J Neurol Neurosurg Psychiatry 82:326-331 doi:10.1136/jnnp.2009.201764
  • Research paper

Clinical and functional outcome and factors predicting prognosis in osmotic demyelination syndrome (central pontine and/or extrapontine myelinolysis) in 25 patients

  1. Sankara P Sarma
  1. Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
  1. Correspondence to Dr Ashalatha Radhakrishnan, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum 695011, Kerala, India; ashalatharadhakrishnan{at}
  • Received 29 November 2009
  • Revised 26 June 2010
  • Accepted 28 June 2010
  • Published Online First 8 September 2010


Aims To assess the functional and clinical outcome in a sizeable cohort of patients with osmotic demyelination syndrome (ODS) and to characterise the factors which could predict the final outcome.

Methods Twenty five consecutive patients with ODS formed the study cohort. The diagnosis of ODS was based on clinical features with corroborating imaging findings. Two functional scales—Functional Independent Measure (FIM) and Disability Rating Scale (DRS)—were applied to assess the functional status at the time of admission, discharge and last follow-up. Patients who became independent for activities of daily living (ADL) at last follow-up were classified as favourable outcome, and those who died or became dependent for ADL were classified as a poor outcome group respectively. The Fisher exact test and Mann–Whitney U test were used to assess categorical and continuous variables respectively.

Results The mean age at diagnosis was 53±14 years. Five (20%) had central pontine myelinolysis, seven (28%) had extrapontine myelinolysis, and 13 (52%) had both. Hyponatraemia and hypokalaemia were noted in 20 (80%) and 10 (40%) patients respectively. Six (24%) received intravenous methylprednisolone. Eleven (46%) had a favourable outcome at a mean follow-up of 2.2±2.5 years. Hyponatraemia ≤115 mEq (p=0.04), associated hypokalaemia (p=0.04) and low Glasgow Coma Scale (GCS) (p=0.008) at presentation were predictive of poor outcome. The mean FIM score at admission (p=0.05) and at discharge (p=0.01), and mean DRS at admission (p=0.05) were predictive of poor outcome.

Conclusions Higher GCS scores, better scores in functional scales in hospital, less severe hyponatraemia and absence of superadded hypokalaemia predicted favourable outcome.


  • Competing interests None.

  • Ethics approval Ethics approval was provided by the Sree Chitra Tirunal Institute for Medical Sciences & Technology.

  • Provenance and peer review Not commissioned; externally peer reviewed.

Visit the full archive of podcasts for JNNP here >>

Free sample
This recent issue is free to all users to allow everyone the opportunity to see the full scope and typical content of JNNP.
View free sample issue >>

Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.

Navigate This Article