Non-invasive Estimation of CSF Pressure Using MRI in Patients With Spontaneous Intracranial Hypotension

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to estimate the intracranial pressure (ICP, the pressure in your head) in subjects with intracranial hypotension (a condition caused by leakage of the fluid that surrounds your brain and spine) using non-invasive magnetic resonance imaging (MRI) techniques, and to determine whether changes in estimated ICP are seen after treatment of this condition.

Detailed Description
-----------------
Subjects with known intracranial hypotension who are scheduled to undergo standard-of-care CSF pressure measurement using lumbar puncture prior to planned epidural patch treatment will first undergo a research MRI of the brain in order to estimate ICP. The imaging protocol is listed in Appendix 1. All research scans are performed without intravenous contrast. Approximate scan time per session will be 20-22 minutes. Subjects will then undergo lumbar puncture according to the standard-of-care treatment plan. Estimated values of CSF pressure derived from MRI will be compared to values measured during lumbar puncture. Patients will then undergo standard-of-care epidural patching. A repeat research MRI after epidural patching will be performed to assess for differences in pre- and post-treatment scans.

Official Title
-----------------
Non-invasive Estimation of CSF Pressure Using MRI in Patients With Spontaneous Intracranial Hypotension

Conditions
-----------------
Intracranial Hypotension

Intervention / Treatment
-----------------
* Device: MRI algorithm
* Procedure: Lumbar puncture
* Procedure: Epidural patching


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Known diagnosis of intracranial hypotension, established by the following criteria: the presence of orthostatic headache, and one or more of the following criteria: prior CSF opening pressure ≤6 cmH20, demonstration of an active spinal CSF leak on prior spine imaging, or cranial MRI changes of intracranial hypotension.15 Ability to provide informed consent. Expected ability to complete standard-of-care procedures (lumbar puncture and epidural patching) Exclusion Criteria: Known contraindication to MRI (pacemaker, MRI incompatible hardware, etc.) Severe claustrophobia or other condition requiring the need for anxiolysis, sedation, or any other medication for MRI scanning Inability or expected inability to complete study interventions as scheduled Any known contraindication to standard-of-care procedures (e.g. coagulopathy, allergic reaction to required medication, lack of vascular access, etc.)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MRICP method<br>MRI sequences have been developed that may be able to estimate ICP in a non-invasive fashion.6-10 The MRI-based method for measurement of ICP (MRICP method) is based on basic principles of the cranio-spinal CSF physiology: The mono-exponential relationship between intracranial volume and pressure leads to a linear relationship between elastance (i.e., the derivative of pressure with respect to volume) and pressure. | Device: MRI algorithm<br>* MRI sequences have been developed that may be able to estimate intracranial pressure in a non-invasive fashion<br>Procedure: Lumbar puncture<br>* Lumbar puncture according to the standard-of-care treatment plan.<br>Procedure: Epidural patching<br>* Epidural patching will be performed to the standard-of -care treatment plan<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intracranial Pressure Measurements Estimated by the MRICP Technique. | The measurement of the momentary differences between the volumes of blood and CSF entering and leaving the cranium during the cardiac cycle provides an estimate of the intracranial volume change, and the pressure difference is estimated using the derivative of the CSF velocities. | During scan, approximately 30 minutes | 
| Cerebro Spinal Fluid Pressure Measured by Lumbar Puncture | The CSF pressure measured at lumbar puncture (LP), is 100-180 mm of H2O (8-15 mm Hg) with the patient lying on the side and 200-300 mm with the patient sitting up. | During lumbar procedure, up to 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Intracranial Pressure Estimated With MR Technique | Description: assessment of change in estimated ICP prior to and following standard-of-care epidural patching; and (2) evaluate changes in diameter and flow velocity through the transverse dural venous sinus prior to and following epidural blood patching. | Baseline, 24 hours | 
| Change in Caliber to the Transverse Venous Sinus Caliber | Change in caliber to the Transverse Venous Sinus caliber has measured by non-contrast 3D phase contrast MR venography. | Baseline, 24 hours | 
| Change in Flow Velocity Through the Transverse Dural Venous Sinus | Description:Change in Flow velocity through the Transverse Dural venous sinus has measured by non-contrast 3D phase contrast MR venography | Baseline, 24 hours |