Botulinum Toxin Effects on Sensorimotor Integration in Focal Dystonias

(1) Background: In dystonia, the somatosensory temporal discrimination threshold (STDT) is abnormally increased at rest and higher and longer-lasting during movement execution in comparison with healthy subjects (HS), suggesting an abnormal sensorimotor integration. These abnormalities are thought to depend on abnormal proprioceptive input coming from dystonic muscles. Since Botulinum toxin-A (BT-A) reduces proprioceptive input in the injected muscles, our study investigated the effects of BT-A on STDT tested at rest and during voluntary movement execution in patients with focal dystonia. (2) Methods: We enrolled 35 patients with focal dystonia: 14 patients with cervical dystonia (CD), 11 patients with blepharospasm (BSP), and 10 patients with focal hand dystonia (FHD); and 12 age-matched HS. STDT tested by delivering paired stimuli was measured in all subjects at rest and during index finger abductions. (3) Results: Patients with dystonia had higher STDT values at rest and during movement execution than HS. While BT-A did not modify STDT at rest, it reduced the abnormal values of STDT during movement in CD and FHD patients, but not in BSP patients. (4) Conclusions: BT-A improved abnormal sensorimotor integration in CD and FHD, most likely by decreasing the overflow of proprioceptive signaling from muscle dystonic activity to the thalamus.

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Does the Somatosensory Temporal Discrimination Threshold Change over Time in Focal Dystonia?

Neural Plasticity ◽

10.1155/2017/9848070 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Antonella Conte ◽

Gina Ferrazzano ◽

Daniele Belvisi ◽

Nicoletta Manzo ◽

Antonio Suppa ◽

...

Keyword(s):

Basal Ganglia ◽

Cervical Dystonia ◽

Healthy Subjects ◽

Temporal Discrimination ◽

Discrimination Threshold ◽

Focal Dystonia ◽

Inhibitory Interneurons ◽

Follow Up Study ◽

Over Time

Background. The somatosensory temporal discrimination threshold (STDT) is defined as the shortest interval at which an individual recognizes two stimuli as asynchronous. Some evidence suggests that STDT depends on cortical inhibitory interneurons in the basal ganglia and in primary somatosensory cortex. Several studies have reported that the STDT in patients with dystonia is abnormal. No longitudinal studies have yet investigated whether STDT values in different forms of focal dystonia change during the course of the disease.Methods. We designed a follow-up study on 25 patients with dystonia (15 with blepharospasm and 10 with cervical dystonia) who were tested twice: upon enrolment and 8 years later. STDT values from dystonic patients at the baseline were also compared with those from a group of 30 age-matched healthy subjects.Results. Our findings show that the abnormally high STDT values observed in patients with focal dystonia remained unchanged at the 8-year follow-up assessment whereas disease severity worsened.Conclusions. Our observation that STDT abnormalities in dystonia remain unmodified during the course of the disease suggests that the altered activity of inhibitory interneurons—either at cortical or at subcortical level—responsible for the increased STDT does not deteriorate as the disease progresses.

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Botulinum Toxin A And Task-specific Training For Hand Dystonia Due To 5 Year Old Stroke

Journal of College of Physicians And Surgeons Pakistan ◽

10.29271/jcpsp.2018.03.s60 ◽

2018 ◽

Vol 28 (3) ◽

pp. S60-S62

Author(s):

Tahir Masood ◽

Muhammad Umar

Keyword(s):

Botulinum Toxin ◽

Botulinum Toxin A ◽

Specific Training ◽

Toxin A ◽

Hand Dystonia ◽

And Task

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POST-STROKE FOCAL HAND DYSTONIA

The Professional Medical Journal ◽

10.29309/tpmj/2018.25.02.444 ◽

2018 ◽

Vol 25 (02) ◽

pp. 205-210

Author(s):

Muhammad Umar ◽

Tahir Masood ◽

Mazhar Badshah

Keyword(s):

Botulinum Toxin ◽

Botulinum Toxin A ◽

Control Group ◽

P Value ◽

Specific Training ◽

Toxin A ◽

Focal Hand Dystonia ◽

Post Stroke ◽

Hand Dystonia ◽

Experimental Group

Objectives: To determine the effects of Botulinum toxin A (BoNTA) with taskspecific training on hand function and quality of life in patients with post stroke focal dystonia ofhand. Study Design: Randomized Controlled Trial. Place and Duration of Study: This studywas conducted in Holy family hospital, The Neurocounsel and Chambeli Rehabilitation centerfrom October 2015 to September 2016. Methodology: Both male and female patients sufferingfrom stroke for at least 6 months with focal hand dystonia were included in this randomizedcontrolled trial. 46 patients were recruited in the study through non probability purposivesampling and then were allocated to control (n=23) and experimental group (n=23) by randomnumber list generated for 46 patients using SPSS software. Control group was provided withonly task specific training while experimental group was provided with an injection of BotulinumToxin A in addition to task-specific training. Data was collected from both groups at baselineand then after 8 weeks by using Action Research Arm Test (ARAT), Stroke specific qualityof life (SS-QOL) and Arm dystonia disability scale (ADDS). Results: Although both groupsshowed significant improvements after training(P value <0.001) in both ARAT scale and SSQOLbut as shown by the difference of means of the groups, experimental group has shownmore improvement than control group at the end of 8 weeks of intervention with P value<0.05.ADDS has also shown better results in reducing disability in experimental group as compared tocontrol group. Conclusion: Botulinum toxin A prior to start of task specific training significantlyimproves outcome in post stroke focal hand dystonia patients than task specific training alone.

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