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Introduction: Few neurological diseases are linked with anti-glutamic acid decarboxylase antibodies (GAD-ab); stiff man syndrome is an example. Cerebellar ataxia is a new feature of this expanding spectrum. No therapeutic trial is yet available in these diseases. We here report on four patients suffering from cerebellar ataxia linked with GAD-ab and review the data in the literature on this recently described syndrome., Method: We conducted an open trial with monthly pulsed steroids. Steroid pulses were given six months followed with placebo for another six months. Main clinical and biological parameters were monitored monthly (International Cooperative Cerebellar Ataxia Rating Scale [ICARS] and GAD-ab)., Result: The clinical response was found limited and inconstant. Transient decline in GAD-ab level was noted in two patients. Moreover, GAD-ab level was found highly variable and did not correlate with clinical parameters., Discussion: Cerebellar ataxia with GAD-ab is an increasingly described syndrome. Outcome can be severe, leading to definitive cerebellar atrophy. Diagnosis is supported by high level of serum GAD-ab with intrathecal secretion. Experimental data have suggested a direct excitotoxic effect of GAD-ab on Purkinje cells. Response to various treatments is often disappointing. Improvement has been obtained with veinoglobulins in individual patients. A weak clinical and biological response was associated with monthly steroid pulses.

In adults, neurological complications of VZV virus usually occur after herpes zoster infection in patients with AIDS. We report a case of acute and benign cerebellar ataxia after chickenpox in a patient without immunodeficiency.

We propose a serotonergic hypothesis for cerebellar ataxia. The levorotatory form of 5 hydroxytryptophan has been shown to be partially active in subtypes of cerebellar ataxia, including cerebellar cortical atrophy (CCA). Buspirone, a 5-HT1A agonist usable in human medicine, has been studied in a group of 14 patients with cerebellar cortical atrophy. Patients were given Buspirone for 2 months. The evaluation of cerebellar ataxia was made by a semi-quantitative scale, 10 fully quantitative measures and measurements of the sway path and sway area of the center of gravity at posturography. The primary endpoints were the modifications of the ataxia scores. At 2 months, the decrease of the ataxia scores was significant, both in the intention-to-treat (14 cases) and target (11 cases) populations. In the target population, secondary endpoints like the time measurements for pronouncing a standard sentence, the time for drawing a ladder and posturographic parameters were significantly improved; the mean global ataxia score was improved by 37.4%. These preliminary data might confirm a link between cerebellar ataxia and the metabolism of serotonin.

A quantitative evaluation of cerebellar ataxia, with an ataxia score (total, static, kinetic) and the measurement of objective values related to the major symptoms, is proposed. 21 patients with heredo-ataxias were treated for 12 months with high doses (16 mg/kg/day) of D-L-5-HTP, L-5-HTP or the association D-L-5-HTP (16 mg/kg/day)-Benserazide(6 mg/kg/day). A computerized processing of the data obtained by regular examination was performed. The ataxia showed a significant regression at the 12th month, mainly in the static performances and in the speed of speech. L-5-HTP appeared to be more active than D-L-5-HTP. The regression of the cerebellar ataxia was also observed in non degenerative conditions such as multiple sclerosis and surgical injury of the anterior lobe vermis, showing that 5-HTP was active on the cerebellar syndrome in general. The regression of the cerebellar ataxia was very slow in inherited diseases and continued for 2 or 4 months after the treatment stopped. A serotoninergic cerebellar control of motricity is discussed.

Unlabelled: This family is the tenth reported world-wide and the second reported in Europe. Two of 3 brothers, their mother and probably their maternal grandmother were affected., Clinical Features: paroxysmal bouts of ataxia and dysarthria, nystagmus of permanent gaze, the dominant autosomal transmission, the benign nature of the affection and the remarkable efficacy of acetazolamide were typical of familial paroxysmal ataxia. Specific points emphasized are the presence of a mild pyramidal syndrome as a permanent finding in 2 of these patients, and the anomalies of visual (longer lag period) and somesthetic (slowed conduction rate in the lemniscus medialis) evoked potentials probably the result of extension into other pathways than the cerebellar system. The finding of some degree of glucose intolerance, noted previously (Aimard, Vighetto et al., 1983) raises the question of the place of this disease in the group of paroxysmal ataxias due to pyruvic metabolism disorders.