Effects of Transcranial Direct Current Stimulation on Clinical Outcomes, Calcitonin Gene-Related Peptide, and Pituitary Adenylate Cyclase-Activating Polypeptide-38 Levels in Menstrual Migraine.

OBJECTIVES: Transcranial direct current stimulation (tDCS) has been suggested as an alternative treatment option for migraine. The present study aimed to evaluate the efficacy of tDCS on clinical outcomes in addition to calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating peptide 38 (PACAP-38) levels in individuals with menstrual-related migraine (MRM) for the first time. MATERIALS AND METHODS: In this parallel study, 58 female patients between the ages of 18 and 45 years, including 36 with MRM and 22 with nonmenstrual migraines (nMM), were recruited. Sessions of 2-mA 20-minute anodal tDCS were administered over the left dorsolateral prefrontal cortex within three consecutive days (1:1 active and sham stimulation). Migraine attack frequency, severity, analgesic usage, CGRP, and PACAP-38 levels of the patients were evaluated before and one month after tDCS. RESULTS: After tDCS, in the active group compared with the sham group, the frequency (p = 0.031), the severity of attacks (p = 0.003), the number of days with headache (p = 0.004), and the analgesic usage (p = 0.024) were all decreased. In both MRM and nMM groups, the frequency and severity of attacks and analgesic usage were decreased in those receiving active stimulation (p < 0.001 for each). CGRP and PACAP-38 levels were no different in the active group and the sham group after tDCS. CONCLUSIONS: tDCS was shown to be efficacious in migraine prophylaxis and a valuable option for migraine and MRM treatment. The absence of changes in serum CGRP and PACAP-38 levels suggests that tDCS efficacy may stem from distinct cerebral electrophysiological mechanisms.

Acute effect of transcranial direct current stimulation on photoparoxysmal response.

INTRODUCTION: Transcranial direct current stimulation (tDCS) is a non-invasive technique, used to modify the excitability of the central nervous system. The main mechanism of tDCS is to change the excitability by subthreshold modulation by affecting neuronal membrane potentials in the direction of depolarization or repolarization. tDCS was previously investigated as an alternative adjunctive therapy in patients with epilepsy. We aimed here to investigate the acute effect of tDCS on the photoparoxysmal response (PPR) in EEG. METHODS: We enrolled 11 consecutive patients diagnosed with idiopathic generalized epilepsy who had PPR on at least 2 EEGs. Three different procedures, including sham, anodal, and cathodal tDCS were applied to the patients at intervals of one week by placing the active electrode over Oz, for 2 mA, 20 minutes. Spike-wave indices (SWI) were counted by two researchers independently and were compared during intermittent photic stimulation (IPS) on EEGs both before and after the application. RESULTS: After cathodal tDCS, SWI increased compared to baseline EEG and sham EEG in 3 patients, and after anodal tDCS, SWI increased in 2 patients. Although the SWI values did not change significantly, 8 patients reported subjectively that the applications were beneficial for them and that they experienced less discomfort during photic stimulation after the sessions. There were no side effects except transient skin rash in one patient, only. CONCLUSIONS: In our sham controlled tDCS study with both cathodal and anodal stimulation, our data showed that there was no significant change in SWI during IPS, despite subjective well-being. tDCS' modulatory effect does not seem to act in the acute phase on EEG parameters after photic stimulation.