Diplegia and Hemiplegia in Childhood

DIPLEGIA        

The term congenital diplegia, or Little's disease, is now used to include a group of cases characterized by bilateral and more or less symmetrical disturbances of motility which are present from birth and which subsequently remain stationary or show a tendency towards improvement. Though commonly the lesion involves chiefly the corticospinal tracts, causing weakness and spasticity,which are most conspicuous in the lower limbs, mental defect, involutary movements, and ataxia may be present either in association with spastic weakness or as the sole manifestations of the cerebral lesion.
There is no doubt that the causes of congenital diplegia are multiple. Earlier theories implicating brain injury or asphyxia at birth are not now widely held but it is believed that the damage, sometimes probably viral, occurs comparatively early in foetal life, and that an arrest of development or an actual degeneration of certain parts of the brain occurs in utero. Occasionally there is a gross maldevelopment.
  The commonest pathological finding has received the name of atrophic lobar sclerosis, and is characterized by a symmetrical atrophy of both cerebral hemispheres with destruction of nerve cells and glial proliferation. Microcephaly, when present, is the result of the cerebral hypoplasia and not its cause. Congenital diplegia is only exceptionally familial.

HEMIPLEGIA

Congenital hemiplegia means hemiplegia which is present at birth. Infantile hemiplegia means hemiplegia acquired during the first few years of life, not necessarily during infancy. This is not a very logical distinction, however, since congenital hemiplegia may be due to a lesion acquired during birth. Indeed, an intracranial vascular lesion so produced is probably a commoncause. Prematurity and postmaturity may be factors. Less frequently there is a congenital cerebral deformity, such as true porencephaly, or an intracranial angioma, or a lesion of unknown pathogenesis acquired during foetal life. Hemiplegia acquired after birth may occur as a complication of many acute infective disorders of childhood, especially whooping cough, and in such cases probably usually has a vascular origin. It may also be due to acute encephalitis, or complicate meningitis. When hemiplegia is associated with convulsions, the convulsions may be the cause of the brain damage. Intracranial tumour and tuberculoma are rare causes.
The pathology varies with the cause, and includes vascular lesions such as haemorrhage and arterial thrombosis, sinus thrombophlebitis, and the various forms of encephalitis. In brains examined long after the onset of hemiplegia, the changes commonly found are meningeal thickening, localized atrophic sclerosis, cysts, and pseudoporencephaly.