Blindness, Weakness, and Tingling

[Combination of post-infectious optic neuritis and Guillain-Barré syndrome]

The coexistence of optic neuritis and Guillain-Barré syndrome is a rare combination of neurological diseases. The trigger of an autoimmune inflammatory process is often a respiratory mycoplasma infection. Ignorance of such combination can lead to diagnostic and therapy mistakes. This article describes the case of a rare combination of overlapping optic neuritis and Guillain-Barré syndrome, associated with Mycoplasma pneumoniae and provides the short literature review. Further studies are required to identify common pathogenetic mechanisms of combined inflammatory lesions of the optic nerves and peripheral nervous system.

Co-occurrence of polyneuritis crainials and visual impairment: a case report and literature review

BACKGROUND

Polyneuritis cranialis (PNC) with the disease characteristics of Guillain-Barré syndrome (GBS) in addition to both ocular and bulbar weakness in the absence of limb paralysis or ataxia is defined as an unusual variant of GBS. As evidence of central nervous system (CNS) involvement, visual impairment is an unusual finding complicating with GBS spectrum disorders and has never been reported in patients with PNC.

METHODS

We describe a very rare case who clinically presented with progressive multiple cranial nerve palsy and visual impairment. Furthermore, a literature search of concurrent GBS and optic neuritis (ON) as well as PNC attributed to GBS was conducted.

RESULTS

A diagnosis of PNC was considered due to the typical clinical characteristics as well as the presence of cerebrospinal fluid cytoalbumin dissociation and serum antibodies against gangliosides. The clinical manifestations and the bilateral optic nerve involvement in brain magnetic resonance imaging further suggested possible optic neuritis (ON). The patient received treatment with intravenous immunoglobulin followed by short-term use of corticosteroids and finally achieved a full recovery. Thirty-two previously reported cases (17 women, mean age 40) of concurrent GBS and ON and 20 cases of PNC (5 women, mean age 40) were analyzed. We further provided a comprehensive discussion on the potential etiologies, clinical features, therapeutic strategies, and prognosis.

CONCLUSIONS

This rare case with the co-occurrence of PNC and visual impairment and the related literature review may help clinicians advance the understanding of GBS spectrum disorders and make appropriate diagnoses and treatment decisions for the rare variants and CNS complications of GBS.

Guillain-Barré Syndrome and Unilateral Optic Neuritis Following Vaccination for COVID-19: A Case Report and Literature Review

A 71-year-old woman presented 2 weeks after vaccination with the first dose of Vaxzevria (AstraZeneca, Oxford) for COVID-19 with a left lower motor neuron facial nerve palsy, which progressed to bilateral involvement. This was accompanied by bilateral proximal leg weakness. She was diagnosed with the 'facial diplegia with paraesthesia' variant of Guillain-Barré syndrome. Seven weeks post vaccination she developed painless loss of vision in the right eye. The visual acuity in that eye was light perception only with a right relative afferent pupillary defect and right optic disc swelling. A diagnosis of optic neuritis was made and she received pulsed intravenous methylprednisolone for 3 days, followed by oral prednisolone. The optic neuritis recurred following initial cessation of steroids requiring an extended course of steroids. Despite this, she made a good visual recovery to 6/6 in the affected eye. We present this case and a review of the literature surrounding vaccination and the development of these conditions.

Mitochondrial damage and "plugging" of transport selectively in myelinated, small-diameter axons are major early events in peripheral neuroinflammation

Background

Small-diameter, myelinated axons are selectively susceptible to dysfunction in several inflammatory PNS and CNS diseases, resulting in pain and degeneration, but the mechanism is not known.

Methods

We used in vivo confocal microscopy to compare the effects of inflammation in experimental autoimmune neuritis (EAN), a model of Guillain-Barré syndrome (GBS), on mitochondrial function and transport in large- and small-diameter axons. We have compared mitochondrial function and transport in vivo in (i) healthy axons, (ii) axons affected by experimental autoimmune neuritis, and (iii) axons in which mitochondria were focally damaged by laser induced photo-toxicity.

Results

Mitochondria affected by inflammation or laser damage became depolarized, fragmented, and immobile. Importantly, the loss of functional mitochondria was accompanied by an increase in the number of mitochondria transported towards, and into, the damaged area, perhaps compensating for loss of ATP and allowing buffering of the likely excessive Ca²⁺ concentration. In large-diameter axons, healthy mitochondria were found to move into the damaged area bypassing the dysfunctional mitochondria, re-populating the damaged segment of the axon. However, in small-diameter axons, the depolarized mitochondria appeared to “plug” the axon, obstructing, sometimes completely, the incoming (mainly anterograde) transport of mitochondria. Over time (~ 2 h), the transported, functional mitochondria accumulated at the obstruction, and the distal part of the small-diameter axons became depleted of functional mitochondria.

Conclusions

The data show that neuroinflammation, in common with photo-toxic damage, induces depolarization and fragmentation of axonal mitochondria, which remain immobile at the site of damage. The damaged, immobile mitochondria can “plug” myelinated, small-diameter axons so that successful mitochondrial transport is prevented, depleting the distal axon of functioning mitochondria. Our observations may explain the selective vulnerability of small-diameter axons to dysfunction and degeneration in a number of neurodegenerative and neuroinflammatory disorders.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1094-8) contains supplementary material, which is available to authorized users.