Magnetic Resonance Imaging Findings in the Pregeniculate Visual Pathway in Leber Hereditary Optic Neuropathy

Abstract

Background: Current research has not provided a consistent and qualitative description of MRI features in Leber hereditary optic neuropathy (LHON). Our study aims to investigate the MRI findings in the pregeniculate visual pathway and discuss their clinical significance in LHON. Methods: Orbital MRI was retrospectively analyzed for 53 patients with LHON (101 afflicted eyes) admitted to the Department of Neurology, Beijing Tongren Hospital, Capital Medical University, from 2014 to 2019. We described the imaging abnormalities and discussed their associations with the time interval from the onset of vision loss to the performance of MRI (TIOVP), prevalence of m.11778G>A, and best-corrected visual acuity (BCVA). Results: T2 hyperintense signal (HS) was determined in 82 afflicted eyes, with 34 located in the intraorbital segment (IO) of the optic nerve (ON), 26 in the IO concurrent with intracanalicular segment (ICn), 14 in the IO and ICn concurrent with intracranial segment (ICr) of the ON, 4 in the IO, ICn, and ICr concurrent with optic chiasm (OCh), and 4 in the IO, ICn, ICr, and OCh concurrent with optic tract (OTr). MRI was normal in the remaining 19 afflicted eyes. Among the 6 groups, no statistical differences were found in the TIOVP ( P = 0.071), prevalence of m.11778G>A ( P = 0.234), and BCVA ( P = 0.076). As T2 HS extended, the BCVA gradually decreased. Nineteen of the 54 afflicted eyes revealed contrast enhancement, with the TIOVP ranging from 0.25 to 6 months. Conclusions: T2 HS was common in the pregeniculate visual pathway in LHON. It was not correlated with the prevalence of m.11778G>A and did not benefit in disease staging. As it extended, the BCVA gradually decreased. Contrast enhancement was relatively rare, always occurring in the subacute stage.

Multishell Diffusion MR Tractography Yields Morphological and Microstructural Information of the Anterior Optic Pathway: A Proof-of-Concept Study in Patients with Leber’s Hereditary Optic Neuropathy

“…The disease is characterized by a sudden, subacute visual loss due to selective loss of RGCs and relative sparing of the melanopsin-expressing RGCs, leading to variable degree of optic nerve atrophy and different degrees of blindness in young adulthood [ 3 , 7 ]. Conventional MRI is normal in the majority of patients with LHON, even though optic nerve and visual pathway hyperintensity have also been reported; the pathophysiology of the MRI changes is not yet understood [ 8 , 9 ].…”

Two cases of MT-ND5-related mitochondrial disorder misdiagnosed as seronegative neuromyelitis optica spectrum disorder

“…In the acute to subacute phase of vision impairment, it may be difficult to differentiate mitochondrial optic neuropathy from optic neuritis before a diagnosis of mitochondrial disease has been made. 10 Patients with LHON and other mitochondrial optic neuropathies often have poorer visual prognosis than those with autoimmune-related optic neuritis. However, spontaneous improvement in visual acuity may occur in some cases of LHON, which may be interpreted as a treatment response if given immunomodulatory agents for presumed optic neuritis.…”

Optic Nerve MRI T2-Hyperintensity: A Nonspecific Marker of Optic Nerve Damage

“…Results: Four hundred seventy-seven patients (698 eyes) were included [mean age 52 years (SD ±18 years); 57% women]. Of the 364 of 698 eyes with optic nerve/chiasm T2-hyperintensity without atrophy, the causes were compressive (104), inflammatory (103), multifactorial (49), glaucoma (21), normal (19), and other (68); of the 219 of 698 eyes with optic nerve/chiasm T2-hyperintensity and atrophy, the causes were compressive (57), multifactorial (40), inflammatory (38), glaucoma (33), normal (7), and other (44); of the 115 of 698 eyes with optic nerve/ chiasm atrophy without T2-hyperintensity, the causes were glaucoma (34), multifactorial (21), inflammatory (13), compressive (11), normal (10), and other (26). Thirty-six eyes with optic nerve/chiasm T2-hyperintensity or atrophy did not have evidence of optic neuropathy or retinopathy on ophthalmologic examination, and 17 eyes had clinical evidence of severe retinopathy without primary optic neuropathy.…”

“…4,5 Orbital MRI performed a few months later often shows ON T2-hyperintensity and decreased ON volume (ONatrophy) due to axonal degeneration and gliosis. However, ON T2-hyperintensity has been reported in the setting of optic neuropathies and retinal disorders of any cause, [6][7][8][9][10][11] as well as in patients without a known pathology. 12 Despite existing studies illustrating the nonspecificity of MRI ON T2-hyperintensity, many providers equate this MRI finding specifically with demyelinating optic neuritis, either acute or chronic.…”

“…4,5 Orbital MRI performed a few months later often shows ON T2-hyperintensity and decreased ON volume (ON-atrophy) due to axonal degeneration and gliosis. However, ON T2-hyperintensity has been reported in the setting of optic neuropathies and retinal disorders of any cause, 6–11 as well as in patients without a known pathology. 12…”