ASNR 53rd Annual Meeting – Poster EP-39, Control # 1239 Arterial Spin Labeled Brain Perfusion in Patients with Disorders of Intracranial Pressure: A Prospective Study of Changes Related to Measured Cerebrospinal Fluid Pressure ASNR 53rd Annual Meeting – Poster EP-39, Control # 1239 Amit M. Saindane, M.D. Deqiang Qiu, Ph.D. John F. Holbrook, M.D. John Oshinski, Ph.D. Department of Radiology and Imaging Sciences Emory University School of Medicine

The authors have no relevant disclosures.

Background: Idiopathic Intracranial Hypertension (IIH) Syndrome with elevated intracranial pressure (ICP) without identifiable cause Associated orbital and skull base MRI findings Friedman DI et al. Neurology. 2002;59:1492-1495

Background: Spontaneous Intracranial Hypotension (SIH) Orthostatic headaches with low ICP due to CSF leak Associated imaging signs of “brain sag”

Background: ICP estimated through lumbar puncture (LP) and CSF manometry to measure an opening pressure (OP). If OP elevated, therapeutic CSF removal performed to decrease ICP, with a closing pressure (CP) checked. If clinical diagnosis of SIH (generally will have low OP), therapeutic epidural blood patch may be performed to increase ICP. L.S.

Purpose: To assess changes in arterial spin labeled (ASL) brain perfusion following lumbar puncture with CSF removal in patients with know or suspected disorders of ICP (IIH and SIH).

Methods: Patients IRB Approved prospective study 5 women with known/suspected ICP disorders 2 with known diagnosis of IIH under treatment 2 with suspected IIH 1 with suspected SIH

Methods: Patient Protocol Therapeutic CSF Removal and CP Measurement n=4 <15 min MRI Part 2 (with ASL Perfusion) <15 min LP with OP Measurement MRI Part 1 (with ASL Perfusion) Therapeutic Epidural Blood Patch n=1 2 hours MRI Part 2 (with ASL Perfusion)

Methods: MR Imaging 3.0-T Siemens Trio MRI Unit 3D GRASE ASL sequence Whole brain mean cerebral blood flow (CBF) calculated

Results: Known/Suspected IIH Patients 1 and 2 with known medically treated IIH had normal OP Patients 3 and 4 with suspected IIH had elevated OP OP (cm water) CSF Removed (ml) CP (cm water) Pre-LP CBF (ml/100g/min) Post-LP CBF % Change from Baseline Patient 1 13 11 12 35.6 33.6 -5.6% Patient 2 16 7 46.3 43.6 -5.8% Patient 3 35 14 20 29.1 31.1 +6.9% Patient 4 26 47.4 47.7 +0.6%

Results: SIH Patient Patient 5 met diagnostic criteria for SIH OP=14.5 cm water. No CSF withdrawn. CP not measured. CBF increased from 34.2 ml/100g/min to 43.9 ml/100g/min (28%) following blood patch with resolution of positional headaches.

Limitations Small number of patients. Closing pressure not available for SIH patient. Medical treatment of IIH patients may impact effect of CSF removal on CBF. Optimal timing for post-LP MRI is unknown. It may take greater time for brain CBF to adapt to removal of CSF.

Conclusions In IIH patients immediately following LP and CSF removal, there is not a substantial change in brain CBF. This may reflect chronic adaptation to high ICP or insufficient time for the CBF to re- equilibrate after LP and CSF removal In one SIH patient 2 hours following therapeutic epidural blood patching, we observed an large (28%) increase in CBF.