CBD dose affects analgesic efficacy
Cannabidiol (CBD) failed to provide consistent dose-dependent pain relief, and in some measures, increased pain, a study suggests.
The study — published in the British Journal of Clinical Pharmacology — explored the dose-dependent analgesic effects of orally-administered 200, 400 and 800 mg (+)-CBD solution versus placebo in 17 patients exposed to the Cold Pressor Test.
Compared to placebo, the 200 mg dose increased participants’ pain threshold (latency to first pain report); the 400 mg dose made an insignificant improvement in pain tolerance (latency to hand withdrawal from cold water), and the 800 mg dose led to a reduction in pain tolerance.
As preclinical studies have “shown promise for CBD analgesia in chronic pain conditions”, the authors believe “CBD use over time in a chronic pain patient population may be more likely to produce effective analgesia than acute dosing in non-pain populations”.
Prenatal exposure to maternal influenza linked to childhood seizures
Prenatal exposure to maternal influenza is associated with increased risk of childhood seizures, an international study has shown.
The study — published in Archives of Disease in Childhood — explored registry data for 1,360,629 children who were born in Australia, Norway or Canada between 2009 and 2013 and received a seizure diagnosis in a secondary or specialist care setting by age seven.
Children exposed to clinical or laboratory-confirmed maternal influenza in utero (n=14,280) “were at increased risk” of seizures (aHR: 1.17, 95% CI: 1.07–1.28) and febrile seizures (aHR: 1.20, 95% CI: 1.07–1.34), although “there was no strong evidence of an increased risk of epilepsy” (aHR: 1.07, 95% CI: 0.81–1.41), the study found.
Those exposed during the second or third trimester had increased seizure risk compared with the first trimester, allowing the study’s authors to consider non-genetic influences.
“It has previously been hypothesised that maternal infection in pregnancy could affect fetal neurodevelopment through various pathways. There could be a direct effect through infection of the fetal brain, or an indirect effect through maternal systemic immunological responses to infection, such as fever or elevated cytokine levels,” the study read.
Stroke risk signs appear up to 10 years early
Patients who had a stroke showed steeper declines in cognition and daily functioning up to 10 years preceding the event compared with stroke-free individuals, European researchers say.
A retrospective analysis of 1662 stroke patients who took part in a 12-year long prevention trial showed that those with a first stroke had a different trajectory in in cognition and daily functioning to participants who did not develop stroke.
Over a period of 10 years significant deviations were seen in scores of MMSE (6.4 years), Stroop (5.7 years), Purdue Pegboard (3.8 years) and BADL and IADL scores (2.2 and 3.0 years, respectively).
Women, carriers of the APOE gene that is associated with Alzheimer’s disease, and those with fewer academic qualifications, seem to be at greatest risk.
Neurologists at the Erasmus Medical Centre, Rotterdam, said the accelerated decline in cognition and daily functioning before stroke suggested that individuals with future stroke suffer from accumulating intracerebral damage years before the acute event, such as cerebral small vessel disease, neurodegeneration, and inflammation.
“Individuals with cognitive and functional decline are at a higher risk of stroke and are possible candidates for prevention trials,” they wrote in the Journal of Neurology Neurosurgery & Psychiatry.