Successful Treatment of Psychiatric Symptoms after Traumatic Brain Injury Using Deep Brain Stimulation to the Anterior Limb of Internal Capsule-Nucleus Accumbens

Neurostimulation for Traumatic Brain Injury: Emerging Innovation

Traumatic brain injury (TBI) is a significant source of brain deficit and death among neurosurgical patients, with limited prospects for functional recovery in the cases of moderate-to-severe injury. Until now, the relevant body of literature on TBI intervention has focused on first-line, invasive treatment options (namely craniectomy and hematoma evacuation) with underwhelming focus on non-invasive therapies following surgical stabilization. Recent advances in our understanding of the impaired brain have encouraged deeper investigation of neurostimulation strategies, owed largely to its demonstrated livening of damaged neural circuitry and capacity to stabilize erratic network activity. The objective of the present study is to provide a scoping review of new knowledge in neurostimulation published in the PubMed, Scopus, and Google Scholar databases from inception to November 2022. We critically assess and appraise the available data on primary neurostimulation delivery techniques, with marked emphasis on restorative opportunities for accessory neurostimulation in the interdisciplinary care of moderate-to-severe TBI (msTBI) patients. These data identify two primary future directions: 1) to relate obtained gain-of-function outcomes to hemodynamic and histological changes and 2) to develop a clearer understanding of neurostimulation efficacy, when combined with pharmacologic interventions or other modulatory techniques, for complex brain insult.

Neurostimulation for Functional Recovery After Traumatic Brain Injury: Current Evidence and Future Directions for Invasive Surgical Approaches

We aim to provide a comprehensive review of the current scientific evidence supporting the use of invasive neurostimulation in the treatment of deficits associated with traumatic brain injury (TBI), as well as to identify future directions for research and highlight important questions that remain unaddressed. Neurostimulation is a treatment modality with expanding applications in modern medical practice. Targeted electrical stimulation of specific brain regions has been shown to increase synaptogenesis and enhance structural reorganization of neuronal networks. This underlying therapeutic effect might be of high value for patients suffering from TBI because it could modulate neuronal connectivity and function of areas that are partially or completely spared after injury. The current published literature exploring the application of invasive neurostimulation for the treatment of functional deficits associated with TBI is scarce but promising. Rodent models have shown that targeted stimulation of the hippocampus or connecting structures can result in significant cognitive recovery, while stimulation of the motor cortex and deep cerebellar nuclei is associated with motor improvements. Data from clinical studies are extremely limited; single-patient reports and case series found neurostimulation to be effective in relieving motor symptoms, improving visuospatial memory, and supporting emotional adjustment. Looking forward, it will be important to identify stimulation targets and paradigms that can maximize improvement over multiple functional domains. It will also be important to corroborate the observed behavioral improvements with histological, electrophysiological, and radiological evidence. Finally, the impact of biological variables such as sex and age on the treatment outcomes needs to be explored.

Treatment of Psychiatric Problems After Traumatic Brain Injury

Psychiatric sequelae of traumatic brain injury (TBI) can cause significant and often chronic impairment in functioning and quality of life; however, their phenomenological and mechanistic complexities continue to present significant treatment challenges. The clinical presentation is often an amalgam of syndromes and co-occurring symptoms that require a highly nuanced and systematic approach to treatment. Although few randomized controlled trials have tested treatments for psychiatric problems after TBI and the synthesis of results continues to be compromised by the heterogeneity of study populations, small samples, and differing inclusion criteria and outcome measures, an increasing body of literature supports evidence-based treatment strategies. We provide a narrative review of pharmacological, psychoeducational/behavioral, and neuromodulation treatments for psychiatric conditions in adults with TBI and discuss known or postulated mechanisms of action for these treatment approaches. Where data are available, we focus on randomized controlled trials and large case series in which a psychiatric condition provides both a selection criterion and a primary or secondary outcome. We conclude by proposing directions for future research, particularly the need for novel neuropharmacological, behavioral, and neurophysiological studies and pragmatic trials of multicomponent and adaptive models that will increase understanding of the mechanisms underlying post-TBI psychiatric disorders and accelerate dissemination and implementation of effective person-centered care.