Cerebral metastasis in association with intrathoracic disease.

The following case reports seemed to me to be worth recording; the phenomena with which they deal, though well recognized in medical literature, are not so commonly encountered in general practice; in one, especially (Case 3), the difficulty in diagnosis in the earlier stages of the illness was not inconsiderable and gave rise to much interesting discussion. The association between bronchiectasis and cerebral abscess has always been admitted; reference to it is to be found in most standard works on general medicine. Jex-Blake (1920) in a survey of iio cases records intracranial abscess as the cause of death in I5, i.e., in 13.63 per cent. Kent and Blades (1942) refer to metastatic abscess in connection with intrathoracic suppuration as occurring almost exclusively in the brain, rarely in other organs. Collis (I944) discussing a series of cases collected from the Brompton Hospital, from an E.M.S. chest centre, and from the Birmingham United Hospitals, reviews some of the literature on the subject. His own figure of three cases of cerebral complication in 54 deaths from bronchiectasis at Brompton, between I933 and 1938 only, gives an incidence of 5.5 per cent.; with empyema he found that the cerebral complications occurred in I.9 per cent. of cases and accounted for i6 per cent. of the mortality of the condition, and with lung abscess the corresponding figures were 4.5 per cent. and 20 per cent. He agrees with Schorstein as saying that 20 per cent. of bronchiectatic patients eventually develop a cerebral complication; it must be remembered, however, that in the earlier days of the work at Brompton, before the introduction of bronchography, many cases of bronchiectasis, in which infection played but a negligible part, must have passed unrecognized, and that therefore the earlier statistics are probably to some extent misleading. Nickerson (1935) in a record of 10,502 unselected autopsies found 12 instances of cerebral abscess associated with thoracic disease. Russell Brain (I947) dealing with the causes of cerebral abscess puts these in order of frequency as (i) Infection of the middle ear, mastoid and nasal sinuses; (2) pyaemic states; (3) metastasis from intrathoracic suppuration; (4) head injury; a statement which is generally. corroborated by other neurological authorities. Enough has been said by way of introduction to indicate the importance of this aspect of chest disease, though it may, perhaps, be observed in parenthesis that brain abscesses do not occur in connection with acute empyema, but only after the chronic variety of at least three months duration and usually much more, and that in fatal cases death takes place with considerable rapidity (Schorstein notes the occurrence of death within an average period of io days, and Collis within'3 days).