High-frequency stimulation of the entopeduncular nucleus improves dystonia in dtsz hamsters

High-frequency stimulation (HFS) of the internal pallidum (GPi) has been reported to improve generalized dystonia in patients. Currently, dystonia is thought to be associated with disturbed neuronal activity of GPi neurons. Similar findings have been observed in the dtsz hamster, a model of idiopathic paroxysmal non-kinesiogenic dystonia. For this reason, we investigated the effect of bilateral HFS of the entopeduncular nucleus (EPN, rodent homologue of GPi) on the severity of dystonia. Bilateral EPN-HFS resulted in a reversible decrease of dystonia severity up to 50% when compared to both pre- and post-HFS scores, and controls. Our results underline the pathophysiological role of the EPN in the dtsz hamster and suggest the suitability of this model to further investigate mechanisms of HFS in dystonia.     

Associations between body satisfaction and physical activity in adolescents: implications for programs aimed at preventing a broad spectrum of weight-related disorders

This study examined associations among body satisfaction and physical and sedentary activities in 4,746 adolescents. Boys with lower body satisfaction reported significantly less physical activity and more TV viewing than boys with higher body satisfaction. In girls, trends were similar, but associations were not statistically significant. Associations were similar among overweight youth. In no instances, were lower levels of body satisfaction significantly associated with higher physical activity levels. These findings suggest that interventions that strive for increased physical activity in youth should avoid strategies that may lead to decreases in body satisfaction. Rather, programs should simultaneously strive to increase physical activity and improve body satisfaction. This type of approach may be effective in preventing obesity while avoiding increasing participants' risk for a low body satisfaction, unhealthy weight control practices, and eating disorders.     

Use of psychotropic medications by youths in therapeutic foster care and group homes

This article examines the use of psychotropic medications among youths in residential community-based placements. Data are from a study funded by the National Institute of Mental Health of therapeutic foster care (June 1999 through May 2001) and group homes (January through June 2001). Data were collected from staff by means of in-person interviews. Many youths in both settings received psychotropic medications, and approximately one-half were taking multiple psychotropic medications. After the authors controlled for demographic and clinical factors, the youths in group homes were nearly twice as likely as the youths in therapeutic foster care to receive medication. However, residential setting was not related to polypharmacology. Additional work is needed to study the appropriateness of use and implications of such patterns for research on intervention outcomes.     

Disentangling the web: neologistic perseverative errors in jargon aphasia

This article explores the relationship between the neologisms and perseverative errors produced by KVH, a man with severe neologistic jargon aphasia. Detailed examination of KVH's level of language processing breakdown revealed mild difficulties with phonological encoding and severe difficulties accessing the lexical form of the word. Many of KVH's neologisms contained phonemes perseverated from previous neologisms, suggesting an integral relationship between the production of neologisms and the perseveration of phonemes. Furthermore, KVH's patterns of whole word (total)and phonological (blended) perseverations reflected his proposed underlying language processing deficits, consistent with recent literature on perseveration (e.g.,Cohen and Dehaene, 1998). However, the simple binary distinction oftotalandblendedperseveration is proposed to be somewhat limited for understanding the underlying nature of KVH's complex neologistic errors. Possible explanations regarding the mechanisms underlying the production of KVH's neologistic and perseverative errors also are discussed.     

Evaluation of chest motion and volumetry during the breathing cycle by dynamic MRI in healthy subjects: comparison with pulmonary function tests

RATIONALE AND OBJECTIVES: To investigate diaphragm and chest wall motion during the whole breathing cycle using magnetic resonance imaging (MRI) and a volumetric model in correlation with spirometry. MATERIALS AND METHODS: Breathing cycles of 15 healthy volunteers were examined using a trueFISP sequence (5 slices in 3 planes, 3 images per second). Time-distance curves were calculated and correlated to spirometry. A model for vital capacity (VC), continuous time-dependent vital capacity (tVC), and investigating the influence of horizontal and vertical parameters on tVC was introduced. RESULTS: Time-distance curves of the breathing cycle using MRI correlated highly significant with spirometry (P < 0.0001). VC calculated by the model was similar to VC measured in spirometry (5.00 L vs. 5.15 L). tVC correlated highly significantly with spirometry (P < 0.0001). Vertical parameters had a more profound influence on tVC change than horizontal parameters. CONCLUSIONS: Dynamic MRI is a simple noninvasive method to evaluate local chest wall motion and respiratory mechanics. It widens the repertoire of tools for lung examination with a high temporal resolution.     

Dynamic magnetic resonance tomography and proton magnetic resonance spectroscopy of prostate cancers in rats treated by radiotherapy

RATIONALE AND OBJECTIVES: To establish an experimental setting for monitoring perfusion and metabolism in orthotopic prostate cancer at 1.5 T using dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) and 1H-MR spectroscopy (MRS). METHODS: Dunning rat prostate cancer cells were injected into the prostate by open surgery. Twelve tumor-bearing rats (5 of these irradiated) and 6 healthy controls were followed up using gadolinium-diethylenetriaminepentaacetic acid -enhanced dynamic MRI and 1H-MRS. Amplitude and the exchange rate constant kep were calculated (2-compartment model). From 1H-MR spectra, ratios of choline (Cho) and creatine (tCr) were calculated. All tumors were examined histologically. RESULTS: On DCE MRI parameter maps, tumors showed increased vascularization. kep and microvessel density were correlated (r = 0.97). Tumors showed elevated Cho/tCr and an unexpected lipid fraction (2.0-2.2 parts per million). Irradiation slowed tumor growth significantly. Changes of perfusion and metabolism could be detected in all tumors during follow up. CONCLUSION: DCE MRI and 1H-MRS has potential to characterize orthotopic Dunning prostate cancer in rats, which is a promising model similar to human prostate carcinomas.     

Outcomes of Fort Jackson's Physical Training and Rehabilitation Program in army basic combat training: return to training, graduation, and 2-year retention

Basic trainees at Fort Jackson, South Carolina, who were unable to continue basic combat training (BCT) because of a serious injury were assigned to the Physical Training and Rehabilitation Program (PTRP). Between January 3, 1998 and July 24, 2001, 4258 trainees were assigned to the PTRP. Using a retrospective cohort study design, return to training and BCT graduation rates were evaluated. PTRP graduates were compared with matched non-PTRP graduates for 2-year retention in the Army. More PTRP women than men were discharged from the PTRP (60% and 48%, respectively, p < 0.01). Of PTRP trainees returning to BCT, 10% and 12% of men and women, respectively, were discharged from the Army compared with overall Fort Jackson discharge rates of 9% and 15% for men and women, respectively. Comparing PTRP graduates to matched non-PTRP graduates, there were no differences in 2-year retention for men (14.9% and 14.7%, respectively; p = 0.93) or women (26.6% and 30.1%, respectively; p = 0.19). Despite the high discharge rate in the PTRP, the BCT discharge rate for trainees who successfully rehabilitated was similar to the overall discharge rate at Fort Jackson. The 2-year retention in service for PTRP trainees who graduated from BCT was similar to that of non-PTRP trainees.     

Facial expression recognition and subthalamic nucleus stimulation

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor signs in Parkinson's disease. However, clinical studies suggest that DBS of the STN may also affect cognitive and emotional functions. OBJECTIVE: To study the impact of STN stimulation in Parkinson's disease on perception of facial expressions. RESULTS: There was a selective reduction in recognition of angry faces, but not other expressions, during STN stimulation. CONCLUSIONS: The findings may have important implications for social adjustment in these patients.     

Coexistence of tuberous sclerosis and Friedreich ataxia

Tuberous sclerosis (TS) is caused by point mutations in the TSC1 or TSC2 genes on chromosomes 9q33-34 or 16p13, respectively. Clinical manifestations can be quite variable but are primarily limited to cutaneous, neurologic, and cardiovascular abnormalities. Phenotypes range from neurologically devastated to those with silent lesions. A 34-year-old patient with genetically documented TSC1 developed progressive ataxia over a decade, without TS lesions to correlate with this finding. After evaluation of common causes including long-term antiepileptic regimens, DNA testing for hereditary ataxias was performed and revealed the presence of an additional mutation on chromosome 9. The patient was homozygous for the Friedreich ataxia (FA) mutation, with 500 and 700 GAA repeats in the FRDA gene on chromosome 9q13. There is no established relationship between these two disorders and the occurrence of two mutations on the same chromosome is probably coincidental but emphasizes the importance of searching for additional genetic causes when the phenotype does not fit with an established genetic diagnosis.