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Extrapyramidal side-effects and dopamine D(2/3) receptor binding in substantia nigra
Heli Tuppurainen1, Jyrki T Kuikka, Heimo Viinamäki
1Department of Forensic Psychiatry, University of Kuopio, Niuvanniemi Hospital, FI-70240 Kuopio, Finland. heli.tuppurainen@niuva.fi
Nordic Journal of Psychiatry
|July 16, 2010
Summary
Antipsychotic-induced movement disorders are linked to dopamine D(2) receptor binding in the substantia nigra. Lower binding potential in this area correlates with increased extrapyramidal symptoms in schizophrenia patients.
Area of Science:
- Neuroscience
- Psychopharmacology
Background:
- The mechanisms underlying antipsychotic-induced extrapyramidal side-effects (EPS) remain unclear.
- Dopamine D(2) receptors in the substantia nigra are implicated in motor control.
Purpose of the Study:
- To investigate the relationship between dopamine D(2) receptor binding in the substantia nigra and temporal cortex and EPS in antipsychotic-treated schizophrenia patients.
Main Methods:
- Single-photon emission-computed tomography (SPECT) with [(123)I]epidepride was used to measure dopamine D(2/3) apparent binding potential.
- 13 patients with schizophrenia receiving antipsychotics were assessed for EPS using the Simpson and Angus Scale (SAS).
Main Results:
- A significant negative correlation was found between dopamine D(2/3) receptor binding potential in the substantia nigra and the severity of EPS (r = -0.62, P = 0.024).
- No significant correlation was observed between dopamine D(2/3) receptor binding in the temporal cortex and EPS.
Conclusions:
- The findings suggest that dopamine D(2) autoreceptors in the substantia nigra play a crucial role in the development of drug-induced movement disorders.
- This highlights the nigrostriatal pathway's involvement in antipsychotic side effects.
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