====== Central pontine myelinolysis ======



Central [[pontine myelinolysis]], is a rare [[disorder]] of [[pontine]] [[white matter]].

Some cases of inordinately rapid [[hyponatremia treatment]] have been associated with [[osmotic demyelination syndrome]] (which includes [[central pontine myelinolysis]] (CPM)
((Fraser CL, Arie AI. Symptomatic Hyponatremia: Management and Relation to Central Pontine Myeli- nolysis. Sem Neurol. 1984; 4:445–452))
and extrapontine [[myelinolysis]], as well as other areas of cerebral [[white matter]].

First described in [[alcoholism]]
((Adams RD, Victor M, Mancall EL. Central Pontine Myelinolysis: A Hitherto Undescribed Disease Occurring in Alcoholic and Malnourished Patients. Arch Neurol Psychiatr. 1959; 81:154–172))
producing insidious flaccid [[quadriplegia]], [[mental status]] changes, and [[cranial nerve]] abnormalities with a pseudobulbar palsy appearance. In one review
((Ayus JC, Krothapalli RK, Arie AI. Treatment of Symptomatic Hyponatremia and Its Relation to Brain Damage.N Engl J Med.1987;317:1190–1195))
no patient developed CPM when treated slowly.

And yet, the rate of correction correlates poorly with CPM; it may be that the magnitude is another critical variable
((Berl T. Treating Hyponatremia: What is All the Controversy About? Ann Intern Med. 1990; 113:417– 419)).
Features common to patients who develop CPM are
((Ayus JC, Krothapalli RK, Arie AI. Treatment of Symptomatic Hyponatremia and Its Relation to Brain Damage.N Engl J Med.1987;317:1190–1195))

● delay in the diagnosis of hyponatremia with resultant respiratory arrest or seizure with probable
hypoxemic event

● rapid correction to normo-or [[hypernatremia]](>135mEq/L) within 48 hours of initiating therapy

● increase of serum sodium by >25 mEq/L within 48 hours of initiation of therapy

● over-correcting serum sodium in patients with hepatic encephalopathy

● NB: many patients developing CPM were victims of chronic debilitating disease, malnourishment,
or alcoholism and never had hyponatremia. Many had an episode of hypoxia/anoxia
((Arie AI. Hyponatremia Associated with Permanent Brain Damage. Adv Intern Med.1987;32:325–344))

● presence of hyponatremia >24 hrs prior to treatment
((Berl T. Treating Hyponatremia: What is All the Controversy About? Ann Intern Med. 1990; 113:417– 419)).

===== Diagnosis =====
{{::central_pontine_myelinolysis.png?400|}}

Axial [[FLAIR]] [[MRI]].