FDG-PET imaging helps identify pathological tissue boundaries in pediatric focal cortical dysplasia surgery
A retrospective study of 14 children with intractable focal cortical dysplasia (FCD) found that 62% of tissue specimens taken from the peripheral hypometabolic borders of FDG-PET scans contained pathological cells, not just the lesion epicentre. Frank FCD was more concentrated at the epicentre (59%) than the borders (31%), while dysmorphic neurons alone were distributed across both regions. The findings suggest FDG-PET hypometabolism may mark the true histopathological extent of FCD type II, supporting broader surgical resections to improve seizure-freedom outcomes.
Researchers conducted a retrospective analysis of 14 pediatric patients (mean age 9.0 years) with intractable extra-temporal focal epilepsy undergoing surgery guided by FDG-PET imaging. A total of 136 tissue specimens were collected from both the lesion epicentre and the surrounding hypometabolic border regions identified on PET scans. Pathology was present in 75% of epicentre specimens and 62% of border specimens, demonstrating that abnormal tissue is not confined to the visually apparent MRI lesion. A Bayesian logistic mixed model confirmed a statistically meaningful gradient: frank FCD IIa/b was significantly more likely at the epicentre, while dysmorphic neurons alone showed no significant location preference. Crucially, all 14 patients achieved Engel Ia seizure-freedom status at one-year follow-up with no long-term neurological deficits, suggesting that resecting these broader hypometabolic zones is both effective and safe. The authors conclude that FDG-PET can serve as a more accurate map of FCD type II's histopathological boundaries than MRI alone, and advocate for including surrounding hypometabolic regions in surgical planning when anatomically feasible.
What's missing
The study has several important limitations: the sample size is small (n=14), limiting statistical power and generalizability. The retrospective design and single-centre nature introduce selection bias. Follow-up is limited to one year, so long-term seizure-freedom and developmental outcomes remain unknown. It is also unclear how consistently the border resection boundaries were defined across patients, and whether the completeness of hypometabolic zone resection was systematically quantified. The study does not address cases where border resection was deemed unsafe, potentially introducing survivorship bias in the outcome data.
What different sources said
- bioRxivCenter
Pathology in resected areas of FDG PET hypometabolism in pediatric epilepsy patients with focal cortical dysplasia
Related
Gut Bacteria Enzyme Found to Break Down Heat-Processed Food Compounds, Producing Novel Biogenic Amines
Researchers have discovered that an enzyme in common gut bacteria can degrade N-epsilon-carboxymethyllysine (CML), a compound formed during thermal food processing, producing previously unknown biogenic amines. The enzyme, ornithine decarboxylase SpeC from enterobacteria, acts on CML and related modified lysine derivatives through a low-level 'underground' catalytic activity. This finding suggests a previously unrecognized communication axis between thermally processed dietary compounds and gut microbial physiology, with potential implications for host health.
Full-Length Gene Sequencing Reveals Two Distinct Bacterial Communities in Black-Legged Ticks Expanding Into Canada
Researchers used Oxford Nanopore full-length 16S rRNA gene sequencing to characterize the microbiome of Ixodes scapularis black-legged ticks collected in Nova Scotia, Canada, distinguishing between tick-adapted bacteria and environmentally acquired bacteria. The study comes as I. scapularis — the primary vector of Lyme disease — is rapidly expanding northward into Canada due to climate change. The findings suggest that environmentally derived bacteria in tick microbiomes are not mere contamination, which has implications for how tick microbiome data is collected and interpreted across surveillance studies.
Study Identifies Metabolic Link Between Cell Envelope Stress and Biofilm Formation in Bacteria
Researchers have discovered that the metabolite acetyl-CoA directly inhibits enzymes that degrade the bacterial signaling molecule c-di-GMP, connecting cell envelope biosynthesis stress to biofilm formation in Pseudomonas aeruginosa. The study found that sub-inhibitory concentrations of antibiotics targeting early peptidoglycan biosynthesis — but not other antibiotic classes — elevate c-di-GMP levels by reducing phosphodiesterase activity, with acetyl-CoA competing for the enzyme active site. Because the relevant enzyme domain is broadly conserved across bacterial species, this checkpoint mechanism may be widespread and could have implications for understanding antibiotic-induced biofilm responses.