A case of apathy due to frontotemporal dementia responsive to memantine

Objective: To study the effect of memantine on apathy, a common symptom of behavioral variant frontotemporal dementia (bvFTD). Design: The patient underwent an off-label trial of memantine with behavioral inventories and [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) scans performed at baseline, 7 weeks and 6 months. Subject: The patient was a 66-year-old male whose main manifestation of bvFTD was affective, behavioral and cognitive apathy. Intervention: The patient began memantine at an oral dose of 5 mg per morning and titrated up by 5 mg per week to the maintenance dose of 10 mg PO bid. Results: Informants reported reduction of the apathy. The insula and cerebellum, both involved in the salience network, showed improved metabolism. Conclusion: Further study to correlate the effects of memantine on apathy and the salience network in bvFTD are warranted.