Guillain-Barré syndrome: a century of progress

In 1916, Guillain, Barré and Strohl reported on two cases of acute flaccid paralysis with high cerebrospinal fluid protein levels and normal cell counts — novel findings that identified the disease we now know as Guillain–Barré syndrome (GBS). 100 years on, we have made great progress with the clinical and pathological characterization of GBS. Early clinicopathological and animal studies indicated that GBS was an immune-mediated demyelinating disorder, and that severe GBS could result in secondary axonal injury; the current treatments of plasma exchange and intravenous immunoglobulin, which were developed in the 1980s, are based on this premise. Subsequent work has, however, shown that primary axonal injury can be the underlying disease. The association of Campylobacter jejuni strains has led to confirmation that anti-ganglioside antibodies are pathogenic and that axonal GBS involves an antibody and complement-mediated disruption of nodes of Ranvier, neuromuscular junctions and other neuronal and glial membranes. Now, ongoing clinical trials of the complement inhibitor eculizumab are the first targeted immunotherapy in GBS

Electrodiagnostic subtyping in Guillain–Barr\ue9 syndrome patients in the International Guillain–Barr\ue9 Outcome Study

\ua9 2024 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.Background and purpose: Various electrodiagnostic criteria have been developed in Guillain–Barr\ue9 syndrome (GBS). Their performance in a broad representation of GBS patients has not been evaluated. Motor conduction data from the International GBS Outcome Study (IGOS) cohort were used to compare two widely used criterion sets and relate these to diagnostic amyotrophic lateral sclerosis criteria. Methods: From the first 1500 patients in IGOS, nerve conduction studies from 1137 (75.8%) were available for the current study. These patients were classified according to nerve conduction studies criteria proposed by Hadden and Rajabally. Results: Of the 1137 studies, 68.3% (N = 777) were classified identically according to criteria by Hadden and Rajabally: 111 (9.8%) axonal, 366 (32.2%) demyelinating, 195 (17.2%) equivocal, 35 (3.1%) inexcitable and 70 (6.2%) normal. Thus, 360 studies (31.7%) were classified differently. The areas of differences were as follows: 155 studies (13.6%) classified as demyelinating by Hadden and axonal by Rajabally; 122 studies (10.7%) classified as demyelinating by Hadden and equivocal by Rajabally; and 75 studies (6.6%) classified as equivocal by Hadden and axonal by Rajabally. Due to more strictly defined cutoffs fewer patients fulfilled demyelinating criteria by Rajabally than by Hadden, making more patients eligible for axonal or equivocal classification by Rajabally. In 234 (68.6%) axonal studies by Rajabally the revised El Escorial (amyotrophic lateral sclerosis) criteria were fulfilled; in axonal cases by Hadden this was 1.8%. Conclusions and discussion: This study shows that electrodiagnosis in GBS is dependent on the criterion set utilized, both of which are based on expert opinion. Reappraisal of electrodiagnostic subtyping in GBS is warranted

Homeostatic regulation of the endoneurial microenvironment during development, aging and in response to trauma, disease and toxic insult

The endoneurial microenvironment, delimited by the endothelium of endoneurial vessels and a multi-layered ensheathing perineurium, is a specialized milieu intérieur within which axons, associated Schwann cells and other resident cells of peripheral nerves function. The endothelium and perineurium restricts as well as regulates exchange of material between the endoneurial microenvironment and the surrounding extracellular space and thus is more appropriately described as a blood–nerve interface (BNI) rather than a blood–nerve barrier (BNB). Input to and output from the endoneurial microenvironment occurs via blood–nerve exchange and convective endoneurial fluid flow driven by a proximo-distal hydrostatic pressure gradient. The independent regulation of the endothelial and perineurial components of the BNI during development, aging and in response to trauma is consistent with homeostatic regulation of the endoneurial microenvironment. Pathophysiological alterations of the endoneurium in experimental allergic neuritis (EAN), and diabetic and lead neuropathy are considered to be perturbations of endoneurial homeostasis. The interactions of Schwann cells, axons, macrophages, and mast cells via cell–cell and cell–matrix signaling regulate the permeability of this interface. A greater knowledge of the dynamic nature of tight junctions and the factors that induce and/or modulate these key elements of the BNI will increase our understanding of peripheral nerve disorders as well as stimulate the development of therapeutic strategies to treat these disorders

Optic neuritis and multiple sclerosis.

What to tell patients regarding the risk of MS remains a matter of opinion. We generally tell all patients that symptoms may occur in the eye or elsewhere in the nervous system, and usually inform younger patients, especially those with banding, of the specific implications so that their long-range plans may be made with the possibility of MS in mind

Optic neuritis in familial MS.

Seven patients with optic neuritis were found in a study of 84 families with familial multiple sclerosis (MS). Evidence obtained from neurologic examination and electrophysiologic testing tended to confirm monosymptomatic optic nerve involvement. The presence of isolated optic neuritis in these families implies that MS and at least some cases of isolated optic neuritis have a similar etiology

Importance of the imaging modality in decision making about carotid endarterectomy.

OBJECTIVE: To determine the influence of all possible imaging strategies on the appropriateness ratings for carotid endarterectomy, because less accurate noninvasive techniques are replacing contrast angiography, which was used in the major efficacy trials. METHODS: An expert panel, using appropriateness methodology, rated 203 scenarios where endarterectomy might be performed. Each scenario was rated where internal carotid artery stenosis was determined using five different imaging sources: 1) conventional angiography, 2) ultrasound carotid Doppler only, 3) CT (CTA) or MR (MRA) angiography only, 4) concordant results from two noninvasive carotid imaging studies, and 5) discordant results from two noninvasive studies. The scenarios deemed appropriate by conventional angiography were identified. The effect of the other imaging modalities on these results was examined. RESULTS: Thirty-three scenarios were identified as being appropriate. Concordant imaging results had no effect on appropriateness ratings in symptomatic carotid artery disease when compared with conventional angiography. Single noninvasive imaging techniques were deemed appropriate for investigation only in the presence of severe symptomatic stenosis. In all other scenarios, single noninvasive imaging and discordant results reduced the appropriateness rating of scenarios to either uncertain benefit or inappropriateness. The single appropriate scenario for asymptomatic carotid artery stenosis was where severe stenosis was determined by concordant noninvasive imaging or by CTA or MRA alone. CONCLUSION: It is important to take into account both the clinical scenario and the imaging modalities utilized to determine the degree of internal carotid artery stenosis in the clinical decision making surrounding carotid endarterectomy

Hand wasting due to mid-cervical spinal cord compression.

Three patients presented with hand wasting and weakness secondary to mid-cervical spinal cord compression. This was due to cervical spondylosis in two patients and a meningioma in one case. This phenomenon is probably similar to that seen with foramen magnum lesions and may be due to spinal cord ischemia distal to the compression, secondary to venous stasis