Improved white matter integrity after contralateral seventh cervical nerve transfer measured by tractographic representation.

Contralateral C7 (CC7) nerve transfer surgery was shown to significantly improve the spasticity condition and the motor function of paralyzed arms. However, the involvement of the white matter tract in the recovery process is not well established. We here investigated the possible biologic explanation for this phenomenon. A 62-year-old female patient, who suffered from spastic hemiparesis due to intracranial hemorrhage, underwent CC7 transfer surgery 13 years after the initial stroke event. Six months after the surgery, the patient's Modified Ashworth Scale and Fugl-Myere score improved, even though no specific rehabilitation programs were applied. Diffusion tensor imaging (DTI) was performed before and 6 months after the surgery. The pre-surgery DTI showed both ipsilesional and contralesional CST from the cerebral peduncles to the cortices. After surgery, however, only the contralesional CST was observed. In conclusion, functional alterations of the brain white matter tract after CC7 nerve transfer surgery possibly provided a neurophysiological substrate for ameliorating the spasticity and improving the motor function in a spastic hemiplegia patient.

High prevalence of leukoaraiosis in cerebral magnetic resonance images of patients on peritoneal dialysis.

BACKGROUND: Leukoaraiosis is a term used to define the abnormal appearance of subcortical white matter of the brain by means of neuroimaging and is regarded as an intermediate surrogate of stroke. The goal of this study is to identify the prevalence of leukoaraiosis and analyze predictors of risk of leukoaraiosis. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: 57 peritoneal dialysis (PD) patients without diabetes treated in 3 academic medical-associated dialysis units who did not have a history of cerebrovascular disease or neurological symptoms compared with a convenience sample of 57 age- and sex-matched hypertensive control subjects with normal renal function. PREDICTOR: End-stage renal disease treated by PD compared with hypertension, adjusted for clinical and laboratory characteristics. OUTCOME & MEASUREMENT: Hyperintense areas on magnetic resonance imaging T2 high-signal intensity scoring system. RESULTS: The prevalence of leukoaraiosis was significantly greater in patients on PD therapy than controls (68.4% versus 17.5%; P < 0.001). High T2 signal intensity score in patients on PD therapy compared with controls was significantly higher in the anterior circulation of the brain, relatively sparing the posterior fossa. End-stage renal disease, age, and poor control of blood pressure were significant independent predictors of leukoaraiosis. LIMITATIONS: There is the possibility that biases regarding the selection of enrolled patients had an influence on a study result. CONCLUSIONS: Cerebral magnetic resonance imaging of PD patients without evidence of cerebrovascular disease showed a high prevalence of leukoaraiosis in the anterior circulation of the brain. Old age, poorly controlled hypertension, and the PD procedure itself and/or end-stage renal disease seem to be associated with the presence of leukoaraiosis.