Many patients with chronic fatigue syndrome (CFS) display features
of hypothalamic dysfunction. We have investigated aspects of
circadian rhythmicity, an important hypothalamicfunction, in
20 CFS patients and in 17 age- and sex-matched healthy
control subjects. There were no differences between the two
groups in the amplitude, mesor (mean value) or timing of the
peak (acrophase) of the circardian rhythm of core temperature,
orin the timing of the onset of melatonin secretion.
However, theCFS patients showed no significant correlation
between the timingof the temperature acrophase and the
melatonin onset (P < 0.5),whereas the normal significant
correlation was observed in thecontrols (P < 0.05).
Dissociation of circadian rhythms could be due to the sleep
deprivation and social disruption, and/or the reduction in
physical activity which typically accompany CFS. By analogy
with jet-lag and shift-working, circadian dysrhythmia could
be an important factor in initiating and perpetuating the
cardinal symptoms of CFS, notably tiredness, impaired
concentration and intellectual impairment.
Williams G, Pirmohamed J, Minors D, Waterhouse J, Buchan I, Arendt
J, Edwards RH