Acta Neurochirurgica (2025) 167:180
This meta-analysis found that the lumbar infusion test (LIT) has poor negative predictive value for predicting non-response to shunting in normal pressure hydrocephalus. LIT cannot reliably exclude patients from shunt surgery and should not be used for this purpose in its current form.
• The lumbar infusion test (LIT) is used to predict which normal pressure hydrocephalus (NPH) patients will benefit from CSF shunting.
• This meta-analysis pooled sensitivity, specificity, and negative predictive value (NPV) of LIT from 10 studies.
• Sensitivity of LIT (using Rout) was moderate (77–82%) at lower cutoffs (12–14 mmHg/ml/min), but specificity was low (34–37%).
• Higher Rout cutoff (18 mmHg/ml/min) increased specificity (78%) but decreased sensitivity (37%).
• NPV was consistently low for all cutoffs (≤33%), meaning LIT is poor at ruling out shunt responders.
• No other LIT parameters (e.g., plateau pressure, CSF amplitude) showed better diagnostic value.
• The test cannot be used to exclude patients from shunt implantation due to high false negative rates.
• Future research should focus on improving the negative predictive value of LIT for NPH.
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