Pressure changes within a chronic subdural hematoma during hemodialysis

Spontaneous intracranial hemorrhage is not an infrequent complication of systemic anticoagulation, as occurs in hemodialysis. The neurological symptoms of subdural hematoma may be similar to those of dialysis disequilibrium. The pressure within a subdural fluid collection was monitored in a patient undergoing hemodialysis. The patient was known to become unresponsive during previous dialysis treatments. The initial pressure within the subdural cavity was measured to be -10.0 cm H2O prior to dialysis. The pressure within the collection decreased to a minimum value of -19.4 cm H2O during dialysis and stabilized at -16.4 cm H2O at the termination of dialysis. The neurological status changed subjectively during the procedure, with the patient becoming unresponsive to verbal stimuli as the intracranial pressure reached a minimum. These findings represent a syndrome similar to aliquorrhea, or low cerebrospinal fluid pressure within an otherwise asymptomatic subdural hematoma. Previously only increased intracranial pressure has been reported with hemodialysis.