This Brazilian study of SPG11 HSP found widespread white-matter damage in the brain, beyond the well-known thinning of the corpus callosum in this form of HSP. It also established that there was shrinkage of grey matter structures deep in the brain.
Background Mutations in SPG11 are the most frequent known cause of autosomal recessive hereditary spastic paraplegia. Corpus callosum thinning is a hallmark of the condition but little is known about damage to other structures in the CNS.
Objective:
To evaluate in vivo cerebral damage in patients with SPG11 mutations.
Methods:
5 patients and 15 age and sex matched healthy controls underwent high resolution diffusion tensor imaging (32 directions) and a T1 volumetric (1 mm slices) acquisition protocol in a 3 T scanner (Philips Achieva). These sequences were then analysed through voxel based morphometry (VBM) and tract based spatial statistics (TBSS).
Results:
Mean age of the patients was 23.6±4.5 years (range 14-45) and mean duration of disease was 12 years (range 5-15). All patients presented with progressive spastic paraplegia and three were already wheelchair bound when first evaluated. Mutations found were: c.529_533delATATT, c.704_705delAT, c.733_734delAT, c.118C>T and c.7256A>G. VBM identified significant grey matter atrophy in both the thalamus and lentiform nuclei. TBSS analyses revealed reduced fractional anisotropy involving symmetrically subcortical white matter of the temporal and frontal lobes, the cingulated gyrus, cuneus, striatum, corpus callosum and brainstem.
Conclusions:
Widespread white matter damage in patients with SPG11 mutations has been demonstrated. Grey matter atrophy was prominent in both the thalamus and basal ganglia but not in the cerebral cortex. These findings suggest that neuronal damage/dysfunction is more widespread than previously recognised in this condition.
SOURCE: J Neurol Neurosurg Psychiatry. 2012 Aug;83(8):828-33. Epub 2012 Jun 13. PMID: 22696581 [PubMed – in process]
White and grey matter abnormalities in patients with SPG11 mutations.
França MC Jr, Yasuda CL, Pereira FR, D’Abreu A, Lopes-Ramos CM, Rosa MV, Cendes F, Lopes-Cendes I.
Department of Medical Genetics, University of Campinas-UNICAMP, Rua Tessália Vieira de Camargo, 126 Cidade Universitaria ‘Zeferino Vaz’, Campinas, São Paulo, Brazil; [email protected].