Spinal cord atrophy (shrinkage) is a common finding in the four genetic types of HSP – being more severe in SPG6 and SPG8 HSP subjects than in other types of HSP studied.
HSP pathology involves axonal degeneration that is most pronounced in the terminal segments of the longest descending (pyramidal) and ascending (dorsal columns) tracts. In this study, we compared the cross-sectional area of the spinal cord in 13 HSP patients with four different types of autosomal dominant hereditary spastic paraplegia (SPG3A, SPG4, SPG6, and SPG8) with age-matched control subjects. The cross-section area of the spinal cord was measured at cervical level C2 [upper neck] and at thoracic level T9 [mid-back].
Both measurements were less than in the healthy controls (p < 0.001). The degree of cord atrophy was more prominent in patients with SPG6 and SPG8 who had signs of severe cord atrophy than in subjects with SPG3 and SPG4.
These observations indicate that spinal cord atrophy is a common finding in the four genetic types of HSP. Spinal cord atrophy was more severe in SPG6 and SPG8 HSP subjects than in other types of HSP we studied. This may suggest a different disease mechanism with more prominent axonal degeneration in these two types of HSP when compared with HSP due to spastin and atlastin mutations.
Neuroradiology. 2005 Oct;47(10):730-4. Epub 2005 Sep 6.
Spinal cord magnetic resonance imaging in autosomal dominant hereditary spastic paraplegia.
Hedera P, Eldevik OP, Maly P, Rainier S, Fink JK.
Department of Neurology, The University of Michigan, Rm. 5214 CCGCB, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-0940, USA.