Although neurological deficits from passing the EVD catheter across the brain are uncommon, there can be an association of a patient's poor neurological status with EVD malplacement.[14] In one report, the EVD was inserted too deeply into the fourth ventricle; the authors hypothesized that the patient's coma was due to irritation of the recticular activating system. The patient's level of consciousness improved after the EVD was adjusted.[14]