The present invention relates to the treatment patient with a 4-repeat (4R) tauopathy using a therapeutically effect amount of a rho kinase inhibitor. One preferred inhibitor is fasudil and preferred methods involve the daily oral administration of between 20 and 250 mg of fasudil. Preferred 4R tauopathies treatable according to the invention include progressive supranuclear palsy with Richardson syndrome (PSP-RS) and corticobasal syndrome with probable sporadic corticobasal degeneration.