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. 2016 Dec 16;11(12):e0168652.
doi: 10.1371/journal.pone.0168652. eCollection 2016.

Grey Matter Microstructural Integrity Alterations in Blepharospasm Are Partially Reversed by Botulinum Neurotoxin Therapy

Free PMC article

Grey Matter Microstructural Integrity Alterations in Blepharospasm Are Partially Reversed by Botulinum Neurotoxin Therapy

Hanganu Alexandru et al. PLoS One. .
Free PMC article

Erratum in


Objective: Benign Essential Blepharospasm (BEB) and hemifacial spasm (HFS) are the most common hyperkinetic movement disorders of facial muscles. Although similar in clinical presentation different pathophysiological mechanisms are assumed. Botulinum Neurotoxin (BoNT) is a standard evidence-based treatment for both conditions. In this study we aimed to assess grey matter microstructural differences between these two groups of patients and compared them with healthy controls. In patients we furthermore tracked the longitudinal morphometric changes associated with BoNT therapy. We hypothesized microstructural differences between the groups at the time point of maximum symptoms representation and distinct longitudinal grey matter dynamics with symptom improvement.

Methods: Cross-sectional and longitudinal analyses of 3T 3D-T1 MRI images from BEB, HFS patients prior to and one month after BoNT therapy and from a group of age and sex matched healthy controls. Cortical thickness as extracted from Freesurfer was assessed as parameter of microstructural integrity.

Results: BoNT therapy markedly improved motor symptoms in patients with BEB and HFS. Significant differences of grey matter integrity have been found between the two patients groups. The BEB group showed lower cortical thickness at baseline in the frontal-rostral, supramarginal and temporal regions compared to patients with HFS. In this group BoNT treatment was associated with a cortical thinning in the primary motor cortex and the pre-supplementary motor area (pre-SMA). Contrary patients with HFS showed no longitudinal CT changes. A decreased cortical thickness was attested bilaterally in the temporal poles and in the right superior frontal region in BEB patients in comparison to HC. Patients in the HFS group presented a decreased CT in the left lingual gyrus and temporal pole.

Conclusions: Although patients with BEB and HFS present clinically with involuntary movements of facial muscles, they exhibited differences in cortical thickness. While BoNT therapy was equally effective in both groups, widespread changes of cortical morphology occurred only in BEB patients. We demonstrated specific disease- and therapy-dependent structural changes induced by BoNT in the studied hyperkinetic conditions.

Conflict of interest statement

The authors have declared that no competing interests exist.


Fig 1
Fig 1. Cortical thickness differences between the BEB and HFS groups.
(A) cross-sectional analysis between BEB and HFS at baseline; (B) cross-sectional analysis between BEB and HFS after the treatment; (C) longitudinal rate of change of cortical thickness over time in BEB compared to HFS. Only clusters that survived the P<0.001 threshold are included. Images are presented at P = 0.05 to better show the extent of cortical changes.

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    1. Hallett M. Blepharospasm recent advances. Neurology. 2002;59(9):1306–12. - PubMed
    1. Barker FG, Jannetta PJ, Bissonette DJ, Shields PT, Larkins MV, Jho HD. Microvascular decompression for hemifacial spasm. Journal of Neurosurgery. 1995;82(2):201–10. 10.3171/jns.1995.82.2.0201 - DOI - PubMed
    1. Berardelli A, Rothwell JC, Day BL, Marsden CD. Pathophysiology of blepharospasm and oromandibular dystonia. Brain. 1985;108(3):593–608. - PubMed
    1. Hallett M, Evinger C, Jankovic J, Stacy M. Update on blepharospasm Report from the BEBRF International Workshop. Neurology. 2008;71(16):1275–82. 10.1212/01.wnl.0000327601.46315.85 - DOI - PMC - PubMed
    1. Jannetta PJ. Observations on the etiology of trigeminal neuralgia, hemifacial spasm, acoustic nerve dysfunction and glossopharyngeal neuralgia. Definitive microsurgical treatment and results in 117 patients. Neurochirurgia. 1977;20(05):145–54. - PubMed


Supplementary concepts

Grant support

This work was supported by the German Research Council (CRC 1193, project B05). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.