Charcot–Marie–Tooth disease associated with recurrent optic neuritis

Aquaporin-4-antibody-positive Neuromyelitis Optica Spectrum Disorder in a Patient with Charcot-Marie-Tooth Disease Type 1A

Charcot-Marie-Tooth disease type 1A (CMT1A) is a hereditary peripheral neuropathy, and its involvement in the central nervous system (CNS) is very rare. We herein report a 51-year-old woman with CMT1A who suffered from recurrent optic neuritis and myelopathy. Under the diagnosis of anti-aquaporin-4 (anti-AQP4) antibody positive neuromyelitis optica spectrum disorder (NMOSD), we treated her successfully with corticosteroids. This is the first report of CMT1A complicated with anti-AQP4-positive NMOSD. Although the coexistence of the two disorders may simply be a coincidence, we speculated that immune cross-reaction between overexpressed peripheral myelin protein 22 and CNS myelin may have caused concomitant CMT1A and NMOSD.

Diffuse brain connectivity changes in Charcot-Marie-Tooth type 1a patients: a resting-state functional magnetic resonance imaging study

BACKGROUND AND PURPOSE

Changes of brain structure and function have been described in peripheral neuropathies. The aim of our study was to systematically investigate possible modifications of major large-scale brain networks using resting-state functional magnetic resonance imaging (RS-fMRI) in Charcot-Marie-Tooth disease type 1A (CMT1A) patients.

METHODS

In this cross-sectional study, 3-T MRI brain scans were acquired of right-handed genetically confirmed CMT1A patients and age- and sex-comparable healthy controls. Patients also underwent clinical and electrophysiological examinations assessing neurological impairment. RS-fMRI data were analysed using a seed-based approach, with 32 different seeds sampling the main hubs of default mode, sensorimotor, visual, salience (SN), dorsal attention, frontoparietal, language and cerebellar networks. Between-group differences in terms of functional connectivity (FC) with the explored seeds were tested voxelwise, correcting for local grey matter density to account for possible structural abnormalities, whilst the relationship between FC modifications and neurological impairment was investigated using robust correlation analyses.

RESULTS

Eighteen CMT1A patients (34.0 ± 11.4 years; M/F 11/7) were enrolled, along with 20 healthy controls (30.1 ± 10.2 years; M/F 11/9). In the CMT group compared to controls, clusters of increased FC with the visual cortex (P = 0.001), SN (P < 6 × 10^-4 ), dorsal attention network (P < 8 × 10^-5 ) and language network (P < 7 × 10^-4 ) were found, along with a single cluster of reduced FC with the visual cortex in the left lentiform nucleus (P = 10^-6 ). A significant correlation emerged between neurophysiological impairment and increased FC with right temporal language areas (r = 0.655, P = 0.006), along with an association between walking ability and increased FC with the left supramarginal gyrus (SN) (r = 0.620, P = 0.006).

CONCLUSIONS

Our data show evidence of diffuse functional reorganization involving multiple large-scale networks in the CMT1A brain, independent of structural modifications and partially correlating with peripheral nerve damage and functional impairment.

Occurrence of Optic Neuritis and Cervical Cord Schwannoma with Charcot-Marie-Tooth Type 4B1 Disease

Charcot-Marie-Tooth neuropathy type 4B1 (CMT4B1) disease is a rare subtype of CMT4 with reported association of facial weakness, vocal cord paresis, chest deformities, and claw hands. We report the unusual occurrence of optic neuritis and cervical cord schwannoma in a male individual with confirmed CMT4B1 disease. Sequencing of the MTMR2 gene revealed a novel nonsense homozygous mutation c.1768C>T (p.Gln590*). The mutation was identified in affected relatives of the proband and a second, apparently unrelated, family. The rare association of optic neuritis or schwannoma with genetically confirmed CMT1A has been individually observed, but never with recessive CMT. To the best of our knowledge, the occurrence of optic neuritis and cervical cord schwannoma in the same patient has never been reported with any form of CMT including CMT4B1. In similar cases, we recommend immediate medical attention to rule out the possibility of schwannomas in patients with all demyelinating CMT subtypes in case of the development of focal neurological signs or acute worsening of clinical status.

Central Nervous System Demyelination in a Charcot-Marie-Tooth Type 1A Patient

Introduction. Central nervous system involvement, either clinical or subclinical, has been reported mainly in X-linked Charcot-Marie-Tooth (CMT-X) patients. Case Presentation. We present the case of a 31-year-old man with a genetically confirmed history of CMT1A who developed CNS involvement mimicking multiple sclerosis (MS). Clinical, imaging, and laboratory findings suggested an autoimmune CNS demyelination. Discussion. Although the simultaneous existence of CMT1A and MS could be coincidental we postulate that overexpression of PMP22, the target protein in CMT1A, might influence the immunological self-tolerance to CNS proteins via molecular mimicry, leading to a CNS autoimmune demyelinating disorder.

Ocular neuropathy in peripheral neuropathies

Ocular movements and coordination require complex and integrated functions of somatic and autonomic nervous systems. Neurological disorders affecting these nervous systems may cause ocular dysfunction involving extraocular muscles and pupils. In this article, the prevalence, clinical presentations, and management of ocular neuropathy related to certain peripheral neuropathies, including diabetic neuropathy, Guillain-Barré syndrome (GBS), chronic inflammatory neuropathies, human immunodeficiency virus (HIV)-associated neuropathy, and hereditary neuropathies, are examined in detail.