Differential pharmacological responses of catatonia-like signs in frontotemporal dementia

Abstract

Sequential therapeutic trials for catatonoid frontal signs in clinically-evident frontotemporal dementia (n = 2) revealed differential benefits for lorazepam, amantadine, memantine, pramipexole, aripiprazole, quetiapine, citalopram, and donepezil, although certain signs also worsened. Citalopram and donepezil were poorly tolerated. Ramelteon was without effect. While memantine appeared to improve cognition in case 1, this remains to be established by more reliable neuropsychological testing. Parkinsonism (case 2) responded to pramipexole, but not amantadine or levodopa. Possible relationships of catatonoid signs requiring future confirmation include insufficient GABA-A (multiple signs) and D2 (mutism) and excessive NMDA (immobility, rigidity), D2/D3 (mannerisms, verbal perseveration), and 5HT1a (staring) receptor stimulation. Low-dose lorazepam and quetiapine required close monitoring.

Keywords:

• Frontotemporal lobar degeneration
• Catatonia
• Neurotransmitter receptors
• Antipsychotic agents
• Benzodiazepines
• Dopamine D2 receptor
• Serotonin receptors
• GABA receptors
• NMDA receptors

Notes

The authors gratefully acknowledge Dr Mario F. Mendez, MD, PhD, who provided helpful comments.