Variants of Guillain-Barré syndrome: low incidence but high impact

Abstract

Guillain-Barre syndrome (GBS) is an acute monophasic immune-mediated neuropathy that still carries significant morbidity and mortality [2, 6, 17]. It is one of the neurological emergencies and places, given the disability associated with it, a significant burden on patients afflicted, their caregivers and families, and the health system. Overall, up to one-third of the patients require mechanical ventilation and 3–10% still die as a consequence of respiratory failure, autonomic dysfunction such as bradyarrhythmia, tachyarrhythmia, and secondary complications of long-term immobility, e.g. thromboembolism and intercurrent infections [8].The classical form of GBS is not difficult to recognize and usually presents with the same clinical symptoms and phenotype, which were already described almost a century ago [5]. However, with more clinical research focused on this disease, it became increasingly clear that GBS is not a single entity, but rather a clinically and pathologically heterogeneous group of neuropathic conditions. This concept first emerged subsequent to the description of the Miller Fisher syndrome in 1956, when Charles Miller Fisher published three cases of acute polyneuritis with the clinical triad of ophthalmoplegia, ataxia and areflexia [1], and was further corroborated by and developed following the discovery of pure axonal variants of GBS in northern China in the 1990s [7]. Over the last two decades other, and rarer variants have been added to that list, including subtypes presenting predominantly with dysautonomia, lower cranial nerve involvement or pure brachio-pharyngeal weakness [11, 16, 18]. In the current issue Susuki and colleagues elaborate the clinical features of another variant of the GBS spectrum, which is characterized by prominent facial diplegia and limb paraesthesiae, with no or only minor motor weakness [14]. Ropper delineated this condition in 1994 in his report of four cases that presented with the symptoms of an acute progressive facial diplegia and numbness in the extremities [13]. Based on clinical and serological data collected from about 8,600 patients, Susuki and colleagues have now identified 22 cases, in which clinical symptoms and disease history were compatible with Ropper‘s initial description. Most of these patients presented with numbness in all limbs and weakness of the facial muscles, while only a minority had mild motor deficits in the extremities or ataxia. However, more important than the recognition of symptoms that differ from those of typical GBS is the identification of features supporting the view that facial diplegia and limb paraesthesiae form indeed part of the GBS spectrum. Susuki and colleagues provide here convincing evidence for this concept, since (1) all of the patients described had albuminocytologic dissociation in the cerebrospinal fluid, (2) most cases had a history of antecedent infection and (3) demyelinating abnormalities were detectable in nerve conduction studies [14]. Although GBS is considered to be the most common flaccid neuromuscular paralysis worldwide, it is not very frequent in comparison to other neurological disorders, with an incidence of 1–2 per 100,000 [8–10, 12]. This raises the question how useful is a splitting of such a rare disease into several subtypes, if each comprises only a small percentage of all GBS cases and especially if the absolute numbers for each subtype become very low? Opinions may be divided between ‘‘splitters’’ and ‘‘lumpers’’. First, the recognition of atypical forms is likely to have a strong clinical impact, since it raises the clinician’s H. C. Lehmann H.-P. Hartung (&) Department of Neurology, Heinrich-Heine-University, Moorenstrasse 5, 40225 Dusseldorf, Germany e-mail: hans-peter.hartung@uni-duesseldorf.de