Osmotic myelinolysis: Does extrapontine myelinolysis precede central pontine myelinolysis? Report of two cases and review of literature
Osmotic myelinolysis is an acute, rare, demyelinating process. After the initial description of the condition by Adam and colleagues in 1959, many case series have been published describing the central and extrapontine myelinolysis. Imaging has a definitive role in establishing the diagnosis of osmotic myelinolysis in vivo and diffusion-weighted imaging reveals earliest changes in affected brain parenchyma. We report two cases of patients with proven malignancy who developed extrapontine myelinolysis after treatment for hyponatremia and progressed to central pontine myelinolysis within a week. This was confirmed with magnetic resonance (MR) imaging and clinical assessment. This temporal progression of MR features, especially on diffusion-weighted imaging, from extrapontine to central pontine myelinolysis in osmotic injury has not been described in literature to the best of our knowledge. An early MRI of the brain in suspected/high-risk cases of osmotic myelinolysis may show features of extrapontine myelinolysis in the form of restricted diffusion in bilateral basal ganglia and may serve as a guide for predicting progression, prognosticating and deciding further treatment of pontine myelinolysis. We propose that in a significant number of cases, central pontine myelinolysis may be predicted by doing an early MRI of the brain with diffusion-weighted imaging, when extrapontine symptoms start to develop. This can potentially increase the window period and possibilities for therapeutic intervention and may even help in prevention.
KeywordsCentral pontine myelinolysis - diffusion weighted magnetic resonance imaging - extrapontine myelinolysis - osmotic myelinolysis
30. Juli 2021 (online)
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- 1 Adams RD, Victor M, Mancall EL. Central pontine myelinolysis: A hitherto undescribed disease occurring in alcoholic and malnourished patients. AMA Arch Neurol Psychiatry 1959;81:154-72.
- 2 Karp BI, Laureno R. Central pontine and extrapontine myelinolysis after correction of hyponatraemia. Neurologist 2000;6:255-66.
- 3 Kleinschmidt-DeMasters BK, Norenberg MD. Rapid correction of hyponatremia causes demyelinization: Relation to central pontine myelinolysis. Science 1981;211:1068-70.
- 4 Ruzek KA, Campeau NG, Miller GM. Early diagnosis of central pontine myelinolysis with diffusion-weighted imaging. AJNR Am J Neuroradiol 2004;25:210-3.
- 5 Chu K, Kang DW, Ko SB, Kim M. Diffusion-weighted MR findings of central pontine and extrapontine myelinolysis. Acta Neurol Scand 2001;104:385-8.
- 6 Martin RJ. Central pontine and extrapontine myelinolysis: The osmotic demyelination syndromes. J Neurol Neurosurg Psychiatry 2004;75(Suppl 3):iii22-8.
- 7 Adrogué HJ, Madias NE. Hyponatremia. N Engl J Med 2000;342:1581-9.
- 8 Miller GM, Baker HL Jr, Okazaki H, Whisnsnt JP. Central pontine myelinolysis and its imitators: MR findings. Radiology 1988;168:795-802.
- 9 Ho VB, Fitz CR, Yoder CC, Geyer CA. Resolving MR features in osmotic Myelinolysis (Central pontine and extrapontine myelinolysis). AJNR Am J Neuroradiol 1993;14:163-7.
- 10 Chu K, Kang DW, Ko SB, Kim M. Diffusion-weighted MR findings of central pontine and extrapontine myelinolysis. Acta Neurol Scand 2001;104:385-8.
- 11 Cramer SC, Stegbauer KC, Schneider A, Mukai J, Maravilla KR. Decreased diffusion in central pontine myelinolysis. AJNR Am J Neuroradiol 2001;22:1476-9.
- 12 Upadhyay A, Jaber BL, Madias NE. Epidemiology of hyponatremia. Semin Nephrol 2009;29:227-38
- 13 Menger H, Jörg J. Outcome of central pontine and extrapontine myelinolysis (n = 44). J Neurol 1999;246:700-5.
- 14 Oya S, Tsutsumi K, Ueki K, Kirino T. Reinduction of hyponatremia to treat central pontine myelinolysis. Neurology 2001;57:1931-2.
- 15 Perianayagam A, Sterns RH, Silver SM, Grieff M, Mayo R, Hix J, et al. DDAVP is effective in preventing and reversing inadvertent overcorrection of hyponatremia. Clin J Am Soc Nephrol 2008;3:331-6.