With regard to the comparative frequency of temporo-sphenoidal and cerebellar abscess, in 100 cases collected from the records of the London Hospital the writer found that in children under ten years of age temporo-sphenoidal abscess occurred in 87% and cerebellar only in 13%, whereas in adults cerebral abscess occurred in 65% and cerebellar in 35%; and that a cerebral and cerebellar abscess occurred together only in 5% of the cases.
These statistics are practically the same as Körner’s (Die otitischen Erkrankungen des Hirns, der Hirnhäute und der Blutleiter). Ballance, on the other hand, considers cerebellar abscess a more frequent occurrence than temporo-sphenoidal.
Multiple abscesses may be met with, usually the result of pyæmia.
Indications. An intracranial abscess must always be opened and drained.
Indications pointing to such a condition are persistent headache, purposeless vomiting, a slow pulse, a subnormal temperature, and optic neuritis. With this there is usually some change in the mental condition, especially in the case of a temporo-sphenoidal abscess. In the early stages there may be attacks of simple forgetfulness or mental aberration, or, on the other hand, that of extreme mental excitement. Owing to the intracranial pressure caused by the increase in size of the abscess, the mental state becomes impaired and the condition known as slow cerebration or the ‘dream state’ may be observed.
It must, however, not be forgotten that the same clinical picture may be produced by other conditions, such as an intracranial tumour: in the case of a middle-ear suppuration, however, an intracranial abscess may be diagnosed unless this can otherwise be excluded.
Before operation is decided on, the site of the lesion must be determined. This can only be done if certain localizing symptoms are present.
In a temporo-sphenoidal abscess, if the cortical region be affected, there may be paralysis or paresis of the opposite side, beginning with the face and then spreading to the arm and leg; or in the opposite order if the internal capsule be involved.
If the left temporo-sphenoidal lobe be the site of the lesion, aphasia may be met with, and if the abscess extends backwards, word-blindness may occur. If the centre of hearing be affected there may be complete deafness of the opposite side owing to its destruction; or tinnitus or hyperacusis if the centre be only irritated by the proximity of the abscess; or if the anterior extremity be involved anosmia or parosmia may be noticed. Another important sign, occurring in conjunction with the above symptoms, is a fixed pupil on the affected side.