Improvement of Apraxia and Hand Function with Transcranial Direct Current Brain Polarization in Patients with Corticobasal Degeneration

ABSTRACT

OBJECTIVE: To see whether anodal direct current (DC) polarization of the inferior parietal cortex (IPC) and the primary sensorimotor area (SM1) in corticobasal degeneration (CBD) patients leads to improvement of praxia and finger motion. METHOD: Twelve patients with CBD were enrolled. This single blind crossover study had three arms, anodal DC to IPC, anodal DC to SM1, and shame polarization on occipital area. DC was delivered for 40 minute at 2 mA with 25 cm2 sponge electrodes. Before and 20 min after the start of polarization, we performed the test of oral and limb apraxia (TOLA), finger tapping frequency, and grooved pegboard test. RESULTS: The total score of TOLA was increased 5.4+/-2.3% after anodal DC to IPC. The scores of limb apraxia and picture gesture subtests of TOLA, not of oral apraxia subtest, increased significantly after anodal DC to IPC compared to sham DC polarization (p<0.05). In anodal DC to SM1 group, the finger tapping frequency increased 15.5+/-14.1%, which was significantly greater than in sham group (p<0.05). CONCLUSION: These results showed beneficial effects of anodal DC polarization on apraxia and hand function in CBD patients. In addition, these effects for apraxia and hand movement were dependent on their stimulation sites of brain.