Paquette, Sebastien

Pain conditions occur at an increasing rate alongside people with temporal lobe epilepsy (TLE) and can include chronic headaches, migraines, and neuropathic pain. In order to begin to understand the concurrence, this experiment aimed to investigate the effect of long-term amygdala kindling, a model of TLE, on the affective and nociceptive components of pain in rats. Formalin-induced affective avoidance was investigated using the conditioned place aversion (CPA) test and found aversion in kindled, but not sham rats. Nociceptive behaviours were observed using the formalin test and found a peripheral reduction of pain, that persisted one-week following the last stimulation in kindled rats. Lower activation of c-Fos in the periaqueductal gray was seen in kindled rats, while no changes in protein kinase C δ activation was found. Amygdala kindling contributed to pain sensitivity changes that persisted into the interictal period, and male and female pain trends were found, requiring further investigation.

Author Keywords: affective pain, amygdala, amygdala kindling, formalin, nociceptive pain, periaqueductal gray

Freezing is a debilitating phenomenon that reduces quality of life for people withParkinson's disease (PwPD). This study tests the hypothesis that: 1) freezing is linked to executive dysfunction; 2) freezing is a global motor phenomenon, not limited to gait. We compared 14 PwPD to 16 controls. Several aspects of executive function were measured using pro- and anti-saccade tasks under gap and overlap timing conditions, where the gap effect is defined as the reduction in saccade latency associated with the removal of fixation before target presentation. As predicted, results showed larger anti-saccade gap effects in PwPD with than without FOG, and that the pro-saccade gap effect predicted FOG severity in PwPD with FOG. PwPD also demonstrated impaired performance on reaching and walking tasks designed to elicit freezing. These findings strengthen the evidence that executive dysfunction, measured by saccade tasks, is linked to freezing in PwPD.

Author Keywords: executive function, eye movements, freezing of gait, freezing of upper limbs, Parkinson's disease