ID 321 – Is intraepidermal nerve fiber density a reliable biomarker of progression in painful and painless diabetic polyneuropathy?

e108

Abstracts / Clinical Neurophysiology 127 (2016) e18–e132

ID 285 – Involvement of A-beta sensory fibres in amyotrophic lateral sclerosis—B. Isak a, H. Tankisi a, B. Johnsen a, K. Pugdahl a, N. Brix Finnerup b, A. Torvin Møller c, P. Brøgger Christensen c, A. Fuglsang-Frederiksen a (a Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark, b Danish Pain Research Center, Aarhus University Hospital, Aarhus, Denmark, c Department of Neurology, Aarhus University Hospital, Aarhus, Denmark) Background: Detection of any sensory abnormality in nerve conduction studies (NCSs) usually leads the physician to exclude amyotrophic lateral sclerosis (ALS). However, increasing evidence suggested that ALS is a multisystem disorder that also involves the sensory nerves. Objective: In this study we wanted to see if proximal and distal large diameter sensory nerves were deteriorated in ALS. Methods: 15 definite-ALS patients and 27 healthy subjects were evaluated based on distal sensory NCSs [i.e., antidromic dorsal sural (DS) and orthodromic medial plantar (MP)] in addition to standardized proximal sensory NCSs [i.e., unilateral median sensory and bilateral sural (SU) nerves]. Also, somatosensory evoked potentials (SEPs) in upper (UE-) and lower extremities (LE-) were recorded. Results: ALS patients had abnormal DS-NCSs (9 patients bilaterally and 3 patients unilaterally) and MP-NCSs (6 patients bilaterally and 1 patient unilaterally) while median sensory- and right SU-NCS were abnormal in 1 and 4 patients, respectively. Also, UE- and LE-SEPs were abnormal in 5 and 7 patients, respectively. Conclusions: Distal sensory NCSs probably deteriorate earlier and more than proximal sensory NCSs in ALS. Key message: A-beta sensory fibers are involved as well as corticospinal fibers in ALS. doi:10.1016/j.clinph.2015.11.363

ID 293 – Evaluation of cognitive functions, electrophysiological findings brain mr and in myotonic dystrophy type 1: Retrospective analyses—A. Bajrami, F. Azman, V. Yayla, S. Çag˘ırıcı, B. Arslan, N. Sözer Topçular (Bakırköy Dr. Sadi Konuk Training and Research Hospital, Neurology Department, Turkey) Objective: Myotonic dystrophy type 1 (DM1) is a progressive multisystemic disease with common cognitive deficits and potential brain involvement beside the cardinal muscular symptoms. In this study, we evaluated the relationship between cognitive functions and cranial MRI findings in DM1 patients. Methods: Clinical, electrophysiological and radiological data of 16 DM1 patients were evaluated. A comprehensive analysis of whitematter hyperintense lesions (WMHL) and brain atrophy detected by 3T MRI was performed. Cognitive impairment was assessed by an extensive neuropsychological battery. Results: The age range of 16 (11M/5F) patients was 19-55 years. EMG showed myotonia and myopathic MUPs in all patients. Mild cognitive impairment was detected in 72% of the patients. WMHL was present in 55% and mild cognitive impairment was prominent in patients with temporal involvement. The severity of cognitive dysfunction was correlated by early onset of myotonia but not with clinical findings or sex. Conclusions: The nature of CNS abnormalities revealed by MRI is still unclear: the ones located at the temporal poles seem to be characteristics of the disease, while small, diffuse WMHLs are similar to the age related alterations.

Key message: Our results indicate that the white matter abnormalities shown by neuroimaging might have implications for cognitive function. doi:10.1016/j.clinph.2015.11.364

ID 309 – Clinical, electrophyisological and serological evaluation of patients with cramp-fasciculation syndrome—M. Poyraz a, Z. Matur b, F. Aysal a, E. Tüzün c, L. Hanog˘lu a, A.E. Öge d (a Dept. of Neurology, Istanbul Medipol University, Medical Faculty, Turkey, b Dept. of Neurology, Istanbul Bilim University, Medical Faculty, Turkey, c Dept. of Neuro Science, Istanbul University, Institute of Experimental Medicine, Turkey, d Dept. of Neurology, Istanbul University, Istanbul Faculty of Medicine, Turkey) Objective: Cramp-fasciculation syndrome (CFS) is a rare peripheral nerve hyperexcitability syndrome. There is little information on the clinical and serological profile of a CFS cohort followed by a single outpatient clinic. Method: Clinical, electrophysiological and serological features of 6 CFS patients (5men/1woman, 27-61years-old) were investigated. Results: All patients presented with cramps, fasciculations, muscle pain and autonomic symptoms, while two of them also reported numbness and burning sensation in the limbs which was reminiscent of neuropathic pain. Nerve conduction studies and RR interval variability tests revealed normal results. Sympathetic skin responses were increased in amplitude, and prolonged after-discharges were recorded from the foot muscles after tibial nerve stimulation in all the patients. Antibodies to voltage-gated potassium channel (VGKC)-complex proteins were found in 3patients, one of whom was also positive for contactin-associated protein-like2(CASPR2) antibody. Two patients with neuropathic pain displayed nonCASPR2 VGKC-complex antibodies. None of the patients had a malignancy. Five patients showed favorable response to carbamazepine or pregabalin treatment, whereas one VGKC-antibody positive patient was resistant to carbamazepine and immunosuppressant treatment. Conclusion: Autonomic symptoms, neuropathic pain and VGKCcomplex antibodies are commonly found in CFS patients. Key message: VGKC-complex antibody positivity might be an indicator of neuropathic pain and resistance to treatment in CFS. doi:10.1016/j.clinph.2015.11.365

ID 321 – Is intraepidermal nerve fiber density a reliable biomarker of progression in painful and painless diabetic polyneuropathy?— J. Bednarik a,b, S. Divisova a,b, E. Vlckova a,b, I. Srotova a,b, S. Kincova a,b, M. Skorna a,b, L. Dusek c, P. Dubovy d (a Central European Institute of Technology, Applied Neuroscience Research Group, Masaryk University, Brno, Czech Republic, b Department of Neurology, University Hospital and Masaryk University Brno, Czech Republic, c Institute of Biostatistics and Analyses, Masaryk University Brno, Czech Republic, d Central European Institute of Technology, Cellular and Molecular Biology Research Group, Masaryk University Brno, Czech Republic) We aimed to confirm usefulness of intraepidermal nerve fiber density (IENFD) as a marker of progression of diabetic polyneuropathy (DPN) in patients with early type 2 diabetes mellitus (DM2).

Abstracts / Clinical Neurophysiology 127 (2016) e18–e132

In a group of 23 healthy subjects (median age 57 years, 14 men) and 30 DM2 patients (median age 60 years, 17 men) we serially evaluated skin biopsies from distal leg. Eighteen DM2 patients complied with the criteria of symptomatic diabetic polyneuropathy (DPN) and 12 had no neuropathy (nDPN). Time interval between biopsies were >2 years (median, range: 29.6, 24.7–58.4, and 33.8, 25.5–54.1 months in controls and DM2 patients, respectively). At first skin biopsy, the IENFD was normal in all controls and nDPN patients compared to abnormal IENFD in 77.8% of DPN patients. Drop in IENFD expressed as a proportion of the 1st IENFD value in % per year in both painful and painless DPN patients was significantly higher (11.95[3.82]%/year, p < 0.001) compared to control subjects (1.92[1.81]) and similar to DM2 patients without DPN (12.16[4.38]). In conclusion, decrease in IENFD values in early DM2 patients is about 12% of the initial IENFD value irrespective of symptoms and/ or signs of DPN at initial evaluation and several times quicker compared to healthy subjects. doi:10.1016/j.clinph.2015.11.366

e109

Objective: To estimate the jitter parameters in confirmed myasthenia gravis (MG) in stimulated Extensor Digitorum (ED) and Frontalis (FR) using concentric needle electrode (CNE). Methods: 57 MG patients, 31 male, mean age 47.7 ± 16.6 years, 10 ocular and 47 generalized, were studied. Jitter was expressed as the mean consecutive difference (MCD). Upper limit of normality (ED and FR) was set to 24 and 21 ls for mean MCD and 35 and 28 ls for individual MCD values. Acetylcholine receptor antibody (AChRAb) was measured together with the jitter studies. Repetitive nerve stimulation (RNS) results were taken from the patients file. Results: Mean MCD (ED and FR) was abnormal in 89.4% and 91.5% (generalized) and 70% and 60% (ocular). Percentage of outliers (ED and FR) was abnormal in 89.4% and 91.5% (generalized) and 50% and 70% (ocular). Some jitter parameters were abnormal in 91.5% (generalized) and 80% (ocular). AChRAb was abnormal in 91.5% (generalized, mean 10.96 nmol/L) and in 60% (ocular, mean 2.75 nmol/L). RNS in different hand, arm and facial muscles was abnormal in 93.5% (generalized) and 40% (ocular). Conclusions: Stimulated jitter recordings measured from CNE can be used for MG diagnosis with a high sensitivity, mainly for ocular form. doi:10.1016/j.clinph.2015.11.368

ID 392 – Subclinic reinnervation in periocular muscles: High jitter values in diabetic polyneuropathy—L. Baysal Kirac, E. Kocasoy Orhan, M.B. Baslo (Department of Neurology and Clinical Neurophysiology, Istanbul University, Istanbul Faculty of Medicine, Turkey) Objective: The aim of this study was to assess jitter abnormalities in periocular muscles of patients with diabetic polyneuropathy (DPN). Methods: Twenty patients (9 F, 11 M; mean age 57.6 ± 10 years) who suffered from moderate and severe DPN were included in the study. Jitter values were assessed in 20 different pairs of voluntarily activated frontalis muscle using 25 mm concentric needle electrode with 1 kHz low-cut filtering. ‘‘Peak counts” were calculated as the number of electronegative peaks firing together with the triggering potential during jitter analysis in 20 different needle positions. Results: For the frontalis muscle the mean jitter of all potential pairs was 30.9 ± 27.6 ls (8 226 ls). The number of abnormal jitter values (P55 ls) were 40 out of 400 jitters (10%). Twenty-two of them were calculated from the traces harbouring 3 or more singlefiber like potentials which could be an indicator for reinnervation with collateral sprouting. Five out of 20 patients (25%) had more than two individual abnormal jitter values. The mean value of peak count was 2.4. Conclusions: Increased jitter in frontalis muscle of patients with DPN is considered a function of reinnervation. Key message: In diabetes frontalis muscle may exhibit jitter abnormalities. doi:10.1016/j.clinph.2015.11.367

ID 376 – Concentric needle jitter in 57 myasthenia gravis patients—J.A. Kouyoumdjian a, E. Stålberg b (a Investigation Neuromuscular Laboratory, Faculdade de Medicina de São José do Rio Preto (FAMERP), São Paulo, Brazil, b Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden)

PS-04-01 Neurological and psychiatric diseases III

ID 41 – High Reward Sensitivity as a biomarker of online gambling. A multi-method study on gambling behaviour— R. Finocchiaro a,b, A. Pecoraro b, M. Balconi a,b (a Research Unit in Affective and Social Neuroscience, Catholic University of Milan, Italy, b Department of Psychology, Catholic University of Milan, Italy)

Objective: The present research explored the main risky factors that can influence subjects’ choices during the decisional process in an online game context. We supposed that reward bias, metacognitive deficit and personality trait make subjects’ strategies more disadvantageous and ‘‘gambling”. Methods: Twenty-one subjects were tested using the IGT and GO/noGo task while the EEG was registered and alpha-band modulation were considered. Secondly, the Behavioral Activation System (BAS)/Behavioral Inhibition System (BIS) scale was use for testing the effect of reward sensitivity and metacognitive questionary was applied. Results: It was found that high-BAS subjects increased their tendency to opt in favour of the immediate reward rather than the long-term option, they tend to have difficulties to inhibit the automatic response, and they show a dysfunctional metacognition abilities. Finally, high-BAS subjects showed an increased left-hemisphere activation in response to immediate reward choices if compared to low-BAS subjects. Conclusions: A reward bias effect was supposed to explain both the bad strategy and the unbalanced hemispheric activation for highBAS and more risk-taking subjects. Key message: These findings could have important repercussions in the social context for the prevention of dysfunctional behaviours that affect compulsive disorders like addiction. doi:10.1016/j.clinph.2015.11.369