Does rTMS Targeting Contralesional S1 Enhance Upper Limb Somatosensory Function in Chronic Stroke? A Proof-of-Principle Study

 Does your hospital even have rTMS available? I was denied entry into some rTMS research because my damage to the motor cortex was so bad that nothing in rTMS would have worked.

But is it better than the simple instructions where Margaret Yekutiel wrote a whole book about this in 2001, 'Sensory Re-Education of the Hand After Stroke'.

Does rTMS Targeting Contralesional S1 Enhance Upper Limb Somatosensory Function in Chronic Stroke? A Proof-of-Principle Study

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Svetlana Pundik, MD, MSc, Margaret Skelly, PhD, Jessica McCabe, DPT, ...

First Published January 29, 2021 Research Article 

https://doi.org/10.1177/1545968321989338

Article information

   

Abstract

Background

Somatosensory deficits are prevalent after stroke, but effective interventions are limited. Brain stimulation of the contralesional primary somatosensory cortex (S1) is a promising adjunct to peripherally administered rehabilitation therapies.

Objective

To assess short-term effects of repetitive transcranial magnetic stimulation (rTMS) targeting contralesional (S1) of the upper extremity.

Methods

Using a single-session randomized crossover design, stroke survivors with upper extremity somatosensory loss participated in 3 rTMS treatments targeting contralesional S1: Sham, 5 Hz, and 1 Hz. rTMS was delivered concurrently with peripheral of sensory electrical stimulation and vibration of the affected hand. Outcomes included 2-point discrimination (2PD), proprioception, vibration perception threshold, monofilament threshold (size), and somatosensory evoked potential (SEP). Measures were collected before, immediately after treatment, and 1 hour after treatment. Mixed models were fit to analyze the effects of the 3 interventions.

Results

Subjects were 59.8 ± 8.1 years old and 45 ± 39 months poststroke. There was improvement in 2PD after 5-Hz rTMS for the stroke-affected (F(2, 76.163) = 3.5, P = .035) and unaffected arm (F(2, 192.786) = 10.6, P < .0001). Peak-to-peak SEP amplitudes were greater after 5-Hz rTMS for N33-P45 (F(2, 133.027) = 3.518, P = .032) and N45-P60 (F(2, 67.353) = 3.212, P = .047). Latencies shortened after 5-Hz rTMS for N20 (F(2, 69.64) = 3.37, P = .04), N60 (F(2, 47.343) = 4.375, P = .018), and P100 (F(2, 37.608) = 3.537, P = .039) peaks. There were no differences between changes immediately after the intervention and an hour later.

Conclusions

Short-term application of facilitatory high-frequency rTMS (5Hz) to contralesional S1 combined with peripheral somatosensory stimulation may promote somatosensory function. This intervention may serve as a useful adjunct in somatosensory rehabilitation after stroke.

Keywords stroke, sensory deficits, somatosensory deficits, repetitive transcranial magnetic stimulation, rTMS, 2-point discrimination, sensory evoked potentials

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