The invention provides a method and apparatus for performing selective hypothermia to the brain and spinal cord for injury protection without the need for systemic cooling. A flexible catheter is inserted into the cerebral lateral ventricle or spinal subdural space. The catheter has lumens with a heat transfer element. The lumens of the catheter circulate a coolant and communicate at the distal heat transfer element for transfer of heat from the cerebrospinal fluid. Furthermore a method of maintaining catheter patency and providing blood clot hemolysis and drainage is also provided through the use of ultrasonic and/or laser energy delivered through the catheter.