Motor and non-motor sequence learning in children and adolescents with cerebellar damage.

Cerebellar involvement in motor and non-motor sequence learning was examined with serial reaction time tasks (SRT). Our sample consisted of 8 children and adolescents who had undergone surgical removal of a benign posterior fossa tumor (PFT) during childhood. None of them had undergone chemotherapy or cranial radiation therapy (CRT). Ages ranged from 1-11 years at surgery and 9-17 years at testing. The children were tested not earlier than 2.5 years after surgery (M = 5.9 years), enabling brain plasticity and recovery of functions. Their performance was compared with a matched control sample. The PFT group was not impaired in the implicit learning of sequences, as reflected in their performance in blocks with a repeated sequence, both before and after a random block. However, in the perceptual task, their performance deteriorated more than that of the control group when a random block was introduced, suggesting that it was more difficult for the patients to respond flexibly or change their response set when encountering changing task demands. These results are in line with another study by our group on task switching with the same patients.     

Is the P300 deficit in alcoholism associated with early visual impairments (P100, N170)? An oddball paradigm

OBJECTIVE: Studies exploring chronic alcoholism with event-related potentials (ERPs) have shown delayed latency and reduced amplitude of the P300, a long-lasting positive potential reflecting decisional processing. This P300 deficit in alcoholism is generally interpreted as a disturbance in central nervous system inhibition or in memory/attention. The present study aimed at identifying if this electrophysiological deficit is already present on earlier components, and advances a new hypothesis concerning the interpretation of the P300 alteration. METHODS: Patients suffering from alcoholism and matched healthy controls had to detect, in an oddball paradigm, emotional faces among a succession of neutral faces. Behavioral performance and ERP data (recorded from 32 electrodes) were analyzed. RESULTS: In line with previous studies, data showed that alcoholism led to a P300 deficit. Moreover, we observed for the first time that this deficit begins at earlier visual (P100) and face-processing (N170) stages, and we found high positive correlations between P100, N170 and P300 for amplitude and latency values, suggesting cumulative deficits on the cognitive continuum. CONCLUSIONS: We suggest that the P300 deficit observed in chronic alcoholism could be linked to earlier visuo-spatial deficits rather than being an impairment of the specific processes linked to the P300. SIGNIFICANCE: These results call for reconsidering the interpretation of P300 impairments at a fundamental and clinical level, and shows that earlier ERP components must be taken into account in future studies.     

Chronic toxicology and carcinogenesis studies of Telone II by gavage in Fischer-344 rats and B6C3F1 mice

Telone II (technical grade, 1,3-dichloropropene), a soil fumigant, was evaluated in chronic toxicology/carcinogenicity studies using Fischer-344 (F344) rats and B6C3F1 mice of both sexes. Doses administered were 0, 25, or 50 mg/kg to rats and 0, 50, or 100 mg/kg to mice. Telone II was given in corn oil by gavage 3 times per week for 104 wk. Ancillary studies were conducted to determine time-related effects, in which dose groups containing 5 male and 5 females rats were killed after receiving Telone II for 9, 16, 21, 24, or 27 mo. The primary organs affected were the forestomach (rats and mice), urinary bladder (mice), lung (mice), and liver (rats). Compound-related non-neoplastic lesions included basal-cell or epithelial hyperplasia of the forestomach (rats and mice), epithelial hyperplasia of the urinary bladder (mice), and hydronephrosis (mice). Neoplastic lesions associated with administration of Telone II included squamous-cell papillomas of the forestomach (male and female rats, female mice), squamous-cell carcinomas of the forestomach (Male rats, female mice), transitional-cell carcinomas of the urinary bladder (female mice), alveolar/bronchiolar adenomas (female mice), and neoplastic nodules of the liver (male rats). Although cis- and trans-1,3-dichloropropene are the principal components of Telone II, the presence of 1% epichlorohydrin, a direct-acting mutagen and carcinogen added as stabilizer, may have influenced the development of forestomach lesions. The results of the ancillary studies supported the findings of the carcinogenesis studies and demonstrated the time-dependent development of lesions in the forestomach (basal-cell hyperplasia and squamous-cell papilloma). Under the conditions of these gavage studies, Telone II was shown to be carcinogenic in male and female F344 rats and female B6C3F1 mice. Although the study in male B6C3F1 mice was considered inadequate because of the low survival resulting from suppurative inflammation of the heart (myocarditis) in the control group, there was some indication of Telone II-related increases of transitional-cell carcinomas of the urinary bladder, squamous-cell papillomas of the forestomach, and alveolar/bronchiolar adenomas and carcinomas of the lung.     

Lymphedema as a presenting sign of toxocariasis

Summary Toxocariasis in children is usually an asymptomatic infection and those with clinical illness have non-specific systemic or local manifestations. We present a 24-month-old boy with bilateral lymphedema of the feet as the main clinical manifestation of toxocariasis. The child presented with limping and nonpitting edema of both feet. Laboratory investigation revealed leucocytosis of <20,000/mm³ with a differential count of <50% eosinophils. No other cause of edema was found. The ELISA for toxocariasis revealed a high titer of 1:4,096. The limping and the lymphedema disappeared during the third week of his illness. We suggest that toxocariasis should be considered as a possible cause of lymphedema and eosinophilia in young children.Zusammenfassung Die Toxocariasis nimmt bei Kindern in der Regel einen asymptomatischen Verlauf. Wenn Krankheitszeichen auftreten, handelt es sich um unspezifische Allgemeinsymptome oder lokale Symptome. Wir berichten über einen 24 Monate alten Jungen, bei dem ein bilaterales Lymphödem der Füße die Hauptmanifestation der Toxocariasis war. Das Kind hinkte und hatte an beiden Füßen ein nicht dellenbildendes Ödem. Dabei bestand eine Leukozytose von >20 000/mm³ mit >50% Eosinophilen im Differentialblutbild. Andere Ursachen für das Ödem waren nicht zu finden. Der ELISA für Toxocariasis ergab einen hohen Titer von >1:4 096. Hinken und Lymphödem verschwanden im Verlauf von drei Wochen. Wir verweisen auf die Möglichkeit einer Toxocariasis als mögliche Ursache für Lymphödem und Eosinophilie bei kleinen Kindern.

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Lymphödem als Primärsymptom einer Toxocariasis

     

Successful chemotherapeutic treatment of diencephalic syndrome with continued tumor presence

A 7-month-old infant with typical features of diencephalic syndrome (DES) associated with a hypothalamic mass, most probably a glioma, was treated with chemotherapy. The tumor showed clear shrinkage, but after more than 2 years regrowth was noted. During the treatment period the child regained normal growth and became free of symptoms. As radiation therapy, especially at a young age, has significant adverse effects and a neurosurgical approach to the diencephalic region also has the potential to cause significant sequelae, a chemolherapeulic option, when it exists, is preferred. Thus, in an infant in whom a glioma is suspected to be the cause of the DES, based on the clinical picture and the neuroimaging appearance, chemotherapy should be considered the primary therapeutic modality. Even if its effect is temporary, its use is well justified. The most appropriate treatment protocol still needs to be determined.     

Liver candidiasis

Liver candidiasis is characterised by small abscesses spread throughout the organ at random. These lesions may be identified sonographically. In the active phase of the disease, hepatomegaly is seen together with the wheel in wheel phenomenon, the wagon wheel appearance and/or the bull's eye lesion. Later on, hypoechoic defects develop. When the echogenic foci are revealed, the healing phase is initiated. These manifestations are demonstrated in 4 pediatric oncology patients. The sonographic patterns as well as its differential diagnosis from primary liver tumors, metastatic infiltrations or other abscess formations are discussed.     

Hemorrhage associated with “bone crisis” in Gaucher's disease identified by magnetic resonance imaging

Children suffering from Gaucher's disease were examined by magnetic resonance imaging (MRI) during a characteristic episode of bone crisis. An unexpectedly high intramedullary as well as subperiosteal signal was observed on both the T1 and T2-weighted sequences in 5 patients, suggesting a subacute hemorrhage or hematoma. It is conceivable that such a painful hemorrhage is an important component of the bone crisis phenomenon. Furthermore, in these cases this is a specific sign which may enable differentiation of bone crises from other types of bone pain associated with Gaucher's disease.     

Visual pathway glioma: an erratic tumour with therapeutic dilemmas

Accepted 12 September 1996
OBJECTIVE—Our experience in children with visual pathway glioma (VPG) was reviewed to delineate its clinical characteristics.
DESIGN—The charts and imaging studies of 21 children with VPG who were followed up in our centre during the last 12 years were reviewed and summarised.
RESULTS—VPG accounted for 13.1% of all brain tumours treated during this period. Sixty two per cent of the children with VPG had neurofibromatosis type 1 (NF-1). Among these, more than 60% were detected as part of routine work up. In some cases decreasing visual function preceded the appearance of the VPG on imaging studies. Tumour growth rate was markedly unpredictable. All treatment modalities employed led to tumour shrinkage and stabilisation for a variable period, but none was successful in totally eradicating the tumour. Complications were less severe after chemotherapy compared with radiotherapy. Three children died, none with NF-1, with a globular hypothalamic/chiasmatic tumour and accompanying electrolyte abnormalities.
CONCLUSIONS—NF-1 is a favourable prognostic marker for VPG. Whenever possible a period of observation is necessary before treatment is initiated, during which time tumour size and visual function should be closely followed up; an untoward change in either of these is an indication for the start of treatment, preferably chemotherapy first. The combination of a globular hypothalamic/chiasmatic glioma and electrolyte abnormalities in a child without NF-1 are related to a poor prognosis.

     

VISUAL PATHWAY TUMORS AND HYDROCEPHALUS

The authors evaluated the impact of hydrocephalus on the clinical picture of children with visua pathway tumor (VPT) with or without neurofibromatosis (NF).Charts of children with VPT treated in the authors' center since 1985 were retrospectively reviewed, and those with hydrocephalus were selected and summarized. Thirty-five children with VPT were found, of whom 20 had NF.Hydrocephalus was found in 4 children with NF (20% ) and in 5 without NF (33.3% ). In 6 ofthechildren, ventricular dilatation with signs of acute increased intracranial pressure already existed at the time of diagnosis and the hydrocephalus was shunted at this time. In the other 3 children, all with NF,the hydrocephalus resulted from slowly developing aqueductal stenosis, leading in 2 to severe visual acuity deterioration. The results suggest that in children with VPT and NF, hydrocephalus, and especially hydrocephalus resulting from aqueductal stenosis, is more frequent than in the general population of NF patients, and less frequent than in VPT patients without NF. The possibility of the indolent development of hydrocephalus should be borne in mind while following children with NF. The optic nerve, when already involved with a glioma, is more vulnerable to increased pressure. Thus, in children with VPT and NF, any ventricular dilatation should lead to a consideration of early shunting.     

Pulse pressure is more susceptible to the white coat effect than is systolic blood pressure: observations from real-life ambulatory blood pressure monitoring

BACKGROUND: Pulse pressure is a derivative of arterial stiffness. We have previously demonstrated ambulatory pulse pressure to be relatively independent from the blood pressure (BP) lowering during sleep, and thus of a neurogenic effect. On the other hand, white coat BP effects are thought to involve neurogenic activation. The aim of this work was to analyze white coat induced variability in pulse pressure. METHODS: Percent clinic-awake differences in systolic BP (SBP) and pulse pressure (white coat effects) were calculated for 688 consecutive subjects (mean age 60 +/- 16 years, 58% female). Of the subjects, 23% had controlled hypertension, 45% uncontrolled hypertension, 8% normotension, and 4% isolated office hypertension; all were referred to our unit for 24 h ambulatory BP monitoring. RESULTS: Pulse pressure highly correlated with SBP (r = 0.82, P <.00001). We found a larger white coat effect on pulse pressure than on SBP (8.3% and 5.2%, respectively, P < or =.0001). This was true in all subgroups except in normotensive subjects. Specifically, the magnitude of the white coat effect on pulse pressure was greater than on SBP in subjects with treated hypertension, untreated hypertension, and isolated office hypertension, and in young hypertensive subjects, older subjects, and those with diabetes. CONCLUSIONS: Although pulse pressure is related to the mechanical properties of large arteries, it is also influenced by the white coat effect, a neurogenic process. Furthermore, in hypertensive but not in normotensive subjects, the white coat effect on pulse pressure is significantly more pronounced than on SBP.