Central pontine myelinolysis

Abstract

The central pontine myelinolysis is a strange neurological alteration of unknown etiology which is not related to genetic factors. Its more significant characteristic is its invariable association with other serious illnesses. In more than half of the cases it is seen in chronic alcoholic patients or in chronic illnesses accompanied by malnutrition or hydroelectrolytic disturbances. It is not related to sex or the age group. The most frequent cause is the treatment of hyponatremia, when there is a too rapid increase of the sodium levels. The basic lesion is the destruction of the myelin sheaths, with relatively unharmed axon; and it affects part or the whole base of the protuberance in a symmetrical form (pontine demyelination). The patients suffering from this illness usually present subacute progressive tetraparesis accompanied by pseudobulbar paralysis with dysarthria and the impossibility of protruding the tongue, together with partial or total paralysis of the ocular horizontal movements. Some patients present mutism and a state of paralysis with preservation of understanding and the sensory ways (pseudocoma or locked-in syndrome). The diagnosis of certainty of this entity is anatomopathologic. Nevertheless, the capacity of the computerized axial tomography (CAT), and especially that of the nuclear magnetic resonance (NMR), to visualize the pontine lesions have largely increased the frequency of the pre-mortem diagnosis. There is not a specific treatment for this illness. It should be prevented avoiding the sharp changes in plasma sodium level in patients with hyponatremia. We present a 58 year-old patient with disorientation and quadriparesis who was diagnosed in life a central pontine myelinolysis.