The usefulness of botulinum toxin A treatment when planning hand surgery in eight children with spastic hemiplegia was evaluated. The hand function of the children was assessed before and after treatment using a test battery consisting of quantitative and qualitative functional assessment. The results of preoperative botulinum treatment supported surgical intervention in four children and serial botulinum treatment in three children. In one child, the preoperative botulinum treatment provided no additional information. We conclude that preoperative botulinum A treatment in most children with spastic hemiplegia, for whom hand surgery is being considered, identifies the patients who would not benefit from the planned surgery or for whom the functional benefit would probably not outweigh the burden of surgical procedure and postoperative rehabilitation.

Neurovascular coupling (NVC) is the link between neuronal metabolic activity and regional cerebral blood flow. NVC is responsible for ensuring adequate delivery of nutrients (O2 and glucose) during periods of increased neuronal metabolic demand. Exposure to high‐altitude (HA) elicits ventilatory and acid‐base adjustments for maintaining blood pH. Acute exposure to HA causes hypoxic vasodilation. Hypoxia also drives a ventilatory response, inducing hypocapnia, a potent vasoconstrictor. Whether these dynamic and conflicting responses affect NVC during incremental ascent to HA is unclear.The aim of this project was to assess whether changes in arterial blood gases (ABGs) associated with ascent to HA influences the NVC response. Given that CBF is particularly sensitive to changes in PaCO2, we hypothesized that hypocapnic vasoconstriction during ascent would decrease the NVC response with ascent.10 healthy study participants (21.7±1.3 yrs, 70.46±13.65kg, mean±SD) were recruited as part of a research expedition to Everest base camp, Nepal. Resting posterior cerebral artery velocity (PCAv), ABGs (PaO2, PaCO2), SaO2, arterial blood pH and bicarbonate [HCO3−] were measured at four locations: Calgary (1045m; baseline; BL), Namche (3440m), Deboche (3820m) and Pheriche (4370m). Resting PCAv was measured using transcranial Doppler ultrasound. Arterial blood draws were taken from the radial artery and analysed using a portable blood gas/electrolyte analyser used to monitor changes in ABGs (PaCO2, PaO2, SaO2), pH and [HCO3−] during ascent. NVC was tested via visual stimulation (VS; Strobe light; 6Hz; 30sec on/off ×3). The NVC response was averaged across three VS trials at each location. NVC was quantified as the change (delta) in mean and peak PCAv from baseline, during VS.A one‐factor‐repeated measures analysis of variance (ANOVA) was used to assess for differences in baseline PCAv, NVC, ABGs, blood pH and [HCO3−] between locations. PaO2, PaCO2 and SaO2 were significantly decreased from BL at each altitude (P<0.001, P<0.016 and P<0.013, respectively). No significant differences were found for pH at any location compared to BL (P>0.05) due to reductions in arterial [HCO3−] (P<0.043). No significant differences were found in baseline PCAv between locations (P>0.05) or for mean or peak NVC responses (P>0.085 and P>0.08 respectively).As expected, incremental ascent to HA induced a state of hypoxic hypocapnia, as demonstrated by significant reductions in PaO2, SaO2 and PaCO2, whereas arterial pH was maintained via reductions in [HCO3−]. Our data suggests that NVC remains remarkably intact during incremental ascent to HA in healthy acclimatized individuals. Despite the array of superimposed stressors associated with ascent to HA, CBF and NVC regulation may be a unique function of arterial pH maintenance.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Neurovascular coupling (NVC) is a phenomenon that matches regional cerebral blood flow to local neuronal metabolic activity. Improvements in NVC may underlie the qualitative reports of improved cognitive performance using standing and active workstations. However, little has been investigated pertaining to body position and the potential effects of sitting, standing or walking on NVC. We hypothesized that sitting, standing and low intensity treadmill walking (2 mph) would increase NVC magnitude in a dose‐dependent fashion. We recruited 20 young, healthy participants (n=20, 11 females), and instrumented them with an electrocardiogram (beat‐by‐beat heart rate; HR; bpm), finger photoplethysmography (mean arterial pressure; MAP; mmHg) and transcranial Doppler ultrasound to quantify posterior cerebral artery velocity (PCAv; cm/s) during sitting, standing and walking trials. Each position included a protocol consisting of a 3‐min baseline (BL) and three x 30‐sec standardized visual stimulus (VS) periods using a 6 Hz strobe light held 15cm away from the eyes. Responses were quantified through (a) visually identified peak(s) PCAv during VS, (b) time to peak peak(s) and (c) mean PCAv response(s) during VS, with all three measures averaged for a representative response for each individual. NVC magnitude was then quantified as a change (delta) in peak and mean responses from BL. At baseline, HR was incrementally higher in sitting, standing and walking (P<0.001), but MAP was unchanged between positions (P=0.12). There were significant increases in the peak and mean responses from BL in all positions during VS (P<0.001), confirming an NVC response. However, there were no differences in delta peak (P=0.47), time‐to‐peak (P=0.29) nor delta mean (P=0.76) NVC responses during VS across all positions. These results suggest that NVC magnitude is unaffected by body position or low intensity physical activity. We conclude that reports of increased cognitive performance while using standing or active work stations in the workplace are not related to NVC, and are likely related to nervous system activation and/or changes in systemic metabolic rate.

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