[Fronto-basal cerebrospinal fluid fistula. Diagnosis and its significance in the etiology of mixed purulent meningitis].

By means of own clinical observations and reports from the literature we want to emphasize the clinical importance of early diagnosis of abnormal communications between the subarachnoid space and other body compartments. Clinical symptoms of these conditions are rather sparse; the diagnosis has to be made therefore by a high index of suspicion. The most relevant criteria for further investigation of a cerebrospinal fluid fistula are in summary: Recurrent purulent meningitis. Sometimes a considerable time interval between the first episode of purulent meningitis and further disease states can be observed. History of trauma to the bony structure encasing the central nervous system and liquorrhea at least sometimes in the past. The trauma may have occurred sometimes in early childhood or infancy and thought to be trivial. A positive culture of pneumococci in the cerebrospinal fluid is the least characteristic sign. Some patients are partially treated with antibiotics before the diagnosis is made and this might prove sufficient, not to culture organisms in the cerebrospinal fluid. In case of a recurrent meningitis a further investigation has to be done to arrive at a satisfactory explanation. A cerebrospinal fluid fistula has to be excluded by all means. If a fistula is found, further recurrences can be prevented only if the abnormal communication is closed surgically.