Parkinson’s disease (PD) is associated with pathologically altered oscillatory activity. tACS
April 28, 2017
Parkinson’s disease (PD) is associated with pathologically altered oscillatory activity. tACS of the contralateral M1 at 10 Hz vs. 20 Hz vs. sham. During isometric contraction neuromagnetic activity was recorded using magnetoencephalography. 20 Hz tACS attenuated beta band CMC during isometric contraction and amplitude variability during finger tapping in PD patients but not in healthy control subjects. 10 Hz tACS yielded no significant after-effects. The present data suggest that PD is usually associated with pathophysiological alterations which abet a higher responsiveness toward frequency-specific tACS – possibly due to pathologically altered motor-cortical oscillatory synchronization at frequencies between 13 and 30 VX-950 Hz. motor score (UPDRS III). Mean UPDRS III score medication was 19.8 ± 3.2 (range: 6-30). Motor control of the more severely affected hand and underlying neuromagnetic activity were assessed prior to and shortly (i.e. 5 min) after tACS (10 Hz vs. 20 Hz vs. sham) of the M1 contralateral to the more severely affected hand. Sessions of 10 Hz vs. 20 Hz vs. sham tACS were separated by at least 1 week in order to avoid carry-over effects. In five patients (three male two female) the right hand was affected more severely and tACS was applied above the contralateral left M1. In five patients (two male three female) the left hand was affected more seriously and the contralateral right M1 was stimulated. All patients participated medication to control for floor effects in the recorded parameters. Medical treatment comprised dopamine agonists and MAO-B-inhibitors. Mean comparative daily L-Dopa dose was 270.9 ± 123.7 mg. Prior to experimental inclusion by default patients had undergone a detailed neurological examination in the Department of Neurology Heinrich-Heine-University including Rabbit polyclonal to PBX3. neuropsychological screening and routine laboratory assessments. General exclusion criteria were clinically manifest depressive disorder or dementia increased disposition for convulsions and seizures metal implants cardiac or brain pacemaker or other severe neurological psychiatric or internal diseases. CONTROL SUBJECTS In order to elucidate whether tACS after-effects observed in patients are specific to PD 10 healthy subjects (five male; imply age 47.8 ± 4.3 years) were included in the study. Control subjects were matched to the patient group with respect to age gender and performing hand. All subjects provided written informed consent prior to study participation and fulfilled the general inclusion criteria. The control group received 20 Hz tACS only administered in one single session with the same activation parameters as PD patients. The order of motor tasks was counterbalanced across subjects. DESIGN Neuromagnetic activity was recorded for 8 min using magnetoencephalography (MEG) during isometric contraction and rest of the VX-950 more severely affected forearm while subjects were seated in the magnetically shielded room (MSR). Outside the MSR subjects performed dynamic fast finger tapping and diadochokinesia for 12 s respectively. Subsequently subjects received a 15 min tACS of the M1 contralateral to the performing more severely affected hand outside the MSR. Shortly (i.e. 5 min) after tACS termination subjects performed the same tasks while neuromagnetic activity and movement characteristics were recorded. Order of tACS (10 Hz vs. 20 Hz vs. sham) and movement tasks was counterbalanced across subjects and sessions but remained constant within one session. The study design is usually schematically illustrated in Physique VX-950 ?Figure11. Physique 1 Experimental design. Isometric contraction during MEG and fast finger tapping/diadochokinesia were investigated prior to and shortly after tACS. PD patients attended three individual VX-950 sessions (10 Hz vs. 20 Hz vs. sham) control subjects received 20 Hz tACS … NEUROMAGNETIC RECORDINGS VX-950 – ISOMETRIC CONTRACTION Neuromagnetic activity was recorded using a 306 channel whole head MEG system (Elekta Neuromag Oy Helsinki Finland) during periods of isometric contraction and relaxation i.e. rest. To this end subjects were seated in a MSR while performing the task. The arms rested on a pad fixed to the chair. Immediately before MEG data acquisition individual maximum contraction strength was.