Korean J Radiol.  2015 Oct;16(5):967-972. 10.3348/kjr.2015.16.5.967.

Differences in Regional Glucose Metabolism of the Brain Measured with F-18-FDG-PET in Patients with Essential Tremor According to Their Response to Beta-Blockers

• Song IU
• Ha SW
• Yang YS
• Chung YA

• KMID: 2160763
• DOI: http://doi.org/10.3348/kjr.2015.16.5.967

Abstract

OBJECTIVE
In this study, there was an investigation as to whether there is a functional difference in essential tremor (ET), according to responses to beta-blockers, by evaluating regional changes in cerebral glucose metabolism.
MATERIALS AND METHODS
Seventeen male patients with ET were recruited and categorized into two groups: 8 that responded to medical therapy (group A); and 9 that did not respond to medical therapy (group B). Eleven age-sex matched healthy control male subjects were also included in this study. All subjects underwent F-18 fluorodeoxyglucose (FDG)-PET, and evaluated for their severity of tremor symptoms, which were measured as a score on the Fahn-Tolosa-Marin tremor rating scale (FTM). The FDG-PET images were analyzed using a statistical parametric mapping program.
RESULTS
The mean FTM score 6 months after the initiation of propranolol therapy was significantly lower in group A (18.13 > 8.13), compared with group B (14.67 = 14.67). The glucose metabolism in group A in the left basal ganglia was seen to be decreased, compared with group B. The ET showed a more significantly decreased glucose metabolism in both the fronto-temporo-occipital lobes, precuneus of right parietal lobe, and both cerebellums compared with the healthy controls.
CONCLUSION
Essential tremor is caused by electrophysiological disturbances within the cortical-cerebellar networks and degenerative process of the cerebellum. Furthermore, ET may have different pathophysiologies in terms of the origin of disease according to the response to first-line therapy.

Keyword

Essential tremor; Beta-blockers; FDG-PET

MeSH Terms

Adrenergic beta-Antagonists/*pharmacology/therapeutic use
Aged
Brain/*drug effects/metabolism/radiography
Brain Mapping
Essential Tremor/*diagnosis/drug therapy/radiography
Fluorodeoxyglucose F18/*chemistry
Glucose/*metabolism
Humans
Male
Middle Aged
*Positron-Emission Tomography
Propranolol/pharmacology/therapeutic use
Radiopharmaceuticals/*chemistry
Adrenergic beta-Antagonists
Fluorodeoxyglucose F18
Glucose
Propranolol
Radiopharmaceuticals

Figure

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  Fig. 1 Analysis of brain FDG-PET in group A, compared with group B of essential tremor. Image shows decreased glucose metabolism in lentiform nucleus, putamen and globus pallidus.

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  Fig. 2 Group differences in patients with essential tremor, compared with healthy controls. Analysis of brain FDG-PET shows decreased glucose metabolism in both fronto-temporo-occipital lobes, precuneus of right parietal lobe, and both cerebellums.

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