Over the last month, many online news articles have drawn our attention to neuroscience-related topics and research. If it exists, I prefer to refer to the original research to interpret such news articles' real significance and claims. The overlapping theme for most of these news articles appears to be brain diseases associated with aging and early detection and even prevention of diseases.
The first news article (Marshall, 2024) was from a local Boston network, CBS News, from a research group at Mass General Brigham (an amalgamation of Massachusetts General and Brigham and Women’s Hospitals. The article stated that self-reports of memory loss, along with spousal reports of these patients’ cognitive functioning, were associated with changes in the brain protein tau. Tau neurofibrillary tangles are a known biomarker of Alzheimer’s disease (AD) (Marshall, 2024.). There was no reference to the original study. A deep dive on Google located a post from the hospital about this (Falone, 2024), which provided the original study link. Additionally, we had another news article about this study in the Harvard Gazette (Bridger, 2024) included on our list for this review without knowing these were the same study. In this study, there were 675 participants drawn from other studies that were classified as cognitively unimpaired (CU), which meant a neuropsychological assessment could not provide evidence of a cognitive decline (Jadick et al., 2024). Despite no evidence of a decline from such an assessment, self and spousal reports of a cognitive decline were correlated with tau protein neurofibrillary tangles, a biomarker of AD, that were shown from PET scans (Jadick et al., 2024). The conclusion was that paring self-reports, spousal reports, and PET scans may reveal preclinical AD. Thus, early screening could lead to interventions and better care. In fact, as we know from last month’s review of the neuroscience-related news blog, there was an article about a documentary that aired yesterday on CNN about reversing AD symptoms through lifestyle changes. Please refer to that blog for details.
Next in our lineup is a news article about PD in relation to tetanus shots (Wilson, 2024). The article suggests that getting a recent tetanus inoculation is correlated with a lower risk of developing PD, and thus, through the logic of transitivity, such a bacterial infection could be a risk factor for the development of PD (Wilson, 2024). As I could not access the full article on NewScientist behind the paywall to locate the original study, I did a Google search. I was able to locate a preprint of a study in the journal medRxiv (Israel et al., 2024). The study cohort was from a national health database in Israel of 1,446 patients with PD, diagnosed within a range of 45 to 75 years of age, compared with a matched control group. The study suggested a correlation between recent diphtheria-tetanus inoculation and a lower risk of PD (Israel et al., 2024). This study suggested a possible protective effect of vaccination, which decreased over time since inoculation, a period of three years (Israel et al., 2024). The study claims there might be a link between the bacterium C. Tetani and the development of PD. Additionally, the possibility of the use of antibiotics might correlate with disease severity in different ways depending on the specific antibiotic, with some decreasing and others increasing PD severity. This article has not gone past peer review and appears to be quite controversial.
Our final news article is about ADHD and medication effectiveness based on brain anatomy (Dolan, 2024). Thankfully, the original study was cited here and I was able to access it. It was published in Nature Mental Health (Parlatini et al., 2024). The study enrolled 60 adults with ADHD diagnoses and 23 control participants (Parlatini et al., 2024). Forty-two adults with ADHD were responders to methylphenidate (MPH), whereas 18 were MPH non-responders, with all ADHD participants presenting with the same clinical profile (Parlatini et al., 2024). Brain structural analysis was done using MRI to examine differences between cortical volume (CV), cortical thickness (CT), and brain surface area (SA) between the two ADHD groups and controls (Parlatini et al., 2024). Additionally, "enriched genes" associated with MPH were examined (Parlatini et al., 2024). Those with ADHD had differences in CV and CT (significantly smaller volume and thickness) in the temporoparietal regions (Parlatini et al., 2024). Differences between the MPH non-responders and controls were seen across all lobes of the brain, which were correlated with non-response on the inattentive ADHD symptoms (Parlatini et al., 2024). Differences within the ADHD group between responders and non-responders included a smaller CV and lower cortical SA for nonresponders across various regions. What I find most interesting is that there may be brain differences in those with ADHD in response to medications. I remember reading in the early 1990s that methylphenidate and dextroamphetamine drew from different dopamine pools at my internship at Harvard Medical School as an undergrad. However, I have not been able to locate a reference about this or any evidence of this in the scientific literature since. It might be that ADHD is a heterogeneous disorder with various subtypes that respond to different medications based on neuroanatomy. Thus, what we classify and cluster together based on common symptomatology might actually be different disorders.
Abbreviations in this blog:
AD: Alzheimer's disease ADHD: Attention-Deficit/Hyperactivity Disorder
CT: cortical thickness
CV: cortical volume
MPH: methylphenidate (the chemical name for Ritalin)
PD: Parkinson's disease
PET: Positron Emission Tomography
SA: Brain surface area
References
Bridger, H. (2024, June 10). Alzheimer’s indicators track with biological changes in brain. Harvard Gazette. https://news.harvard.edu/gazette/story/2024/06/alzheimers-indicators-track-with-biological-changes-in-brain/?utm_source=SilverpopMailing&utm_medium=email&utm_campaign=Daily+Gazette+20240611+%281%29
Dolan, E. W. (2024, June 3). Neuroanatomy appears to impact ADHD medication effectiveness. PsyPost. https://www.psypost.org/neuroanatomy-appears-to-impact-adhd-medication-effectiveness/?utm_source=dlvr.it&utm_medium=facebook&fbclid=IwZXh0bgNhZW0CMTEAAR1WyFEOyJXoKMD30ajGxUB5Ez5ag6_vkJI6DyvlU15niy5-BI9KPebvfq8_aem_AeYUzIOqPaOoAapMaMr-261l4JFuzPoyUFR2-bhsWrKDZwqpqSQmjvK4Bg6je45Ob7Kjg25u_RaBc13B0qDh_j52
Falone, C. (2024, May 29). Mass General Brigham Study Finds that Memory Complaints Can Predict Biological Changes in the Brain. Mass General Brigham.
Israel, A., Magen, E., Merzon, E., Ruppin, E., Vinker, S., & Giladi, N. (2024). Anti-Tetanus Vaccination Is Associated with Reduced Occurrence and Slower Progression of Parkinson’s Disease. https://doi.org/10.1101/2024.05.03.24306800
Jadick, M. F., Robinson, T., Farrell, M. E., Klinger, H., Buckley, R. F., Marshall, G. A., Vannini, P., Rentz, D. M., Johnson, K. A., Sperling, R. A., & Amariglio, R. E. (2024). Associations between self and study partner report of cognitive decline with regional tau in a multicohort study. Neurology, 102(12). https://doi.org/10.1212/wnl.0000000000209447
Marshall, M. (2024, May 29). Massachusetts researchers find memory loss may predict brain changes associated with Alzheimer’s. CBS News. https://www.cbsnews.com/boston/news/memory-loss-alzheimers-mass-general-brigham/?fbclid=IwZXh0bgNhZW0CMTEAAR1CC8vlPqdJeIGk9XbUjNV3ghE8ZNVHfXqJCE5TrGeYozbfx9u-pxygDVw_aem_AY1SN69P1JHBSfzoiGQM7gmH35uRupKN74OgsTt8knvHwX-9G6pKNDZray_7XkJ8goAsmPZMdiTp-7Uposm283A7
Parlatini, V., Andrews, D. S., Pretzsch, C. M., Arenella, M., Daly, E., Ecker, C., & Murphy, D. G. (2024). Cortical alterations associated with lower response to methylphenidate in adults with ADHD. Nature Mental Health, 2(5), 514–524. https://doi.org/10.1038/s44220-024-00228-y
Wilson, C. (2024, June 5). Parkinson’s disease could be prevented by a recent tetanus vaccine. New Scientist. https://www.newscientist.com/article/2433051-parkinsons-disease-could-be-prevented-by-a-recent-tetanus-vaccine/?utm_medium=social&utm_campaign=echobox&utm_source=Facebook&fbclid=IwZXh0bgNhZW0CMTEAAR1th31A9leKBmR958mB9C1BtHja9k9X99TFKFUI1KZZbKvK0TU-yKdf1w4_aem_ASV9kEXLpNhI_uaDmCKQnthu1CJLPlzRVkvmIqJ-Msk7_aQqj9WM0Cu4gORz_1YO-Jj6O66JacKVGeYM8AE-0P6S#Echobox=1717070061