Severe inflammatory disease activity 14 months after cessation of Natalizumab in a patient with Leber's optic neuropathy and multiple sclerosis - a case report

A Comprehensive Review of Leber Hereditary Optic Neuropathy and Its Association with Multiple Sclerosis-Like Phenotypes Known as Harding's Disease

Leber Hereditary Optic Neuropathy (LHON) stands as a distinctive maternally inherited mitochondrial disorder marked by painless, subacute central vision loss, primarily affecting young males. This review covers the possible relationship between LHON and multiple sclerosis (MS), covering genetic mutations, clinical presentations, imaging findings, and treatment options. LHON is associated with mutations in mitochondrial DNA (mtDNA), notably m.11778G>A, m.3460G>A, and m.14484T>C, affecting complex I subunits. Beyond ocular manifestations, LHON can go beyond the eye into a multi-systemic disorder, showcasing extraocular abnormalities. Clinical presentations, varying in gender prevalence and outcomes, underscore the nature of mitochondrial optic neuropathies. Hypotheses exploring the connection between LHON and MS encompass mitochondrial DNA mutations triggering neurological diseases, immunologically mediated responses inducing demyelination, and the possibility of coincidental diseases. The research on mtDNA mutations among MS patients sheds light on potential associations with specific clinical subgroups, offering a unique perspective into the broader landscape of MS. Imaging findings, ranging from white matter alterations to cerebrospinal fluid biomarkers, further emphasize shared pathological processes between LHON-MS and classical MS. This comprehensive review contributes to the understanding of the complex relationship between LHON and MS.

Hereditary Myelopathies

Hereditary myelopathies are an important and likely underappreciated component of neurogenetic disease. While previously distinctions have been made by age of onset, the growing power and availability of high-quality neuroimaging and next-generation sequencing are increasingly expanding classical phenotypes and diminishing the utility of age-based classifications. Increasingly, cases of "atypical" disease presentations are challenging past assumptions regarding the age of onset and survival in many disorders and identifying allelic syndromes in others. Despite this, there is poor awareness of the potential for spinal involvement in many diseases that typically affect the brain. Broadly speaking, congenital myelopathies can be neuroanatomically grouped into motor neuron, axonopathy, spinocerebellar, cerebroleukodystrophy, and pan-neuraxis (generally central nervous system predominant with associated axonopathy) disorders.Here, we review hereditary causes of myelopathy, organized by neuroanatomy, and highlight atypical presentations. We discuss findings concerning an underlying genetic etiology for myelopathy, as well as practical, technical, and ethical considerations of diagnostic genetic testing.

Optic nerve atrophy and whole and regional brain atrophy in Leber's hereditary optic neuropathy with multiple sclerosis-like disease with m.11778G>A mutation

Leber's hereditary optic neuropathy (LHON) is a maternally inherited form of mitochondrial optic nerve degeneration with bilateral optic atrophy. Its coexistence with multiple sclerosis (MS)-like disease (LHON-MS) is rare and also known as Harding's syndrome. The presence of LHON-MS complicates the diagnosis of optic neuritis associated with MS, which can delay the correct diagnosis and necessary treatment. Here we report optic nerve atrophy in a patient with LHON-MS coexistent with severe global and regional brain atrophy. Furthermore, we also reviewed the available literature on this rare clinical entity.

Involvement of the Spinal Cord in Mitochondrial Disorders

This review aims at summarising and discussing the current status concerning the clinical presentation, pathogenesis, diagnosis, and treatment of spinal cord affection in mitochondrial disorders (MIDs). A literature search using the database Pubmed was carried out by application of appropriate search terms and their combinations. Involvement of the spinal cord in MIDs is more frequent than anticipated. It occurs in specific and non-specific MIDs. Among the specific MIDs it has been most frequently described in LBSL, LS, MERRF, KSS, IOSCA, MIRAS, and PCH and only rarely in MELAS, CPEO, and LHON. Clinically, spinal cord involvement manifests as monoparesis, paraparesis, quadruparesis, sensory disturbances, hypotonia, spasticity, urinary or defecation dysfunction, spinal column deformities, or as transverse syndrome. Diagnosing spinal cord involvement in MIDs requires a thoroughly taken history, clinical exam, and imaging studies. Additionally, transcranial magnetic stimulation, somato-sensory-evoked potentials, and cerebro-spinal fluid can be supportive. Treatment is generally not at variance compared to the underlying MID but occasionally surgical stabilisation of the spinal column may be necessary. It is concluded that spinal cord involvement in MIDs is more frequent than anticipated but may be missed if cerebral manifestations prevail. Spinal cord involvement in MIDs may strongly determine the mobility of these patients.