Purpose: There is uncertainty regarding the appropriate dose of Cannabidiol (CBD) for childhood epilepsy. We present the preliminary data of seven participants from the Cannabidiol in Children with Refractory Epileptic Encephalopathy (CARE-E) study. Methods: The study is an open-label, prospective, dose-escalation trial. Participants received escalating doses of a Cannabis Herbal Extract (CHE) preparation of 1:20 Δ9-tetrahydrocannabinol (THC): CBD up to 10-12 mg CBD/kg/day. Seizure frequency was monitored in daily logs, participants underwent regular electroencephalograms, and parents filled out modified Quality of Life in Childhood Epilepsy (QOLCE) and Side Effect rating scale questionnaires. Steady-state trough levels (Css, Min) of selected cannabinoids were quantified. Results: All seven participants tolerated the CHE up to 10-12 mg CBD/kg/day and had improvements in seizure frequency and QOLCE scores. CSS, Min plasma levels for CBD, THC, and cannabichromene (CBC) showed dose-independent pharmacokinetics in all but one participant. CSS, Min CBD levels associated with a >50% reduction in seizures and seizure freedom were lower than those reported previously with purified CBD. In most patients, CSS, Min levels of THC remained lower than what would be expected to cause intoxication. Conclusion: The preliminary data suggest an initial CBD target dose of 5-6 mg/kg/day when a 1:20 THC:CBD CHE is used. Possible non-linear pharmacokinetics of CBD and CBC needs investigation. The reduction in seizure frequency seen suggests improved seizure control when a whole plant CHE is used. Plasma THC levels suggest a low risk of THC intoxication when a 1:20 THC:CBD CHE is used in doses up to 12 mg/kg CBD/kg/day.
The T-maze is a sensitive behavioral test used to measure functional outcome in rodent models of global ischemia. As our laboratory is investigating the adverse effects of protein-energy malnutrition (PEM) on global ischemia, this study determined: 1) if a sunflower seed reward used with the T-maze would interfere with PEM, and 2) whether PEM impairs working memory prior to the induction of global ischemia. Male Mongolian gerbils (11–12 wks) were randomized for 6 wks to either modified AIN-93M control diet (12% protein; n=12) or PEM (2% protein; n=12). Gerbils were habituated in the T-maze for 5 days, followed by 10 win-shift trials/day for 10 days. A mean body weight loss of 20% and 17% lower food intake compared to that of controls suggests that PEM was achieved; this will be confirmed by serum albumin measurements. Gerbils on control diet required a mean (± SEM) of 7.3 ± 0.7 trials in the T-maze to meet criterion (≥90% correct on 3 consecutive days), compared to 5.4 ± 0.4 trials in the PEM group (p = 0.025; unpaired t-test). The number of animals reaching criterion was 8/12 in the control group, and 12/12 in the PEM group [χ2(n=24, df=1) = 4.800, p=0.028]. These results suggest that the reward does not interfere with the model of PEM, and that T-maze performance is not impaired, but rather may be enhanced by PEM prior to ischemia. Future studies will unravel the influence of both PEM and nutritional repletion on cognitive deficits produced by global ischemia. Funded by CIHR/RPP and Heart and Stroke Foundation of Saskatchewan.
Our laboratory is investigating the effects of protein–energy malnutrition (PEM) on cognitive outcome following global ischemia. Here, we investigated whether PEM independently impairs working memory in the T-maze and if the associated food reward reverses PEM. Gerbils were fed 12.5% (control diet) or 2% protein. A loss of body weight (20.1%) in the 2% protein group and decreased food intake and serum albumin concentration compared to controls (17.5% and 18.2%, respectively) indicated that PEM was achieved. Based on T-maze criterion frequently used in ischemia studies, no difference was observed in the mean (±SEM) number of trials required (control 5.2 ± 0.7; PEM 4.9 ± 0.4; p = 0.758) or the number of animals reaching criterion (control 10/12; PEM 12/12; p = 0.140). Using more stringent criterion, PEM animals required fewer trials (control 7.3 ± 0.7; PEM 5.4 ± 0.4; p = 0.035), and more reached criterion (control 8/12; PEM 12/12; p = 0.028). PEM may increase motivation to obtain a food reward.
Protein-energy malnutrition (PEM) affects ~16% of patients at admission for stroke. We previously modeled this in a gerbil global cerebral ischemia model and found that PEM impairs functional outcome and influences mechanisms of ischemic brain injury and recovery. Since this model is no longer reliable, we investigated the utility of the rat 2-vessel occlusion (2-VO) with hypotension model of global ischemia for further study of this clinical problem. Male, Sprague-Dawley rats were exposed to either control diet (18% protein) or PEM induced by feeding a low protein diet (2% protein) for 7d prior to either global ischemia or sham surgery. PEM did not significantly alter the hippocampal CA1 neuron death (p = 0.195 by 2-factor ANOVA) or the increase in dendritic injury caused by exposure to global ischemia. Unexpectedly, however, a strong trend was evident for PEM to decrease the consistency of hippocampal damage, as shown by an increased incidence of unilateral or no hippocampal damage (p=0.069 by chi-square analysis). Although PEM caused significant changes to baseline arterial blood pH, pO(2), pCO(2), and fasting glucose (p<0.05), none of these variables (nor hematocrit) correlated significantly with CA1 cell counts in the malnourished group exposed to 2-VO (p>0.269). Intra-ischemic tympanic temperature and blood pressure were strictly and equally controlled between ischemic groups. We conclude that co-existing PEM confounded the consistency of hippocampal injury in the 2-VO model. Although the mechanisms responsible were not identified, this model of brain ischemia should not be used for studying this co-morbidity factor.
Co-existing protein-energy malnutrition (PEM), characterized by deficits in both protein and energy status, impairs functional outcome following global ischemia and has been associated with increased reactive gliosis. Since temperature is a key determinant of brain damage following an ischemic insult, the objective was to investigate whether alterations in post-ischemic temperature regulation contribute to PEM-induced reactive gliosis following ischemia. Male Sprague-Dawley rats (190-280g) were assigned to either control diet (18% protein) or PEM induced by feeding a low protein diet (2% protein) for 7 days prior to either global ischemia or sham surgery. There was a rapid disruption in thermoregulatory function in rats fed the low protein diet as assessed by continuous recording of core temperature with bio-electrical sensor transmitters. Both daily temperature fluctuation and mean temperature increased within the first 24 hours, and these remained significantly elevated throughout the 7 day pre-ischemic period (p < 0.027). In the immediate post-surgical period, PEM decreased body temperature to a greater extent than that in well-nourished controls (p = 0.003). The increase in daily temperature fluctuation caused by PEM persisted throughout the 7 day post-surgical period (p < 0.001), and this interacted with the effects of global ischemia on days 8 (p = 0.018) and 11 (p = 0.021). The astrocytic and microglial responses induced at 7 days after global ischemia were not influenced by PEM, but this preliminary analysis needs to be confirmed with a more reliable global ischemia model. In conclusion, exposure to a low protein diet rapidly impairs the ability to maintain thermoregulatory homeostasis, and the resultant PEM also diminishes the ability to thermoregulate in response to a challenge. Since temperature regulation is a key determinant of brain injury following ischemia, these findings suggest that the pathophysiology of brain injury could be altered in stroke victims with coexisting PEM. Keywords: Global brain ischemia, protein-energy malnutrition, rat, reactive gliosis, thermoregulation, two-vessel occlusion, Homeostasis
Results from three large, randomized, multicenter FOOD (Feed or Ordinary Food) Collaboration Trials showed no reduction in death or poor outcome with routine oral protein-energy supplementation of stroke patients who were primarily well nourished upon admission to the hospital. Nasogastric tube feeding was favored over percutaneous endoscopic gastrostomy as the early route of feeding in dysphagic stroke patients.
Previously it has been demonstrated that protein-energy malnutrition (PEM) impairs habituation in the open field test following global ischemia. The present study examined the hypothesis that PEM exerts some of its deleterious effects on functional outcome by altering the post-ischemic expression of the plasticity-associated genes brain-derived neurotrophic factor (BDNF), its receptor tropomyosin-related kinase B (trkB), and growth-associated protein-43 (GAP- 43). Male, Mongolian gerbils (11-12wk) were randomized to either control diet (12.5% protein) or PEM (2% protein) for 4wk, and then underwent 5min bilateral common carotid artery occlusion or sham surgery. Tympanic temperature was maintained at 36.5± 0.5°C during surgery. Brains collected at 1, 3 and 7d post-surgery were processed by in situ hybridization or immunofluorescence. BDNF and trkB mRNA expression was increased in hippocampal CA1 neurons after ischemia at all time points and was not significantly influenced by diet. However, increased trkB protein expression after ischemia was exacerbated by PEM at 7d in the CA1 region. Post-ischemic GAP-43 protein increased at 3 and 7d in the CA1 region, and PEM intensified this response and extended it to the CA3 and hilar regions. PEM exerted these effects without exacerbating CA1 neuron loss caused by global ischemia. The findings suggest that PEM increases the stress response and/or hyper-excitability in the hippocampus after global ischemia. Nutritional care appears to have robust effects on plasticity mechanisms important to recovery after brain ischemia. Keywords: Brain-derived neurotrophic factor, growth-associated protein-43, nutrition, plasticity, stroke, tropomyosin-related kinase B, nutrition, plasticity, CA1, brain ischemia, Ca2+, PEM, nuclear factor-κB, CA3, mRNA, GAP-43, BCCAO, CON-S, CON-I, PEM-S, OCT, In situ Hybridization, BDNF, trkB, Global Ischemia, Immunofluorescence, CON, DAPI, ±SEM, IDV
Results from three large, randomized, multicenter FOOD (Feed or Ordinary Food) Collaboration Trials showed no reduction in death or poor outcome with routine oral protein-energy supplementation of stroke patients who were primarily well nourished upon admission to the hospital. Nasogastric tube feeding was favored over percutaneous endoscopic gastrostomy as the early route of feeding in dysphagic stroke patients.
The plant Cannabis sativa produces over 140 known cannabinoids. These chemicals generate considerable interest in the medical research community for their possible application to several intractable disease conditions. Recent reports have prompted parents to strongly consider Cannabis products to treat their children with drug resistant epilepsy. Physicians, though, are reluctant to prescribe Cannabis products due to confusion about their regulatory status and limited clinical data supporting their use. We provide the general paediatrician with a brief review of cannabinoid biology, the literature regarding their use in children with drug resistant epilepsy, the current Health Canada and Canadian Paediatric Society recommendations and also the regulations from the physician regulatory bodies for each province and territory. Given the complexities of conducting research on Cannabis products for children with epilepsy, we also discuss outstanding research objectives that must be addressed to support Cannabis products as an accepted treatment option for children with refractory epilepsy.
