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Central Pontine Myelinolysis

Central pontine myelinolysis (CPM), also referred to as osmotic demyelination syndrome, is a demyelinating disease that is caused by significant damage to the myelin sheath of nerve cells in the middle of the brainstem, specifically the pons region.


The clinical presentation of central pontine myelinolysis is variable. Patients may be asymptomatic, or have mild to severe symptoms, including rapid onset of pseudobulbar symptoms (e.g., difficulty swallowing or speaking), paraparesis, quadriparesis, confusion, psychiatric symptoms (e.g., delirium or hallucinations), "locked-in syndrome," in which there is paralysis of the lower limb musculature and cranial nerves resulting in a lack of expressive communication ability, although the intellectual activity is unaffected [1].

The symptoms may appear with a biphasic course, consisting of seizures and/or encephalopathy, with a period of improvement, followed by deterioration consisting of spastic quadriplegia, dysarthria, dysphagia, and occasionally oculomotor abnormalities such as horizontal gaze paralysis [2].

High Fever
  • A 78-year-old Japanese woman presented to a neighborhood clinic with persistent high fever, edema, and general weakness.[ncbi.nlm.nih.gov]
  • Mild bilateral pleural effusion, prominent subcutaneous edema, and splenomegaly were detected on her systemic computed tomography scan.[ncbi.nlm.nih.gov]
  • We report a patient admitted with severe dyspnea due to bilateral vocal fold immobility (BVFI), associated with hyponatremia and pneumonia that required emergency tracheotomy.[ncbi.nlm.nih.gov]
Pleural Effusion
  • Mild bilateral pleural effusion, prominent subcutaneous edema, and splenomegaly were detected on her systemic computed tomography scan.[ncbi.nlm.nih.gov]
  • The rapid correction or over-correction of hyponatremia is believed by many to be the crucial factor in the causation of central pontine myelinolysis (CPM).[ncbi.nlm.nih.gov]
  • Over the next 5 days, spastic quadriparesis and pseudobulbar palsy developed.[nejm.org]
Progressive Dysphagia
  • Case Report A 47-year-old man was admitted to the hospital with complaints of progressive dysphagia and dysarthria for a week, and this occurred just 2 days after he stopped drinking. His medical history was unremarkable.[doi.org]
Emotional Lability
  • Case 1: 24-year-old male, known alcoholic, was admitted with left hemiplegia and features of bulbar and pseudobulbar palsy with dysphagia, dysarthria and emotional lability.[endocrine-abstracts.org]
  • lability ( pseudobulbar affect ), with other more variable neurological features associated with brainstem damage.[en.wikipedia.org]
  • Neurological examination was significant for emotional lability, dysarthria, and gait ataxia with bilateral dysmetria. Motor examination showed normal tone, power grade 5 in all limbs, absent knee and ankle jerks, and flexor plantar response.[smj.org.sg]
Visual Hallucination
  • It was also possible to distinguish our case from alcoholic psychosis in view of the absence of visual hallucinations, intact orientation and the unusual time course unlike alcoholic psychosis in which the peak symptoms occur within 2–4 days after alcohol[doi.org]
  • There was little improvement in the dysarthria or psychiatric symptoms in the first month.[ncbi.nlm.nih.gov]
  • He only displayed bulbar palsy and dysarthria.[doi.org]
  • A 26-year-old man with a history of chronic alcohol abuse presented with dysarthria, lethargy, and horizontal nystagmus.[nejm.org]
Altered Mental Status
  • Although her bicarbonate deficit was 365 mEq, we treated her with an overdose of intravenous sodium bicarbonate, 480 mEq for 24 hours, due to the severity of her acidemia and her altered mental status.[ncbi.nlm.nih.gov]
  • Some of the signs and symptoms include: Difficulty in speaking Difficulty in swallowing Double vison Muscle cramps Convulsions Hallucinations Poor reflexes Paralysis of various parts of the body Loss of sensation in various parts of the body Altered mental[dovemed.com]
  • mental status Specialty Neurology Central pontine myelinolysis ( CPM ) is a neurological condition involving severe damage to the myelin sheath of nerve cells in the pons (an area of the brainstem ).[en.wikipedia.org]
Spastic Quadriplegia
  • Key features of the neurologic exam include confusion, horizontal gaze paralysis, and spastic quadriplegia.[emedicine.com]
  • The symptoms may appear with a biphasic course, consisting of seizures and/or encephalopathy, with a period of improvement, followed by deterioration consisting of spastic quadriplegia, dysarthria, dysphagia, and occasionally oculomotor abnormalities[symptoma.com]
  • They published their findings in 1958, observing that patients who suffered from alcoholism or malnutrition developed spastic quadriplegia, pseudobulbar palsy, and varying degrees of encephalopathy or coma from acute, noninflammatory demyelination that[coolmristuff.wordpress.com]
  • It is characterized by spastic quadriplegia, pseudobulbar palsy and encephalopathy. It is observed in patients with severe hyponatremia, particularly when the hyponatremia is corrected too rapidly.[fpnotebook.com]
  • A 26-year-old man with a history of chronic alcohol abuse presented with dysarthria, lethargy, and horizontal nystagmus.[nejm.org]
  • Common symptoms included lethargy and dysarthria. Five of the 6 patients had chronic alcoholism. All had improvements in their clinical conditions upon hospital discharge.[ncbi.nlm.nih.gov]
  • Acute symptoms Paralysis (can affect two or all of the limbs) Difficulties swallowing (dysphagia) and speaking (dysarthria) Problems with the vision (diplopia) Loss of consciousness Confusion and delirium Balance problems (unstable gait) Hallucinations Lethargy[mddk.com]
  • Signs and symptoms include confusion, lethargy, dysarthria, dysphagia, tremor, and profound bilateral weakness that may progress to spastic quadriplegia and “locked in syndrome.”[ijam-web.org]
  • Large lesions cause spastic bulbar paralysis, quadriplegia, stupor or coma, or the locked-in syndrome, developing in a background of severe electrolyte abnormalities.[neuropathology-web.org]
  • Clinical manifestations of CPM include stupor and spastic tetraparesis[ 51 ]. Neuroimaging studies typically show area of T2 hyperintensity on MRI imaging in central pons[ 19 ].[dx.doi.org]
  • The Diagnosis of Stupor and Coma. FA Davis: Philadelphia, 1966. 2.Recommendations for use of uniform nomenclature pertinent to patients with severe alterations of consciousness. American Congress of Rehabilitation Medicine.[consultant360.com]


Workup of central pontine myelinolysis consists of a history, physical exam, laboratory testing, and imaging. Patients with a history of rapid correction of severe hyponatremia (plasma serum level <120 mq/L persisting for two or more days, that has been corrected at a rate greater than 8 mq/L in 48 hours), patients with liver disease or alcohol abuse should be considered at high-risk for central pontine myelinolysis [3] [4]. During the neurologic exam, the clinician should assess signs of confusion, occulomotor dysfunction (e.g., horizontal gaze paralysis), impaired speech or swallowing, and signs of spastic quadriplegia such as limb weakness, increased tonicity of the limb muscles, and hyperreflexia). The primary laboratory test consists of a chemistry panel (sodium, potassium, chloride, bicarbonate, glucose, creatine, and BUN). Liver function test can also be performed when clinically indicated.

Computed tomography (CT) and magnetic resonance imaging (MRI) have been used to aid in the diagnosis [5] [6] [7] [8]. Imaging test results may be normal during the early stages of the disease (through two weeks); after this period imaging abnormalities indicative of central pontine myelinolysis emerge. MRI is more sensitive for diagnosing abnormalities than CT scan [9] [10]. Comparison of changes between earlier and later CT or MRI scans is also useful.

CT scan images are prone to streak artifact in the region of the pons (and thus not as sensitive as MRI). CT scan may reveal low attenuation crossing the midline in the lower pons.

On T2-weighted MRI scans, areas of demyelination are marked by hyperintense and bright areas. T1 signal may be mildly or moderately hypointense; fluid attenuation inversion recovery (FLAIR) signal will usually appear hyperintense. A classic trident shaped pattern is indicative of ventrolateral pons, corticospinal tract, and tegmentum sparing. Extrapontine lesions are usually bilateral; they are commonly found on the cerebellar peduncles, globus pallidus, lateral geniculate body, thalamus, and putamen [5] [11].

Cerebral spinal fluid evaluation may show an elevated opening pressure, mononuclear pleocytosis, or an elevated protein level.

Few advanced neuroimaging studies like positron emission tomography have been studied for its efficacy in the diagnosis of central pontine myelinosis; studies have shown a high FDG-18 uptake initially, followed by decreased uptake in affected regions [12].

Electroencephalography (EEG) can be used to supplement imaging results, particularly when neuroimaging is not definitive. EEG usually reveals diffuse bihemispheric slowing in patients with central pontine myelinolysis.

Pleural Effusion
  • Mild bilateral pleural effusion, prominent subcutaneous edema, and splenomegaly were detected on her systemic computed tomography scan.[ncbi.nlm.nih.gov]


  • There is no consensus for its treatment. We describe here a case of CPM that occurred in a young patient after correction of hyponatremia, its treatment by intravenous thyrotropin-releasing hormone, and its outcome.[ncbi.nlm.nih.gov]


  • In general, this neurological disorder has a fatal prognosis. We observed a 30-year-old woman with a history of chronic alcohol abuse but without evidence of hyponatremia, who developed severe pontine central myelinolysis.[ncbi.nlm.nih.gov]
  • We aimed to describe the baseline characteristics, the management, the long-term prognosis, and the prognostic factors in central or extrapontine myelinolysis.[doi.org]


  • The etiology of central pontine myelinolysis (CPM) is usually related to rapid correction of hyponatremia and alcoholism.[ncbi.nlm.nih.gov]


  • Epidemiology The exact incidence of central pontine myelinolysis is unknown. A study by Singh et al demonstrated that central pontine myelinolysis was present in 29% of postmortem examinations of liver transplant patients.[emedicine.com]
  • Sandrine Leroy 1 Department of Epidemiology of Emerging Diseases Unit, Insititut Pasteur, Paris, France Ariel Gout 2 Department of Neuropediatrics, Bicetre Hospital, Paris, France, Beatrice Husson 3 Department of Pediatric Neurology, Bicêtre University[doi.org]
  • Definition / general Central pontine and extrapontine myelinolysis are complications of treatment of marked hyponatremia Terminology Also termed osmotic demyelination syndrome Epidemiology Occurs most commonly in setting of chronic alcoholism ( 40% of[pathologyoutlines.com]
Sex distribution
Age distribution


  • We also discuss factors that may contribute to the development of central pontine myelinolysis after orthotopic liver transplant and its pathophysiology.[ncbi.nlm.nih.gov]
  • The morbidity and mortality of CPM/EPM has been greatly reduced by recognition of pre-disposing conditions, increased understanding of the pathophysiology, intensive treatment, and rapid diagnosis and monitoring with advanced neuroimaging.[oadoi.org]


  • Both share the diagnostic methods, and their prevention and therapy are the same. The etiology and pathogenesis of this disorder are unclear and will be discussed. However, almost all cases of CPM are related to severe diseases.[ncbi.nlm.nih.gov]
  • Prevention Slow correction of electrolytic imbalance. central pontine myelinolysis Neuropathology A condition characterized by softening of the base of the brain at the pons with damage to the myelin sheath, related to aggressive correction of hyponatremia[medical-dictionary.thefreedictionary.com]
  • Prevention and Treatment The most certain way to prevent central pontine myelinolysis is to correct the reduced sodium levels in a gradual manner.[mddk.com]
  • It is a preventable injury often caused by a physician’s negligence when he does not follow the standard protocols that mandate slowly increasing the sodium level.[r-klaw.com]



  1. Vermetten E, Rutten SJ, Boon PJ, Hofman PA, Leentjens AF. Neuropsychiatric and neuropsychological manifestations of central pontine myelinolysis. Gen Hosp Psychaitry. 1999;21:296-302.
  2. Martin RJ. Central pontine and extrapontine myelinolysis: the osmotic demyelination syndromes. J Neurol Neurosurg Psychiatry. 2004;75(suppl 3): iii22-iii28.
  3. Verbalis JG, Martinez AJ. Neurological and neuropathological sequelae of correction of chronic hyponatremia. Kidney Int. 1991;39:1274-82.
  4. Laureno R. Central pontine myelinolysis following rapid correction of hyponatremia. Ann Neurol. 1983;13:232-42
  5. Chua GC , Sitoh YY , Lim CC , et al. MRI findings in osmotic myelinolysis. Clin Radiol. 2002; 57:800–806
  6. Kumar S , Fowler M , Gonzalez-Toldeo E , et al. Central pontine myelinolysis, an update. Neurol Res. 2006; 28:360–6.
  7. Venkatanarasimha N , Mukonoweshuro W , Jones J. AJR teaching file: symmetric demyelination. AJR Am J Roentgenol. 2008; 191:S34–S36
  8. Howard SA , Barletta JA , Klufas RA , et al. Best cases from the AFIP: osmotic demyelination syndrome. Radiographics. 2009; 29:933–8.
  9. Karp BI, Laureno R. Pontine and extrapontine myelinolysis: a neurologic disorder following rapid correction of hyponatremia. Medicine (Baltimore). 1993;72:359.
  10. Brunner JE, Redmond JM, Haggar AM, Kruger DF, Elias SB. Central pontine myelinolysis and pontine lesions after rapid correction of hyponatremia: a prospective magnetic resonance imaging study. Ann Neurol. 1990;27:61.
  11. Roh JK , Nam H , Lee MC. A case of central pontine and extrapontine myelinolysis with early hypermetabolism on 18FDG-PET scan. J Korean Med Sci 1998; 13:99–102.
  12. Juergenson I, Zappini F, Fiaschi A, Tonin P, Bonetti B. Teaching neuroimages: neuroradiologic findings in pontine and extrapontine myelinolysis: clue for the pathogenesis? Neurology. 2012;78:e1-2.

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Last updated: 2019-07-11 20:18