Electrical stimulation therapy as treatment for poststroke dystonia

Allison N Capizzi; Kelly Horstmann; Monica Verduzco-Gutierrez; Gerard E Francisco; Sheng Li

doi:10.4103/2349-7904.324872

CASE REPORT

Year : 2021 | Volume : 4 | Issue : 3 | Page : 156-158

Electrical stimulation therapy as treatment for poststroke dystonia

Allison N Capizzi¹, Kelly Horstmann², Monica Verduzco-Gutierrez³, Gerard E Francisco⁴, Sheng Li⁴
¹ Department of Physical Medicine and Rehabilitation, UC Davis Health, Sacramento, USA
² TIRR Memorial Hermann Hospital, Houston, TX, USA
³ Department of Rehabilitation Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
⁴ Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center at Houston, TIRR Memorial Hermann Hospital, Houston, TX, USA

Date of Submission	19-Oct-2020
Date of Decision	09-May-2021
Date of Acceptance	11-May-2021
Date of Web Publication	28-Aug-2021

Correspondence Address:
Dr. Allison N Capizzi
Department of Physical Medicine and Rehabilitation, UC Davis Health, Sacramento, California
USA

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/2349-7904.324872

Abstract

This case describes success using high-dose submotor threshold electrical stimulation (EStim) therapy for the management of dystonia in a chronic stroke patient. The authors find this novel EStim treatment is safe and offers the potential to manage poststroke dystonic movements.

Keywords: Cerebrovascular accident, dystonia, movement disorders, transcutaneous electrical nerve stimulation

How to cite this article:
Capizzi AN, Horstmann K, Verduzco-Gutierrez M, Francisco GE, Li S. Electrical stimulation therapy as treatment for poststroke dystonia. J Int Soc Phys Rehabil Med 2021;4:156-8

How to cite this URL:
Capizzi AN, Horstmann K, Verduzco-Gutierrez M, Francisco GE, Li S. Electrical stimulation therapy as treatment for poststroke dystonia. J Int Soc Phys Rehabil Med [serial online] 2021 [cited 2022 May 20];4:156-8. Available from: https://www.jisprm.org/text.asp?2021/4/3/156/324872

Introduction

Dystonia is often painful and limits the use of the affected limb or body region. Successful treatment options are limited. Botulinum toxin or phenol injections may not be the best options in patients with dynamic tone. Alternately, pharmacologic measures are often less effective than desired, may be cost prohibitive, and are usually accompanied by unwanted side effects such as sedation and cognitive impairment. Anecdotally, sensory tricks used by patients are able to provide transient correction of dystonia. This case highlights the long-term use of electrical stimulation (EStim) therapy as a sensorimotor retraining tool to successfully correct dystonic movements in a stroke patient.

Case Report

JB is a 63-year-old female who sustained an ischemic left middle cerebral artery (MCA) territory stroke secondary to spontaneous carotid artery dissection with subsequent malignant MCA syndrome 10 years before referral to the authors' clinic for the management of right arm dystonia and spasticity. She was previously followed by an outside provider who retired. Her prior management consisted of a combination of pharmacologic management and several sessions of botulinum toxin injections without a significant change in the dystonia. At the time of initial evaluation, she reported the limb dystonia was most limiting to her quality of life as she could not clear doorways or tight spaces with her right arm extended, subsequently hitting her arm repeatedly throughout the day, it was also a source of social embarrassment for her.

Computed tomography (CT) and CT angiography of the head and neck at the time of her stroke demonstrated an early acute left MCA infarct with an abnormal appearing left internal carotid artery (ICA) consistent with flow-limiting dissection. An intraluminal thrombus was present within the supraclinoid portion of the ICA, extending to the carotid terminus as well as the proximal left anterior cerebral artery and posterior communicating artery. There was complete occlusion of the left MCA with minimal peripheral collateral flow to cortical vessels through the leptomeningeal branches. Her brain magnetic resonance imaging 8 months poststroke showed a large area of encephalomalacia in the left hemisphere, consistent with the previously diagnosed left MCA territory ischemic stroke involving the left frontal, parietal, and temporal lobe regions. Subcortical areas (basal ganglia, internal capsule, and/or corona radiata) were unremarkable.

On examination, she demonstrated expressive aphasia, normal muscle strength, and active range of motion in the right upper limb when sitting, but right arm dystonia presented during ambulation. Dystonia was characterized by right shoulder abduction and elbow extension during gait [Figure 1], left. Sensory testing revealed markedly reduced or absent pinprick, light touch and cold sensation to the right face, arm, forearm, and hand. Proprioception was also impaired. She underwent botulinum toxin injections with 500 units distributed to the right trapezius (50 units), deltoid (100 units), triceps (75 units), extensor digitorum communis (50 units), gluteus maximus (75 units), rectus femoris (25 units), vastus lateralis (25 units), tibialis posterior (25 units), flexor hallucis longus (25 units), and flexor digitorum longus (50 units). At 6-week follow-up, the patient denied any noticeable improvement when the peak effect was expected.

Figure 1: Left side demonstrates posture during gait before electrical stimulation therapy and right side demonstrates posture during gait after 160 cumulative hours of electrical stimulation

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As a therapeutic trial and with the patient's consent, two EStim pads were applied to the right forearm and proximal arm along the median and musculocutaneous nerves. Stimulation was set at sensory settings with the pulse width at 200–300 μs, 20–40 pulses per second, intensity was set at 5–7 milliamps (no more than 20 milliamps to ensure submotor threshold), the ramp time was set at 0–2 s, on-time was set to 10–30 s, off time was set to 0 s (to make the EStim continuous). On the first trial, she was able to flex her right elbow and hold the arm close to her side during gait. She was instructed to wear the EStim unit for 8 h/day. The arm dystonia was largely suppressed while walking at the next 1-month follow-up reflecting 160 cumulative hours of EStim use [Figure 1], right. Of note, sensory examinations demonstrated improvement in proprioception, light touch, cold, and pinprick on the right face and upper limb. In summary, the patient was followed in clinic at approximately 4-week intervals for 3 months during which time she and her caregiver felt the EStim was helpful for her arm dystonia. She chose to stop botulinum toxin injections for upper limb dystonia management. She was contacted by phone 6 months after starting EStim treatment at which time she reported satisfaction with her progress, no subsequent clinic visits were scheduled.

Discussion

This patient demonstrated improvement in the right arm dystonia and right-sided sensation with high-dose sensory input to opposing muscle groups. The clinical findings of sensory impairment in this patient are consistent with the prevalence of sensory and proprioception deficits in patients with dystonia documented in the literature.^[1],[2] Parallel improvement in dystonia and sensation suggests that sensory input has a gating or modulating effect on motor output to the motor network.^[3],[4] The improvement in sensation and movement seen with EStim in this patient also suggests the root of the movement disorder is secondary not only to disinhibition from the motor cortex but also impaired sensory input. The literature demonstrates spatial, temporal, and proprioception deficits may be related to a lack of sensory feedback which in turn may impair input from the motor cortex, thus supporting the motor network hypothesis of dystonia pathophysiology.^[3],[4] Given these theories, sensory restoration could be realized through long-term EStim treatment.^[5] The authors cannot provide evidence to explain why sensory function of the right face improved in this case. However, it is possible that sensory adaptation to electrical stimulation occurs at the sensory cortical level.^[6]

There are several limitations within this case study. As a case report and not a randomized controlled trial, this intervention does not have statistical power, and selection bias is unavoidable. It is not possible to verify the exact dose of EStim treatment as this was self-reported and not tracked on the device. The optimal dose for treatment is unclear. Considering the patient received botulinum toxin injections approximately 1 month before initiating the EStim therapy, it is possible that the toxin injections could have played a role in the improvement of the patient's limb dystonia.

Conclusion

EStim therapy for dystonia is currently not a common practice. This case report suggests that EStim treatment may improve the movement disorder. Future research is necessary to further investigate the underlying mechanism of sensory restoration after EStim and to better quantify the results of this therapy.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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2.	Tinazzi M, Rosso T, Fiaschi A. Role of the somatosensory system in primary dystonia. Mov Disord 2003;18:605-22.
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