Gangliosides and neurological diseases

Functional and structural effects of GM-1 ganglioside treatment on peripheral nerve grafting in the rat

Peripheral nerve regeneration after traumatic injury and standard repair with a nerve autograft is usually incomplete. This study tested the influence of graft vascularity and pharmacological intervention with GM-1 ganglioside on nerve regeneration in a rat sciatic nerve model. Controls included an unoperated contralateral side and sham-operated groups either with or without the GM-1. During the 5 months of recovery, locomotion was tested by the sciatic function index (SFI). At killing, anesthetized animals were prepared for nerve conduction velocity (NCV) studies, followed by the wet weight of the gastrocnemius muscle (expression of atrophy), toe-chewing (expression of lesion severity and sensory loss), and histological examination of the nerve segments. The SFI showed a slight but significant recovery for both the vascular and avascular groups (34% at 20 weeks), but when GM-1 ganglioside treatment was included, the SFI was poor throughout (20-33%). The average NCV of the graft groups without GM-1 was 46% to 57% of the normal nerve (52.7 m/s), whereas for the groups treated with GM-1, it was 63% to 64% of normal; treatment of the non-vascular graft group significantly improved recovery. A uniformly poor recovery from muscle atrophy was seen for all nerve graft groups (62-67%) compared with normal controls. The mean number of toes per foot chewed was 1.9 and 2.4 in graft groups without GM-1 treatment and 0.9 and 1.3 in graft groups treated with GM-1. This treatment significantly reduced both the extent and the number of animals exhibiting autotomy. The qualitative microscopic appearance of the distal nerve segment in all surgical groups was similar. We conclude that the systemic addition of GM-1 ganglioside enhances only some aspects of regeneration in grafted nerves, possibly with a preferential effect on sensory nerve regeneration and functional recovery.

Guillain-Barré syndrome in Cantabria, Spain. An epidemiological and clinical study

Seventy-one patients with Guillain-Barré syndrome (GBS) were retrospectively selected from within a defined area (Cantabria) in northern Spain, from 1975 to 1988. Excluding two non-resident cases, epidemiological analysis was based on 69 cases. The annual incidence rates were stable during the 14-year period of study with an average incidence of 0.95 (age-adjusted, 0.86) cases per 100,000 population. No significant difference was found for sex, urban or rural residence and there was no significant seasonal clustering. Antecedent event were recorded in 57% of patients, the most frequent events being upper respiratory infection and gastroenteritis. No association between use of gangliosides and the syndrome was found. Eight patients had variant syndromes including Fisher's syndrome (2 cases), and axonal (4 cases) and sensory (2 cases) GBS. Recurrences occurred in 3 cases. Excluding nine patients with incomplete follow-up and two with Fisher's syndrome, clinical analysis was based on 60 cases. Patients were divided into three groups as a function of their peak weakness. Significant features of the severe group were a requirement for ventilation, presence of bulbar palsy or dysautonomia and a longer duration of the plateau phase. However, it was not possible at an early stage of the clinical course to predict future motor deficit. Four (6.7%) patients belonging to the severe group died during the acute phase of the disease. No specific treatment for GBS was given. Outcome was assessed by means of serial examination up to 24 months after the onset of symptoms using a functional scale. At 3, 6 and 24 months 70%, 46% and 12% of patients, respectively, had a poor outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

The Therapeutic Role of Gangliosides in Neurological Disorders

Numerous in vitro and in vivo experimental animal studies have demonstrated that gangliosides, particularly GMI ganglioside (siagoside), may stimulate or accelerate the repair of peripheral and central nervous system neurons after various types of damage. Clinical studies of GMl in peripheral neuropathies and stroke, disorders in which the effects of GM 1 have been studied most extensively, have yielded inconsistent results. Problems of inadequate study design, inclusion of heterogenous clinical popUlations and variations in dosage, duration of treatment and timing of initial administration make it difficult to compare results from individual studies and to conclusively assess efficacy of GMl treatment. Therefore, further clinical studies of gangliosides seem warranted.Despite efforts to link gangliosides with the development of Guillain-Barre syndrome, there are no valid data to support such an association. Gangliosides, in particular GM I, are well tolerated after repeated administration to humans and do not appear to be immunogenic.GM1 may be a useful therapeutic agent if administered to particular patients with a specific spectrum of symptoms and disease severity. In addition, to be effective the agents need to be administered in appropriate dosages and at an appropriate time after neuronal injury. Human clinical trials of gangliosides should continue cautiously and with restraint.