Myopathy, hypokalaemia and pica (geophagia) in pregnancy

DiSCuSSion Hypnic Headache is a benign nocturnal headache which predominantly affects elderly people. This case illustrates some classic features of the syndrome. Evers and Goadsby 1 reviewed the 71 reported cases giving us the clearest picture of the syndrome to date. 37% were male and 63% female. Mean age of onset was 63 +/-11 years (range 36-83). Average duration was 67 +/-44 minutes (range 15-180). Onset was 60-120 minutes after falling asleep in 77%. nausea was reported in 19%. The pathophysiology of HHS is currently theoretical, but associations with the sleep/wake cycle and circadian rhythms form the basis for theories of its nature. Polysomnography has revealed the onset of hypnic headaches may be associated with REM sleep. 2 It may be that inactivation of antinociceptive structures, e.g. dorsal raphe, during REM mediates the headache. 3 Commonly patients experience the headache at a predictable time each night, suggesting a link with the circadian rhythm, which is orchestrated by the suprachiasmatic nuclei in the hypothalamus (also involved in antinociception). These nuclei produce, among others, melatonin, an important mediator of circadian rhythm. With advancing age the function of the hypothalamus, and thus melatonin secretion, is impaired. 4 This could also be involved in the pathogenesis of hypnic headache. Lithium is believed to increase melatonin levels 5 and may explain its mode of action. However, undoubtedly it is more complex than any one of these associations as many different drugs have been tried with variable success. Lithium remains the most effective but is often limited by side effects and interactions, and requires monitoring of plasma concentrations to avoid toxicity. Awareness of benign headaches is important to avoid unnecessary investigation but it must be stated that brain imaging and routine biochemical/haematological investigations are usually indicated when presented with new onset headaches in the elderly. et al. Twenty four hour melatonin and cortisol plasma levels in relation to timing of cluster headache. Myopathy, hypokalaemia and pica (geophagia) in pregnancy Editor, Pica describes the persistant ingestion of nonnutritive substances. 1 Geophagia describes pica of clay. 2 We present a case of geophagia resulting in hypokalaemic myopathy. Case History: A 29 year Gravida 3 Para 2 presented to a tertiary referral centre in Cape Town, South Africa, at 30 +4 weeks gestation. She gave a two week history of photophobia, vomiting and weakness of the left side of her body. no other symptoms were reported. fetal movement was …