PUNCTURE OF THE CISTERNA MAGNA

A situation occasionally arises in which lumbar puncture is either impossible, impracticable or insufficient, when access to the upper reservoirs of the cerebrospinal fluid are desirable or imperative.The necessity of reaching the subarachnoid space at other points than the lumbar sac has led to such procedures as puncture in the thoracic and cervical regions, puncture through the sphenoidal fissure and intra- ventricular puncture.In the literature one finds no mention of cisterna puncture 1 as a clinical procedure, although it has for long been the routine method for obtaining cerebrospinal fluid in animals, and drainage of the cisterna has been employed by a number of surgeons.2With other routes besides the lumbar and ventricular, the writer has had no experience, all seeming of too hazardous a nature for other than extremely rare application.Cisterna puncture, reaching as it does "the distributing center of the cerebrospinal fluid system" should, however, render access to a point of even more strategic value than thoracic, cervical or sphenoidal puncture, and should in some cases render intraventricular puncture unnecessary. TECHNICThe method of approach to the cisterna cerebello-medullaris (cisterna magna) was published by Wegeforth, Ayer and Essick in 19193 after careful preliminary study on the cadaver.In practice the procedure has been found almost always easy, and no alarming symptoms have been observed, either at the time of puncture or sub¬ sequently.