Abstract
Three cases are presented which depict the spectrum of neurological disability attendant on intra-axial brain-stem metastases, ranging from fulminant decline to a more leisurely and less disabling course. The rarity of primary glioma of brain-stem compared with brain-stem metastases in a general hospital population in the age group from 50 years and over is emphasized. Clinical deficit, certain ancillary findings, and response to therapy do not serve to separate brain-stem glioma from secondary brain-stem metastasis. The primary tumour may not be apparent when central nervous system symptoms appear or even for as long as two years after. It is recommended that the diagnosis of primary brain-stem glioma in the middle-aged adult be provisional and increasingly tentative over the age of 50 years.