Functional and structural lesion network mapping in neurological and psychiatric disorders: a systematic review

Beyond the surface: understanding psychiatric disorders in individuals with spinal cord injury- a narrative exploration

PURPOSE

Spinal Cord Injury (SCI) presents a life-threatening condition that compromises the spinal cord's integrity. Among the complications affecting SCI patients are psychiatric disorders, whose causal mechanisms remain elusive. These disorders are often attributed to multifactorial aspects, encompassing physiological, neurobiological, psychological, and social factors. In the context of SCI patients, we are interested in identifying the specific factors that contribute to the development of psychiatric disorders in this population, emphasizing the critical need for prevention strategies and comprehensive therapeutic management, ultimately aiming to improve the affected patients' quality of life.

METHODS

The process of searching and selecting information was performed between August and December of 2023, utilizing PubMed, ResearchGate, and NCBI as the requisite databases for this review. To ensure precise information retrieval, keywords were strategically employed, focusing on publications spanning from 1985 to the present. MeSH terms, including spinal cord injury, acute spinal cord injury, psychiatric disorders, neuropsychiatry, cognitive impairment, and chronic pain, were applied. A total of 127 articles were identified through electronic searches, and 55 of these were chosen for inclusion in this review. The consulted studies encompassed various types, such as meta-analyses, systematic reviews, animal model experiments, and others.

RESULTS

Various factors contributing to the onset of psychiatric disorders in patients with SCI were proposed, all grounded in evidence: neurobiological pathology; cognitive impairment; the impact of systemic diseases on psychological well-being; and, lastly, the correlation between chronic pain and diminished daily functionality, experiences widely encountered by SCI patients.

CONCLUSION

The diagnosis of psychiatric disorders remains largely clinical and syndromic, with unclear causal mechanisms. Understanding psychiatric symptoms in SCI patients requires further investigation. Key contributing factors include neurobiological pathology linked to SCI, cognitive impairment, systemic and organ-specific diseases, and chronic pain associated with reduced functionality. We emphasize the importance of therapeutic and rehabilitative measures that address both physical and psychological health to improve overall quality of life.

A neural circuit for spatial orientation derived from brain lesions

There is disagreement regarding the major components of the brain network supporting spatial cognition. To address this issue, we applied a lesion mapping approach to the clinical phenomenon of topographical disorientation. Topographical disorientation is the inability to maintain accurate knowledge about the physical environment and use it for navigation. A review of published topographical disorientation cases identified 65 different lesion sites. Our lesion mapping analysis yielded a topographical disorientation brain map encompassing the classic regions of the navigation network: medial parietal, medial temporal, and temporo-parietal cortices. We also identified a ventromedial region of the prefrontal cortex, which has been absent from prior descriptions of this network. Moreover, we revealed that the regions mapped are correlated with the Default Mode Network sub-network C. Taken together, this study provides causal evidence for the distribution of the spatial cognitive system, demarking the major components and identifying novel regions.