Low spinal fluid pressure syndromes

THE MECHANISMS of production and the factors participating in the control of cerebrospinal fluid dynamics have been the source of many intriguing studies. That cerebrospinal fluid issues from the choroid plexus was suggested by Cushing,l who observed the appearance of drops of fluid on the surface of the choroid plexus during surgery. Dandy2 provided further evidence when he occluded the outlet of one lateral ventricle and produced a unilateral ventricular dilation. Such observations, however, were not universally accepted, and other sources of cerebrospinal fluid were described.3.4 The accumulated evidence from numerous experimental and clinical studies on the problem has now given most support to the theory that the choroid plexus certainly represents the most important site of fluid formation. After formation, many and vaned factors are responsible for maintaining an equilibrium, so that the relationships of the intracranial contents in their rigid skeletal container remain relatively constant. With certain disturbances of these regulating mechanisms, clinical syndromes of cerebrospinal fluid hypertension or hypotension appear. Those entities associated with intracranial hypotension are the subject of this report. It has long been known that clinical symptoms could result from alterations in intracranial pressure. H o ~ e m a n , ~ in 1909, provided one of the original reports on headache from cerebrospinal fluid hypotension after spinal anesthesia. Thereafter, many reports conceming the various forms of intracranial hypotension and its management appeared in the foreign literature. A classification of low spinal fluid pressure syndromes might be listed as follows: [ 11 spontaneous or primary, [2] postoperative (cranial), [3] after head trauma, either with or without manifest external loss of cerebrospinal fluid, [4] after lumbar puncture or nerve sleeve