Regulation of sensory nerve conduction velocity (SCV) of human bodies responding to annual temperature variations in natural environments

The extensive research interests in environmental temperature can be linked to human productivity/performance as well as comfort and health; while the mechanisms of physiological indices responding to temperature variations remain incompletely understood. This study adopted a physiological sensory nerve conduction velocity (SCV) as a temperature-sensitive biomarker to explore the thermoregulatory mechanisms of human responding to annual temperatures. The measurements of subjects’ SCV (over 600 samples) were conducted in a naturally ventilated environment over all four seasons. The results showed a positive correlation between SCV and annual temperatures and a Boltzmann model was adopted to depict the S-shaped trend of SCV with operative temperatures from 5 °C to 40 °C. The SCV increased linearly with operative temperatures from 14.28 °C to 20.5 °C and responded sensitively for 10.19 °C - 24.59 °C, while tended to be stable beyond that. The subjects’ thermal sensations were linearly related to SCV, elaborating the relation between human physiological regulations and subjective thermal perception variations. The findings reveal the body SCV regulatory characteristics in different operative temperature intervals, thereby giving a deeper insight into human autonomic thermoregulation and benefiting for built environment designs, meantime minimizing the temperature-invoked risks to human health and well-being

Valores normais das velocidades de condução nervosa em um grupo de 101 pessoas

Foram estudadas as medidas de condução nervosa em 101 pessoas normais, 53 do sexo masculino e 48 do feminino. A idade variou de 16 a 81 anos (média, 44 anos). Foram estudadas tanto a velocidade de condução sensitiva quanto a velocidade de condução motora nos nervos mais frequentemente avaliados em neurofisiologia clínica. Em relação ao fator idade, observou-se declínio significativo nas faixas etárias mais avançadas

Sensory Impairments of the Lower Limb after Stroke: A Pooled Analysis of Individual Patient Data

Objective: To obtain more generalizable information on the frequency and factors influencing sensory impairment after stroke and their relationship to mobility and function. Method: A pooled analysis of individual data of stroke survivors (N = 459); mean (SD) age = 67.2 (14.8) years, 54% male, mean (SD) time since stroke = 22.33 (63.1) days, 50% ft-sided weakness. Where different measurement tools were used, data were recoded. Descriptive statistics described frequency of sensory impairments, kappa coefficients investigated relationships between sensory modalities, binary logistic regression explored the factors influencing sensory impairments, and linear regression assessed the impact of sensory impairments on activity limitations. Results: Most patients' sensation was intact (55%), and individual sensory modalities were highly associated (κ = 0.60, P <.001). Weakness and neglect influenced sensory impairment (P <.001), but demographics, stroke pathology, and spasticity did not. Sensation influenced independence in activities of daily living, mobility, and balance but less strongly than weakness. Conclusions: Pooled individual data analysis showed sensation of the lower limb is grossly preserved in most stroke survivors but, when present, it affects function. Sensory modalities are highly interrelated; interventions that treat the motor system during functional tasks may be as effective at treating the sensory system as sensory retraining alone. © 2013 Thomas Land Publishers, Inc