Nicholas J. Lenn

Moyamoya and other causes of stroke in patients with Down syndrome

Twenty-seven new cases of stroke in Down syndrome are reported, two probands, 13 patients from review of institutional records, and 12 patients from a survey of child neurologists. Forty-one patients from previous reports are summarized. Most stroke episodes were related to congenital heart disease and infections. Seven cases were associated with angiographic abnormalities; there were three cases of unknown etiology and four cases of moyamoya. The understanding of moyamoya and other causes of stroke may be advanced by further study of stroke in Down syndrome patients.

Postinfectious encephalomyelitis with localized basal ganglia involvement

The diagnosis of postinfectious encephalomyelitis with symmetric lesions in the basal ganglia was confirmed by magnetic resonance imaging in 2 patients. A 7-year-old patient experienced severe dystonia and hyperreflexia; magnetic resonance imaging demonstrated bilateral lesions in the putamina and basis pontes. The other patient, a 2-year-old female, manifested hypotonia, facial grimacing, and athetosis. Symmetric lesions in the globus pallidus and substantia nigra were demonstrated by imaging studies. The nature and monophasic course of illness in these 2 patients, as well as the symmetric involvement of specific regions of the basal ganglia, may result from an immune-mediated postinfectious demyelinating process.

Subdivisions of the interpeduncular nucleus: A proposed nomenclature

A compromise terminology for subdivisions is proposed which integrates the two previous standard and two recent and more detailed subnuclear schemes. The unpaired median subnuclei are called rostral, central and apical. The paired subnuclei are called rostral lateral, dorsal lateral, intermediate and lateral. A plea is made for attention to these consistent subdivisions, and for uniformity of terminology regardless of the parameters studied.

Choline acetyltransferase immunoreactivity is localized to four types of synapses in the rat interpeduncular nucleus

The cholinergic synapses of the rat interpeduncular nucleus (IPN) were demonstrated by immunostaining that utilized a monoclonal antibody directed against choline acetyltransferase. The rostral, central, intermediate and lateral subnuclei of the IPN each contained a single type of immunoreactive terminal. Immunoreactivity was localized to synaptic vesicle membranes (especially at the contact zones), and longitudinal microtubules in preterminal portions of axons. Terminals were identified by comparison to previous studies of the synaptic organization of the IPN. In the rostral subnucleus, the immunoreactive terminals were characterized by their content of spherical vesicles, 45 nm in diameter, intermixed with moderate numbers of dense-cored vesicles, 75-100 nm in diameter. These terminals formed asymmetrical contacts. They correspond to the more numerous of the two types of axodendritic terminals described in this subnucleus, i.e. those which degenerate after lesions of the habenula. The moderate number of immunoreactive terminals in the lateral subnucleus contained pleomorphic vesicles, 30-45 nm in diameter. Up to three of these formed symmetrical contacts with individual dendrites, which ranged in diameter from 0.35 to 0.55 micron. The other types of axodendritic terminal in this subnucleus, which often contacted the same dendrites, were unstained. These latter terminals have been interpreted as being those which contain substance P. The immunoreactive terminals in the diameter, and formed markedly asymmetrical en passant contacts with small dendritic processes or spines. The immunoreactive terminals in the intermediate subnucleus had the same presynaptic and contact morphology. Many were clearly crest synapses. The remainder appeared to be such, but seen only partially within the plane of section. In the intermediate subnucleus there were up to several hundred immunostained terminals per grid square in some sections. These findings are consistent with the existence of a dense cholinergic projection to the IPN. The habenular region, are shown to crest and S synapses, both of which generate after lesions of the cholinergic innervation of other subnuclei of the IPN increases understanding of the relation of cholinergic to other transmitters localized to various portions of this nucleus.

Fatal Hepatocerebral Syndrome in Siblings Discordant for Exposure to Valproate

Summary: Occurrence of a progressive encephalopathy with seizures in siblings was associated with hepatic pathology. One of these patients was exposed to valproate (VPA) and developed hepatic necrosis, confirmed at autopsy. The other had not been exposed to VPA, and her hepatic lesions at autopsy were less severe. The liver pathology in both was within the range described in previous cases of liver disease attributed to VPA. These facts and the otherwise similar course of their disease suggests that in these patients, and probably in other cases of fatal liver failure attributed to VPA, the drug actually either had no effect or acted only to increase the severity of the preexisting hepatic component of the hepatocerebral disorder.

Gestational Changes in the Germinal Matrix of the Normal Rhesus Monkey Fetus

ABSTRACT: To explain the reported predisposition to germinal matrix hemorrhage in premature infants, pathogenetically important morphological features of the germinal matrix should be present in the 3rd trimester and rapidly change near term. Such features were sought in this study of the germinal matrix and its vasculature in normal rhesus monkey fetuses. The matrix cells, glia, ependyma, and capillaries showed no important structural changes during the 3rd trimester. The terminal vein tributaries were greatly enlarged by 148 days, but cellular and collagen support in their walls was minimal at this time. The latter features developed by the final days of gestation. These findings do not support a structural immaturity or specialization of the germinal matrix predisposing to germinal matrix hemorrhage. Our results, therefore, support the recent emphasis on physiological parameters in the pathogenesis and prevention of germinal matrix hemorrhage.

Congenital Radial Nerve Pressure Palsy

of the hemorrhagic ascites was certainly the inflamed, hemorrhagic omentum. Leakage of pancreatic enzymes from the ectopic pancreatic rests are postulated to be the inciting factor of the omental abnormality. The elevation of amylase in the ascitic fluid and the presence of inflammation in the pancreatic rests offers support for this proposal. The inflammation and pathologic changes were less extensive than those usually seen in true pancreatitis. This can, perhaps, be explained by the relatively small size of the pancreatic rests, the apparent isolation of the process by omental adherence, and the relative deficits in secretion of pancreatic enzymes in infants.’ The gradual increase of the potency of pancreatic secretions may have played a role in the progressive development of symptoms in this patient.~

HLA-DR2 in childhood narcolepsy

A 6-year-old boy with behavioral changes was found to have clinical and electrographically defined narcolepsy. He has HLA-DR2 as do virtually all adult narcoleptics. This finding raises new diagnostic, etiopathogenetic, and future therapeutic issues.

Facial sparing as a feature of prenatal-onset hemiparesis

The presence of facial weakness was prospectively correlated with age of onset of hemiparesis. Facial weakness was not associated with prenatal-onset hemiparesis, but sometimes occurred with onset of hemiparesis during the first year of life. In contrast, facial weakness was generally present when all patients with postnatal-onset hemiparesis were considered as a group. With double hemiparesis, facial weakness was common, regardless of age at onset. These findings suggest that facial sparing results from plasticity of the developing corticobulbar tract, the critical period ending during the first year of life. Decreased synapse elimination of uninjured, ipsilateral terminals is suggested as the mechanism of facial sparing. Facial weakness accompanying double hemiparesis thus would be a reflection of absence of an uninjured pathway.

Neurogenesis in subnuclei of the rat interpeduncular nucleus and medial habenula

Development of the rat habenulo-interpeduncular system is of interest because of its highly ordered adult structure, including seven subnuclei within the interpeduncular nucleus (IPN), localization of synapses of different types and medial habenular (MH) sites of origin within the subnuclei, and differential localization of neurochemicals amongst the subnuclei. In order to further investigate the mechanisms by which these features are produced, the birthdays of neurons within IPN and MH were investigated. All IPN neurons were formed on embryonic days (E) 12 to 16. Birthdays varied for the subnuclei of IPN with the earliest being the serotonin containing apical subnucleus (p less than 0.0001) and the latest being the rostral subnucleus (p less than 0.0001). Rostral lateral and lateral subnuclei were approximately simultaneous with apical, and the intermediate and central subnuclei, related to each other in a number of other ways, had simultaneous birthdays earlier than the rostral subnucleus (p less than 0.0001) and later than the other subnuclei (p less than 0.0001). The medial habenula was found to consist of three regions, termed medial, lateral and dorsal, whose neurons undergo their final mitoses on E15-16, 16-17 and 17-18, respectively. These findings provide additional support for the validity of IPN subnuclei as currently delineated. They suggest mechanisms of development which involve early interactions between specific groups of MH neurons and specific groups of IPN neurons. It is proposed that a sequence of several control mechanisms operates during development to produce this complex system.