QuantalX Neuroscience has announced the publication of a follow-up study in Fluids and Barriers of the CNS confirming the potential of measurements made by its Delphi-MD device as predictors of sustained clinical response for more than 12 months after ventriculoperitoneal shunting (VPS) in patients with normal-pressure hydrocephalus (NPH).
In the study, conducted at the Sheba Medical Center (Ramat Gan, Israel), 41 patients with possible idiopathic NPH (iNPH) underwent Delphi-MD evaluation of waveform adherence (WFA)—a composite measure assessing how closely their transcranial evoked potentials (TEPs) resembled an ideal benchmark TEP. Of these, 18 patients received VPS treatment following a multidisciplinary team decision based on standard practice that was blinded to the TEP results.
Response to the intervention was evaluated over a period of more than one year, from 12–18 months, using the clinical global impression of change (CGI-C) scale, in addition to assessments with a 10-metre ‘timed up and go’ (TUG) test and the modified Rankin scale (mRS). Based on previous findings, this study aimed to test the hypothesis that left primary motor cortex (M1L) stimulation may be sufficient to identify iNPH patients likely to demonstrate sustained gait improvement following VPS.
Using a binary cutoff at baseline, the neurophysiological measures obtained by Delphi-MD were able to predict patients who would respond to VPS after more than one year of follow-up. The prediction demonstrated a sensitivity of 90.9%, a specificity of 85.7%, and an overall accuracy of 88.9%. This suggests that the measure is potentially a highly effective predictor of long-term treatment response, according to QuantalX.
Additionally, the cerebrospinal fluid (CSF) tap results did not significantly differentiate responders from non-responders. Responders had higher M1L WFA values than non-responders, with medians of 0.51 (95% confidence interval [CI], 0.36–0.76) and 0.14 (95% CI, -0.02–0.38), respectively (p=0.012). M1L WFA at baseline—prior to VPS—was successful in discriminating responders (11 out of 18) from non-responders (seven out of 18) with an area under the curve (AUC) of 0.935 (95% CI, 0.792–1; p<0.0001), as assessed by the CGI-C at ≥12 months of follow-up.
“By extending beyond the early postoperative window, this study evaluated whether Delphi-MD retains predictive accuracy beyond 12 months,” said study author Sharon Hassin-Baer (Sheba Medical Center, Ramat Gan, Israel). “This longitudinal analysis found that Delphi-MD may provide an objective, accurate and non-invasive ancillary screening tool for iNPH candidates prior to referral for VPS treatment, enabling better patient selection and long-term management of NPH.”
“While VPS is an effective treatment for NPH, current diagnostic tools for VPS candidacy don’t predict long-term clinical response, making the risk-benefit evaluation challenging for physicians. QuantalX fills this diagnostic gap with a non-invasive tool to objectively measure neurophysiological biomarkers,” added Iftach Dolev, QuantalX chief executive officer (CEO) and co-founder. “This latest study indicates that the Delphi-MD can more accurately predict which patients will benefit from treatment. Knowing which patients might benefit enables physicians to make more informed and objective evaluations of the risk-benefit ratio, and may increase the rates of clinical benefit and minimise unnecessary interventions.”
