New hope for spinal cord injuries – studies

Objective
This randomized, double-blind, parallel-group clinical trial investigated the neurophysiological effects of combining transcranial direct current stimulation (tDCS) with robotic-assisted gait training (RAGT) in individuals with incomplete spinal cord injury (SCI). The focus was on changes in cortical activity and gait function.

Methodology

• Participants: 26 individuals with incomplete SCI, randomized into two groups: active tDCS (n = 13) vs. sham tDCS (n = 13).
• Intervention: 30 sessions of RAGT with tDCS over 6–12 weeks (3–5 times per week), administered using the Lokomat system.
• tDCS: Anodal stimulation over the leg area of ​​the primary motor cortex (M1).
• Measurement: Using functional near-infrared spectroscopy (fNIRS), changes in oxygen saturation (oxyHb) in various brain areas were recorded before and after the intervention.
• Clinical Endpoint: Improvement in the Walking Index for Spinal Cord Injury II (WISCI-II).

Results
The active tDCS group showed significantly increased oxy-Hb concentrationsin the Supplementary Motor Area (SMA) and M1 after the intervention.

• These activity increases correlated positively with improved walking ability (WISCI-II).
• No significant changes were observed in the dorsolateral prefrontal cortex (DLPFC) and the primary somatosensory cortex (S1).
• Limitation: A lower proportion of tetraplegics in the tDCS group may have influenced the results.

Every year, thousands of people suffer from spinal cord injury – often with drastic consequences for mobility, independence, and quality of life. Especially in cases of injuries to the neck (cervical spinal cord injuries), the loss of arm and hand function is extremely stressful for those affected.

A research team led by Dr. Lynda Murray has now investigated whether targeted brain stimulation – specifically, so-called anodal transcranial direct current stimulation (a-tDCS) – can help improve nerve activity. The results are promising: Even a single 20-minute treatment showed measurable effects in the study.

What’s behind it?

Transcranial direct current stimulation (tDCS) is a non-invasive procedure in which a weak current is passed through specific brain regions via two small electrodes on the scalp. The goal is to activate or modulate the nerve cells in the motor areas of the brain – thus, to utilize the brain’s natural “plasticity.”

In the study presented, the procedure was specifically used in individuals with chronic cervical spinal cord injury whose forearm muscles were weakened. The treatment consisted of a single stimulation session lasting 20 minutes, with two different current intensities (1 mA and 2 mA), as well as a sham treatment (placebo). The researchers wanted to determine whether this resulted in measurable changes in muscle control.

The study results in plain text

• Participants: 9 patients with a spinal cord injury in the neck region that had existed for at least 8 months, all with limited mobility in the forearm.
• Treatment: Each participant received three sessions, each one week apart: one with 1 mA, one with 2 mA, and one without actual current flow (placebo).
• Measurements: Before, immediately after, and 20 minutes after treatment, nerve conduction (via so-called motor evoked potentials), as well as muscle strength and tactile sensation, were checked.

What was measured?

• At 2 mA a-tDCS, the nerve activity (motor stimulus response) in the affected muscle increased by an average of approximately 40% – but only in the short term.
• The sense of touch improved noticeably at both 1 mA and 2 mA.
• Muscle strength itself did not increase significantly after a single treatment.
• Side effects were rare and mild: slight itching under the electrodes, occasional headaches – all reversible.

Why is this important?

Even if an immediate cure is not possible, the results clearly show: The brain remains active – even after a spinal cord injury. The connection between brain and muscles is often not completely interrupted, but rather disrupted or weakened. This is precisely where neuromodulation comes in by reactivating the natural reserves.ert.

The study also showed that the effects are dose-dependent – ​​stronger stimulation produced better results. This underscores the importance of precise adjustment and individualized therapy adaptation.

What are the consequences?

The study was planned as a feasibility study – that is, as initial proof that the method fundamentally works and is safe. Long-term improvements or sustainable rehabilitation gains cannot yet be derived from it. Further studies with multiple sessions over weeks are needed – this is precisely the next goal of the research.

Nevertheless, the results provide a valuable building block in the overall picture of modern neurorehabilitation. They show that even years after a spinal cord injury, not all hope is lost – and that targeted brain stimulation has the potential to provide decisive support for rehabilitation.