Cerebrospinal fluid leakage and pathogenesis of orthostatic headache in low pressure headache

• Main Authors: Yen-Feng Wang, 王嚴鋒
• Other Authors: Shuu-Jiun Wang
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/22707372959609256121

博士 === 國立陽明大學 === 臨床醫學研究所 === 103 === Background Low pressure headaches, including spontaneous intracranial hypotension (SIH) and post-lumbar puncture headache (PLPH), are characterized by an orthostatic headache accompanied by nausea, vomiting, and neck stiffness, and result from decreased intracranial pressure or cerebrospinal fluid (CSF) volume. It is uncertain whether the visualized spinal CSF leakages on neuroimaging accurately co-localize with the actual dural defects. Whether the amount or pattern of spinal CSF leakage is correlated with the development of low pressure headache is inconclusive. In addition, the pathogenesis of orthostatic headache has not been explored. Objectives We intended to validate the findings of spinal CSF leakages on HT2W MRM with those on CTM. The distribution of CSF leakages after lumbar puncture is analyzed, and the correlation between the amount and pattern of spinal CSF leakages with clinical presentations was determined. Besides, orthostatic changes in the extra- and intracranial venous structures are examined in patients with low pressure headaches. Methods Study 1: Patients with SIH were recruited prospectively, and first underwent HT2W MRM and then CTM. The results of HT2W MRM were compared with CTM, focusing on 1) CSF leaks along the nerve roots (periradicular leaks), 2) epidural collections, and 3) high-cervical (C1–3) retrospinal collections. Comparisons of these 3 findings between the 2 studies were made by κ statistics and agreement rates. Targeted epidural blood patches (EBPs) were placed at the levels of CSF leaks if supportive treatment failed Study 2: Adult in-patients who received diagnostic lumbar punctures (LPs) were recruited prospectively. HT2W MRM was carried out to assess the extent and distribution of post-LP spinal CSF leakages. Comparisons were made focusing on PLPH. Study 3: Patients with SIH or PLPH and healthy controls were recruited prospectively. Neurosonography was carried out for intracranial dural sinuses, internal jugular veins (IJVs) and vertebral veins (VVs) in both sitting and supine positions. Results Study 1: Nineteen patients (6M/13F, mean age 37.9±8.6 years) with SIH completed the study. HT2W MRM did not differ from CTM in the detection rates of CSF leaks along the nerve roots (84% vs 74%, p < 0.23), high-cervical retrospinal collections (32% vs 16%, p < 0.13), and epidural collections (89% vs 79%, p<0.20). HT2W MRM demonstrated more spinal levels of CSF leaks (2.2±1.7 vs 1.5±1.5, p < 0.011) and epidural collections (12.2±5.9 vs 7.1±5.8, p < 0.001) than CTM. The overall level-by-level concordance was substantial for CSF leaks along the nerve roots (C1–L3) (κ = 0.71, p < 0.001, agreement = 95%) and high-cervical retrospinal collections (C1–3) (κ = 0.73, p < 0.001, agreement = 92%), and moderate for epidural collections (C1–L3) (κ = 0.47, p < 0.001, agreement = 72%). Study 2: Eighty patients (51F/29M, age 49.4±13.3 years) completed the study, including 23 (28.8%) with PLPH. Overall, 63.6% of periradicular leaks and 46.9% of epidural collections were within three vertebral segments of the level of LP (T12-S1). PLPH was associated with more extensive and more rostral distributions of periradicular leaks (length 3.0±2.5 vs. 0.9±1.9 segments, p = 0.001; maximum rostral migration 4.3±4.7 vs. 0.8±1.7 segments, p = 0.002) and epidural collections (length 5.3±6.1 vs. 1.0±2.1 segments, p = 0.003; maximum rostral migration 4.7±6.7 vs. 0.9±2.4 segments, p = 0.015). Study 3: For patients with low pressure headache, there was a trend toward lower flow volume in the IJVs (0.44±0.69 vs 1.73±3.34 mL/sec, p = 0.050) in a sitting position, and the flow velocities in the transverse sinuses were lower (maximum 27.23±3.18 vs 35.08±9.42 cm/sec, p = 0.042; minimum 8.78±6.02 vs 18.88±6.54 cm/sec, p = 0.006; mean 11.81±3.53 vs 18.10±4.07 cm/sec, p = 0.005) in a sitting position. Conclusions Whole-spine HT2W MRM is comparable to CTM, the purported gold standard, in localizing spinal CSF leaks in patients with SIH. Our findings challenged the widely held belief that the visualized periradicular leaks accurately co-localize with the actual dural defects. However, about two thirds of the visualized periradicular leaks lie in the vicinity of the dural defects, making them a reasonable guide for targeted EBPs but not surgical interventions. On the other hand, epidural collections had a wide distribution, and therefore are of limited use in localizing dural defects. Finally, reduced cerebral venous return and dilatation of intracranial venous sinuses in an upright posture resulting in traction and distension of the overlying dura could be an important mechanism underlying orthostatic headache in patients with SIH and PLPH.