Safety and Preliminary Efficacy of Intranasal Insulin for Cognitive Impairment in Parkinson Disease and Multiple System Atrophy

A double-blinded placebo-controlled pilot study in parkinson disease and
multiple system atrophy.

Parkinson disease (PD) is associated with cognitive impairment. We aimed to
determine the effects of intranasal insulin (INI) on cognition and motor
performance in PD. This was a proof of concept, randomized, double-blinded,
placebo-controlled trial evaluating the effects of 40 international units (IU)
of insulin or saline once daily for four weeks on cognitive and functional
performance. Of 16 subjects enrolled, eight in the INI group and six in the
placebo group completed verbal fluency (FAS), Unified Parkinson Disease Scale
(UPDRS), and modified Hoehn and Yahr scale (HY, PD severity) at baseline and
post-treatment and were included in the analyses. After treatment, the INI
group had a better total FAS score (p=0.02) (41 ± 8.2 vs. 30.8 ± 7.1, mean ±SD
_,_ __ p=0.02) compared to the placebo group. The INI group also had improved
HY (p=0.04) and UPDRS-Motor (Part III) (p=0.02) scores when compared to
baseline. One INI treated patient with multiple system atrophy (MSA) remained
stable and did not show disease progression. The placebo group had no change.
INI administration was well tolerated and there were no hypoglycemic episodes
or serious study related adverse events or medications interactions.

INI is safe in PD and MSA patients and may provide clinically relevant
functional improvement. Larger studies are warranted to determine the INI
effect in treatment of cognitive and motor impairment in Parkinson disease.
NCT02064166.