Reversible ophthalmoplegia in CPEO

[Chronic progressive external ophthalmoplegia that could not be diagnosed by biceps muscle biopsy, but was genetically diagnosed by extraocular muscle biopsy]

A 48-year-old Japanese male experienced slowly progressive diplopia. He had no family history and was negative for the edrophonium chloride test. Blood analysis showed elevated lactic acid and pyruvic acid levels, suggesting mitochondrial disease. A muscle biopsy from the biceps brachii was performed, but no pathological or genetical mitochondrial abnormalities were detected. Subsequently, he underwent muscle plication for diplopia in which the right inferior rectus muscle was biopsied. Genetic examination of genomic DNA extracted from the extraocular muscle tissue revealed multiple mitochondrial gene deletions, with a heteroplasmy rate of approximately 35%, resulting in the diagnosis of chronic progressive external ophthalmoplegia. In mitochondrial diseases, the tissue distribution of mitochondria with disease-associated variants in mtDNA should be noted, and it is important to select the affected muscle when performing a biopsy for an accurate diagnosis.

Treatment for mitochondrial disorders

BACKGROUND

Mitochondrial respiratory chain disorders are the most prevalent group of inherited neurometabolic diseases. They present with central and peripheral neurological features usually in association with other organ involvement including the eye, the heart, the liver, and kidneys, diabetes mellitus and sensorineural deafness. Current treatment is largely supportive and the disorders progress relentlessly causing significant morbidity and premature death. Vitamin supplements, pharmacological agents and exercise therapy have been used in isolated cases and small clinical trials, but the efficacy of these interventions is unclear.

OBJECTIVES

To determine whether there is objective evidence to support the use of current treatments for mitochondrial disease.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group trials register (searched September 2003), the Cochrane Central Register of Controlled Trials, MEDLINE (January 1966 to October 3 2003), EMBASE (January 1980 to October 3 2003) and the European Neuromuscular Centre (ENMC) clinical trials register, and contacted experts in the field.

SELECTION CRITERIA

We included randomised controlled trials (including crossover studies) and quasi-randomised trials comparing pharmacological treatments, and non-pharmacological treatments (vitamins and food supplements), and physical training in individuals with mitochondrial disorders. The primary outcome measures included an improvement in muscle strength and/or endurance, or neurological clinical features. Secondary outcome measures included quality of life assessments, biochemical markers of disease and negative outcomes.

DATA COLLECTION AND ANALYSIS

Details of the number of randomised patients, treatment, study design, study category, allocation concealment and patient characteristics were extracted. Analysis was based on intention to treat data. We planned to use meta-analysis, but this did not prove necessary.

MAIN RESULTS

Six hundred and seventy-eight abstracts were reviewed, and six fulfilled the entry criteria. Two trials studied the effects of co-enzyme Q10 (ubiquinone), one reporting a subjective improvement and a significant increase in a global scale of muscle strength, but the other trial did not show any benefit. Two trials used creatine, with one reporting improved measures of muscle strength and post-exercise lactate, but the other reported no benefit. One trial of dichloroacetate showed an improvement in secondary outcome measures of mitochondrial metabolism, and one trial using dimethylglycine showed no significant effect.

AUTHORS' CONCLUSIONS

There is currently no clear evidence supporting the use of any intervention in mitochondrial disorders. Further research is needed to establish the role of a wide range of therapeutic approaches.

The universality of bioenergetic disease. Age-associated cellular bioenergetic degradation and amelioration therapy

During the present century there has been a dramatic change in life expectancy in advanced societies, now exceeding 80 years. As distinct from life expectancy, life potential is said to be at least 120 years, so that the continuing increase in knowledge has the potential for further major changes in the survival of humans conceivably in the near future. This presentation will be concerned with one aspect of the development of biomedical advances related in part to a concept of an "age-related universality of bioenergetic disease," and its potential amelioration and proposed impact on age-related disease and lifestyle. Aging is a complex biological process associated with a progressive decline in the physiological and biochemical performance of individual tissues and organs, leading to age-associated disease and senescence. Consideration of the progressive accumulation of mitochondrial DNA mutation with age and the tissue/cellular bioenergy decline associated with the aging process has led us to the proposal of a "universality of bioenergetic disease" and the potential for a redox therapy for the condition. This concept envisages that a tissue-bioenergetic decline will be intrinsic to various diseases of the aged and thereby contribute to their pathology, in particular, heart failure, degenerative brain disease, muscle and vascular diseases, as well as other syndromes. The information and concepts embodied in this proposal will be reviewed under the following headings: (1) mitochondrial DNA deletion mutation in some tissue is very extensive and shows mosaicism; (2) age-associated tissue/cellular bioenergy mosaic closely corresponds to the mtDNA profile; (3) cellular bioenergy as a function of mitochondrial bioenergy, glycolysis, and plasma membrane oxidoreductase; (4) redox therapy for the reenergization of cells, tissues, and whole organs. A redox therapy based on coenzyme Q10 has demonstrated profound alteration in heart function of old rats; no significant effect was observed with young rats.