Studies of the cerebrospinal fluid circulation in tuberculous meningitis in children. Part I. The use of penicillin as a tracer substance.

It has been conclusively proved that the cerebrospinal* route for the administratiod of streptomycin is essential in the treatment of tuberculous meningitis (Medical Research Council, 1948; Rubie and Mohun, 1949). Only a few workers consider it unnecessary (Levinson, 1949; Mouriquand, 1948). There is, however, less general agreement about the optimum site of cerebrospinal administration of streptomycin. The lumbar, ventricular, and cisternal routes are most commonly used, but streptomycin has also been injected through indwelling polyethylene catheters direct into the interpeduncular space (Cairns, 1949; Smith, Vollum, and Cairns, 1948) or into the pontine cistern (Komrower, 1950). Early in the experimental stage of streptomycin treatment of tuberculous meningitis it became obvious that obstruction within the cerebrospinal pathways was frequent and that this factor must influence the choice of route. The sites of obstruction are the same as those in other forms of meningitis, namely the Sylvian aqueduct, the foramina of Magendie and Luschka in the roof of the fourth ventricle, and especially at the tentorial opening and within the spinal theca (Cairns, 1949). There are various views regarding the aetiology of these blocks. Tuberculous granulation tissue (M.R.C., 1948); fibrinous exudate which may become fibrous later (Cairns, 1949; Cathie, 1949; Smith et al., 1948; DanieL 1949); reaction to 'bloody tap' (Cairns and Taylor, 1949); the irritant effect of streptomycin (Cathala and Bastin, 1948; Winter, 1950); and herniation of the brain into the foramen magnum or tentorial opening (Cairns, 1949; Smith et al., 1948) have all been blamed. These may be responsible singly or in combination. Early recognition of these blocks is necessary because they have an important therapeutic and prognostic signifi. Such early