Light and electronmicroscopy of the bowel in an unusual form of Hirschsprung's disease.

In a histological and histochemical study of multiple biopsies of unaffected segments of the bowel from 15 patients with Hirschsprung's Disease (H.D.), the AChE or non-specific esterase and the NADPH tetrazolium reductase enzyme reactions proved to be useful in identification of myenteric plexus islands; and acid phosphatase for the delineation of individual neurones. In the affected segment (usually aganglionic), this myenteric plexus tissue was not reactive for esterase, but individual nerve fibres among muscle fibres of the two muscle coats showed the enzyme product in a third of the cases. Fine structural study of biopsies from a typical case of H.D., showed normal looking axons and Schwann cytoplasm with terminals bearing both andrenergic and cholinergic vesicles in the unaffected colon, smooth muscle fibres with normal fine structure in all parts of the bowel, and loss of neurons with myenteric plexus replaced by nerve fibre groups in the affected rectosigmoid. One patient clinically presenting as a case of severe H.D., with histologically and histochemically normal myenteric and submucous ganglion cells, and not responding to resection of the bowel, showed degeneration of the unmyelinated axons with prominent Schwann cytoplasm, depleted cholinergic but persistent adrenergic vesicles, and markedly thinned and degenerating smooth muscle fibres and myofilaments, suggesting either a primary disorder of muscle tissue of the colon or, less likely, a denervation atrophy with secondary degeneration of the smooth muscle fibres.

Meningoceles and neurological involvement.

The term meningocele is used in this communication to include all lesions presenting as swellings associated with spina bifida, when neural tissue is not exposed on the surface. 144 meningoceles were operated on during an 18-year period. The stalk of the meningocele was connected with the neural tissue in 113 of them. Two distinct types of lesions have been noted in these patients and have been designated "meningocele with tethered cord" (52) and "meningocele with tethered roots" (56). In both conditions about half the number of cases presented clinically before the age of 3 months, when paraplegia was evident in only 5 of the 26 infants with tethered cord and 3 of the 25 with tethered roots. In contrast, all or the majority of babies reporting after the age of one year, had paraplegia. Hence, a case is made out for an early operation in all these patients. At surgery the main lesion was a fatty mass in 29 babies with tethered cord, and a cystic mass in 30 with tethered roots. While hydrocephalus was virtually absent in these babies, there were 5 others who manifested obstructive hydrocephalus with meningocele. "Meningomyelocele", the commonest lesion associated with spina bifida, presents with an exposed spinal cord at birth, is associated with communicating hydrocephalus, and can be clearly distinguished from the meningocele.