The invention provides pharmaceutical compositions comprising human immature dental pulp stem cells (hIDPSCs) wherein the hIDPSCs express CD44 and CD13. The invention also provides methods of treating a neurological disease or condition comprising systemically administering to a subject a pharmaceutical composition comprising hIDPSCs wherein the hIDPSCs express CD44 and CD13. For example, for treating neurological diseases or conditions including supporting the neuro-protective mechanism in subjects diagnosed with early HD or repairing lost DA neurons in subjects diagnosed with PD.