# Balance Training-Related Changes in Intracortical Inhibition and Symptom Severity in a Patient with Chronic Neuropathic Pain: A Single-Case Study

## TL;DR

Balance training improved chronic pain and well-being by enhancing GABA-related brain inhibition in a single patient.

## Contribution

Balance training is shown to upregulate GABAergic inhibition and reduce chronic pain without drugs.

## Key findings

- Balance training increased GABA-mediated intracortical inhibition and reduced chronic neuropathic pain.
- Improved sleep and well-being were observed after balance training.
- Effects of balance training were reversed during detraining periods.

## Abstract

What are the main findings?
Several weeks of balance training reduced chronic neuropathic pain and improved sleep and well-being.GABA-mediated intracortical inhibition, measured by transcranial magnetic stimulation, was enhanced.

Several weeks of balance training reduced chronic neuropathic pain and improved sleep and well-being.

GABA-mediated intracortical inhibition, measured by transcranial magnetic stimulation, was enhanced.

What are the implications of the main findings?
Targeted physical activity can be used to improve pain perception.The most likely mechanism is upregulation of GABAergic inhibitory circuits in cortical regions.

Targeted physical activity can be used to improve pain perception.

The most likely mechanism is upregulation of GABAergic inhibitory circuits in cortical regions.

Background/Objectives: It is widely recognized that malfunctions in the GABAergic system can be one of the underlying mechanisms in chronic pain. However, the use of GABAergic drugs to improve pain perception has strong and unwanted side effects, particularly in terms of sedation. Therefore, the present exploratory single-case study tested an alternative treatment using balance training to upregulate the GABAergic system in a 62-year-old patient with widespread chronic pain. Previously, balance training was shown to increase short-interval intracortical inhibition (SICI), a neurophysiological marker commonly associated with GABA-mediated intracortical inhibition, as assessed using paired-pulse transcranial magnetic stimulation (TMS), in healthy young and older adults. Therefore, we hypothesized that the balance-training-induced increase in GABAA-related intracortical inhibition would alleviate pain and increase quality of life. Methods: After two baseline measures, the patient participated in two balance training periods of 4 weeks each, followed by two detraining phases of 2 months each. At baseline and after each intervention and each detraining, intracortical inhibition (i.e., SICI) as well as pain and ‘well-being’ (questionnaires) was assessed. Results: Our results demonstrated enhanced and better modulated intracortical inhibition after 4 weeks of balance training, which was in line with analgesia and improved sleep and mood scores. However, after the first detraining, all parameters went back to baseline. In a subsequent second period of 4 weeks of balance training, intracortical inhibition was again increased, even above the values of the first training period. Pain, sleep, and mood scores were also further improved. After the second detraining period, all values dropped back close to their baseline values. Conclusions: The findings support the assumption that the GABAergic system is highly relevant in the processing and perception of pain. More importantly, our results suggest the possibility that balance training may be an effective way not only to upregulate intracortical inhibition but also to alleviate pain and improve well-being in patients with unspecific chronic pain.