Evidence of somatotopic organization of the sensory thalamus based on infarction in the nucleus ventralis posterior.

BACKGROUND: This is to describe a restricted sensory syndrome of unique distribution due to thalamic infarct. CASE DESCRIPTION: We report a case of pure sensory disturbance involving the left intraoral and perioral regions and the tips of the thumb and forefinger of the left hand. Magnetic resonance imaging revealed a small infarct in the contralateral thalamus, presumably affecting the nucleus ventralis posterior. CONCLUSIONS: This patient provides an excellent correlation between clinical findings and thalamic representation of body surface as established during stereotactic procedures.     

The perineuronal net in the fastigial nucleus of the rat cerebellum. A Golgi and quantitative study

Summary The morphological study of the rat fastigial nucleus with the Golgi-Rio Hortega method showed the presence of glial perineuronal nets surrounding the large neurons, but not the small ones. This perineuronal net appeared as a mesh of tenuous glial processes which covers the neuronal perikarya and proximal dendrites. The small alveolate compartments in this mesh seem to correspond to the holes for the synaptic boutons. Our results also indicate that the perineuronal net is derived from interneuronal protoplasmic and velate astrocytes.Using camera lucida drawings of this perineuronal net we have made a quantitative estimation of the size and density of synaptic boutons on these large neurons. The average numerical density of synaptic boutons was about 19 per 100 m² of the neuronal surface, the mean area of the synaptic holes being 2.5 m². Furthermore, the quantitative data evidence that about 52.5% of the neuronal surface is presumably occupied by synaptic boutons whereas the remaining 47.5% is covered by the glial processes of the perineuronal net.Semithin sections prepared from thick Golgi sections were used for the cytological study of the neurons surrounded by this glial pericellular network. The possible functional significance of the perineuronal net in the regulation of synaptic transmission in the fastigial cerebellar nucleus is briefly discussed.     

Serum levels of total IgE in non-allergic children

The purpose of this study was to establish the range of total serum IgE in a healthy population lacking personal and family history of allergy, as well as the influence of genetic factors (family history of allergy), environmental factors (degree of air pollution), age, and sex on the serum IgE levels. Using a commercial enzyme immunoassay (Phadezym IgE Prist) the mean serum level of IgE was determined in 363 non-atopic children from 0 to 12 years of age. The geometric mean of serum IgE increased according to age, indicating a positive correlation between both. Higher mean values of serum IgE were found for children with a family history of allergy, than for children without (27.82 and 14.49 U/ml respectively). The percentage of variation due to age was about 94.5% in children with no family history of allergy. The mean value of serum IgE increased with the degree of air pollution in the living area (15.49 U/ml in non-polluted areas, 20.78 U/ml in very polluted areas). However, the influence of air pollution was smaller than the influence of family history on the mean values of serum IgE. The mean value of serum IgE was not modified by sex.     

Early onset cerebellar ataxia and preservation of tendon reflexes: clinical phenotypes associated with GAA trinucleotide repeat expanded and non-expanded genotypes

The aim of this study was to determine phenotypie characteristics of patients with early onset cerebellar ataxia (EOCA) with preserved tendon reflexes. The series comprises 25 patients, representing 10% of all ataxic patients who have been genetically studied in our laboratory since 1990. There were 11 males and 14 females. Fourteen patients were homozygous for the GAA expansion on chromosome 9q13 (group 1) and therefore a diagnosis of Friedreich's ataxia with retained reflexes (FARR) was given. The remaining 11 patients had two normal non-expanded alleles (group 2) and a working diagnosis of EOCA with retained reflexes (EOCARR) was established. Mean ages of onset were 13.7 +/- 5.9 years (3-25) for group 1 and 10.3 +/- 7.3 for group 2; the difference was not significant. Frequencies of symptoms and signs were also comparable for both groups the only significant differences being the higher frequency of nystagmus, cardiomyopathy and sensory neuropathy in group 1 patients. There was a tendency for FARR patients to have higher frequencies of hypopallesthesia in the lower limbs and skeletal deformities. In none of the cases diabetes mellitus was observed. We conclude that differentiation of FARR and EOCARR may be suspected by classical clinical and electrophysiological data and confirmed by analysis of the GAA repeat.     

Friedreich's ataxia presenting with pure sensory ataxia: a long-term follow-up study of two patients

We describe two patients with Friedreich's ataxia whose presenting symptomatology was for years progressive tabetic ataxia. Based upon the initial clinical, electrophysiological and nerve biopsy data, a diagnosis of idiopathic sensory neuropathy was established. Subsequent examination of the kin showed that three sisters of case 1 had Friedreich's ataxia. Upon serial clinical and electrocardiographic study, both patients eventually developed a florid Friedreich's ataxia, including cardiomyopathy. Our findings indicate that at onset Friedreich's ataxia may be indistinguishable from sensory neuropathy and also that serial examination and investigation of kinship are essential steps for accurate diagnosis.     

Organization of nucleoli and nuclear bodies in osmotically stimulated supraoptic neurons of the rat

This study has analyzed variations in the number of nucleoli and nuclear bodies, as well as in their ultrastructural and cytochemical organization, after the osmotically induced activation of supraoptic nucleus (SON) neurons of the rat. The number of nucleoli and nuclear bodies and also the nucleolar size were determined on smear preparations of previously block-impregnated SON. The mean number of nucleoli per cell was 1.35 +/- 0.6 (mean +/- SDM) in control rats. No significant variations in this value were registered either in dehydrated or rehydrated rats. The mean nucleolar volume and the total nucleolar volume per cell showed a significant increase in dehydrated rats with respect to the controls, whereas these two parameters tended to return to control values in rats rehydrated after dehydration. The mean number of nuclear bodies per cell increased significantly from 0.56 +/- 0.50 (mean +/- SDM) in control rats to 1.54 +/- 1.1 after 6 days of dehydration. By electron microscopy, SON neurons displayed a reticulated nucleolar configuration. After the osmotically induced neuronal activation, there was an increase in the proportion of the total nucleolar area occupied by the granular component, and also a reduction in the mean fibrillar-center area. The most characteristic nucleolar features in rehydrated rats were the tendency for the granular component to be segregated and the occurrence of intranucleolar vacuoles. Ultrastructural cytochemistry with a specific silver method revealed a selective silver reaction on the coiled threads of the nuclear bodies--identified as "coiled bodies"--and on the nucleolar fibrillar components in all animal groups studied. Since nucleoli play a major role in ribosome biogenesis, a relationship between these nucleolar changes and the level of cellular activity of SON neurons is proposed. Furthermore, the response of nuclear "coiled bodies" to neuronal activation suggests their participation in the processing and transport of rRNA precursors.     

Fatal familial insomnia: clinical, neuropathological, and genetic description of a Spanish family

The clinical presentation and evolution, neuropathological findings, and genotyping of three members of a Spanish family affected with fatal familial insomnia are reported. The mother and two of her offspring developed a rapidly evolving disease with insomnia and behavioural disorders as the initial symptoms and died between 5 and 10 months after the onset of the illness. Frontal brain biopsy in the mother disclosed only non-significant spongiosis, and full neuropathological examination of her offspring showed thalamic and olivary degeneration with isolated focal cortical spongiosis. Genetic examination could only be performed in the contemporary patients and both harboured the prion protein (PrP) 178Asn mutation and homozygous 129 Met/Met genotype.