In Vivo Involvement of the Cholinergic and Dopaminergic Systems in the Pathophysiology of Apathy.
Status:
Recruiting
Trial end date:
2022-05-13
Target enrollment:
Participant gender:
Summary
Apathy is a neurocognitive syndrome characterized by reduced goal-directed behaviors,
contributing to decreased patient and caregiver quality of life. Apathy pathophysiology
involves disruption of cortico-striato-thalamo-cortical loops, modulated by several
neurotransmitter systems including dopamine and acetylcholine, thus complexifying
pharmacological management. Post-stroke apathy (PSA) can provide a proper in vivo model to
study the underlying neurochemical substrates of apathy as a syndrome. The present project
aims to provide a better characterization of the cholinergic and dopaminergic functioning in
apathy as a syndrome.
In order to precise the respective alterations of these two systems, investigators will use a
positron emission tomography (PET) molecular imaging of dopaminergic (with [18F]-FDOPA, a
marker of the decarboxylating enzyme of dopamine) and - for the first time in apathetic
patients - cholinergic (with [18F]-FEOBV, a marker of the vesicular acetylcholine
transporter) transmissions in 15 apathetic and 15 unapathetic patients 3 months after stroke,
without overlapping depression. This dual imaging study may provide help in guiding
therapeutic management of PSA. The functional network analysis allowed by functional MRI is
crucial to complement regional neurotransmitter deficits observed with PET. Altogether, a
multimodal approach in apathy, combining PET and MRI, can allow identifying which circuits of
the cortico-striato-thalamo-cortical loops are disrupted and how these circuits are modulated
by other neurotransmitters.