Buscar en
Toda la web
Inicio Neurología Osmotic demyelination syndrome amidst COVID-19: A case report with literature re...
Información de la revista
Vol. 39. Núm. 2.
Páginas 213-217 (Marzo 2024)
Descargar PDF
Más opciones de artículo
Vol. 39. Núm. 2.
Páginas 213-217 (Marzo 2024)
Letter to the Editor
Acceso a texto completo
Osmotic demyelination syndrome amidst COVID-19: A case report with literature review
Síndrome de desmielinización osmótica en medio de COVID-19
G. Dimitrova,
Autor para correspondencia

Corresponding author.
, D. Naevaa,1, R. Duparinovaa,1, S. Stratievaa,1, V. Manevb,1, K. Prinovaa,1
a Clinic of Neural Diseases, Military Medical Academy, Sofia, Bulgaria
b Fakultät für Mathematik und Informatik, Ruprecht Karl University of Heidelberg, Germany
Este artículo ha recibido
Información del artículo
Texto completo
Descargar PDF
Figuras (1)
Tablas (1)
Table 1. Review of publications about COVID-19 and osmotic demyelination syndrome as of May 2023.
Texto completo
Dear Editor,

Osmotic demyelination syndrome (ODS) is of the most feared rare brain complications that could lead to protracted neurological consequences or death. Its occurrence is strongly associated with rapid correction of chronic hyponatremia.

Hyponatremia is common in COVID-19 patients and is associated with poor prognosis.1 However, few publications have described ODS in COVID-19 patients. As of May 2023, we found 12 papers in English, five case reports and seven retrospective studies, containing a total of 16 COVID-19 patients with certain (n=14) or presumable (n=2) ODS2–13 (Table 1).

Table 1.

Review of publications about COVID-19 and osmotic demyelination syndrome as of May 2023.

First author  Type of study  Patients with ODS  Initial sodium levels (mmol/L)  Maximum sodium correction (mmol/L)  Known risk factors for ODSa  Neurological symptoms  Additional important details  Outcomes 
Chougar et al. 20202  Retrospective MRI  3 (n=73)  N/A  N/A  N/A  N/A  N/A  N/A 
Fitsiori et al. 20203  Retrospective MRI  1 (n=9)  N/A  N/A  Hypertension, diabetes  Confusion  N/A  N/A 
Neumann et al. 20204  Retrospective  1 (n=30)  N/A  N/A  N/A  Gait disturbance, altered mental state, dysarthria  N/A  N/A 
Saleh et al. 20205  Case report  103  +11b  Urinary retention, SIADH, hypokalemia, hyponatremia hypertension  Confusion, disorientation, anosmia, dysgeusia  N/A  Improvement 
Chang et al. 2020c,6  Case report  Normal  N/A  Hypertension  Coma, bilateral ophthalmoplegia, quadriplegia  Presumable, not confirmed diagnosis.  Improvement 
Lambrecq et al. 20217  Retrospective MRI/EEG  3 (n=57)  N/A  N/A  N/A  N/A  N/A  N/A 
Rehman et al. 20218  Case report  123  +38 (for 48–72h)  Hyponatremia, diabetes, hypertension  Disorientation, gait disturbance, disorganized speech  The lowest level of measured sodium was 88mmol/L.  Improvement 
Jensen-Kondering et al. 2021c,9  Retrospective imaging  1 (n=12)  N/A  N/A  N/A  N/A  Presumable, not confirmed diagnosis. Not hyponatremic.  N/A 
Ser et al. 202110  Retrospective MRI  1 (n=26)  N/A  N/A  N/A  New-onset encephalopathy  N/A  N/A 
Elizondo et al. 202111  Retrospective MRI  1 (n=47)  N/A  N/A  N/A  Quadriplegia  N/A  N/A 
Ghosh et al. 202212  Case report  136  +6b  Diabetes, in a hyperglycemic state  Akinetic mutism, Parkinsonism  Non-dyselectrolytemic ODS. Closely monitored serum sodium, according to authors.  Improvement 
Ivanova et al. 202313  Case report  130  +17 (for 48h)  Hyponatremia  Bulbar syndrome, quadriplegia, resting tremor  The lowest level of measured sodium was 116mmol/L.  Survived but no improvement. 

ODS=osmotic demyelination syndrome, MRI=magnetic resonance imaging, N/A=not available, SIADH=Syndrome of Inappropriate Antidiuretic Hormone Secretion, EEG=electroencephalogram.


Risk factors that may secondarily lead to ODS are also included.


Unknown period of correction.


Unconfirmed but presumable ODS according to the authors’ description or imaging findings.

Surprisingly, none of the case reports contain information about the 24-h change in serum sodium, which is of utmost importance in current guidelines.14

Herein, we present the case of a 44-year-old male, who was admitted to our intensive care unit (ICU) with altered consciousness, positive for COVID-19. His complaints started two weeks prior when he felt nauseous, vomited several times daily, had fever and cough. On day 10 of symptom onset, the patient experienced a single tonic–clonic seizure with loss of consciousness for the first time. The nationwide shortage of hospital beds due to the pandemic has restricted his immediate hospitalization. Subsequent blood tests at a laboratory revealed severe hyponatremia of 112mmol/L.

On admission (three days later), repeated blood tests revealed hyponatremia of 122mmol/L, or +10mmol/L, indicating that the patient had experienced sodium autocorrection, where the exact correction rate is unknown.

Notable features in the patient's medical history exist. He had managed hypertension with a thiazide diuretic. Thiazide diuretics are a well-known cause of hyponatremia. He also maintained a restrictive diet for a year. In addition, he lost appetite and had been eating less for a week. Finally, he had multiple episodes of vomiting prior to hospital admission. The loss of gastrointestinal fluid results in the release of antidiuretic hormone (ADH), which could cause hyponatremia.

The patient became comatose, and required intubation in early hospitalization days, which made adequate neurologic examination difficult, and magnetic resonance imaging (MRI) impossible. Initial and repeated CT scans of the brain on day 4 were normal. On day 13, his general condition allowed for better examination. Quadriparesis, extraocular muscle palsy, and bulbar syndrome were observed. We performed MRI of the head, which confirmed the diagnosis of ODS (Fig. 1).

Figure 1.

Axial fluid-attenuated inversion recovery magnetic resonance imaging (FLAIR MRI) demonstrating a centrally located area of increased signal in the pons (A) and a moderately homogeneous signal enhancement bilaterally symmetrical in the basal ganglia with symmetrical foci of enhancement in the posterior thalami (B), typical for pontine (A) and extrapontine (B) myelinolysis or osmotic demyelination syndrome.


Diagnosing ODS is difficult in ICU where encephalopathies are common, including during the COVID-19 era.3 The gold standard is using MRI. However, the need for intensive care limits its feasibility. CT of the brain, while being more accessible and performed under these circumstances, is not sufficiently sensitive.

The question arises whether ODS is underdiagnosed and underreported in COVID-19 patients. Existing studies on COVID-19 patients indicate that ODS may not be rare, particularly in severely ill. In a study by Chougar et al., among 35 COVID-19 patients hospitalized in the ICU with neurological symptoms, three (8.6%) were identified with ODS.4 Fitsiori et al. found one ODS case among nine ICU patients (11.1%),5 Neumann et al. identified one case among 30 COVID-19 patients (3.3%), with the patient being in a critical condition,6 and Jensen-Kondering et al. reported one case of ODS in 12 patients (8.3%), with the patient being severely ill.11 However, these studies suffer from small sample sizes, and conclusions would be premature.

Our patient had stable sodium levels during the hospital stay before establishing diagnosis. The maximum measured increase in serum sodium over 24h (+8mmol/L) was within the current recommended therapeutic limits. Multiple cases in literature have also reported ODS, despite adherence to guidelines. Tandukar et al. highlight 19 publications encompassing 21 patients, 19 of whom (90.5%) had risk factors for ODS.15

However, MacMillan et al. recently showed that ODS can develop in the absence of rapid sodium correction, and an accompanying editorial by Ayus and Moritz questioned current guidelines. This is a large study including 22,858 patients, 3632 of whom (17.7%) had rapid correction of hyponatremia, defined as >8mmol/L/24h. ODS appeared to be a rare condition, developing in only 12 (0.05%) patients. Most notably, seven (58%) of the 12 patients were not rapidly corrected.16,17 Yet, they might have undergone uncontrolled sodium correction. As illustrated by our case report, autocorrection may occur at any time and sodium levels may change dramatically, particularly outside the hospital setting. Also, serum sodium levels of patients are unknown prior to first measurement. These limitations apply in general.

Thus, we posit that undocumented correction of hyponatremia could significantly contribute to the uncertainty regarding established therapeutic guidelines. Further research is needed to explore its role.

Ethical standards

This research was conducted in accordance with the principles of the Declaration of Helsinki.

Informed consent

Written informed consent was obtained from the relative in accordance with the Declaration of Helsinki.

Consent to publish

The relative has consented to submitting the case report to the journal.

Availability of data and materials

The authors take full responsibility for the data, analysis, and interpretation of the research, and have full access to all data.


This work is supported by the Bulgarian Ministry of Education and Science under National Program “Young Scientists and Postdoctoral Students – 2”.

Conflict of interests

The authors declare that they have no conflict of interest.

S. Purja, S. Oh, E. Kim.
A systematic review on neurological aspects of COVID-19: exploring the relationship between COVID-19-related olfactory dysfunction and neuroinvasion.
L. Chougar, N. Shor, N. Weiss, D. Galanaud, D. Leclercq, B. Mathon, et al.
Retrospective observational study of brain MRI findings in patients with acute SARS-CoV-2 infection and neurologic manifestations.
Radiology, 297 (2020), pp. E313-E323
A. Fitsiori, D. Pugin, C. Thieffry, P. Lalive, M.I. Vargas.
COVID-19 is associated with an unusual pattern of brain microbleeds in critically ill patients.
J Neuroimaging, 30 (2020), pp. 593-597
B. Neumann, M.L. Schmidbauer, K. Dimitriadis, S. Otto, B. Knier, W.-D. Niesen, et al.
Cerebrospinal fluid findings in COVID-19 patients with neurological symptoms.
J Neurol Sci, 418 (2020), pp. 117090
A.O. Saleh, S.D. Al-Shokri, A. Ahmed, A.E. Musa, M.F.H. Mohamed.
Urinary retention and severe hyponatremia: an unusual presentation of COVID-19.
Eur J Case Rep Intern Med, (2020),
P. Chang, E.S. Tasch, L.N. Rapoport, K. Bakhadirov.
A post-infectious steroid-responsive brainstem lesion associated with COVID-19.
Neurohospitalist, 11 (2020), pp. 152-155
V. Lambrecq, A. Hanin, E. Munoz-Musat, L. Chougar, S. Gassama, C. Delorme, et al.
Association of clinical biological, and brain magnetic resonance imaging findings with electroencephalographic findings for patients with COVID-19.
JAMA Netw Open, 4 (2021), pp. e211489
M. Abd Ur Rehman, A.F. Abdulrahman, A. Zainab, Y. Paksoy, N. Kharma.
Hyponatremia and extrapontine myelinolysis in a patient with COVID-19: a case report.
Clin Case Rep, 9 (2021),
U. Jensen-Kondering, A. Neumann, N.G. Margraf, F. Gövert, N. Brüggemann, D. Schunk, et al.
Cerebral imaging in patients with COVID-19 and neurological symptoms: first experience from two University Hospitals in Northern Germany.
RöFo – Fortschritte Auf Dem Gebiet Der Röntgenstrahlen Und Der Bildgebenden Verfahren, (2020),
M.H. Ser, U. Tanrıverdi, Ç. Özkara, S. Saip, C. Aliş, Z.E.K. Güleç, et al.
Analysis of neurology consultations in hospitalized patients with COVID-19.
Acta Neurol Belg, 122 (2022), pp. 1011-1018
E.F. Mendez Elizondo, J.A. Valdez Ramírez, G. Barraza Aguirre, P.M. Dautt Medina, J. Berlanga Estens.
Central nervous system injury in patients with severe acute respiratory syndrome coronavirus 2: MRI findings.
R. Ghosh, A. Ray, D. Roy, S. Das, S. Dubey, J. Benito-León.
Parkinsonism with akinetic mutism following osmotic demyelination syndrome in a SARS-CoV-2 infected elderly diabetic woman: a case report.
Neurología, 37 (2022), pp. 706-708
N.I. Ivanova, M.E. Tsalta-Mladenov, D.K. Georgieva, S.P. Andonova.
Central pontine myelinolysis as a late complication after hyponatremia and COVID-19 infection.
E.J. Hoorn, R. Zietse.
Diagnosis and treatment of hyponatremia: compilation of the guidelines.
J Am Soc Nephrol, 28 (2017), pp. 1340-1349
S. Tandukar, R.H. Sterns, H. Rondon-Berrios.
Osmotic demyelination syndrome following correction of hyponatremia by ≤10mEq/L per day.
Kidney360, 2 (2021), pp. 1415-1423
T.E. MacMillan, S. Shin, J. Topf, J.L. Kwan, A. Wainerman, T. Tang, et al.
Osmotic demyelination syndrome in patients hospitalized with hyponatremia.
J.C. Ayus, M.L. Moritz.
Hyponatremia treatment guidelines—have they gone too far?.

These authors contributed equally to this work.

Copyright © 2024. Sociedad Española de Neurología
Opciones de artículo
es en pt

¿Es usted profesional sanitario apto para prescribir o dispensar medicamentos?

Are you a health professional able to prescribe or dispense drugs?

Você é um profissional de saúde habilitado a prescrever ou dispensar medicamentos

Quizás le interese:
No mostrar más