Abstract
Intracranial hypotension is a syndrome in which the predominating symptom is orthostatic headache due to cerebrospinal fluid leakage. It has been known for over 70 years, so this syndrome is not a newly established clinical entity. However, this syndrome is attracting much attention today, because there are currently many discussions about the relationship between this syndrome and "Whiplash" after traffic accidents. The terms "Cerebrospinal fluid hypovolemia" and "Intracranial hypotension" are often used synonymously. The former is used more often recently because there are patients whose intracranial pressures are normal. In order to clarify the clinical characteristics of intracranial hypotension following head injury, the Japan Society for Neurotraumatology reviewed over 300 articles about this syndrome. According to their report, the clinical entity of intracranial hypotension following head injury treated in Japan seems to differ from that treated in foreign countries. As mentioned above, there is still controversy about the mechanism and diagnosis of cerebrospinal fluid hypovolemia including intracranial hypotension following head injury. From 2007, the "Cerebrospinal fluid hypovolemia research group" granted by the Ministry of Health, Labour and Welfare has worked to solve issues about this syndrome. In this paper, we want to present a concept for and several issues of intracranial hypotension following head injury, based on the interim report of that research group.
