The symptoms of carriers
Although it has been the experience that many carriers eventually will develop symptoms as a result of damage done to the nervous system, to date very few studies have addressed this. Some 20 to 50% of female carriers will eventually have sign of neurological dysfunction. In a study conducted in the Netherlands between 1992 and 1999 (Table 2), 32 to 48% of the women of at least 20 years of age had symptoms. Also, it appeared that with increasing age, the frequency of carriers that became symptomatic increased. In the age group of women 60 to 80 years of age, 52 to 79% had signs of neurological involvement.
It is very important to point out that symptoms in childhood are extremely rare. Also, brain disease in older women with spinal cord involvement is very uncommon. The symptoms in affected women are mainly due to abnormalities in the spinal cord and nerves in the legs, just like in AMN. Over decades, weakness and spasticity of the legs, disturbed sensation of the lower limbs, and impaired control over bladder and bowel develop. Unlike the affected men, it is very unlikely that women develop adrenocortical insufficiency, although it has been described in 1% in a large group. None of the Dutch carriers studied had signs of adrenocortical dysfunction.
Many carriers experience lower back pain, or pain in the ankles, knees and hips, caused by the increased muscle tone in the legs and consequent abnormal walking. Nonopioid analgesics, such as acetaminophen and nonsteroidal anti-inflammatory drugs (e.g. ibuprofen, naproxen or diclofenac) may be particularly useful in the treatment of pain. The main side effects are stomach complaints, which results in discontinuation of the drugs in 10 to 15%. Selective COX-2 inhibitors (such as celecoxib (Celebrex ®), rofecoxib (Vioxx ®) and valdecoxib (Bextra ®) have become available in the recent years: in comparison they need to be taken less frequently, but have the same side effects as the nonsteroidal anti-inflammatory drugs.
Sometimes surgery may be considered. Knees and hips can be replaced, bladder surgery may help in coping with incontinence. It should be clear though that the underlying disease is not treated with these procedures, and that things may not get better.