Intraventricular or lumbar infusion test in adult communicating hydrocephalus? Practical consequences and clinical outcome of shunt operation.
BACKGROUND
To investigate the therapeutic consequences of restricting the CSF dynamic evaluation to a lumbar infusion test (LIT), as opposed to our formerly applied intraventricular assessment (VIT), in patients with communicating hydrocephalus (CH).


METHODS
All patients over 18 years of age referred with clinical and radiological indication of treatment-requiring secondary CH (n = 50) or idiopathic normal-pressure hydrocephalus (INPH, n = 33) were subjected to a LIT. Subsequently, a combination of the results of the LIT (mainly the resistance to CSF outflow) and the clinical presentation determined whether to proceed with (a) VIT before a decision about shunt surgery, (b) shunt surgery or (c) no further diagnostic investigation or surgery.


RESULTS
In 88 percent of the patients with secondary CH and 80 percent of the patients with INPH the decision on shunt surgery was made after performing exclusively a LIT. The shunting success rate was 90 percent in patients with secondary CH and 82 percent in patients with INPH, which however in the latter group decreased to 76 percent, when including the patients undergoing an additional VIT. The achieved shunt success rates are equal or better, compared to the results from previous studies using intraventricular assessment.


CONCLUSIONS
LIT and VIT are equally reliable for selecting shunt responsive patients with CH, using clinical improvement rate as the main criterion for comparison. The practical and economic consequences are substantial: the LIT can be performed in an outpatient setting, whereas VIT necessitates hospitalisation for 1-2 days including occupation of the neurosurgical theatre and postoperative neuro-intensive monitoring.
Bech-Azeddine
R
R
University Clinic of Neurosurgery, The Neuroscience Center, Rigshospitalet, H:S, Copenhagen, Denmark. rbechazeddine@dadlnet.dk
Gjerris
F
F
Waldemar
G
G
Czosnyka
M
M
Juhler
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology*; D002557:Cerebrospinal Fluid Shunts / Q000592:standards*; D003661:Decision Support Techniques; D003663:Decision Trees; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D006850:Hydrocephalus, Normal Pressure / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D019586:Intracranial Hypertension / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D007427:Intracranial Pressure / Q000502:physiology; D020547:Lateral Ventricles / Q000503:physiopathology*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011300:Preoperative Care / Q000379:methods* / Q000592:standards; D013129:Spinal Puncture / Q000379:methods / Q000592:standards; D013346:Subarachnoid Space / Q000503:physiopathology*; D016896:Treatment Outcome; D014696:Ventriculostomy / Q000379:methods / Q000592:standards