A case of chronic asymptomatic central pontine myelinolysis with histological evidence of remyelination

Harry R Haynes,Patrick J Gallagher,Marcus Likeman,Seth Love,Andrea Cordaro

doi:10.1007/s12024-017-9933-y

Abstract

Central pontine myelinolysis (CPM) is a neurological demyelinating disease of the pons. Although usually associated with rapid correction of hyponatremia, CPM may occur despite normonatremia, is often associated with chronic alcoholism and may be asymptomatic. Histological confirmation of asymptomatic CPM is rare. We describe an unusual post-mortem case of extensive but asymptomatic CPM in a chronic alcoholic patient with normonatremia. The affected part of the pons contained thinly myelinated axons with appearances supporting remyelination. We suggest that remyelination may account for the subclinical nature of this patient's CPM.

Highlights

Clinical summaryCentral pontine myelinolysis (CPM) is a non-inflammatory demyelinating disease of the pons, first described in 1959 [1]
This most often occurs in the context of alcoholic liver disease
It has been proposed that osmotic injury to vascular endothelial cells after the rapid reversal of hyponatremia releases myelinotoxic factors [5]

Summary

Introduction

Central pontine myelinolysis (CPM) is a non-inflammatory demyelinating disease of the pons, first described in 1959 [1]. Examination of the brain revealed a symmetrical, central region of discoloration and partial cavitation within the pons, up to 25 mm across (Fig. 1a). E Staining with luxol fast blue and cresyl violet revealed a sharply demarcated region of reduced staining of myelin in the central part of the base of the pons, with good preservation of neurons (scale bar = 200 μm). H Included within this region were many large-caliber but thinly myelinated axons (blue arrowhead), in contrast to the normally myelinated, large-caliber fibers in the adjacent pons (green arrowhead) (scale bar = 50μm) with luxol fast blue and cresyl violet revealed a sharply demarcated region of demyelination in the central part of the base of the pons, with good preservation of neurons (Fig. 1e). This pattern of immunopositivity suggested reparative myelination had occurred (Fig. 1h)

Discussion

Key points