Central pontine myelinolysis, an update

Abstract

Central pontine myelinolysis (CPM) can be regarded as one of the demyelinating syndromes. First described by Adams et al. in 1959 in their chronic alcoholic patients, it has now been described in the malnourished, the chronically debilitated, the renal, the hepatic and the transplant patient among others. Pathologically, it is defined as a symmetric area of myelin disruption in the center of the basis pontis, although similar symmetric lesions have also been described occurring with CPM as well as independently in other brain areas (extrapontine myelinolysis or EPM) including the cerebellar and neocortical white/gray junctional areas, thalamus and striatum. Possible mechanisms include a hyperosmotically induced demyelination process resulting from rapid intracellular/ extracellular to intravascular water shifts producing relative glial dehydration and myelin degradation and/or oligodendroglial apoptosis. The process most often occurs during rapid rebalancing of the electrolyte parameters in the hyponatremic patient. Avoidance of CPM/EPM is dependent upon recognizing those patients with conditions pre-disposing them to osmotic myelinolysis and then moderating the rate of normalization of the electrolyte imbalance. The morbidity and mortality of CPM/EPM has been greatly reduced by recognition of pre-disposing conditions, increased understanding of the pathophysiology, intensive treatment, and rapid diagnosis and monitoring with advanced neuroimaging.

Rapid Correction Rate of Hyponatremia as an Independent Risk Factor for Neurological Complication Following Liver Transplantation

“…CPM is defined pathologically as a symmetric area of myelin disruption in the center of the basis pontis and shows characteristic findings on imaging studies: 1. MRI findings of symmetric hypointense signals in T1-weighted images and hyperintense signals in T2-weighted images in the central pons; 2. diffusion-weighted MR showing hyperintensities in the central pons with decreased apparent diffusion coefficient values in the same areas; 3. brain CT showing low density in the central pons (Kumar et al 2006;Lee et al 2009). Although we could not find definite cases of CPM or patients with permanent neurologic sequelae in the medical records, cases with minor symptoms that resolved might have existed.…”

Reversible Clinical and Magnetic Resonance Imaging of Central Pontine Myelinolysis Following Surgery for Craniopharyngioma: Serial Magnetic Resonance Imaging Studies -Case Report-

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Similar symmetrical lesions also occur in extrapontine locations, including the subcortex, thalamus, putamen, and globus pallidus, a condition termed extrapontine myelinolysis. 9) CPM has been generally observed in patients with a history of alcoholism and malnutrition, 1) but has also been found in patients with anorexia nervosa, orthotopic liver transplantation, diabetes, burns, sepsis, end-stage renal disease, and other diseases.…”

Central Pontine Demyelination: A Case Report

“…Possible mechanisms include a hyper osmotically induced demyelination process resulting from rapid intracellular/ extracellular to intravascular water shifts producing relative glial dehydration and myelin degradation and/or oligodendroglial apoptosis. 6 Another possible explanation of central pontine demyelination is that the brain begins to adapt to hypotonicity almost immediately after a fall in serum sodium, and the adaptation is complete within two days. The rapid correction thus results into this disease.…”

“…Lesions are symmetric or asymmetric and hypointense on T1-weighted images, typically sparing the periphery of pons and hyperintense on T2 weighted and FLAIR images. 1,6,7,9 In subacute and chronic phases, extrapontine lesions become smaller in size and more clearly defi ned 2 . The early identifi cation of patient at the risk of disease is fi rst step for its treatment.…”