Lower serotonin transporter binding in patients with cervical dystonia is associated with psychiatric symptoms

E. Zoons,J. Booij,Y. E. M. Dreissen,J. D. Speelman,M. Smit,M. A. J. Tijssen

doi:10.1186/s13550-017-0338-4

E. Zoons, J. Booij + Show 4 more

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https://doi.org/10.1186/s13550-017-0338-4

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Abstract

BackgroundCervical dystonia (CD) is often accompanied by depressive symptoms, anxiety, and jerks/tremor. The dopamine transporter (DAT) binding is related with both depressive symptoms and jerks/tremor in CD. Serotonergic and dopaminergic systems are closely related. As serotonin is involved in the pathophysiology of psychiatric symptoms and jerks, we expected an altered serotoninergic system in CD. We hypothesized that CD is associated with reduced serotonin transporter (SERT) binding, more specific that SERT binding is lower in CD patients with psychiatric symptoms and/or jerks/tremor compared to those without, and to controls. The balance between SERT and DAT binding can be altered in different CD phenotypes.ResultsIn 23 CD patients and 14 healthy controls, SERT binding in the diencephalon/midbrain was assessed using [123I]FP-CIT SPECT, with a brain-dedicated system. The specific to non-specific binding ratio (binding potential; BPND) to SERT was the main outcome measure. There was a clear trend towards reduced SERT BPND in CD patients with psychiatric symptoms compared to those without (p = 0.05). There was no correlation between SERT binding and dystonia, jerks, or anxiety. There was a significant positive correlation between extrastriatal SERT and striatal DAT BPND in CD patients with jerks, but not in patients without jerks.ConclusionCD patients with psychiatric symptoms have lower SERT binding in the midbrain/diencephalon, while dystonia and jerks appear unrelated to SERT binding. The balance between extrastriatal SERT and striatal DAT binding is different in CD with and without jerks.

Highlights

Cervical dystonia (CD) is often accompanied by depressive symptoms, anxiety, and jerks/tremor
We recently showed normal striatal dopamine transporter (DAT) binding but decreased D2/3 receptor binding in CD
8/11 (73%) of the patients without comorbid jerks/tremor fulfilled the criteria for a psychiatric diagnosis compared to 6/12 (50%) of the patients with comorbid jerks/tremor

Summary

Introduction

Cervical dystonia (CD) is often accompanied by depressive symptoms, anxiety, and jerks/tremor. The dopamine transporter (DAT) binding is related with both depressive symptoms and jerks/tremor in CD. As serotonin is involved in the pathophysiology of psychiatric symptoms and jerks, we expected an altered serotoninergic system in CD. We hypothesized that CD is associated with reduced serotonin transporter (SERT) binding, more specific that SERT binding is lower in CD patients with psychiatric symptoms and/or jerks/tremor compared to those without, and to controls. The balance between SERT and DAT binding can be altered in different CD phenotypes. Previous imaging studies in different types of dystonia have mostly shown normal radiotracer binding to striatal dopamine transporters (DAT) and normal or decreased binding to striatal dopamine D2/3 receptors (D2/3 receptors) [3, 4].

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