Parkinson's Disease and Gamma-transcranial Alternating Current Stimulation

Neuromed IRCCS84 enrolled

Overview

Cortical-basal ganglia gamma oscillations are pathologically reduced in Parkinson's disease (PD) and the plasticity of the primary motor cortex (M1) is impaired. Enhancing gamma oscillations through transcranial alternating current stimulation (tACS), a non-invasive neurophysiological tool that modulates cortical rhythms, can restore this alteration. However, whether tACS-related normalization of M1 plasticity results in positive clinical effects is unknown. Motor learning is also impaired in PD and gamma oscillations play a relevant role in different forms of learning in humans. Nevertheless, whether motor learning abnormalities relate to reduced gamma oscillations in PD is another unclear issue. It can be hypothesized that gamma oscillations impairment in M1 contributes to altered motor control, plasticity and learning in PD. Accordingly, in this project, the authors intend to test whether gamma-tACS on M1 in PD patients ameliorates motor performance and learning, as objectively assessed with kinematic techniques.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Conditions

Parkinson Disease

Interventions

Transcranial alternating current stimulation (tACS) will be delivered using a BrainSTIM (EMS, Italy) connected to two electrodes (5x5cm) enclosed in sponges soaked with saline solution. One electrode will be centred over the first dorsal interosseus (FDI) hotspot and the other over P3. tACS will be delivered at peak-to-peak amplitude of 1 milliampere (mA), and with 3-seconds ramp-up and down periods. The stimulation frequency will be 70 Hz, as representative of the endogenous motor network-related gamma frequency.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * PD diagnosis Exclusion Criteria: * severe cognitive and psychiatric comorbidities * H\&Y\>3 * levodopa-induced dyskinesia and tremor-dominant phenotype * history of additional neuropsychiatric disorders * intake of medications acting on brain excitability or plasticity * contraindications to non-invasive brain stimulation

Outcomes

Primary Outcomes

Changes in bradykinesia features as objectively assessed by kinematic techniques

The velocity of finger tapping movements will be kinematically measured and expressed in degrees/second.

Time frame: post 5, 15 and 30 minutes

Changes in motor learning performance as objectively assessed by kinematic techniques

The acceleration peak of finger index abductions will me kinematically measured and expressed as millimeters/seconds