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Preface

Masamichi Shinonaga

Cerebrospinal fluid hypovolemia is a disease that has attracted attention in Japan because of its association with traffic accidents sequelae, sports posttraumatic sequelae, and school non-attendance due to refractory headache and dizziness in children. The mild traffic injury sequelae and sports posttraumatic sequelae often have a diagnosis of mild traumatic brain injury (m-TBI)in Europe and USA. In m-TBI, image diagnosis is not easy and treatment is not established. Among cases diagnosed with m-TBI, not a few are caused by cerebrospinal fluid leakage. Cerebrospinal fluid hypovolemia is a disease with a possible image diagnosis and established treatment. Cerebrospinal fluid leakage is a main cause of cerebrospinal fluid hypovolemia.

Spontaneous intracranial hypotension (SIH) with a chief complaint of orthostatic headache is a rare disease, but many reports have published on it. Orthostatic headache has not been described as an essential symptom for intracranial hypotension-related headache in the international headache classification of 2013 (third edition). Cerebrospinal fluid leakage replaced it in 2003 and was announced as one of the causes of whiplash associated disease in an official journal of Japan neurotrauma society, but this general idea met with intense criticism. The following were the objection: there is absolutely no possibility that the cerebrospinal fluid leakage occurs in rear-end collision, leaking images from the lumbar spine in the RI cisternographyonly represents the leakage at the needle hole of lumbar puncture, and the effect of blood patch is only a placebo effect. However, in a public study group (Chief researcher,Professor Takamasa Kayama, Current director of the Japan neurosurgical society) of the Ministry of Health, Labour and Welfare in 2007, in which many associated societies participated, based on accumulating evidence from several years, it was revealed that cerebrospinal fluid leakage was present in a mild traffic injury, and it was confirmed that blood patch therapy was effective.(*blood patch therapy has been approvedfor national health insurance coverage in Japan from April 1, 2016)

Is cerebrospinal fluid caused by a mild traffic clinical condition found only Japan? Although this clinical condition could occur anywhere worldwide, there are very few reports on cerebrospinal fluid hypovolemia caused by mild trauma or with cerebrospinal fluid leakage symptom. We suggest that cerebrospinal fluid hypovolemia may be significantly present in patients with mild traumatic brain injury with military activity. In some respects, cerebrospinal fluid due to mild trauma is different in comparison with SIH, which often occurs acutely: there are many causes becoming chronic, orthostatic change is not remarkable, symptom are various (headache , neck pain, dizziness, ringing in the ears, abnormal vision, gastrointestinal symptoms, memory impairment, fatigue, malaise, ataxia, insomnia), there is little “diffuse duralcontrast enhancement” in the brain-enhanced MRI, cerebrospinal fluid pressure is normal, more time is required to confirm the effect of the blood patch therapy and so on. At present, the diagnosis of cerebrospinal fluid leakage is carried out generally by RI cisternography, computed tomography(CT)myerography, and magnetic resonance(MR)myerography. As for treatment, epidural blood patch is effective, but many cases need long-term therapy for improvement and multiple blood patch is necessary for chronic cases. Moreover, there are cases where the cerebrospinal fluid does not readily increase even if cerebrospinal fluid leakage stops by blood patch therapy, and artificial cerebrospinal fluid intradural injection treatment is often required and effective.

The cerebrospinal fluid is a very important role in normal neurological functions, and decrease of the cerebrospinal fluid results in serious neurological dysfunction. The research meeting of cerebrospinal fluid hypovolemia was first conducted in Japan in 2004, and the meeting is held every year since. Numerous cases have been accumulated so far, and diagnosis and therapy reports have been studied. The basic research on the production and absorption of the cerebrospinal fluid in progress. We hope that more studies on cerebrospinal fluid and cerebrospinal fluid hypovolemia are undertaken in the future.

We hope that this website will help patients suffering from cerebrospinal fluid hypovolemia all over the world to find relief. Professor Masamichi Shinonaga, Department of neurosurgery, International University of Health and Welfare Atami Hospital