Chronic fatigue syndrome/myalgic encephalomyelitis

Chronic fatigue syndrome, also known as myalgic encephalomyelitis (CFS/ME), is a complex, multi-system condition that affects 2-4 per 1,000 New Zealanders.¹ 

This MedCase describes a typical case of CFS/ME encountered in general practice with a focus on management ideas around caring for these complex patients.

Yes. Miss C has described several of the neuroendocrine, cognitive, autonomic, immune, and metabolic changes that characterise CFS/ME (Figure 1).^1,2

Figure 1. Multisystem Dysregulation in ME/CFS

Diagnosis requires careful analysis of the patient’s history and pattern of symptoms, plus exclusion of other fatiguing illnesses.¹ The key symptoms that distinguish CFS/ME from other fatiguing illnesses are:

• post-exertional malaise (PEM), and
• symptom exacerbation in response to stressors.

There are no specific examination findings, though some subtle signs may assist diagnosis (ref Figure 1).

Basic laboratory testing is indicated initially to look for other causes (e.g. chest x-ray for cough). More specific testing should be guided by symptoms, but again there are no specific diagnostic findings.

The CFS/ME Healthcare professionals site provides guidance on the appropriate work-up when considering a diagnosis of CFS/ME, including specific guidance for diagnosis in young people.¹

Making the diagnosis can provide relief for patients, who have often been living with difficult and unexplained symptoms for some time.¹

Offering information about the biological changes underpinning the symptoms can help patients and their families understand and accept the diagnosis. 

Useful patient resources:

• The ANZMES website (including regional and Facebook support groups)
• Chronic fatigue Health Navigator NZ
• Dr Vallings website - for handouts, reading suggestions and research updates

There are no curative therapies for CFS/ME. Treatment aims to reduce symptoms and improve quality of life, with a focus on patient self-management, which is why establishing a collaborative therapeutic relationship is essential.

An important step is to acknowledge the impact of CFS/ME on the individual’s ability to work, to maintain relationships, to undertake basic self-care and to maintain self-identity. Frustration and anxiety can arise if there is scepticism towards CFS/ME patients - who may not appear ill - from their family, friends and medical practitioners.

This section describes strategies for managing some of the symptom groups of CFS/ME in ambulatory patients; a complete guide for management, including ideas for managing non-mobile patients, can be found in the CCFS/ME Primer for Clinical Practitioners.

Post-exertional malaise (PEM) is thought to arise from altered aerobic metabolism in CFS/ME patients, which creates an inappropriate reliance on anaerobic metabolism.¹ PEM can last up to weeks after minimal physical or mental exertion.

An important management strategy is to avoid PEM by finding an appropriate amount of activity for the individual patient.

Some useful concepts are:

1. The energy envelope. This is the energy available to accomplish tasks, and it is reduced in CFS/ME. In some patients, the activities of daily living will use up all of their available energy. In others, adding an appropriate exercise programme can improve function and quality of life.
2. Pacing. This means staying within the patients’ individual energy envelope. The optimal amount of activity allows the patient to remain as active as possible while avoiding PEM.

Fatigue severity declines when patients stay within energy envelope.

There is no evidence-based diet for CFS/ME and patients should eat a balanced range of foods.

Some useful treatment suggestions are:

• Small frequent meals may be helpful to minimise energy expenditure.
• Patients with orthostatic symptoms or low blood pressure can benefit from increasing salt intake (a pinch every 2-3 hours).
• A bedtime carbohydrate snack can help with fatigue.
• Magnesium at bedtime may help with relaxation and pain.
• Co-enzyme Q10 may help with myalgia.
• Vitamin B12 injections may improve symptoms in some patients, as shown in a Finnish study. (Note B12 use should be guided by clinical response rather than blood results. Try a course of weekly injections for six weeks then assess the effect).

As with other symptoms, treatments for pain must be individualised and non-pharmacological methods should be considered alongside medications. A general rule is to start low and go slow, as CFS/ME patients can be hypersensitive to medications. Opiates are generally discouraged (though may be necessary and beneficial for some patients). The agents most likely to be effective are tricyclics, and gapapentin or pregabalin, though beware of exacerbating daytime sedation.¹

Low-dose naltrexone has gained recent attention and may be a useful non-addictive option. It is thought to reduce pain sensitivity over time via opioid antagonist activity, plus there is evidence of an anti-inflammatory effect at microglial cells.³

A suggested strategy is to start at a low dose, for example 1.5mg daily for one week, then titrate up according to effect; see here for a summary of evidence and suggested dosing strategies.

In addition to standard sleep hygiene measures, patients with CFS/ME may benefit from targeted sleep advice, including:

• Consider a bedtime carbohydrate snack.
• Targeted use of medications, taken early enough that sedation takes effect around bedtime. For example, taking tricyclics five hours before bedtime.
• Rotating medications may be more effective than using a single agent.

This MedCase was written by Dr Vicki Mount, General Practitioner, MBChB, DipPaeds, with expert review by Dr Rosamund Vallings, MNZM, MB BS (Lond), MRCS LRCP, Dip Clin Hyp, BA (Massey).