Russell D. Snyder

Cerebral infarction in childhood bacterial meningitis

Forty-nine children with complicated bacterial meningitis were studied. Thirteen had abnormalities on computed tomography compatible with the diagnosis of brain infarction; one had a brain biopsy with the histological appearance of infarction. Factors exist in childhood bacterial meningitis which are associated with the development of brain infraction.

Adrenoleukodystrophy and adrenomyeloneuropathy associated with partial adrenal insufficiency in three generations of a kindred

Four cases of adrenoleukodystrophy (ALD) and one case of adrenomyeloneuropathy (AMN) have developed in a kindred over three generations demonstrating that AMN is a clinical variant of ALD. Pituitary-adrenal function studies were performed in 10 family members, including two affected males and four females identified as carriers of ALD/AMN. No pituitary-adrenal abnormality was found in the carriers. However, basal morning plasma adrenocorticotropic hormone (ACTH) levels were markedly elevated in the two males with ALD and AMN, despite the fact that they had no clinical signs of adrenal insufficiency and that morning plasma cortisol levels and their response to maximal exogenous ACTH stimulation appeared to be normal. In addition, the integrated 24-hour response to the administration were also subnormal in these two cases. Thus, people with ALD and AMN may have subclinical partial adrenocrotical insufficiency. No other endocrinologic dysfunction was identified.

Computed tomography in childhood bacterial meningitis.

Computed tomography has been applied to childhood bacterial meningitis in an attempt to analyze the structural basis for neurologic complications. The CT findings in meningitis patients include acute cerebral swelling; moderate widening of basal cisterns, interhemispheric fissue, and subarachnoid convexity space; ventricular widening; subdural collection; focal cortical necrosis; cerebral infarcts; contrast enhancing basal meninges, ependymitis, and generalized cerebral atrophy. Bacterial meningitis in childhood is more than an inflammation of the subarachnoid space. It is a disease process which often exerts a profound effect on the brain parenchyma.

Subcortical visual function in the newborn

Early behavioral visual function in infants may not depend upon the geniculocalcarine pathway but may be mediated through more primitive subcortical pathways. This subcortical visual system may exist in early life and be responsible for visual pursuit and perhaps fixation. In some infants with damage to the visual cortex, the subcortical pathway may persist beyond the neonatal period. Three infants with major defects in the visual cortex are reported. These infants displayed persistent preservation of visual pursuit movements without evidence of visual recognition. Limited behavioral expressions of vision in the infant with damage to the visual cortex may not always be an indicator of preserved function of the visual cortex.

Neurofibromatosis xenografts. Contribution to pathogenesis

We transplanted Schwann cells of 3 patients with neurofibromatosis from neurofibromas, sural nerve, and from a malignant schwannoma into sciatic nerves of immunoincompetent mice. Three and six months later, the grafts and distal nerve segments contained normal myelinated fibers. After rendering host animals immune competent again, neurofibroma and malignant schwannoma Schwann cells were rejected, but grafts retained normally myelinated fibers indicating that these were of mouse origin. Sural nerve Schwann cells from a neurofibromatosis patient were rejected also leaving naked axons in the grafted segments showing that human Schwann cells from the sural nerve of one patient had invested and myelinated the regenerating mouse axons. The nature of putative signals passing between axons and Schwann cells might be elucidated by the combination of human and animal cells in immunoincompetent host nerves. Hypothetical signals for myelination of mouse axons were normally received by sural nerve Schwann cells of a patient with neurofibromatosis, but not by Schwann cells from neurofibromas or malignant schwannomas.

Autonomic failure in hydrencephaly

Autonomic functions were studied in three patients with hydrencephalus and five with hydrocephalus. Autonomic failure of central origin was found in the patients with hydrencephalus; whereas, those suffering from hydrocephalus had essentially normal autonomic function. In two patients with hydrencephalus, the hypothalamus was markedly abnormal but the rest of the autonomic nervous system was histologically normal. From this it is concluded that in some patients with mental and motor retardation, autonomic failure may be of cerebral origin but that this is not a feature of patients with hydrocephalus.

Sural Nerve Biopsies in Pediatric Neurological Disorders

The results of sural nerve biopsies in 18 patients with disorders of the nervous system are reported. Involvement of the peripheral nerves was found histologically in some cases in which this was not suspected clinically or from electrodiagnostic examination. Peripheral nerve involvement was found not only in metachromatic leukodystrophy but also in a miscellaneous group of patients with nervous involvement characterized by hypotonia and in some with polymyositis. It is suggested that sural nerve biopsy, which is well tolerated by children, should find a place in the investigation of patients with neuromuscular and other neurological disorders even in the absence of clinical or electrodiagnostic evidence of peripheral nerve involvement.