So, do I actually have chronic fatigue syndrome according to the official criteria? Well that question is made much more complex by the fact that there is no one agreed upon set of criteria, and in fact the major criteria in use are vastly different. The three major sets of criteria used currently are the Oxford criteria, the Fukuda (or CDC) definition and the Canadian guidelines.
The Oxford criteria are the simplest:
- fatigue as the main symptom
- CHECK
- definite onset
- CHECK (3:30pm, 31st December 2007)
- fatigue is severe, disabling and affects physical and mental function
- I suppose it depends how you define severe, but it certainly feels pretty bad to me. Definitely disabling, in the sense that it stops me doing things that I could do before I got sick. While my symptoms are predominantly physical, I do get brain fog on bad days. So, CHECK
- fatigue should be persist for 6 months or more and be present 50% of the time
- CHECK (over 3 and a half years now, and it's present all the time)
- other symptoms, especially myalgia, sleep and mood disturbances
- CHECK (all three, plus some others)
So, I don't think there's any doubt that I meet the Oxford criteria, but they have been widely criticised for how vague they are (they really only define chronic fatigue, not chronic fatigue syndrome, and you could meet them just with depression), so I'll move on.
The Fukuda criteria (CDC definition) are intended for research use, not diagnosis, but they do get used a lot for diagnosis. So...
- Clinically evaluated, unexplained, persistent or relapsing fatigue persistent for six months or more
- CHECK. I think "clinically evaluated" refers to the every-blood-test-known-to-man experience. And as above, I'm well over the 6 month mark.
- of new or definite onset
- CHECK (as above)
- not the result of ongoing exertion
- I wake up feeling like crap even I've done nothing the previous day. CHECK
- not substantially alleviated by rest
- Similarly, CHECK
- results in substantial reduction in previous levels of occupational, educational, social or personal activities
- Before I got sick, I was working full-time. Now I dream of being able to work school hours. CHECK
- impaired short-term memory or concentration
- As I said before, my symptoms are primarily physical. But I do have mild cognitive issues as well. I'll completely lose track of where I'm up to in the middle of a conversation. When I'm having a bad day, I can't even bear to do something like a read book. So CHECK.
- sore throat
- I would have to say no to this one. I have more sore throats than I did before (because I get more colds), but it's not constant. I think my pain in the general neck region falls better into the next couple of categories
- tender cervical or axillary lymph nodes
- I really suck at finding my lymph nodes, since they aren't enlarged, just sore, but I'm pretty sure my cervical lymph nodes are a source of pain. CHECK.
- muscle pain
- Definitely CHECK. Moreover, muscle pain that correlates very well with my fatigue level and not at all with which muscles I've actually been using.
- multi-joint pain without arthritis
- This started as a major symptom for me about two weeks into my illness and then significantly improved over the following year. It's no longer a particularly disabling symptom, but I still feel it in my fingers if I've been doing a lot of writing or typing and in my toes if I've been walking. CHECK.
- headaches of a new type, pattern or severity
- Not sure about this one. I had random unexplained headaches before I got sick, and it's hard to say whether my current headaches are different or even more frequent.
- unrefreshing sleep
- Refer to earlier comment about waking up feeling like crap. In fact I usually feel worse when I get up than when I went to bed. CHECK.
- post-exertional malaise lasting more than 24 hours
- CHECK. I know my limits well enough now that most of the time I can avoid a crash that long, but when I work two fullish days in a row I feel it for days afterwards.
6 out of 8 is enough to meet the cut-off of 4, so by the Fukuda criteria, yes I have chronic fatigue syndrome.
Finally, the Canadian criteria. These are the most comprehensive, and are supposed to be the best for actual diagnosis, so how do I compare?
Post-exertional Malaise and Fatigue (all of these):
- marked degree of new onset, unexplained, persistent, or recurrent physical and mental fatigue that substantially reduces activity level
- This is pretty much the entire Oxford criteria in one line. CHECK
- post-exertional fatigue, malaise and/or pain, and a delayed recovery period (> 24 hours)
- As in the Fukuda criteria, CHECK
- symptoms can be exacerbated by exertion or stress of any kind
- CHECK. Although my mental symptoms are minor compared to my physical ones, both mental and physical exertion/stress have a huge impact on the severity of my symptoms.
Sleep Disorder:
- Unrefreshing sleep or altered sleep pattern (including circadian rhythm disturbance)
- CHECK. The unrefreshing sleep part is in the Fukuda definition, but the altered sleep pattern is a major symptom for me. I have insomnia, hypersomnia, periodic limb movement syndrome, delayed sleep phase syndrome and night terrors. For the most part these existed before I got sick, but they are now much more severe and disabling.
Pain:
- Arthralgia and/or myalgia without clinical evidence of joint swelling or redness, and/or significant headaches of new type, pattern or severity
- This combines a few of the points from the Fukuda criteria. I definitely have arthralgia and myalgia, with the headaches possibly being comorbid rather than a symptom. CHECK
Neurological/Cognitive Manifestations (2 or more):
- Impairment of concentration and short-term memory
- As above, while it's relatively mild, I do have it. CHECK
- Difficulty with information processing, categorising, and word retrieval, including intermittent dyslexia
- None that I've noticed
- Overload phenomena: information, cognitive, and sensory overload (e.g., photophobia and hypersensitivity to noise) and/or emotional overload which may lead to relapses and/or anxiety
- CHECK. This is most significant of my cognitive symptoms, I think. If I've been in a conversation too long, I just can't cope any more and have to leave the room. Certainly have hypersensitivity to noise, too, especially on bad days, to the point that I have to ask people to talk softer because regular voice volume bothers me. And strong emotions tend to freak me out.
- Perceptual/sensory disturbances
- Not apart from ones related to orthostatic intolerance
- Disorientation or confusion
- No
- Ataxia
- Nothing more than my premorbid clumsiness :)
Autonomic/Neuroendocrine/Immune Manifestations (at least one symptom from at least two of the categories below):
Autonomic Manifestations:
- Orthostatic Intolerance
- Not officially diagnosed, but I definitely experience symptoms (lightheadedness and loss of vision) regularly (at least once a day) when I stand up from sitting or lying down. I did have this a bit before I got sick, but it's much worse since. CHECK.
- Postural orthostatic tachycardia syndrome
- Not that I'm aware of
- Vertigo and/or light-headedness
- CHECK. This is usually the symptom that first tells me I'm having a bad day and/or crash
- Extreme pallor
- Depends on your definition of extreme, I suppose, but on bad days my Mum nearly always tells me that I look pale. CHECK
- Intestinal or bladder disturbances
- Thankfully, no
- Palpitations
- No
- Vasomotor instability
- Didn't know before reading this list that this could be a symptom. But no.
- Respiratory irregularities
- Not that I'm aware of
So three symptoms from this category.
Neuroendocrine Manifestations:
- Loss of thermostatic stability
- Tentative CHECK. I'm not sure that my symptoms in this area are new or even particularly abnormal. I do know though, that there is a very fine line for me between too hot and too cold.
- Heat/cold intolerance
- Though I do get hot/cold quite easily, I think that fits into the previous point rather than this one, so no.
- Anorexia or abnormal appetite, weight change
- No
- Hypoglycaemia
- When I've had blood tests done my sugar readings have always been normal. Some of my symptoms could be symptoms of hypoglycaemia, but without a diagnosis I'm going to say no.
- Loss of adaptability and tolerance for stress, worsening of symptoms with stress and slow recovery, and emotional lability
- Not really sure how this differs from previous points like 'symptoms being exacerbated by stress', but CHECK. Stress is a bit of a problem for me - just thinking about doing something that might be stressful has a tendency to send me into a crash. I've never considered emotional lability before - I'm wondering now if I'm sometimes mistaking lability for depression...
One, maybe two symptoms from this category.
Immune Manifestations:
- Tender lymph nodes
- CHECK
- Recurrent sore throat
- Apart from the lymph nodes, no.
- Flu-like symptoms and/or general malaise
- CHECK. It's hard to objectively separate the malaise feeling from the fatigue feeling, but I do constantly feel like I'm coming down with something.
- Development of new allergies or changes in status of old ones
- Not that I've noticed
- Hypersensitivity to medications and/or chemicals
- Again, not that I've noticed.
Two symptoms from this category.
So overall the Autonomic/Neuroendocrine/Immune Manifestations criterion is met, as I have symptoms in all three categories.
And finally:
- The illness persists for at least 6 months
- CHECK
So even using the stricter Canadian guidelines I meet the criteria for chronic fatigue syndrome. So why won't my doctor believe it?
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