A novel homozygous variant in the SPG7 gene presenting with childhood optic nerve atrophy.

PURPOSE: To describe a case of hereditary spastic ataxia (HSP) presenting with childhood optic nerve atrophy and report a novel homozygous variant in the SPG7 gene. OBSERVATIONS: A 57-year-old man suffering from progressive optic nerve atrophy since childhood eventually underwent genetic testing. A targeted whole exome gene sequencing panel for optic neuropathy identified a novel homozygous variant in the SPG7 gene, c.2T > G, p.(Met?), which likely abolished production of paraplegin, an inner mitochondrial membrane protein. Subsequent neurologic examination revealed subtle signs of spastic paraplegia and ataxia in keeping with the genetic diagnosis of SPG7. CONCLUSION AND IMPORTANCE: Spastic paraplegia 7 (SPG7) is an autosomal recessive form of the neurodegenerative disorder HSP. Pure HSP is characterized by spastic paraparesis in the lower limbs, whereas complicated HSP presents additional neurological manifestations. This case report adds to the evidence that SPG7 can present with childhood optic nerve atrophy, preceding the characteristic SPG7 manifestations. SPG7 should be considered in the workup of suspected hereditary optic neuropathy.

Bilateral calcification of the optic nerve sheath: A diagnostic dilemma.

PURPOSE: To present a case of symptomatic optic nerve sheath calcification and highlight clues and pitfalls for the final diagnosis: bilateral optic nerve sheath meningioma. OBSERVATIONS: A 48-year-old man presented with painless vision loss in his left eye and findings consistent with left optic nerve atrophy. Magnetic resonance imaging (MRI) displayed thinning of the left optic nerve without contrast-enhancement or evidence of compressive lesions. A supplementary computed tomography angiography (CTA) exposed scattered dural calcification, which included the optic nerves. This was regarded as an incidental finding. The initial diagnosis was ischemic optic neuropathy. Over the next two years, the vision loss in the left eye progressed. A CT of the orbits revealed extensive calcification surrounding both optic nerves. A second MRI was unchanged in comparison to the first MRI. The diagnosis was changed to idiopathic duro-optic calcification. The vision in the left eye further declined over another two years. Consecutive optical coherence tomography measurements of the peripapillary retinal nerve fiber layer suggested bilateral progressive thinning. A third MRI displayed progression of tubular contrast-enhancement surrounding the optic nerves. On the basis of this finding, the patient was finally diagnosed with a bilateral optic nerve sheath meningioma and received external beam radiotherapy. CONCLUSION AND IMPORTANCE: It is crucial to differentiate an optic nerve sheath meningioma from idiopathic calcification of the optic nerve. In the present case the initial MRI did not detect optic nerve sheath abnormalities. To better demonstrate characteristic calcification, additional CT imaging should be considered when a bilateral optic nerve sheath meningioma is suspected.

The Value of Macular Optical Coherence Tomography in Watchful Waiting of Suprasellar Masses: A 2-Year Observational Study.

BACKGROUND: A possible benefit of optical coherence tomography (OCT) in the approach to tumors involving the optic chiasm may be the ability to foresee visual deterioration. This study investigated the value of OCT in watchful waiting for compressive optic neuropathy as the primary management of suprasellar masses. METHODS: The research was conducted as a 2-year observational study of a patient cohort with conservatively managed mass lesions involving the optic chiasm on MRI. Threshold perimetry and macular OCT were performed at baseline and each follow-up examination. Univariate Cox regression was used to determine the effect of baseline and longitudinal covariates upon development of visual field (VF) loss compatible with chiasmal dysfunction. RESULTS: Nineteen eyes of 19 patients were included. The optic chiasm-tumor relationship on baseline MRI was abutment in 6 cases and compression in 13 cases. Seven eyes developed VF loss. None of the baseline covariates were predictors of VF loss. The longitudinal decrease in mean macular ganglion cell complex (mGCC) thickness on OCT was 2.5 µm/yr for eyes that developed VF loss and 0.2 µm/yr for eyes that did not develop VF loss (P = 0.02). The hazard ratio for VF loss per 1-µm/yr decrease in mGCC thickness was 1.30 (95% confidence interval [CI] 1.04-1.62; P = 0.02) for the inferior nasal quadrant and 1.45 (95% CI 1.02-2.07; P = 0.04) for the inferior temporal quadrant. CONCLUSIONS: OCT offers a valuable complement to perimetry in monitoring for compressive optic neuropathy. Longitudinal mGCC thinning can anticipate VF loss.

Loss of horizontal macular ganglion cell complex asymmetry: an optical coherence tomography indicator of chiasmal compression.

OBJECTIVE: To estimate the macular ganglion cell complex (GCC) asymmetry in patients with suprasellar tumours, to compare its diagnostic performance to the nasal GCC thickness and visual field (VF) and to investigate how the parameters correlate with magnetic resonance imaging (MRI) findings. METHODS AND ANALYSIS: Cross-sectional study of patients with suprasellar tumours affecting the optic chiasm. Macular optical coherence tomography (OCT) scans were evaluated for nasal GCC sector thinning and loss of normal GCC asymmetry between corresponding nasal-temporal sectors. Equivalently, VFs were analysed for defects compatible with chiasm dysfunction. The relationship between optic chiasm and tumour was measured on MRI. RESULTS: Thirty-three eyes of 33 patients were included. There were OCT findings in 14 eyes. Nasal GCC thinning was found in 9 eyes and loss of GCC asymmetry in 12 eyes; the two parameters were not significantly different with respect to number of positive findings (p=0.45). Loss of GCC asymmetry, however, occurred in 5 eyes among 24 without GCC thinning (proportion 0.21; 95% confidence interval 0.071 to 0.42). In 8 eyes, VF indicated pathology; of these, 7 had concurring OCT findings. The prevalence of OCT and VF findings increased significantly with suprasellar tumour extension on MRI. CONCLUSION: The diagnostic capabilities of nasal GCC thinning and loss of GCC asymmetry were comparable, whilst their complementary performances increased the proportion of eyes in which OCT suggested compression. The prevalence of both OCT and VF findings grew with suprasellar tumour extension. In several cases, however, structural findings on OCT preceded detectable VF deficits.