Assessment of cerebral dopamine D_{2/3} -receptors in patients with bilateral vestibular failure
J Vestib Res. 2014 Jan 1;24(5):403-13. doi: 10.3233/VES-140526.
| Authors/Editors: | Jansen NL, Feuerecker R, Becker-Bense S, Zwergal A, Wulff M, Xiong G, Wängler B, Cumming P, Bartenstein P, Dieterich M, la Fougère C. |
|---|---|
| Publication Date: | 2014 |
Abstract
BACKGROUND:
Absence of peripheral vestibular input in bilateral vestibular failure (BVF) has been suggested to induce plastic reorganization in various brain regions. Among several neurotransmitters, dopamine is known to play a key role in cortico-striatal-sensorimotor processing. However, the role of dopamine in vestibular plasticity is scantly documented.
OBJECTIVE:
Assessment of D<formula>_{2/3}</formula>-receptors in patients with BVF.
METHODS:
D<formula>_{2/3}</formula>-receptor-PET using [<formula>^{18}</formula>F]fallypride and MRI examinations were performed in 12 BVF-patients and 13 healthy controls.
RESULTS:
BVF-patients showed reduced D<formula>_{2/3}</formula>-receptor availability (approximately 40%) in the temporo-parieto-occipital cortex bilaterally, including the multisensory vestibular cortex and visual motion-sensitive areas (MT/MST), as well as in the striatum and the right thalamus. Longer illness duration was associated with bilaterally lower D<formula>_{2/3}</formula>-receptor availability in the middle/superior temporal gyrus (GTm/s). D<formula>_{2/3}</formula>-receptor availability in the right GTm/s and bilateral insula decreased with severity of symptoms. BVF-patients with oscillopsia showed reduced D<formula>_{2/3}</formula>-receptor availability in the right MT/MST and midbrain tectum.
CONCLUSIONS:
Reduced D<formula>_{2/3}</formula>-receptor availability in multisensory vestibular cortical network areas and basal ganglia may indicate a receptor down-regulation due to the lack of peripheral vestibular input. The more pronounced decline in D<formula>_{2/3}</formula>-receptor availability in the multisensory vestibular cortex in patients with prolonged illness suggests the occurrence of progressive changes in dopamine transmission.
