Amantadine hydrochloride treatment in olivopontocerebellar atrophy: a long-term follow-up study.

The efficacy of amantadine, a dopamine-releasing agent and antagonist of the N-methyl-D-aspartate glutamate receptor, was evaluated in patients with olivopontocerebellar atrophy. By contrast to an untreated control group whose terminal performance deteriorated on 8 of 8 measurements of reaction time and movement time, patients treated with amantadine for a mean duration of over 40 months had improved performances in 1 of 4 reaction time measurements and in 3 of 4 movement time measurements and remained stable on the others. These results demonstrate long-term benefits of amantadine in olivopontocerebellar atrophy-induced deficits of movement initiation and movement completion.

[Clinical identification of hereditary ataxias. A study of 38 cases in Colombia]. / Identificación clínica de las ataxias hereditarias: estudio de 38 casos en Colombia.

INTRODUCTION: Hereditary ataxias are a complex group of degeneratives diseases of the CNS. Material and methods. We studied 38 patients who were diagnosed inherited ataxia according to recent classification and radiologic criteria. We proposed flow sheet in order to reduce the cost of the studies. RESULTS: The most frequent findings we encountered were the congenital ataxias and the late onset ataxia forms, olivopontocerebellar ataxias (OPCA) and the late cortical cerebellar ataxias (CCA), following were the Friedreich ataxias, the intermittent ataxias, and cerebellar ataxias with myoclonus. We found finally two multisystemic atrophies. We didn't find dominant inheritance in the late onset ataxias, some of these were recessive forms and the others could be the novo mutations or idiopathic cerebellar ataxias of adult onset. CONCLUSION: It would be appropriate to enlarge the studies in the metabolic and treatable forms and try to define the forms that have a known genetic mutation.

Amantadine hydrochloride treatment in heredodegenerative ataxias: a double blind study.

OBJECTIVE: A group of 27 patients with Friedreich's ataxia and another group of 30 patients with olivopontocerebellar atrophies were each randomly divided into two subgroups, one receiving placebo and the other amantadine hydrochloride (AH; 200 mg daily) for three to four months. METHODS: The effect of double blind treatment was evaluated by simple visual and auditory reaction time (RT) and movement time (MT) for both right and left hands. RESULTS: The subgroup with olivopontocerebellar atrophies receiving AH showed significant improvement on seven out of eight variables studied by analysis of covariance. In patients with Friedreich's ataxia, improvement was definitely less. Treatment remained contraindicated for those with cardiomyopathies or drug intolerance. CONCLUSION: The rationale of AH use in heredodegenerative ataxias can be explained by its replacement effect (dopamine release) and by direct involvement of N-methyl-D-aspartate (NMDA) in glutamate mediated neurotoxicity in cerebellar granular cells; memantine, an AH analogue, is a potent blocker of NMDA receptors.

Radiologic correlates of reaction time measurements in olivopontocerebellar atrophy.

We measured simple visual and auditory reaction time (RT) and movement time (MT) in 32 patients with olivopontocerebellar atrophy (OPCA) in comparison to 32 control subjects. In addition, we followed 2 approaches to radiologic assessment by computed tomographic scans: subjective (by inspection of films) and objective (by measurement of 4 radiologic ratios at the level of the posterior fossa and 1 ratio at the supratentorial level). All OPCA patients had various degrees of cerebellar atrophy and lengthened RT and MT in comparison to their controls. There were no significant differences in RT and MT performances in patients with mild-moderate versus those with severe cerebellar atrophy as assessed by inspection of their films. OPCA patients with severe versus mild-moderate atrophy evaluated by 3 measures, i.e., brainstem, brachium pontis and fourth ventricle ratios, presented few significantly lengthened RT and MT performances. In contrast, patients with severe atrophy revealed by the midbrain ratio had significantly lengthened RT and MT performances compared to those with mild-moderate atrophy assessed by this ratio on 7 of 8 measures; the 8th measure showed a borderline significant difference. This could be explained by the fact that atrophy at the midbrain level is the only one which involves dopaminergic, noradrenergic and glutamatergic structures and pathways.

Thiamine status in inherited degenerative ataxias.

Blood thiamine levels in ataxia patients were studied. No significant differences were found between 30 patients with Friedreich's ataxia and 29 patients with olivopontocerebellar atrophy (OPCA) compared with control subjects. Both OPCA and Friedreich's ataxia patients presented significantly lower cerebrospinal fluid thiamine levels than their controls (p less than 0.001 and p less than 0.04 respectively). These results, discussed in terms of the high degree of cerebellar atrophy on CT scans in OPCA v Friedreich's ataxia patients, seem to correlate with cerebellar thiamine turnover and content.

Treatment of heredo-degenerative ataxias with amantadine hydrochloride.

Amantadine hydrochloride (AH) was administered (200 mg/day) for more than three months to 17 patients with Friedreich's ataxia (FA) and to 12 patients with olivopontocerebellar atrophies (OPCA) in an open clinical trial. Reaction time (RT) and movement time (MT) with the right and left hand were measured before and after treatment. A striking improvement on both RT and MT was observed in the OPCA group (on seven out of eight measures), whereas in the FA patients improvement was seen only in two out of four MT measures with no improvement in RT. Both groups had low levels of homovanillic acid (HVA) in their cerebrospinal fluid before treatment, relative to their controls. However, improvement with AH was not related to HVA levels.