Parkinson’s disease (PD) is characterized by resting tremor, rigidity and bradykinesia. Dopaminergic medications such as L-dopa treat these motor symptoms, but can have complex effects on cognition. Impulse control is an essential cognitive function. Impulsivity is multifaceted in nature. Motor impulsivity involves the inability to withhold pre-potent, automatic, erroneous responses. In contrast, cognitive impulsivity refers to improper risk-reward assessment guiding behavior. Informed by our previous research, we anticipated that dopaminergic therapy would decrease motor impulsivity though it is well known to enhance cognitive impulsivity. We employed the Go/No-go paradigm to assess motor impulsivity in PD. Patients with PD were tested using a Go/No-go task on and off their normal dopaminergic medication. Participants completed cognitive, mood, and physiological measures. PD patients on medication had a significantly higher proportion of Go trial Timeouts (i.e., trials in which Go responses were not completed prior to a deadline of 750 ms) compared to off medication (p = 0.01). No significant ON-OFF differences were found for Go trial or No-go trial response times (RTs), or for number of No-go errors. We interpret that dopaminergic therapy induces a more conservative response set, reflected in Go trial Timeouts in PD patients. In this way, dopaminergic therapy decreased motor impulsivity in PD patients. This is in contrast to the widely recognized effects of dopaminergic therapy on cognitive impulsivity leading in some patients to impulse control disorders. Understanding the nuanced effects of dopaminergic treatment in PD on cognitive functions such as impulse control will clarify therapeutic decisions.

Background: Endovascular therapy is the new standard of care for certain patients with acute ischemic stroke. We aimed to determine whether procedural volumes at an academic health sciences centre in northeastern Ontario exceeded the minimum of 20 procedures annually to support establishment of an endovascular therapy centre and thus improve regional access to this type of care. Methods: We conducted a retrospective chart review at Health Sciences North, a regional stroke centre for northeastern Ontario that currently does not offer endovascular therapy for patients with acute ischemic stroke. Medical records and neurovascular imaging results for patients with a discharge diagnosis of cerebral infarction who were seen by the stroke on-call team at Health Sciences North between May 1, 2016, and Apr. 30, 2017, were retrospectively examined in accordance with criteria of the ESCAPE trial to identify potential candidates for endovascular therapy. The number of candidates was extrapolated to include patients discharged with cerebral infarction from referral centres within a 2-hour transport radius from the study institution. Results: Of 71 patients who met the inclusion criteria, 9 were identified as candidates. Of the 71 cases reviewed, 62 (87%) presented within the window for administration of recombinant tissue plasminogen activator of 4.5 hours from symptom onset, 66 (93%) within the endovascular therapy window of 6 hours and 69 (97%) within the extended endovascular therapy window of 12 hours. Expanding these estimates to include regional referral centres, we conservatively estimated that Health Sciences North has the potential to perform 22 or 23 procedures annually. Interpretation: The projected annual number of procedures met the minimum requirement to maintain competency. Establishing Health Sciences North as a centre for endovascular therapy could be an important step in improving equity in stroke outcomes across northeastern Ontario.