Boosting Motor Recovery After TBI: A Practical Guide to Using tDCS with Physical Therapy

As neuro-rehabilitation therapists, we're all too familiar with the long and often arduous journey our patients with traumatic brain injury (TBI) face. Motor deficits are a common and debilitating consequence, and we're constantly seeking effective strategies to maximize recovery. While our conventional therapies form the bedrock of rehabilitation, emerging evidence suggests that non-invasive brain stimulation, specifically transcranial direct current stimulation (tDCS), could be a powerful adjunct to our existing treatment protocols. A recent landmark phase 2, multicentre, randomised, sham-controlled, triple-blind trial, the TRANSPORT2 study, published in *The Lancet Neurology* in 2025 by Schlaug and colleagues, provides compelling, high-quality evidence for the use of tDCS in post-stroke motor recovery. While this study focused on stroke survivors, its findings and methodology offer invaluable insights for us as TBI clinicians, given the overlapping neural mechanisms of injury and recovery. The study, which included 228 patients, found that anodal tDCS combined with constraint-induced movement therapy (CIMT) led to significantly greater improvements in motor function compared to sham stimulation with CIMT. The effect size was moderate but clinically meaningful, suggesting that tDCS can amplify the effects of our standard rehabilitation therapies. So, how can we translate this to our TBI patients? The principles are largely the same. The goal of anodal tDCS in this context is to increase cortical excitability in the motor cortex of the injured hemisphere, promoting neuroplasticity and enhancing the brain's ability to rewire itself. The TRANSPORT2 trial used a specific protocol that we can adapt. They applied the anodal electrode over the primary motor cortex (M1) of the affected hemisphere, with the cathode placed over the contralateral supraorbital ridge. The stimulation was delivered at an intensity of 2.0 mA for 20 minutes, immediately prior to each of the 10 daily CIMT sessions. This pre-treatment priming of the motor cortex appears to be a key factor in the observed benefits. While the evidence in TBI is not as robust as in stroke, smaller studies and case series are showing promise. A 2025 case series by Cordeiro et al. in *Frontiers in Human Neuroscience* on five patients with severe TBI in the subacute phase reported substantial improvements in cognitive and functional measures (MMSE, FIM) after five daily sessions of anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC). This suggests that tDCS may have broader applications beyond motor recovery in the TBI population, potentially addressing cognitive and affective symptoms as well. A 2024 systematic review by Galimberti et al. also found that while evidence for overall effectiveness is still limited, NIBS techniques like tDCS showed small but significant effects on anxiety and headache post-TBI. **Clinical Application: A Practical Protocol** Based on the available evidence, here is a practical protocol for integrating tDCS into your TBI motor rehabilitation sessions: * **Patient Selection:** Patients with subacute or chronic TBI with upper or lower limb motor deficits who are able to participate in intensive physical therapy would be ideal candidates. Ensure a thorough screening for contraindications. * **Electrode Placement:** For upper limb motor recovery, place the anodal electrode over the primary motor cortex (M1) of the injured hemisphere (C3 or C4 according to the 10-20 EEG system). Place the cathode (return electrode) over the contralateral supraorbital ridge (above the opposite eyebrow). * **Stimulation Parameters:** * **Intensity:** 2.0 mA * **Duration:** 20 minutes * **Frequency:** Daily, 5 days a week, for at least 2 weeks, in conjunction with a course of intensive physical therapy. * **Timing:** Apply tDCS immediately before the physical therapy session to prime the motor cortex for the subsequent motor learning. **Contraindications and Precautions:** tDCS is generally considered safe, but it's crucial to be aware of the contraindications and precautions: * **Absolute Contraindications:** * Presence of metallic implants in the head (e.g., aneurysm clips, cochlear implants). * Implanted electronic devices (e.g., pacemakers, deep brain stimulators). * Skull defects or open wounds at the electrode sites. * **Relative Contraindications/Precautions:** * History of seizures or epilepsy. * Pregnancy. * Sensitive skin or skin allergies. Always conduct a thorough medical history and screening before initiating tDCS. The most common side effects are mild and transient, including itching, tingling, or a mild burning sensation under the electrodes, and occasionally a mild headache. In conclusion, while we await large-scale RCTs specifically in the TBI population, the strong evidence from the stroke literature, coupled with promising smaller studies in TBI, provides a solid rationale for considering tDCS as an adjunct to our physical therapy interventions. By carefully selecting patients and adhering to evidence-based protocols, we may be able to enhance motor recovery and improve the quality of life for our patients with TBI.