Cortical excitability in CBS patients.

Some CBS patients had a relatively inexcitable motor cortex and transcranial magnetic stimulation measures could not be determined. The remaining CBS patients had evidence of cortical excitability, characterized by reduced peak and average SICI, and increased motor evoked potential amplitude expressed as a percentage of compound motor action potential amplitude. CBS = corticobasal syndrome, RMT = resting motor threshold, SICI = short-interval intra-cortical inhibition, MEP = motor evoked potential, CSP = cortical silent period. *P-value calculated using the Chi-Square test for 2×3 table (i.e. CBD/Control v Inexcitable/50%)