Clinical and serological features of acute sensory ataxic neuropathy with antiganglioside antibodies.

There is as yet no consensus for considering pure acute sensory ataxic neuropathy (ASAN) as a variant of Guillain-Barré syndrome (GBS). Reactivity against gangliosides sharing disialosyl epitopes has been reported in these patients. The aim of this study was to determine the spectrum of reactivity against gangliosides in ASAN and to define the clinical pattern. From our database we identified patients with suspicion of ASAN. We defined ASAN as the presence of ataxia of peripheral origin with loss of proprioception, and areflexia, absence of ophthalmoplegia and no or minimal muscle weakness. Patients who met these criteria were retrospectively reviewed for their spectrum of reactivity against gangliosides and clinical features. We identified 12 patients fulfilling pre-defined criteria for ASAN. Reactivity against gangliosides containing disialosyl epitopes was present in seven patients. Concomitant reactivity against other gangliosides was present in 6/7 patients. All patients presented good prognosis and an antecedent illness was present in nine. Our results support the previously described clinico-immunological association between ASAN and disialosyl specificity, and widen the spectrum of reactivity against gangliosides. The acute presentation with a monophasic course, and good prognosis in all cases, together with transient immunoglobulin G antiganglioside antibodies and infectious antecedent in 7/12 patients support the inclusion of ASAN as a GBS variant.

Bulbar involvement in patients with antiganglioside antibodies against NeuNAc(alpha2-3)Gal.

BACKGROUND: Reactivity against terminal NeuNAc(alpha2-3)Gal, common to several gangliosides such as GD1a, GT1b and GM3, has rarely been reported. The authors recently described a patient with a clinical picture of acute relapsing sensory ataxic neuropathy and bulbar involvement in whom they demonstrated concomitant reactivity against NeuNAc(alpha2-3)Gal and disialosyl epitopes. The authors suggested a correlation between NeuNAc(alpha2-3)Gal reactivity and bulbar involvement. AIM: To determine the frequency of reactivity against terminal NeuNAc(alpha2-3)Gal in acute and chronic immune-mediated disorders, and its possible correlation with bulbar involvement. METHODS: The authors retrospectively reviewed reactivity in the serum of more than 3000 consecutive patients with acute and chronic disorders in which antiganglioside antibodies were studied. The authors selected those patients who were simultaneously positive, by ELISA or thin-layer chromatography, for IgG or IgM antibodies anti-GM3, GD1a and GT1b, and reviewed their clinical features. RESULTS: Reactivity against NeuNAc(alpha2-3)Gal, shared by GM3, GD1a and GT1b gangliosides, was detected in 10 patients: isolated in one patient, and concomitant with reactivity against other gangliosides in the remaining patients. Reactivity against NeuNAc(alpha2-3)Gal was frequently associated (8/10) with symptoms suggestive of bulbar involvement, such as dysphagia, dysarthria or dysphonia. Severe respiratory failure requiring mechanical ventilation was observed in four patients. CONCLUSIONS: Reactivity against the NeuNAc(alpha2-3)Gal epitope is rare and is generally found in association with reactivity against the disialosyl epitope. It can be detected in patients with acute or chronic disorders and could be a serological marker of clinical bulbar involvement and, to a lesser extent, associated with the development of severe respiratory failure.

[Clinical usefulness of transcranial Doppler in diagnosis of brain death]. / Utilidad clínica del Doppler transcraneal en el diagnóstico de muerte encefálica.

BACKGROUND AND OBJECTIVE: The use of transcranial doppler (TD) for the assessment of critical neurological patients and brain death (BD) is steadily growing. In this study we describe the daily clinical practice around BD diagnosis and compare the usefulness of TD, including advantages and shortcomings, with that of other tests. PATIENTS AND METHOD: A series of 100 patients diagnosed of brain death is presented including the demographic and clinical data as well as the results of ancillary tests (CE). RESULTS: Fifty eight patients were males with a mean age of 46. The most frequent etiology of coma was spontaneous cerebral hemorrhage. Central nervous system depressants had been administered to 62 patients within a few hours prior to the diagnosis. When ancillary tests were performed, only 55% patients fulfilled the currently accepted clinical criteria for brain death. TD was performed in 44 patients and 80% of them showed a pattern supporting a brain death diagnosis. Definitive diagnostic tests were electroencephalogram (EEG) in 53% patients and TD in 35% of them. In ten cases, discrepancies were observed between the results offered by these tests. CONCLUSIONS: Transcraneal Doppler stands out as a safe, fast, inexpensive and bloodless method of assessment of the critical neurological patient and for BD diagnosis. It is the choice test in the presence of central nervous system depressant drugs, abuse of substances or coma of unknown etiology. The main limitations of this technique are the presence of extensive craniotomies and the absence of an adequate acoustic window.