Increased intracranial pressure is associated with elevated cerebrospinal fluid ADH levels in closed-head injury.
OBJECTIVE
Head injury frequently results in increased intracranial pressure and brain edema. Investigators have demonstrated that ischemic injury causes an increase in cerebrospinal fluid (CSF) levels of antidiuretic hormone (ADH); increased CSF ADH levels exacerbate cerebral edema, and inhibition of the ADH system with specific ADH antagonists reduces cerebral edema. The current study was designed to test the hypothesis that elevated levels of ADH are present in the CSF of subjects with head injury.


METHODS
Ventricular CSF and blood samples were taken from 11 subjects with head injury and 12 subjects with no known head trauma or injury. ADH levels were analyzed using radioimmunoassay. Severity of increased intracranial pressure (ICP) was rated in head-injured subjects using a four-point ordinal scale, based on which treatments were necessary to reduce ICP.


RESULTS
Subjects with head injury had higher CSF (3.2 versus 1.2 pg/ml; P<0.02) and plasma (4.1 versus 1.4 pg/ml; P<0.02) levels of ADH than did control subjects. In head-injured subjects, CSF ADH levels positively correlated with severity of ICP.


CONCLUSIONS
The results of this study suggest that ADH plays a role in brain edema associated with closed head injury.
Widmayer
Marsha A
MA
Department of Neurosurgery, The Methodist Hospital, Houston, TX 77030, USA.
Browning
Jeffrey L
JL
Gopinath
Shankar P
SP
Robertson
Claudia S
CS
Baskin
David S
DS
D000328:Adult; D000368:Aged; D001929:Brain Edema / Q000097:blood / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D001930:Brain Injuries / Q000097:blood / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D002648:Child; D016489:Head Injuries, Closed / Q000097:blood / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D006801:Humans; D019586:Intracranial Hypertension / Q000097:blood / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009481:Neurophysins / Q000097:blood / Q000134:cerebrospinal fluid*; D011498:Protein Precursors / Q000097:blood / Q000134:cerebrospinal fluid*; D014667:Vasopressins / Q000097:blood / Q000134:cerebrospinal fluid*
C438657:AVP protein, human; D009481:Neurophysins; D011498:Protein Precursors; D014667:Vasopressins