Diagnosing idiopathic normal-pressure hydrocephalus.
OBJECTIVE
The precise incidence and prevalence of idiopathic normal-pressure hydrocephalus (INPH) is not known, and evidence-based clinical diagnostic criteria have not been developed previously. This report contains evidence-based guidelines for clinical diagnosis of INPH that are intended to facilitate future epidemiological studies of INPH, promote earlier and more accurate diagnosis, and ultimately improve treatment outcome.


METHODS
The criteria for the diagnosis of INPH are based on evidence from the medical literature, supplemented as necessary by expert opinion. From 1966 to 2003, 653 publications on "normal-pressure hydrocephalus" were cited in MEDLINE, including 29 articles that met the more stringent criteria of including "idiopathic normal-pressure hydrocephalus" in their title. Additional studies were considered that explicitly identified INPH cases and/or specified the criteria for a diagnosis of INPH. Studies were graded according to the class of evidence and results summarized in evidentiary tables. For issues of clinical relevance that lacked substantive evidence from the medical literature, the opinions of consulting experts were considered and contributed to "Options."


RESULTS
Evidence-based guidelines for the clinical diagnosis of INPH have been developed. A detailed understanding of the range of clinical manifestations of this disorder and adherence to practice guidelines should improve the timely and accurate recognition of this disorder.


CONCLUSIONS
It is recommended that INPH be classified into probable, possible, and unlikely categories. We hope that these criteria will be widely applied in clinical practice and will promote greater consistency in patient selection in future clinical investigations involving INPH.
Relkin
Norman
N
Department of Neurology and Neuroscience, The New York Presbyterian-Weill Cornell Medical College, New York, New York, USA.
Marmarou
Anthony
A
Klinge
Petra
P
Bergsneider
Marvin
M
Black
Peter McL
PM
D001526:Behavioral Symptoms; D015170:Cerebrospinal Fluid Pressure; D002557:Cerebrospinal Fluid Shunts; D003072:Cognition Disorders / Q000209:etiology; D003952:Diagnostic Imaging; D019317:Evidence-Based Medicine; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000150:complications / Q000175:diagnosis* / Q000523:psychology / Q000601:surgery; D001523:Mental Disorders / Q000209:etiology; D009069:Movement Disorders / Q000209:etiology