Brain Pulsatility, Idiopathic Normal Pressure Hydrocephalus (INPH)
Conditions
Keywords
transcranial ultrasound, cerebral pulsatility, idiopathic normal pressure hydrocephalus (iNPH),
Brief summary
This will be a single-center, prospective, analytical cohort study. All included patients will undergo transcranial ultrasound (TPI) with measurement of cerebral pulsatility parameters prior to subtractive lumbar puncture during hospitalization in the neurosurgery department, followed by a second ultrasound assessment either at one year after surgery for operated patients, or at one year after the initial ultrasound assessment for non-operated patients. This ultrasound evaluation will be integrated into the routine work-up, which is already systematically performed in cases of suspected idiopathic normal pressure hydrocephalus (iNPH). The neurosurgical team's decision to perform cerebrospinal fluid (CSF) shunting will be made blinded to the ultrasound measurements and based solely on the standard clinical protocol. The primary objective of the study is to demonstrate that the mean amplitude of cerebral pulsatility (MeanBTP) prior to subtractive lumbar puncture is significantly higher in patients who show clinical improvement 12 months after CSF shunting compared with those who do not, with a type I error risk (alpha) of 0.05."
Detailed description
This will be a prospective, single-center cohort study including patients with suspected idiopathic normal pressure hydrocephalus (iNPH). Eligibility will require fulfillment of inclusion criteria and confirmation of non-opposition after written informed consent procedures. All patients will undergo transcranial pulse imaging (TPI) with measurement of cerebral pulsatility parameters prior to subtractive lumbar puncture during hospitalization. Operated patients will have a second TPI assessment at 12 months post-surgery, while non-operated patients will undergo repeat TPI 12 months after baseline. Ultrasound assessments will be integrated into the standard hydrocephalus work-up. The decision to perform cerebrospinal fluid (CSF) shunting will be made by the neurosurgical team blinded to ultrasound findings and based solely on standard clinical and radiological criteria. Baseline clinical (demographics, vascular risk factors, cognitive/gait/urinary symptoms, neurological history) and radiological variables (ventricular volume, Evans index, callosal angle, DESH, Radscale) will be collected. During hospitalization, gait and cognitive function will be evaluated before and 48 hours after lumbar puncture. TPI will provide two indices of cerebral pulsatility: mean brain tissue pulsatility (MeanBTP) and maximal brain tissue pulsatility (MaxBTP), expressed as peak amplitude, peak amplitude mean, and root mean square. Follow-up will include standardized clinical and radiological assessments. Non-operated patients will be evaluated at 12 months. Operated patients will be seen at 2 months and 12 months postoperatively, with documentation of complications, shunt valve settings, ventricular volume changes, and subdural collections. Statistical analyses will be performed using STATA v11 (StataCorp, USA). Continuous variables will be expressed as means ± SD or medians; categorical variables as percentages. Normality will be assessed with the Kolmogorov-Smirnov test, and variance equality with F-test. Comparisons will use Student's t-test, chi-square, or Fisher's exact test as appropriate. Cox proportional hazards regression will be applied for multivariable analysis. P \< 0.05 will be considered significant. The primary objective will be to demonstrate that the mean amplitude of cerebral pulsatility (MeanBTP) measured prior to subtractive lumbar puncture will be significantly higher in patients who show clinical improvement 12 months after cerebrospinal fluid (CSF) shunting compared with those who do not, with a type I error risk (alpha) of 0.05. The secondary objectives will be to correlate cerebral pulsatility (measured by transcranial pulse imaging, TPI) with functional indices of iNPH and CSF shunting outcomes, including: speech therapy evaluation, physiotherapy-based gait assessment, global neurological disability, ventricular volume, and shunt valve opening pressure.
Interventions
None listed
Sponsors
University Hospital, Tours
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adult * Suspected iNPH (= at least 1/3 of the triad symptoms + ventriculomegaly on brain imaging) * Hospitalised at Tours University Hospital for 'hydrocephalus assessment' * Patient who has provided written and signed consent Non-inclusion criteria * Individuals who objected to data processing * Walking assessment by the physiotherapy team impossible AND cognitive assessment by the speech therapy team impossible
Exclusion criteria
* Patients already fitted with a CSF shunting system (VPS) * Suspicion of obstructive hydrocephalus (aqueduct stenosis, tumour, etc.) * Patients under legal protection (guardianship, curatorship, judicial protection).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Clinical improvement | 12 months | Clinical improvement at 12 months in patients who undergo CSF shunt surgery (ventriculoperitoneal shunt, VPS). Clinical improvement will be defined as cognitive improvement at 12 months and/or gait improvement at 12 months. * Cognitive improvement: improvement in at least two cognitive tests. Improvement in a single test will be defined as an increase ≥ 1 standard deviation between the baseline pre-lumbar puncture (pre-LP) speech therapy evaluation and the 12-month postoperative assessment. * Gait improvement: improvement in the Get Up and Go test and/or the 10-meter walk test (10MWT) between baseline and the 12-month postoperative assessment. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Mattis Dementia Rating Scale score (MDRS) | 12 months | Detailed speech therapy (neuropsychological) assessment: Mattis Dementia Rating Scale score (/144) |
| Wechsler Adult Intelligence Scale - 4th edition (WAIS-IV) | 12 months | Detailed speech therapy (neuropsychological) assessment: WAIS-IV - Coding, Digit Span Forward, Digit Span Backward; Verbal fluency - literal and categorical; Trail Making Test A - duration (s) and errors; Rey-Osterrieth Complex Figure - copy duration (s) and copy score (/36); Rey Word List score (/15). |
| Get Up and Go test (s) | 12 months | Detailed physiotherapy (motor) assessment: Get Up and Go test (s); Tinetti test (/28) |
| 10-meter walk test | 12 months | Detailed physiotherapy (motor) assessment: 10-meter walk test (10MWT) (s). |
| Reduction in modified Rankin Scale score (≤ 1 point compared with baseline) at 12 months | 12 months | Global neurological disability assessment: modified Rankin Scale (/6). |
| Reduction in ventricular volume (total ventricular volume and third ventricular volume) at 12 months | 12 months | Ventricular volume: measurement of total cerebral ventricular volume (mm³) and third ventricle volume (mm³) using a semi-automated technique with ITK-SNAP 4.2.0®. |
| Shunt valve opening pressure (mmH₂O) at 12 months | 12 months | Shunt valve opening pressure: opening pressure value (mmH₂O) at 12 months postoperatively |
Countries
France
Contacts
CONTACTIlyess ZEMMOURA, Pr
PRINCIPAL_INVESTIGATORIlyess ZEMMOURA, Pr
University Hospital, Tours
Outcome results
None listed