Intranasal Insulin and Post-stroke Cognition: A Pilot Study

Almost two-thirds of survivors have cognitive impairment (CI), manifested as memory, language, and judgement problems. Post-stroke CI at 2 weeks is a significant predictor of long-term functional outcome, and more generally, cognitive impairments have a major impact on functional outcome and ability to participate in rehabilitation. CI is associated with increased systemic inflammation. Intranasally-administered insulin is a promising new therapy for enhancing memory in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD), shown in multiple randomized controlled studies. Likely mechanisms of benefit are intranasal insulin's ability to restore normal cerebral insulin signaling. Based on the overlap in cerebral insulin resistance that occurs in both AD and post-stroke CI, we have designed an innovative proof-of-concept, feasibility trial designed to provide pilot data as to whether post-stroke survivor CI and caregiver burden is improved with intranasal insulin early after stroke. We will explore the impact of intranasal insulin on inflammatory biomarkers, since inflammation is a major underlying cause of CI, as shown by others and in our preliminary studies of VCAM-1. Specific Aims are: 1. Determine if patients with ischemic stroke randomized to intranasal insulin 20 IU BID for 3 weeks have improved cognition, compared to patients who receive intranasal saline. Primary outcome is a composite of (a) memory and executive function z scores. 2. To assess the impact of intranasal insulin vs saline on change in inflammatory biomarker levels (VCAM-1, TNF-alpha, TNFR-I and II) before and after the treatment period. 3. To measure differences in burden among caregivers of participants in the intranasal insulin vs intranasal saline groups. We will prospectively randomize 40 subjects to intranasal insulin (40 IU) vs saline treatment. Following baseline cognitive testing 2 weeks post stroke, subjects will receive the assigned treatment for 3 weeks, followed