Acute Motor Axonal Neuropathy Pattern Research Articles

A multicentre prospective study of Guillain-Barré Syndrome in Japan: a focus on the incidence of subtypes

ObjectiveGuillain–Barré Syndrome (GBS) is classified into the two major subtypes; acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). Previous studies have suggested that AIDP is predominant and...

The demyelination neurophysiological criteria can be misleading in Campylobacter jejuni-related Guillain–Barré syndrome

ObjectiveThe exclusive association of Campylobacter jejuni infection with the axonal variant of Guillain–Barré syndrome (GBS) is debatable. The current study aims to elucidate the GBS subtypes of patients with an antecedent C. jejuni infection. MethodsNerve conduction study results of 73 patients with GBS were reviewed. Patients were defined as having a recent C. jejuni infection when there was a positive stool culture or serological evidence of C. jejuni in the presence of preceding diarrhea. ResultsA total of 23 patients had evidence of a recent C. jejuni infection. At the early stage, patients were classified as AMAN (n=9; 39%), AIDP (n=3; 13%) or equivocal (n=9) using existing electrophysiological criteria. Prolonged distal latencies and conduction slowing that were seen in 11 patients rapidly normalized within 3weeks in seven, whereas four had minor abnormalities throughout the course. Subsequently, all patients showed either acute motor axonal neuropathy pattern or reversible conduction failure. ConclusionSerial neurophysiology suggests that C. jejuni infections are exclusive to axonal GBS. SignificanceOur findings suggest that AMAN can demonstrate the full complement of demyelinating features at the early stages of disease.

Antiganglioside antibodies are associated with axonal Guillain–Barré syndrome: A Japanese–Italian collaborative study

BackgroundWhether or not antiganglioside antibodies are related to axonal or demyelinating Guillain–Barré syndrome (GBS) is still a matter of controversy, as detailed in previous studies conducted in Western and Asian...

Patterns and serial changes in electrodiagnostic abnormalities of axonal Guillain–Barré syndrome

In Guillain-Barré syndrome (GBS), anti-ganglioside antibodies are strongly associated with the acute motor axonal neuropathy (AMAN) form, but there are also cases of the demyelinating form of GBS (acute inflammatory demyelinating polyneuropathy [AIDP]) with anti-ganglioside antibodies. To elucidate the patterns and sequential changes in electrodiagnostic abnormalities of anti-ganglioside-positive GBS. Detailed serial electrodiagnostic findings were reviewed for 51 patients with GBS. Anti-ganglioside antibodies were measured by ELISA. Antibodies to GM1, GM1b, GD1a, or GalNAc-GD1a were present in 25 patients. Of these, 12 (48%) showed the AMAN pattern, 5 (20%) the AIDP pattern, and 3 (12%) isolated F-wave absence in the first examination. All five patients with the AIDP pattern showed prolonged distal latencies, but three eventually showed the AMAN pattern or rapid normalization. The remaining two still had similarly prolonged distal latencies in weeks 4 to 6, but the serial changes were distinct from those in the anti-ganglioside-negative AIDP patients who showed progressive increases in distal latencies over 2 months after onset. Besides the simple axonal degeneration pattern, patients with anti-ganglioside-positive Guillain-Barre syndrome can show transient conduction slowing/block in the distal or proximal nerve segments, mimicking demyelination, but anti-ganglioside antibodies do not appear to be associated with acute inflammatory demyelinating polyneuropathy.

Hyperreflexia in axonal Guillain–Barré syndrome subsequent to Campylobacter jejuni enteritis

We describe a patient with the acute motor axonal neuropathy (AMAN) form of Guillain–Barré syndrome (GBS), who showed generalized hyperreflexia. A 24-year-old man developed acute paralysis following Campylobacter jejuni enteritis. He showed exaggerated tendon reflexes with abnormal reflex spread to other segments, and was initially diagnosed as having post-infectious myelitis. Nerve conduction studies showed motor axonal degeneration (the AMAN pattern), and increased soleus H-reflex amplitudes. His serum was positive for IgG antibodies to gangliosides GM1b and GalNAc-GD1a. He was treated with plasmapheresis, resulting in rapid recovery. Hyperreflexia was still present 12 months after onset when muscle strength was completely normal. This case provides further evidence that patients with AMAN can develop increased motor neuron excitability, and possible mechanisms for the hyperreflexia are discussed.

Axonal Guillain‐Barré syndrome: Relation to anti‐ganglioside antibodies and Campylobacter jejuni infection in Japan

To clarify the relations of the axonal form of Guillain-Barré syndrome (GBS) to anti-ganglioside antibodies and Campylobacter jejuni infection, 86 consecutive Japanese GBS patients were studied. Electrodiagnostic criteria showed acute inflammatory demyelinating polyneuropathy in 36% of the patients and acute motor axonal neuropathy (AMAN) in 38%. Frequent anti-ganglioside antibodies were of the IgG class and against GM1 (40%), GD1a (30%), GalNAc-GD1a (17%), and GD1b (21%). Identified infections were C. jejuni (23%), cytomegalovirus (10%), Mycoplasma pneumoniae (6%), and Epstein-Barr virus (3%). There was a strong association between AMAN and IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b. Almost all the patients with at least one of these antibodies had the AMAN pattern or rapid resolution of conduction slowing/block possibly because of early-reversible changes on the axolemma. C. jejuni infection was frequently associated with AMAN or anti-ganglioside antibodies, but more than half of the patients with AMAN or anti-ganglioside antibodies were C. jejuni–negative. These findings suggest that the three phenomena “axonal dysfunctions (AMAN or early-reversible conduction failure),” “IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b,” and “C. jejuni infection” are closely associated but that microorganisms other than C. jejuni frequently trigger an anti-ganglioside response and elicit axonal GBS. Ann Neurol 2000;48:624–631

Axonal Guillain-Barr� syndrome: Relation to anti-ganglioside antibodies andCampylobacter jejuni infection in Japan

To clarify the relations of the axonal form of Guillain-Barré syndrome (GBS) to anti-ganglioside antibodies and Campylobacter jejuni infection, 86 consecutive Japanese GBS patients were studied. Electrodiagnostic criteria showed acute inflammatory demyelinating polyneuropathy in 36% of the patients and acute motor axonal neuropathy (AMAN) in 38%. Frequent anti-ganglioside antibodies were of the IgG class and against GM1 (40%), GD1a (30%), GalNAc-GD1a (17%), and GD1b (21%). Identified infections were C. jejuni (23%), cytomegalovirus (10%), Mycoplasma pneumoniae (6%), and Epstein-Barr virus (3%). There was a strong association between AMAN and IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b. Almost all the patients with at least one of these antibodies had the AMAN pattern or rapid resolution of conduction slowing/block possibly because of early-reversible changes on the axolemma. C. jejuni infection was frequently associated with AMAN or anti-ganglioside antibodies, but more than half of the patients with AMAN or anti-ganglioside antibodies were C. jejuni-negative. These findings suggest that the three phenomena "axonal dysfunctions (AMAN or early-reversible conduction failure)," "IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b," and "C. jejuni infection" are closely associated but that microorganisms other than C. jejuni frequently trigger an anti-ganglioside response and elicit axonal GBS.

A prospective clinical and electrophysiologic survey of acute flaccid paralysis in Chinese children.

We studied 29 children admitted to Beijing Children's Hospital (BCH) with acute flaccid paralysis between June 1991 and June 1993. Twenty-seven patients had Guillain-Barré syndrome--7 with acute inflammatory demyelinating polyneuropathy and 20 with acute motor axonal neuropathy (AMAN). Two had poliomyelitis. The most common cause of acute flaccid paralysis at BCH is the AMAN pattern of GBS.

Early nodal changes in the acute motor axonal neuropathy pattern of the Guillain-Barré syndrome.

The axonal patterns of Guillain-Barré syndrome, associated in many cases with antecedent Campylobacter jejuni infection, are now recognized as frequent causes of acute flaccid paralysis in some regions of the world. This study examined ultrastructurally the PNS of seven cases of the acute motor axonal neuropathy form of Guillain-Barré syndrome. In this disorder previous studies of advanced cases have found Wallerian-like degeneration of motor fibres in the spinal roots and peripheral nerves, with little lymphocytic inflammation or demyelination. The present study was focused on identifying early changes and establishing the sequence of changes. By electron microscopy the earliest and mildest changes consisted of lengthening of the node of Ranvier with distortion of the paranodal myelin, and in some instances with breakdown of the outermost myelin terminal loops. At this stage many nodes had overlying macrophages which extended their processes through the Schwann cell basal lamina covering the node and apposed the axolemma. Macrophage processes then extended beneath the myelin terminal loops, and the whole macrophage entered the periaxonal space at the paranode. Macrophage processes dissected the axon from the adaxonal Schwann cell plasmalemma and the macrophages advanced into the internodal periaxonal space, where they typically surrounded a condensed-appearing axon. At this stage the adaxonal Schwann cell cytoplasm regularly degenerated and disappeared, so that the periaxonal space was bounded by the innermost myelin lamella, and the axolemma of many fibres could not be seen. The internodal myelin sheath and the abaxonal Schwann cell cytoplasm remained normal. This arrangement appeared to be stable for some time, but in many fibres the axon subsequently underwent Wallerian-like degeneration. By interfering with impulse conduction, these nodal and periaxonal changes may explain paralysis in some pathologically mild cases. In addition, at early stages, these changes may be reversible, thus explaining the rapid recovery of some patients who become paralysed with acute motor axonal neuropathy. These observations, taken together with previous studies, suggest that acute motor axonal neuropathy is an antibody- and complement-mediated disorder in which the relevant epitopes are present on the nodal and internodal axolemma.