Neurology

tNAA and tNAA/tCr show genotype-specific, reproducible differences in early SCA2 and SCA3 across sites

In 72 participants scanned at four sites with harmonized 3T MRS, tNAA and glutamate were lower and mI and tCr higher in cerebellum and pons in SCA2 and SCA3 versus controls. Pontine tNAA and mI and cerebellar tNAA, mI, and glutamate differed between SCA2 and SCA3 with large effect sizes (|d| = 1.1–2.1). The tNAA/tCr ratio correlated best with clinical outcomes (|r| ≥ 0.5), stronger in cerebellum for SCA2 and in pons for SCA3. Test–retest CVs were similar across sites and vendors, but concentration estimates required site-wise adjustment for vendor bias. 1

Age alters DMT outcomes in real-world MS: younger patients relapse more, older patients progress more

From the Austrian MS registry (n=2,117; mean follow-up 6.0–7.8 years), estimated ARR was 0.12 in <50 and 0.09 in ≥50 age groups (p<0.001). Younger patients had a higher hazard of first relapse (HR 1.34, 95% CI 1.12–1.60, p=0.001). Sustained EDSS progression risk favored younger patients at 12 and 24 weeks (HRs 0.76 and 0.70), indicating greater progression in older patients. These real-world differences suggest age should factor into treatment selection and counseling. 2

Stiff person syndrome is rare but rising in Denmark and carries substantial long-term mortality

Population-based Danish data (2001–2022) identified 30 incident SPS cases matched to 3,000 controls. Incidence increased from 0.11 to 0.43 per 1,000,000 person-years and prevalence rose from 1.32 to 3.94 per 1,000,000. Ten-year cumulative mortality was 27.5%, with adjusted mortality hazard ratio 4.1 versus matched controls. Though numbers are small, findings indicate rising detection and a markedly increased long-term mortality risk. 3