The mantoux test in tuberculous meningitis

Abstract

Summary o (1) In 63 out of a series of 75 unselected cases of tuberculous meningitis Mantoux tests were done during the first weeks in hospital. (2) Tuberculin sensitivity as a whole was low: 39 per cent of those tested with 0.1 ml. O.T. 1/1,000 were negative and 22 per cent of all cases were negative to 0.1 ml. O.T. 1/100. (3) The intensity of the tuberculin test did not vary with the age of the patient or the type of systemic disease. (4) The prognosis was worse among those cases in which the Mantoux test was negative than among the rest. In spite of this a negative reaction by no means precluded the possibility of a smooth recovery. (5) Serial Mantoux tests showed that in 5 of the fatal tuberculin-negative cases the Mantoux test converted before death. (6) It is concluded, therefore, that the commonly accepted explanation for the negative Mantoux test in tuberculous meningitis — that it simply reflects the terminal cachexia — requires modification. (7) The bearing of the relatively large proportion of tuberculin-negative cases on both diagnosis and treatment is briefly discussed.