
New imaging data show distinctive brain changes that appear to explain memory and cognitive problems following Lyme disease .
Using fMRI and diffusion tensor imaging (DTI) techniques, investigators found modifications in white matter and other brain tissues in patients with posttreatment Lyme illness (PTLD) in comparison with healthy control persons who did not have a history of the disease.
“It is important for clinicians to know that PTLD leads to real, quantifiable brain adjustments and that patients’ cognitive complaints may be a direct consequence of these brain changes, rather than a side effect of other symptoms, such as fatigue, for example, ” lead author Cheri Marvel, PhD, associate professor of neurology and psychiatry and behavioral sciences, Johns Hopkins University School associated with Medicine, Baltimore, Maryland, told Medscape Medical News .
“I think if individuals heard this, they might feel validated that there is a biologic basis for their persistent symptoms, even if there is no good way to treat the intellectual difficulties yet — plus this may be analogous to what is being reported in infection-associated persistent illnesses, such as long-haul COVID, ” said Marvel, who is associated with the Cognitive Neuropsychiatric Research Laboratory at Johns Hopkins.
The study was published online October 26 in PLOS ONE.
Unknown Mechanisms
PTLD will be a “chronic illness consisting of persistent or recurrent symptoms” in people who have been treated for Lyme disease, the authors write. Research into this condition is “relatively sparse, ” and the particular underlying mechanisms of mind changes that will may affect cognition are “largely unknown. ”
“We were motivated by the persistent issues of cognitive difficulties by patients that have been treated with regard to their Lyme disease, with a lack of data in order to explain the reason behind these symptoms, ” stated Marvel.
“It seemed logical to us that if there were intellectual and neurological symptoms involved, then the particular brain may reveal something about this. Then we could begin to connect the dots between the patient experience and the underlying mechanisms driving them, inch she added.
Previous studies had pointed to human brain abnormalities in patients with PTLD, such as an increase in the number associated with white matter hyperintensities, but these studies “took a broader view of the particular brain than our approach did, inches she mentioned.
The researchers compared 12 male and female adults with PTLD (mean age [SD], 45. 16 [13.62] years) to 18 adult control participants (mean age group, 47. 01 [13.10] years) who underwent fMRI scanning. Twelve control persons (mean age, 45. 33 [13.76] years) were included in the DTI analysis.
PTLD participants completed a 36-item post-Lyme questionnaire of signs and symptoms (PLQS), plus the experts correlated clinical variables along with multimodal MRI findings. All participants performed a short-term working memory space task in the MRI scanner.
The scientists identified functionally defined regions of interest (ROIs) for each participant’s scan and used DTI to investigate the potential relationship between PTLD and white issue structural integrity.
“Surprising” Findings
On the memory task, the PTLD group responded more slowly (but no less accurately) in comparison with the particular control individuals ( F [1,27] = 60. 9; P <. 001; η p =. 34). The PTLD group also showed “general motor slowing, ” the authors note.
The manage persons had been found in order to have fMRI activations — increased blood oxygen level–dependent (BOLD) signal associated with verbal working memory in the frontal lobe, the particular premotor cortex, the caudate, the thalamus, the inferior parietal lobe, and the superior cerebellum. The PTLD group furthermore showed increased BOLD signal within the frontal lobe, the particular premotor cortex, the caudate, as well as the precuneus but less activity inside the premotor cortex, the thalamus, and the inferior parietal lobe.
The results suggested that group differences in the storage task “were due to the PTLD group showing hypo-activation (or not activating at all) in brain regions normally associated along with the job, even though their accuracy was normal, ” the particular authors note.
Conversely, “novel” activated regions were observed in the PTLD group but not really in the control group. Increased task-related activity was noticed in PTLD participants when compared with the handle persons primarily in three white matter regions of the frontal lobe: BA8, BA9, plus BA6.
DTI analyses found parts of task-related activation that will overlapped with the activity found on fMRI.
Area of task-related activation (ROI) | Overlap along with white issue |
---|---|
Left BA8 | 25. 00% |
Left BA9 anterior | 22. 35% |
Left BA9 posterior | 24. 46% |
Right BA6 | 13. 46% |
Whole-brain DTI analyses identified several frontal lobe regions that had higher axial diffusivity within the sufferers with PTLD, which were correlated with longer duration associated with illness. This higher axial diffusivity “correlated with fewer cognitive and neurological symptoms. ”
In particular, axial diffusivity in the particular BA9 anterior ROI “negatively correlated” with all 3 clinical measures.
Clinical measure | Correlation | P value |
---|---|---|
Total | r(12) sama dengan -. 76 | . 004 |
Neurologic | r(12) = -. 78 | . 003 |
Cognitive | r (12) = –. 81 | . 001 |
“We found that the brains of PTLD patients had already been altered simply by the condition — specifically, white matter function increased while performing a cognitive task, which is unusual to observe with the MRI methods we utilized, and we did not see such exercise in the particular healthy control group, ” said Marvel.
“We then looked more closely at the white-colored matter in the PTLD team, and we were very surprised in order to find that will axon diffusion — or even ‘leakage’ from the white issue, which is usually considered to be pathological — was associated with better cognitive plus neurologic outcomes in the PTLD individuals, ” she added.
“This led all of us to speculate that white matter changes are usually a healthy response to Lyme disease’s effects upon the mind, ” the girl said.
State-of-the-Art Methodology
Commenting for Medscape Medical News , John Keilp, PhD, associate teacher of medical psychology (in psychiatry), Vagelos College associated with Physicians and Surgeons, Columbia University, New York City, called the particular work an “important, carefully executed study that expands upon earlier brain imaging studies of patients along with PTLD. inch
Although the sample size was small, “the authors used rigorous strategies to diagnose and characterize their sufferers and utilized state-of-the-art human brain imaging plus analysis methods, ” said Keilp, who else heads the neuropsychology laboratory within the particular Division associated with Molecular Imaging and Neuropathology, New York State Psychiatric Institute, and has been not involved with the research.
The authors “have shown us the way forward to examine these patients and this disorder in greater detail because we attempt to unlock the uncertainties surrounding the physiological basis of these patients’ signs and symptoms, ” he said.
Funding for the study was provided by an anonymous donor. The authors and Keilp report no relevant financial relationships.
PLoS One. Published on the internet October twenty six, 2022. Full text
Batya Swift Yasgur MA, LSW is a freelance writer with a counseling practice within Teaneck, NJ. She is definitely a regular contributor to numerous medical publications, including Medscape plus WebMD, and is the author of a number of consumer-oriented health books as well as Behind the particular Burqa: Our Lives in Afghanistan and How We Escaped to Freedom (the memoir of two brave Afghan sisters which told her their story).
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