Authors: Joseph Holmes
Mentors: Jared Nielsen
Insitution: Brigham Young University
BACKGROUND
Anosognosia is characterized by a stroke victim’s inability to acknowledge their acquired physical deficits. Such patients could believe they can operate their limbs normally even when they cannot. Patients will often attribute other reasons to explain their deficit (unwillingness to move, a sprain, arthritis, etc).
Previous research has reported damage from various brain areas, including several fronto-temporal-parietal areas, insula, and subcortical regions. Many studies suggest that the deficit is caused from impaired sensory feedback coupled with spared motor intentions, which involves premotor, sensory-motor regions, basal ganglia, temporal-parietal junction, insular cortex, and prefrontal cortex. The objective of this study is to confirm the involvement of these brain areas. It is also to identify other possible networks that could contribute to the development of AHP.
METHODS
We performed a literature review for case studies of patients presenting with anosognosia for hemiplegia (n=17). The majority of cases were attributed to ischemic stroke (n=15) while the others resulted from hemorrhagic stroke. Lesion network mapping analysis was performed on the 17 lesions with a large cohort of healthy control resting-state scans (n=1000).
RESULTS
The main regions to which the lesions were functionally connected included the right transverse temporal gyrus (n=17) and the anterior left insula (n=17). It is also important to note that the lesion networks were found to be negatively correlated with a few areas in the prefrontal cortex.
CONCLUSION
Further research should be done to investigate the involvement of specific areas of the prefrontal cortex in AHP. Some regions in the prefrontal cortex may be negatively correlated; however, past research suggests a positive correlation of other prefrontal regions.
It is important that clinicians understand the lesion networks of AHP, as it will guide them to treat patients more effectively. Interventions such as transcranial brain stimulation could become more beneficial to patients, as clinicians will know specific areas of the brain to stimulate to mitigate symptoms of AHP.