The blood supply of the incus.

IT ^generally held that the incus has a poor blood supply although it would appear that, in health, it is adequate. In disease, it has been observed that the long process of the incus is frequently necrosed and, as the result of the clinical examination of a recent case, it is interesting to consider the nutrition of this ossicle. A boy, now aged n , had a bicycle accident at the age of 5, was unconscious for a short time, and had slight bleeding from the right ear. Radiological examination showed no evidence of any fracture of the skull and, some time afterwards, his mother noticed that he was becoming deaf in the affected ear. On examination a year ago his right drum appeared to show a small scar just behind the handle of the malleus; he was not stone deaf in that ear but an audiometric chart, with masking of the left ear, showed that he could hear only a few notes at, approximately, 80 decibels; his caloric response on the right side was normal. The deafness appeared to be cochlear deafness but there were some points which made one suspect that there might also be a middle-ear element in the deafness, and_the middle ear was inspected by means of the stapes mobilization approach. The middle-ear mucosa was perfectly normal, there were no adhesions, no congestion, and the only abnormality found was the absence of, approximately^ 3 millimeters of the tip of the long process of the incus, including the lenticular process. The alignment of the long process was not disturbed and the tip, instead of being square cut, as it were, tapered to a point, the outer surface appearing to be eroded rather more than the medial surface. The stapes was completely mobile and the normal round window reflex was present. The articular surface of the head of the stapes, instead of showing a smooth glistening surface, had a slightly congested velvety appearance. After the middle ear had been carefully inspected, the drum was replaced and held in contact with the head of the stapes by means of gelatine sponge. On examination some weeks later, it was found that the drum had apparently become firmly adherent to the head of the stapes. The drum remained mobile, but no improvement in the hearing occurred.