Marked differences between HSP types
Spinal cord damage in both grey matter and white matter has been found in SPG4 and SPG11 but was not identified in SPG3A, nor in SPG7.
This imaging study of the spinal cord in the neck region comprised 37 people with HSP. The average age was 47 years with an average of 22 years with HSP.
7 with SPG3A
8 with SPG11
10 with SPG7 and
12 with SPG4.
In the SPG4 group, it was found that with longer disease duration, imaging showed greater reduction in the area of grey matter.
Background and purpose: Spinal cord damage is a hallmark of hereditary spastic paraplegias, but it is still not clear whether specific subtypes of the disease have distinctive patterns of spinal cord gray (GM) and white (WM) matter involvement. We compared cervical cross-sectional GM and WM areas in patients with distinct hereditary spastic paraplegia subtypes. We also assessed whether these metrics correlated with clinical parameters.
Materials and methods: We analyzed 37 patients (17 men; mean age, 47.3 [SD, 16.5] years) and 21 healthy controls (7 men; mean age, 42.3 [SD, 13.2] years). There were 7 patients with spastic paraplegia type 3A (SPG3A), 12 with SPG4, 10 with SPG7, and 8 with SPG11. Image acquisition was performed on a 3T MR imaging scanner, and T2*-weighted 2D images were assessed by the Spinal Cord Toolbox. Statistical analyses were performed in SPSS using nonparametric tests and false discovery rate-corrected P values < .05.
Results: The mean disease duration for the hereditary spastic paraplegia group was 22.4 [SD, 13.8] years and the mean Spastic Paraplegia Rating Scale score was 22.8 [SD, 11.0]. We failed to identify spinal cord atrophy in SPG3A and SPG7. In contrast, we found abnormalities in patients with SPG4 and SPG11. Both subtypes had spinal cord GM and WM atrophy. SPG4 showed a strong inverse correlation between GM area and disease duration (ρ = -0.903, P < .001).
Conclusions: Cervical spinal cord atrophy is found in some but not all hereditary spastic paraplegia subtypes. Spinal cord damage in SPG4 and 11 involves both GM and WM.
SOURCE: AJNR Am J Neuroradiol. 2021 Jan 21. doi: 10.3174/ajnr.A7017. Online ahead of print. PMID: 33478946 © 2021 by American Journal of Neuroradiology.
Spinal Cord Gray and White Matter Damage in Different Hereditary Spastic Paraplegia Subtypes
1 From the School of Medical Sciences (K.R.S., F.D.d.L. T.J.R.R., M.C.F.), University of Campinas, Campinas, Brazil.
2 Seaman Family MR Research Center (R.F.C.), University of Calgary, Calgary, Alberta, Canada.
3 From the School of Medical Sciences (K.R.S., F.D.d.L. T.J.R.R., L.P.R., M.C.F.), University of Campinas, Campinas, Brazil