Rivastigmine for cognitive impairment after spontaneous subarachnoid haemorrhage: a pilot study

Rivastigmine has been shown to be effective for patients with mild-to-moderate Alzheimer's disease. Its effect on cognitive impairment after aneurysmal subarachnoid haemorrhage has not been previously studied. The aim of the study is to evaluate the efficacy and safety of rivastigmine 3 mg/day over 12 weeks in patients with aneurysmal subarachnoid haemorrhage and persistent cognitive impairment.

Twenty Chinese patients with spontaneous subarachnoid haemorrhage at least 9 months after the initial ictus, and with persistent cognitive impairment, were recruited. The primary outcome measure was Cognitive Subscale of Alzheimer Disease Assessment Scale (ADAS-cog) for global function; the secondary outcome measures were the Frontal Assessment Battery (FAB) for frontal lobe function and the Rivermead Behavioural Memory Test (RBMT) for prospective memory. Baseline cholinergic dysfunction (with pupillometry) was assessed for relationship with treatment efficacy.

Sixteen of 20 (80%) patients completed the 12-week course of rivastigmine 1.5 mg twice daily. In comparison with the baseline assessment, ADAS-cog showed significant improvement after treatment (mean difference 6.5, 95% CI 3.5-9.5, P < 0.001); FAB and RBMT also showed significant improvement. Baseline cholinergic dysfunction (with pupillometry) was not correlated with improvement in ADAS-cog, FAB or RBMT.

The use of rivastigmine was safe in patients with spontaneous subarachnoid haemorrhage and persistent cognitive impairment. A prospective double-blind placebo-controlled trial is required to establish the efficacy of rivastigmine for patients with spontaneous subarachnoid hemorrhage and persistent cognitive impairment and whether it can be translated to improvement in instrumental activity of daily living and quality of life.