With respect to the desirability of carrying out lumbar puncture in brain tumours and the value of the information obtained, considerable difference of opinion exists. Lumbar puncture supplies information as to the tension of cerebro-spinal fluid and as to its bacteriological and cytological character. The evidence so obtained as to tension is of little value in view of the proved increase of intracranial pressure as evidenced by the mental condition of the patient, the headache, optic neuritis, &c. On the other hand, bacteriological and cytological examination of the fluid may point to the tuberculous or syphilitic composition of the tumour, thus offering help from the point of view of treatment. Still, information of almost equal importance can be obtained by tuberculin, Wassermann, and other tests. There is also considerable risk attendant on the process. The rapid withdrawal of cerebro-spinal fluid has been followed by disastrous results, the medullary stem being suddenly forced downwards into the foramen magnum, with corking up of that aperture, and complete upset of the medullary centres. Such a disaster is the more likely to occur when the tumour is subtentorial in position. Looking at the question from the broadest point of view, it would appear that the performance of lumbar puncture in cases of suspected brain tumour is fraught with considerable peril.
X-ray examination.
X-ray examination should always be carried out. More commonly the results are negative, the nature of the tumour seldom permitting sufficient shadow formation. Occasionally the firmer and denser tumours allow of a more definite result. When the tumour arises from the bone, or is so situated as to change the shape of the part with which it is in contact, valuable information will be obtained. For example, the hollowing out and general enlargement of the sella turcica in pituitary tumour formation.
Treatment.
Indications for operation.
The indications for operation must be considered under two groups:—
Those for radical operation aiming at the removal of the tumour.
Those for palliative operation aiming at the alleviation of symptoms.
For the radical operation.
According to Risien Russell,[46] the following are the main indications:—