T. W. Ho

Anti-GD1a antibody is associated with axonal but not demyelinating forms of Guillain-Barré syndrome

Immunopathological studies suggest that the target of immune attack is different in the subtypes of Guillain‐Barré syndrome (GBS). In acute motor axonal neuropathy (AMAN), the attack appears directed against the axolemma and nodes of Ranvier. In acute inflammatory demyelinating polyneuropathy (AIDP), the attack appears directed against a component of the Schwann cell. However, the nature of the antigenic targets is still not clear. We prospectively studied 138 Chinese GBS patients and found that IgG anti‐GD1a antibodies were closely associated with AMAN but not AIDP. With a cutoff titer of greater than 1:100, 60% of AMAN versus 4% of AIDP patients had IgG anti‐GD1a antibodies; with a cutoff titer of greater than 1:1,000, 24% of AMAN patients and none of the AIDP patients had IgG anti‐GD1a antibodies. In contrast, low levels of IgG anti‐GM1 antibodies (>1:100) were detected in both the AMAN and the AIDP forms (57% vs 35%, NS). High titers of IgG anti‐GM1 (>1:1,000) were more common in the AMAN form (24% vs 8%, NS). Serological evidence of recent Campylobacter infection was detected in 81% of AMAN and 50% of AIDP patients, and anti‐ganglioside antibodies were common in both Campylobacter‐infected and noninfected patients. Our results suggest that IgG anti‐GD1a antibodies may be involved in the pathogenesis of AMAN. Ann Neurol 1999;45:168–173

Clinical and electrophysiological aspects of acute paralytic disease of children and young adults in northern China

Acute peripheral nervous system diseases leading to paralysis in children are rare in Europe and the USA, whereas epidemics of a Guillain-Barré-like syndrome occur annually among children in rural parts of northern China. To clarify the features of this disorder 36 patients, aged 15 months to 37 years (median 7) with this syndrome were investigated; 91% were from rural areas. In 47%, a prodromal illness was reported in the preceding 4 weeks. Leg weakness and resistance to neck flexion were the earliest symptoms. The weakness ascended rapidly and symmetrically to affect the arms and respiratory muscles, with maximum weakness occurring a mean of 6 days after onset of weakness. Bulbar weakness occurred in 61% of patients, but only 1 had extraocular paresis. Respiratory assistance was needed by 31% of patients. Tendon reflexes were lost as weakness developed. 42% of patients had raised concentrations of protein in the cerebrospinal fluid, and the mean cell count was 3 cells/microliters (range 0-12/microliters). Electrodiagnostic studies in 22 patients showed severe reductions in motor evoked amplitudes from distal stimulation. Sensory action potentials were normal. Electromyography revealed denervation potentials in limb muscles. The distinctive epidemiological, clinical, and neurophysiological characteristics of this illness suggest that the disorder is different from both Guillain-Barré syndrome and poliomyelitis. The neurophysiological findings support the hypothesis that the disorder is a reversible distal motor nerve terminal or anterior horn cell lesion.

Patterns of recovery in the Guillain-Barre syndromes

Article abstract-Clinical, electrodiagnostic, and pathologic studies indicate that the Guillain-Barre syndromes (GBSs) include both primary demyelinating and primary axonal forms. The axonal forms are usually thought to have a poorer prognosis, with less chance for rapid or complete recovery. In northern China, epidemics of one axonal form, acute motor axonal neuropathy (AMAN), occur annually in the summer. Autopsy studies in some fatal cases have demonstrated wallerian-like degeneration of motor roots and motor fibers in the peripheral nerves. Recovery of such patients would require axonal regeneration along the entire length of the nerve fiber. In a 2-year prospective study of GBS at a single hospital in northern China, 42 patients were classified as having either AMAN (32 patients), acute inflammatory demyelinating polyneuropathy (AIDP) (8 patients), or as undetermined (2 patients) by electrodiagnostic criteria. Their recoveries were monitored clinically. The recovery times of AMAN and AIDP patients were similar: the median time to regain the ability to walk 5 meters with assistance was 31 days for patients classified as having AMAN and 32 days for those classified as having AIDP. These rapid recovery times are incompatible with severe wallerian degeneration of the ventral roots and motor nerve fibers. The rapid recoveries observed in AMAN patients could be explained by relatively quickly reversible immune-mediated changes at nodes of Ranvier in motor fibers, by degeneration and regeneration of intramuscular motor nerve terminals, or both. NEUROLOGY 1997;48: 695-700

Etiology, neurologic correlations, and prognosis in alpha coma

OBJECTIVEnTo determine the factors affecting prognosis in alpha coma (AC).nnnMETHODSnRetrospective review of 36 study patients, 36 control coma patients matched for age and etiology, and meta-analysis of 335 cases in the world literature.nnnRESULTSnPrincipal causes were cardiorespiratory arrest (CRA) (21 patients); infection, metabolic dysfunction, head trauma (3 each); and drugs, stroke and hypoxia (2 each). Outcome was predicated by EEG reactivity to noxious stimuli. Fourteen of the 15 patients with reactive EEGs, had measurable outcome, 8 awoke - all but two had etiologies other than CRA. Fourteen of 19 patients without EEG reactivity died; two had support discontinued and 3 awoke. Following CRA, 16/21 patients died and 3 had support discontinued. Only 3 patients made a good recovery - all with toxic or metabolic etiologies. Literature meta-analysis of 335 cases showed that overall, AC carried a poor prognosis (76% died). CRA (226 cases) had an 88% mortality; strokes (29 cases), a 90% mortality; hypoxia without cardiac arrest (28 cases), a 61% mortality; drug-induced AC (25 cases), an 8% mortality.nnnCONCLUSIONSnAlthough the cause of AC largely predicts outcome, EEG reactivity in AC predicted survival: most patients with reactivity awoke; most of those without, died. Few survivors had meaningful recovery.

Differential Distribution of HLA-DQβ/DRβ Epitopes in the Two Forms of Guillain-Barré Syndrome, Acute Motor Axonal Neuropathy and Acute Inflammatory Demyelinating Polyneuropathy (AIDP): Identification of DQβ Epitopes Associated with Susceptibility to and Protection from AIDP

Guillain-Barré syndrome (GBS), an acute, immune-mediated paralytic disorder affecting the peripheral nervous system, is the most common cause of acute flaccid paralysis in the postpolio era. GBS is classified into several subtypes based on clinical and pathologic criteria, with acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN) being the most common forms observed. To better understand the pathogenesis of GBS and host susceptibility to developing the disease, the distribution of HLA class II Ags along with the seroreactivity to Campylobacter jejuni were investigated in a population of GBS patients from northern China. Using DNA-based typing methods, 47 patients with AMAN, 25 patients with AIDP, and 97 healthy controls were studied for the distribution of class II alleles. We found that the DQβ RLD55–57/ED70–71 and DRβ E9V11H13 epitopes were associated with susceptibility to AIDP (p = 0.009 and p = 0.004, respectively), and the DQβ RPD55–57 epitope was associated with protection (p = 0.05) from AIDP. These DQβ/DRβ positional residues are a part of pockets 4 (DQβ 70, 71, DRβ13), 6 (DRβ11), and 9 (DQβ 56, 57, DRβ9); have been demonstrated to be important in peptide binding and T cell recognition; and are associated with other diseases that have a pathoimmunological basis. Class II HLA associations were not identified with AMAN, suggesting a different immunological mechanism of disease induction in the two forms of GBS. These findings provide immunogenetic evidence for differentiating the two disease entities (AMAN and AIDP) and focuses our attention on particular DRβ/DQβ residues that may be instrumental in understanding the pathophysiology of AIDP.

Clinical correlates and prognosis in early spindle coma

OBJECTIVEnTo determine the prognostic significance of spindle coma (SC) according to etiology and EEG reactivity.nnnMETHODSnWe reviewed 15 patients with SC due to various causes within 8 days of coma to determine the prognostic significance of this EEG pattern.nnnRESULTSnThe outcome among survivors was favorable: among 13 survivors, 9 were independent in all activities of daily living (ADLs) at 6 months; 3 were dependent in all ADLs; and one remained in coma. EEG reactivity to noxious stimuli best predicted outcome: All patients (whatever the coma etiology) with EEG reactivity survived; conversely, not all patients without EEG reactivity died.nnnCONCLUSIONnIn our patients, EEG reactivity independent of etiology predicted survival, neurological examination did not predict outcome. Most SC survivors had a meaningful recovery achieving all ADLs. From the literature, the cause of SC was predictive of outcome: encephalopathy, seizures and trauma had the best prognosis while hypoxia, CRA and structural lesions carried the worst. Literature review revealed that 23% of patients [56/242] died or remained in a persistent vegetative state (PVS). Best outcomes occurred when SC was due to drugs, encephalopathy or seizures: (0/14 died or were in a PVS). With trauma 15% [25/169] died or were in a PVS). Intermediate outcomes occurred with hypoxia and cardio-respiratory arrest (CRA): 33% [7/21] died or were in a PVS. The gravest outcomes occurred with brain-stem and cerebral infarctions, and tumors: 73% [22/30] died or were in a PVS.