preview

Central Pontine Myelinolysis Essay

explanatory Essay
1669 words
1669 words
bookmark

Central pontine myelinolysis (CPM) is a demyelinating condition that affects the pontine base and also other areas of the brain, which are termed extrapontine myelinolysis (EPM). A demyelinating condition is present in the nervous system when the myelin sheath covering the neurons is damaged (Norenberg 2010). CPM formerly was believed to be found only in the pontine base of the brain in humans where grey-white admixture was highest. However, lesions on the brain have been found in other areas as well that have high amounts of grey-white admixture. Other parts of the brain in which myelinolysis can have an affect are the basal ganglia and the thalamus (Norenberg 2010).
Initial studies and reports showed CPM only occurring in individuals who suffered from alcoholism, were malnourished, or were chronically ill (Adams and colleagues 1959). However, less than 10 years later, CPM began to be diagnosed in children. This recent diagnosis lead to further research and the latest conclusion that alcoholism is absent in most individuals who develop CPM. CPM has never been observed in seclusion and instead, is seen as a complication of a pre-existing medical condition and is observed only in a hospital setting (Norenberg 2010). Due to the hospital setting in which it is observed, both researchers and physicians believe that an iatrogenic agent, relating to an illness caused by medical treatment, was used in preventing further complications (Gheorghita 2010). Identification of CPM paralleled the arrival of the use of intravenous fluid therapy occurring in the late 1950’s (Messert 1979).
The imbalance of fluid and electrolytes took on a central position as a factor supplementing CPM. The brain is able to keep plasma tonicity discrepancies at...

... middle of paper ...

...r spaces of the brain (Chang et al. 2012).
Pietrini and colleagues completed a study that drew the conclusion that diuretics can influence development of hyponatremia in individuals. There are two types which differ in their site of action. The first type is loop diuretics and inhibits sodium chloride reabsorption in the ascending limb of the loop of Henle. Consumption of this type of diuretic interferes with the accumulation of NaCl in the medulla. The second type of diuretic is thiazides which work in the distal tubule cortex but do not interfere with medullary function. However, this type of diuretic increases water permeability and water reabsorption while also increasing sodium excretion higher in concentration than that of the plasma. Loss of fluid can directly promote development of hyponatremia independently of the amount of water intake (Pietrini et al.).

In this essay, the author

  • Explains that central pontine myelinolysis (cpm) is a demyelinating condition that affects the pontine base and other areas of the brain.
  • Explains that alcoholism is absent in most individuals who develop cpm. it is seen as a complication of pre-existing medical conditions and is observed only in hospital settings.
  • Explains how the brain keeps plasma tonicity discrepancies at a minimum through an osmoregulation mechanism. changes in the na+ balance are caused by iatrogenic or pathological factors.
  • Explains that hyponatremia is caused by a reduction in na+ and dehydration, and is the most common electrolyte disorder.
  • Explains that hromanik presents three types of hyponatremia, each with different characteristics and initiating factors.
  • Explains that the severity of hyponatremia is an important aspect in methods of treatment as well as cpm development. acute conditions can change rapidly and often times worsen with no warning.
  • Explains that organic osmolytes aid in preserving cell volume and are lost with the rapid correction of chronic hyponatremia.
  • Explains that rapid correction of hyponatremia is an essential element in the trigger of cpm, which is accompanied by demyelination, amplified quantities of macrophages, and astrocytosis.
  • Explains that hyponatremic cells loose organic osmolytes, such as amino acids, which are slower than inorganic ions in the ability to return to normal levels, allowing for dysfunction of protein structure and function.
  • Explains that cpm is accompanied by lesions on the pontine base of the brain. the pons functions as a bridge connecting the medulla with higher cortical centers.
  • Explains that lesions in the pons are symmetrical and contain microglia that have been activated.
  • Explains that hyponatremia is the leading factor of cpm development, although it has not been diagnosed in every case. other conditions may play an influential role, such as hepatic dysfunction, liver transplantation, renal failure, and diuretics.
  • Explains that after a liver transplant, the morbidity of the central nervous system elevates as does the chances of neurological complications.
  • Explains that chang and colleagues discovered that hepatic dysfunction arises in two forms, acute and chronic.
  • Explains that loop diuretics inhibit sodium chloride reabsorption in the ascending limb of the loop of henle, while thiazides interfere with medullary function.
Get Access