Abstract
BackgroundReduction of retinal nerve fibre layer (RNFL) thickness was shown as part of the neurodegenerative process in a range of different neurodegenerative pathologies including Alzheimer′s disease (AD), idiopathic Parkinson’s disease (PD), spinocerebellar ataxia (SCA) and multiple system atrophy (MSA). To further clarify the specificity of RNFL thinning as a potential marker of neurodegenerative diseases we investigated RNFL thickness in Hereditary Spastic Paraplegia (HSP), an axonal, length-dependent neurodegenerative pathology of the upper motor neurons.MethodsSpectral domain optical coherence tomography (OCT) was performed in 28 HSP patients (clinically: pure HSP = 22, complicated HSP = 6; genetic subtypes: SPG4 = 13, SPG5 = 1, SPG7 = 3, genetically unclassified: 11) to quantify peripapillary RNFL thickness. Standardized examination assessed duration of disease, dependency on assistive walking aids and severity of symptoms quantified with Spastic Paraplegia Rating Scale (SPRS).ResultsHSP patients demonstrated no significant thinning of global RNFL (pglobal = 0.61). Subgroup analysis revealed significant reduction in temporal and temporal inferior sectors for patients with complex (p<0.05) but not pure HSP phenotypes. Two of three SPG7-patients showed severe temporal and temporal inferior RNFL loss. Disease duration, age and severity of symptoms were not significantly correlated with global RNFL thickness.ConclusionClinically pure HSP patients feature no significant reduction in RNFL, whereas complex phenotypes display an abnormal thinning of temporal and temporal inferior RNFL. Our data indicate that RNFL thinning does not occur unspecifically in all neurodegenerative diseases but is in HSP restricted to subtypes with multisystemic degeneration.
Highlights
Reduction of retinal nerve fibre layer (RNFL) thickness was shown as part of the neurodegenerative process in a range of different neurodegenerative pathologies including Alzheimer0s disease (AD), idiopathic Parkinson’s disease (PD), spinocerebellar ataxia (SCA) and multiple system atrophy (MSA)
Two pure Hereditary Spastic Paraplegia (HSP) patients with a mutation of the SPG4 gene and one patient with complex HSP displayed glaucomatous optic disc cupping with positive family history of primary open angle glaucoma in 2 of 3 patients
One patient with SPG7 was diagnosed with optic atrophy but was not excluded from the analysis as optic atrophy was regarded as part of the multidegenerative process in complex HSP that is subject of this study
Summary
Reduction of retinal nerve fibre layer (RNFL) thickness was shown as part of the neurodegenerative process in a range of different neurodegenerative pathologies including Alzheimer0s disease (AD), idiopathic Parkinson’s disease (PD), spinocerebellar ataxia (SCA) and multiple system atrophy (MSA). To further clarify the specificity of RNFL thinning as a potential marker of neurodegenerative diseases we investigated RNFL thickness in Hereditary Spastic Paraplegia (HSP), an axonal, length-dependent neurodegenerative pathology of the upper motor neurons. Hereditary spastic paraplegias (HSPs) are a group of genetically determined progressive neurodegenerative disorders where dysfunction of axonal transport processes predominantly leads to a length-dependent degeneration of corticospinal tract fibres [1]. They are clinically classified as “pure” or “uncomplicated” HSPs when the pathology is limited to the core symptom of progressive lower limb weaknesses and spasticity, optionally accompanied by neurogenic bladder disturbance. To investigate possible RNFL reduction in HSP patients, we designed a prospective observational study as our observations e.g. in MSA patients with significant RNFL thinning confirm, that these changes might very well remain subclinical and not likely to be detected in routine clinical examination [Fischer et al, unpublished data]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
