Previous studies have focused on the curative effects of
memantine in patients with mild-to-moderate
frontotemporal lobar degeneration (
FTLD); however, its benefits in patients with moderate-to-severe
FTLD have not been investigated. The present study explores the behavioral, cognitive and functional effects of
memantine on behavioral variant
frontotemporal dementia (bvFTD) in patients with mild and moderate-to-severe stage bvFTD. A total of 42 patients with bvFTD completed a 6-month treatment plan of 20 mg
memantine daily in an open-label, self-controlled clinical trial. Patients were divided into two groups according to their Mini-Mental State Examination (MMSE) score: Mild (score, 21-26); and moderate-to-severe (score, 4-20). Primary endpoints included Neuropsychiatric Inventory Questionnaire (NPI-Q) and Clinic
Dementia Rating (CDR) scores, and secondary endpoints comprised Neuropsychiatric Inventory Caregiver Distress Scale (NPI-D), MMSE, Montreal Cognitive Assessment (MoCA), Activity of Daily Life (
ADL) and Hamilton Depression Rating Scale (HAMD) scores.
Memantine treatment had no effect on overall NPI-Q scores, with the exception of the agitation subdomain in all patients with bvFTD. However, patients with moderate-to-severe bvFTD exhibited a better performance than patients with mild bvFTD, demonstrated by improved NPI-Q total scores and subscales of agitation, depression, apathy and disinhibition. In the moderate-to-severe group, CDR and HAMD scores remained stable, but MMSE, MoCA and
ADL scores were reduced after 6 months of treatment.
Memantine was well-tolerated in patients. In conclusion, patients with moderate-to-severe bvFTD responded significantly better to
memantine in comparison to patients with mild bvFTD with regard to their neuropsychiatric scores, while
memantine did not present any cognitive or functional benefits in patients with mild bvFTD. A randomized, double-blind, placebo-controlled clinical trial with a larger number of patients is required to verify these promising results for patients with moderate-to-severe bvFTD.