Mitochondrial myopathy or mitochondrial dysfunction in ME/CFS? A case of mistaken identity | 5 October 2015

October 5, 2015

An interesting case study of a patient initially diagnosed with chronic fatigue syndrome but who was then re-diagnosed with mitochondrial disease during follow-up was published in the Journal of Investigative Medicine last week.

Our medical adviser, Dr Charles Shepherd, comments: “It is important to consider this possibility where there are muscle symptoms or signs that are either not fully consistent with ME/CFS, or are suggestive of a primary muscle/mitochondrial disease.”

From the Journal of Investigative Medicine – high impact case reports, 27 September 2015. Full paper available via the link.

Mitochondrial Myopathy in Follow-up of a Patient With Chronic Fatigue Syndrome

Fernando Galán, AOPT(1,*), Isabel de Lavera, PhD(2), David Cotán, PhD(2), José A. Sánchez-Alcázar, AOPT(2)
1) University of Seville, Seville, Spain
2) Universidad Pablo de Olavide-Consejo Superior de Investigaciones Científicas-Junta de Andalucía, Seville, Spain
*Fernando Galán, Department of Medicine, Medical School, University of Seville, Internal Medicine Service, University Hospital Virgen Macarena, Avda. Doctor Fedriani s/n, Seville 41009, Spain. Email:



Symptoms of mitochondrial diseases and chronic fatigue syndrome (CFS) frequently overlap and can easily be mistaken.


We report the case of a patient diagnosed with CFS and during follow-up was finally diagnosed with mitochondrial myopathy by histochemical study of muscle biopsy, spectrophotometric analysis of the complexes of the mitochondrial respiratory chain, and genetic studies.


The results revealed 3% fiber-ragged blue and a severe deficiency of complexes I and IV and several mtDNA variants. Mother, sisters, and nephews showed similar symptoms, which strongly suggests a possible maternal inheritance. The patient and his family responded to treatment with high doses of riboflavin and thiamine with a remarkable and sustained fatigue and muscle symptoms improvement.


This case illustrates that initial symptoms of mitochondrial disease in adults can easily be mistaken with CFS, and in these patients a regular reassessment and monitoring of symptoms is recommended to reconfirm or change the diagnosis.


This interesting case report from Spain links in with a discussion currently taking place on MEA Facebook:

From anon:

I would like to ask if many people with M.E. have been tested for adult mitochondrial disease, or what would the main differentiating symptoms be between the two illnesses? Thanks for any information you can provide.

CS reply:

I assume that you are referring to some form of primary muscle/mitochondrial disease and not the type of mitochondrial dysfunction that has been shown to be present in at least a sub-group of people with ME/CFS, and which is being investigated in a number of research studies being funded by the MEA Ramsay Research Fund

As there have been cases where people with a primary muscle/mitochondrial disorder have been misdiagnosed as ME/CFS, it is important to consider this possibility where there are muscle symptoms or signs that are either not fully consistent with ME/CFS, or are suggestive of a primary muscle/mitochondrial disease.

For example – as was discussed on MEA Facebook a few days ago – significant muscle wasting is unusual in people who have mild or moderate ME/CFS and who remain active. So if someone has a degree of muscle wasting/atrophy that is not consistent with their level of activity (or inactivity) then the possibility of a primary muscle disease will probably need to be considered and possibly investigated. And if someone has other neurological symptoms or signs that are not consistent with ME/CFS, along with muscle weakness and/or wasting, then this is another reason to consider a primary muscle/mitochondrial disease.

There are a number of hospital-based investigations that can help here – including blood tests, electromyography, a muscle biopsy and looking at the mitochondria under an electron microscope, and the use of magnetic resonance spectroscopy to look at how the muscle is performing at a biochemical level and how it is producing energy.

This is quite an old medical review but it is still very useful and comes from the muscle ‘centre of excellence' in Newcastle where some of the MEA funded research into mitochondrial function in ME/CFS is/has been taking place:

Research into the role of mitochondrial dysfunction in ME/CFS currently being funded by the MEA Ramsay Research Fund:

Professor Anne McArdle et al, University of Liverpool:

Dr Sarah Jayne Boulton et al, University of Newcastle:

Dr Charles Shepherd
Hon Medical Adviser, MEA

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