Related Experiment Video
Updated: Aug 18, 2026

Neuronavigation and Laparoscopy Guided Ventriculoperitoneal Shunt Insertion for the Treatment of Hydrocephalus
Published on: October 14, 2022
Lumbar infusion test in normal pressure hydrocephalus
B Kahlon1, G Sundbärg, S Rehncrona
1Department of Neurosurgery, University Hospital, Lund, Sweden. babar.kahlon@neurokir.lu.se
Objective:
To compare potential clinical value of plateau pressure (P(pl)), resistance to outflow (R(out)), pulse-pressure amplitude (P(plA)) and rate of pressure increase (v(P)), taken from the constant rate lumbar infusion test (LIT), as predictors for the outcome of shunt surgery.
Methods:
Recordings from preoperative LIT in 55 patients were scrutinized for the values of P(pl), P(plA), v(P) and R(out). Gait, memory, spatial capacity and reaction ability were tested before and 6 months after shunt surgery.
Results:
Forty-three (78%) of the patients improved. There were no statistically significant differences in P(pl), R(out), P(plA) or v(P) between improved and not improved patients. Five patients with P(pl) below 22 mmHg (the cut off level) improved after shunting, while 16 and eight patients with R(out) below the cut off levels of 18 and 14 mmHg/ml/min improved. P(plA) correlated with P(pl) and R(out) (r = 0.74 and 0.63, respectively). In the group of patients with high P(plA) (>/=20 mmHg) as many as 93% improved but a high P(plA) did not recruit more improved patients than P(pl) or R(out) alone.
Conclusion:
v(P) or P(plA) does not add useful information to P(pl) for selecting patients with suspected NPH for surgery. R(out) calculations from LIT does not provide advantage over using the steady-state plateau pressure for selecting patients for surgery and may increase the risk of missing patients who should benefit from surgery.
Related Concept Videos
Increased Intracranial Pressure l: Introduction
Increased Intracranial Pressure ll: Pathophysiology
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies
