the neuronal circuits involved in ALS have yet to be fully endorsed. To contribute to our understanding of the responsible neuronal circuits, we aimed to investigate the spinal recurrent inhibition (RI) and post-activation depression (P-AD) in ALS patients.

Methods: In two groups of ALS patients, i.

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The last decade has proven that amyotrophic lateral sclerosis (ALS) is clinically and genetically heterogeneous, and that the genetic component in sporadic cases might be stronger than expected. This study investigates 1,200 patients to revisit ALS in the ethnically heterogeneous yet inbred Turkish population. Familial ALS (fALS) accounts for 20% of our cases.

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Purpose: This study aims to determine the intrarater and interrater reliability of the Heckmatt score in the upper extremity muscles in patients with amyotrophic lateral sclerosis and to investigate its relationship with the clinical features and quantitative echo intensity measurements.

Methods: The Heckmatt scores of multiple upper extremity muscles were calculated in 28 patients with amyotrophic lateral sclerosis and examined the relationships of these values with quantitative ultrasound (QUS) measurements and the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised.

Results: The Heckmatt scores showed strong intrarater and interrater correlations with Cohen's Kappa scores ranging from 0.

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Objective: To determine symptoms and characteristics of chronic sensory neuropathy in patients treated with oxaliplatin and docetaxel, including patterns of somatosensory abnormalities, pain descriptors, and psychological functioning.

Design: A retrospective cross-sectional study.

Setting: A chronic pain research center.

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Objective: The electrodiagnosis of polyneuropathy (PNP) may benefit from examination using near-nerve needle technique (NNT) and from inclusion of distal nerves. This study compared the diagnostic utility of distal nerve conduction studies (NCS) and NNT recording.

Methods: Bilateral NNT and surface recording of the sural nerve and surface recording of the dorsal sural and medial plantar nerves were prospectively done in 91 patients with clinically suspected PNP.

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Objective: In this prospective study, involvement of sensory nerve fibres in ALS patients was assessed using functional and structural measures in the form of quantitative sensory testing (QST) and skin and nerve biopsies.

Methods: Thirty-two ALS patients and 32 healthy subjects were evaluated with a QST battery comprising thresholds of mechanical detection, mechanical pain, vibration detection, cold detection, warm detection, heat pain, and pinprick sensation. Skin biopsies were evaluated in 31 ALS patients by intraepidermal nerve fibre density (IENFD) and axonal swelling ratios, and growth-associated protein 43 (GAP-43) antibody staining.

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Objective: Mild involvement of sensory nerves has been reported in previous studies in ALS patients. In this study, we assessed sensory pathways in ALS patients using laser evoked potentials (LEPs) and somatosensory evoked potentials (SSEPs).

Methods: We recruited 18 ALS patients and 31 healthy subjects.

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Introduction: The diagnostic criteria for amyotrophic lateral sclerosis (ALS) require normal sensory nerve conduction studies (NCS) or abnormal NCS only in the presence of neuropathy of identified etiology. In this study, we investigated the presence and extent of involvement of Aß sensory fibers in ALS.

Methods: Distal sensory NCS [antidromic dorsal sural (DS) and orthodromic medial plantar (MP)] and conventional sensory NCS (unilateral median sensory and bilateral sural nerves) were performed in 16 definite and 2 probable ALS patients (based on Awaji criteria) and 31 controls.

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Objective: To investigate the cutaneous silent period (CSP), a spinal inhibitory reflex mainly mediated by A-delta fibres, in demyelinating and axonal polyneuropathy (PNP) and evaluate whether CSP parameters differ between patients with and without neuropathic pain.

Methods: Eighty-four patients with demyelinating PNP, 178 patients with axonal PNP and 265 controls underwent clinical examination, DN4 questionnaire, standard nerve conduction study, motor-root stimulation and CSP recordings from abductor digiti minimi. We calculated the afferent conduction time of CSP (a-CSP time) with the formula: CSP latency-root motor evoked potential latency.

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Objective: This study aimed to assess palmar cutaneous branch of the median nerve (PCBm) conduction in patients with clinically diagnosed carpal tunnel syndrome (CTS), to compare PCBm conduction with that of the median and ulnar nerves, and to determine the PCBm conduction abnormality rate in patients with CTS.

Materials And Methods: The study included 99 hands of 60 patients with clinical CTS and 38 hands of 38 healthy controls. Sensory nerve conduction study (NCS) was performed on the median nerve, ulnar nerve, and PCBm, and onset latency, conduction velocity and amplitude were recorded.

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Objective: To investigate the F wave parameters (F duration, F minimum latency, F maximum latency, F mean latency, F chronodispersion, and F persistence) of the tibial nerve with unilateral S1 radiculopathy. We evaluated the differences of these parameters between the affected and unaffected sides and also with the control group.

Methods: The study was performed from September 2007 to January 2008 in the Electrophysiology Laboratory of Marmara University Medical Faculty, Istanbul, Turkey.

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Established electrophysiological methods have limited clinical utility in the diagnosis of small-fiber neuropathy (SFN). In this study, diabetic patients with clinically diagnosed SFN were evaluated with autonomic tests and cutaneous silent periods (CSPs). Thirty-one diabetic patients with clinically suspected SFN and normal nerve conduction studies were compared with 30 controls.

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An association between small fiber neuropathy and primary Restless Legs Syndrome (RLS) is suggested since both of them share common characteristics. Our aim was to investigate the existence of autonomic neuropathy on the basis of autonomic tests. The patients and the age-matched controls were evaluated with Neuropathy Symptom Profile and Autonomic Symptom Profile, nerve conduction studies (NCS), and autonomic tests.

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Objective: It is generally accepted that F-wave duration (FWD) and the cutaneous silent period (CSP) are influenced by diminished central inhibition. The aim of this study was to diagnose patients of restless legs syndrome (RLS) with the help of FWD and/or CSP parameters.

Methods: In all, 24 patients with primary RLS were compared with 31 age- and sex-matched controls.

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Pandysautonomia is a severe and rare clinical condition characterized by widespread sympathetic and parasympathetic dysfunction. Consideration of whether symptoms and presentation are acute, subacute, or chronic is often helpful in establishing a differential diagnosis. The underlying mechanisms leading to pure pandysautonomia are unclear; however, there is some evidence suggestive of an immune-mediated pathogenesis.

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We present a 19-year-old female patient complaining of hoarseness and eyelid drooping. The neurological examination and laboratory investigations including genetic, radiological and electrophysiological evaluations were consistent with a juvenile-onset, predominantly bulbar, motor neuron disease with sensorineural hearing loss. The syndrome fulfilled the diagnostic criteria of Madras Motor Neuron Disease (MMND).

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Background: We have aimed to investigate the presence of peripheral and autonomic neuropathy in individuals who had been diagnosed with impaired glucose tolerance (IGT) on the basis of an oral glucose tolerance test, by comparing with age-matched healthy subjects with an oral glucose tolerance test (OGTT) in normoglycemic ranges.

Material And Methods: Conventional nerve conduction studies, heart rate variation variability, heart rate response to deep breathing, heart rate response to valsalva maneuvre, blood pressure response to standing up quickly, hand grip test and sympathetic skin response tests were used to evaluate the IGT and the control subjects.

Results: No obvious statistical difference indicating peripheral neuropathy and/or cardiac autonomic neuropathy was detected between patient group and controls.

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Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is a recently described disorder with autosomal recessive mode of inheritance. Lately, mutations in the DARS2 gene, which encodes mitochondrial aspartyl-tRNA synthetase, have been found as the underlying defect. We report a 19-year-old male patient with cerebellar, pyramidal and dorsal column dysfunctions and specific magnetic resonance imaging (MRI) and characteristic magnetic resonance spectroscopy (MRS) abnormalities.

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Objective: Clinical utility of nerve conduction studies (NCS) of the medial plantar and dorsal sural nerves in the early detection of polyneuropathy have already been shown separately. However, at present, there is no data about the combined assessment of these two nerves in distal sensory neuropathy. In the present study, we aimed to evaluate the medial plantar and dorsal sural NCS in a group of diabetic patients with distal sensory neuropathy (DSN) and in healthy controls.

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