Coenzyme Q10 and vitamin E deficiency in Friedreich's ataxia: predictor of efficacy of vitamin E and coenzyme Q10 therapy.

BACKGROUND AND PURPOSE: A pilot study of high dose coenzyme Q(10) (CoQ(10))/vitamin E therapy in Friedreich's ataxia (FRDA) patients resulted in significant clinical improvements in most patients. This study investigated the potential for this treatment to modify clinical progression in FRDA in a randomized double blind trial. METHODS: Fifty FRDA patients were randomly divided into high or low dose CoQ(10)/ vitamin E groups. The change in International Co-operative Ataxia Ratings Scale (ICARS) was assessed over 2 years as the primary end-point. A post hoc analysis was made using cross-sectional data. RESULTS: At baseline serum CoQ(10) and vitamin E levels were significantly decreased in the FRDA patients (P < 0.001). During the trial CoQ(10) and vitamin E levels significantly increased in both groups (P < 0.01). The primary and secondary end-points were not significantly different between the therapy groups. When compared to cross-sectional data 49% of all patients demonstrated improved ICARS scores. This responder group had significantly lower baseline serum CoQ(10) levels. CONCLUSIONS: A high proportion of FRDA patients have a decreased serum CoQ(10) level which was the best predictor of a positive clinical response to CoQ(10)/vitamin E therapy. Low and high dose CoQ(10)/vitamin E therapies were equally effective in improving ICARS scores.

Clinical correlation of brain MRI and MRS abnormalities in patients with Wilson disease.

BACKGROUND: The progression of Wilson disease (WD), a disorder of copper metabolism, can be arrested by chelation therapy. However, neurologic deficits may persist despite adequate treatment. MRI is used to assess patients with WD, but previous attempts to correlate clinical progression with the investigation findings have often been unsuccessful. OBJECTIVE: To identify MR visible markers that could help stratify disease severity and to clarify the mechanism of persistent neurologic deficit after treatment. METHODS: MRI and proton MR spectroscopy (1H-MRS) were performed in 17 patients with WD. MRI was assessed semiquantitatively and used to locate volumes of interest (voxels) in the striatum for 1H-MRS. RESULTS: MRI showed abnormalities predominantly confined to those patients with neurologic features of WD. The 1H spectra demonstrated a reduction of N-acetylaspartate and N-acetylaspartylglutamate (2.05 mM; p < 0.01) in those patients with neurologic features but not in patients without clinical neurologic involvement (0.42 mM; p > 0.1) in comparison with age-matched normal control subjects. Choline was also reduced in both patient groups (0.08 mM; p < 0.01) compared with age-matched controls. CONCLUSIONS: There may be a biochemical correlate of tissue-specific dysfunction in patients with Wilson disease who develop neurologic features. These changes appear to be present despite prior clinical improvement and may imply a need for additional treatment.

Updated guidelines for the management of Parkinson's disease.

New data on diagnosis, drug therapy, surgery and psychosocial concerns have emerged since the publication of the 1998 Guidelines for the Management of Parkinson's Disease. This article reviews new data and addresses issues left unanswered in the previous guidelines.

Antioxidant treatment improves in vivo cardiac and skeletal muscle bioenergetics in patients with Friedreich's ataxia.

Friedreich's ataxia (FA) is the most common form of autosomal recessive spinocerebellar ataxia and is often associated with a cardiomyopathy. The disease is caused by an expanded intronic GAA repeat, which results in deficiency of a mitochondrial protein called frataxin. In the yeast YFH1 knockout model of the disease there is evidence that frataxin deficiency leads to a severe defect of mitochondrial respiration, intramitochondrial iron accumulation, and associated production of oxygen free radicals. Recently, the analysis of FA cardiac and skeletal muscle samples and in vivo phosphorus magnetic resonance spectroscopy (31P-MRS) has confirmed the deficits of respiratory chain complexes in these tissues. The role of oxidative stress in FA is further supported by the accumulation of iron and decreased aconitase activities in cardiac muscle. We used 31P-MRS to evaluate the effect of 6 months of antioxidant treatment (Coenzyme Q10 400 mg/day, vitamin E 2,100 IU/day) on cardiac and calf muscle energy metabolism in 10 FA patients. After only 3 months of treatment, the cardiac phosphocreatine to ATP ratio showed a mean relative increase to 178% (p = 0.03) and the maximum rate of skeletal muscle mitochondrial ATP production increased to 139% (p = 0.01) of their respective baseline values in the FA patients. These improvements, greater in prehypertrophic hearts and in the muscle of patients with longer GAA repeats, were sustained after 6 months of therapy. The neurological and echocardiographic evaluations did not show any consistent benefits of the therapy after 6 months. This study demonstrates partial reversal of a surrogate biochemical marker in FA with antioxidant therapy and supports the evaluation of such therapy as a disease-modifying strategy in this neurodegenerative disorder.

Normal in vivo skeletal muscle oxidative metabolism in sporadic inclusion body myositis assessed by 31P-magnetic resonance spectroscopy.

Sporadic inclusion body myositis (s-IBM) is a chronic inflammatory myopathy of unknown pathogenesis. The common findings of ragged red fibres, cytochrome c oxidase-negative fibres and multiple mitochondrial DNA deletions in the muscle of patients with s-IBM have suggested that a deficit of energy metabolism may be of pathogenic relevance. To test this hypothesis we used 31P magnetic resonance spectroscopy to assess in vivo skeletal muscle mitochondrial function in the calf muscles of 12 patients with definite s-IBM. Eleven patients showed multiple mitochondrial DNA deletions in skeletal muscle and 67% showed ragged red fibres and/or cytochrome c oxidase-negative fibres. T1-weighted MR images showed increased signal intensity in the calf muscle of all patients except one. The involvement of calf muscle was confirmed by 31P magnetic resonance spectroscopy of resting muscle, which disclosed abnormalities in metabolite ratios in all patients. However, muscle oxidative metabolism assessed during recovery from exercise was normal in patients with s-IBM, as maximum rates of mitochondrial ATP production and post-exercise ADP recovery rates were within the normal range in all cases. We conclude that muscle mitochondrial abnormalities are a secondary process and unlikely to play a significant role in the pathogenesis of s-IBM.

Two pregnant women with vomiting and fits.

Two women with hyperemesis gravidarum were first seen with a short history of confusion diplopia, unsteadiness, and fits caused by Wernicke's encephalopathy. The neurologic presentation had been precipitated by a carbohydrate load inadvertently administered without vitamin supplementation. We stress the importance of prescribing thiamine supplements to all women with prolonged vomiting during pregnancy.

L-dihydroxyphenylalanine and complex I deficiency in Parkinson's disease brain.

There is evidence for a 37% deficiency of complex I activity in Parkinson's disease (PD), which appears to be specific for PD amongst parkinsonian syndromes and selective for the substantia nigra within the central nervous system. Rat studies have shown that, in the context of a normal nigrostriatal dopaminergic cell population, L-dihydroxyphenylalanine (L-dopa) causes a reversible 25% defect of complex I activity in nigral and striatal tissue. Analysis of striatal tissue from PD patients after prolonged exposure to high-dose L-dopa does not show such a defect. Results of these and other studies suggest that L-dopa therapy does not cause complex I deficiency in PD striatum. However, it cannot be excluded that, in the particular environment of the PD substantia nigra, L-dopa may enhance a preexisting complex I defect.

A 31P magnetic resonance spectroscopy study of mitochondrial function in skeletal muscle of patients with Parkinson's disease.

The activity of complex I of the respiratory chain is decreased in the substantia nigra of patients with Parkinson's disease (PD) but the presence of this defect in skeletal muscle is controversial. Therefore, the mitochondrial function of skeletal muscle in patients with PD was investigated in vivo using 31P magnetic resonance spectroscopy. Results from 7 PD patients, 11 age matched controls and 9 mitochondrial myopathy patients with proven complex I deficiency were obtained from finger flexor muscle at rest, during exercise and in recovery from exercise. In resting muscle, the patients with mitochondrial myopathy showed a low PCr/ATP ratio, a low phosphorylation potential, a high P(i)/PCr ratio and a high calculated free [ADP]. During exercise, stores of high energy phosphate were depleted more rapidly than normal, while in recovery, the concentration of phosphocreatine and free ADP returned to pre-exercise values more slowly than normal. In contrast, the patients with PD were not significantly different from normal for any of these variables, and no abnormality of muscle energetics was detected. Three of the PD patients also had mitochondrial function assessed biochemically in muscle biopsies. No respiratory chain defect was identified in any of these patients by polarography or enzyme analysis when compared with age-matched controls. These results suggest that skeletal muscle is not a suitable tissue for the investigation and identification of the biochemical basis of the nigral complex I deficiency in PD.

The susceptibility of Plasmodium falciparum to sulfadoxine and pyrimethamine: correlation of in vivo and in vitro results.

In 1982, 2 of 14 Plasmodium falciparum infections acquired in East Africa and diagnosed in Copenhagen were resistant to treatment with sulfadoxine plus pyrimethamine (Fansidar), while in 1983, 6 of 18 were so. The in vivo tests were supplemented by determinations of drug concentrations in serum, and 4 isolates from in vivo-sensitive cases and 6 from in vivo-resistant cases were selected for in vivo tests. These were performed in ordinary RPMI 1640 medium and in a medium with physiological p-aminobenzoic acid and folic acid concentrations. Pharmacokinetic aberrations were found to be of possible importance in only 2 of the in vivo-resistant cases. In vitro susceptibility to sulfadoxine was found to be uniformly low in all isolates. Testing with a combination of sulfadoxine and pyrimethamine in the medium with physiological concentrations of cofactors probably reflects the in vivo situation most accurately, but in all but 1 of the isolates studied in vitro the in vivo susceptibility to Fansidar would be predicted by in vitro susceptibility to pyrimethamine in either medium. The concentration of p-aminobenzoic acid in serum, quantitated by high performance liquid chromatography, was found to be subject to wide variation, and this may have implications for in vitro testing.