Browsing by Author "Uysal, Hilmi"

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    Abnormal subcortical activity in congenital mirror movement disorder with RAD51 mutation
    (2018) Demirayak, Pinar; Onat, Onur Emre; Gevrekci, Aslıhan Ors; Gulsuner, Suleyman; Uysal, Hilmi; Bilgen, Rengin; Doerschner, Katja; Ozcelik, Tayfun; Boyaci, Hueseyin; 30406765
    PURPOSE Congenital mirror movement disorder (CMMD) is characterized by unintended, nonsuppressible, homologous mirroring activity contralateral to the movement on the intended side of the body. healthy controls, unilateral movements are accompanied with predominantly contralateral cortical activity, whereas in CMMD, in line with the abnormal behavior, bilateral cortical activity is observed for unilateral motor tasks. However, task-related activities in subcortical structures, which are known to play critical roles in motor actions, have not been investigated in CMMD previously. METHODS We investigated the functional activation patterns of the motor components in CMMD patients. By using linkage analysis and exome sequencing, common mutations were revealed in seven affected individuals from the same family. Next, using functional magnetic resonance imaging (fMRl) we investigated cortical and subcortical activity during manual motor actions in two right-handed affected brothers and sex, age, education, and socioeconomically matched healthy individuals. RESULTS Genetic analyses revealed heterozygous RAD51 c.401C>T mutation which cosegregated with the phenotype in two affected members of the family. Consistent with previous literature, our fMRI results on these two affected individuals showed that mirror movements were closely related to abnormal cortical activity in M1 and SMA during unimanual movements. Furthermore, we have found previously unknown abnormal task-related activity in subcortical structures. Specifically, we have found increased and bilateral activity during unimanual movements in thalamus, striatum, and globus pallidus in CMMD patients. CONCLUSION These findings reveal further neural correlates of CMMD, and may guide our understanding of the critical roles of subcortical structures for unimanual movements in healthy individuals.
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    The Effects of Hyperventilation on Axonal Excitability Parameters in Patients with Diabetes Mellitus and Polyneuropathy
    (2016) Akca, Gokcen; Yerdelen, Deniz; Balci, Mustafa Kemal; Uysal, Hilmi; 0000-0002-6063-377X; 0000-0001-6799-5100; 0000-0002-6494-3249; 27368063; C-3651-2016; AAE-7933-2021; C-2979-2016
    Aims: We aimed to explore axonal excitability parameters in patients with diabetes mellitus (DM) and polyneuropathy (PNP) as well as those without PNP. Methods: We used the short TROND protocol by QTRAC to measure axonal excitability parameters (strength-duration time constant (SDTC), rheobase, etc.) in 12 healthy subjects and 14 DM patients with PNP and 10 DM patients without PNP. The short TROND protocol was performed before and after 20 min of deep hyperventilation in healthy subjects and patients with DM. Also, venous blood pH and partial pressure of O-2 and CO2 were recorded before hyperventilation (HPV) and after 20 min of HPV. A "hyperventilation score" was evaluated before and after HPV. Results: When the values of DM with PNP group and control group before HPV were compared, SDTC and latency were statistically significant. Comparing the values of the excitability parameters after HPV showed statistically significant changes in the SDTC, rheobase, and refractoriness at 2.5 ms in controls and DM patients without PNP. HPV resulted in no changes in SDTC in DM patients with PNP. Conclusion: The results of this study suggest that patients with DM and healthy subjects have different responses to HPV, and pH changes have different effects on diabetic PNP compared with healthy controls and DM patients without PNP. (C) 2016 Elsevier Ireland Ltd. All rights reserved.