What is Chronic Fatigue Syndrome and How is XMRV Related?

Dr. Donnica's Decisionnaire for CFS

I have had new, unexplained, persistent, or relapsing physical and mental fatigue for at least 6 months.  This fatigue is not the result of ongoing exertion or another medical diagnosis; it is not relieved by appropriate rest. 

I have at least 4 of the following symptoms:

• Unrefreshing sleep, insomnia or excessive daytime sleepiness, despite sleeping for more than 9 hrs per night
• Weakness and exhaustion, lasting more than 24 hours, following mental or physical activity ("post exertional malaise")
• Substantial impairment of short-term memory or concentration, problems with my short-term memory, confusion, disorientation, "brain fog"; difficulty finding the right words or numbers
• Widespread or migratory muscle pain; pain in the joints (without swelling or redness); headaches of a new type, pattern or severity that don't respond to OTC medicines
• Tender armpit and/or neck lymph nodes 
• Persistent or frequent sore throats
• In addition to the symptoms of the case definition, many patients develop other symptoms commonly associated with CFS including:  
• Neutrally mediated hypotension or orthostatic intolerance
• Multiple chemical sensitivities
• New allergies or food intolerances
• Painful gastrointestinal symptoms similar to irritable bowel syndrome
• New onset of asthma
• Hypersensitivity to light (photophobia) or noise 
• Dizziness
• Palpitations
• Low body temperature or intolerance to heat or cold 
• Often feeling "feverish" (without an elevated body temperature) or having chills
• Inappropriate sweating
• Abnormal appetite or decreased sense of thirst