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].

• Inflammation

  No inflammation is seen. There is no selective involvement of fiber systems. In severe cases, the lesion becomes necrotic. Extension to the cerebral hemispheres and the cerebellum (extrapontine myelinolysis) is seen in some cases. [neuropathology-web.org]

  There is usually no inflammatory reaction associated with osmotic demyelination, differentiating the process from multiple sclerosis, which is characterized by marked perivascular inflammation. [ajnr.org]

  The authors intentionally avoided the term ‘demyelination’ to describe the condition, in order to differentiate the pathology of this condition from multiple sclerosis and other neuroinflammatory disorders in which myelin loss is associated with inflammation [ipfs.io]

• Acute Intermittent Porphyria

  MRI showed CPM and EPM, and cortical laminar necrosis, all of which are not common in acute intermittent porphyria [ 62 ]. [transbiomedicine.com]

• Dysphagia

  English central pontine myelinolysis demyelination disease that is characterized by severe damage to the myelin sheath of the pons' nerve cells and has symptom acute paralysis, has symptom dysphagia, and has symptom dysarthria central pontine myelinolysis [wikidata.org]

  We report a very case of a patient with dysarthria, dysphagia and psychiatric symptoms including abnormal behavior starting after alcohol withdrawal, with radiological evidence of CPM and EPM. [ncbi.nlm.nih.gov]

  Because of his dysphagia, he was kept on a Lavin tube and was treated with conservative care, including a thiamine supplement. [dx.doi.org]

• Polydipsia

  Here is a case of a disabled female who presented with polydipsia, polyuria, seizures, fetal death in utero, hyperglycemia, and hyper-osmolar hypernatremia on her 31st gestational week. [ncbi.nlm.nih.gov]

  "Psychogenic Polydipsia (Exessive Fluid seeking Behaviour)" (PDF). American Psychological Society Divisions. ↑ Lim, Leslie; Krystal, Andrew (2007-06-01). "Psychotic disorder in a patient with central and extrapontine myelinolysis". [ipfs.io]

  "Psychogenic Polydipsia (Excessive Fluid seeking Behaviour)" (PDF). American Psychological Society Divisions. ^ Lim, Leslie; Krystal, Andrew (2007-06-01). "Psychotic disorder in a patient with central and extrapontine myelinolysis". [en.wikipedia.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. [dx.doi.org]

• Dysarthria

  There was little improvement in the dysarthria or psychiatric symptoms in the first month. [ncbi.nlm.nih.gov]

  Our patient presented initially with the symptoms of CPM, exhibiting lethargy, quadriparesis, and dysarthria. [movementdisorders.org]

  He only displayed bulbar palsy and dysarthria. [dx.doi.org]

• Seizure

  Castilla-Guerra L, del CF-M, Lopez-Chozas JM, Fernandez-Bolanos R (2006) Electrolytes disturbances and seizures. Epilepsia 47:1990–1998 CrossRef PubMed Google Scholar 5. [dx.doi.org]

  Clinical presentation of CPEPM is heterogeneous and can even include seizures. Cognitive impairment should be screened as it is a significant factor limiting return to normal life. [ncbi.nlm.nih.gov]

• Tremor

  This case highlights the unusual presentation of central pontine myelinosis as tremor in a malnourished child with celiac disease. [ncbi.nlm.nih.gov]

  […] myelinolysis (EPM) occurs in approximately 10% of patients with CPM, but the symptoms are underdiagnosed because they are often masked by involvement of the pyramidal tract and brain stem. [3] The features are typically cognitive deficits, seizures, tremor [movementdisorders.org]

  Clinical findings Weakness, double vision, muscle spasms, speech defects, delirium, sleep disorders, hallucinations, tremors and uncontrolled eye movements. Imaging Defects by MRI. [medical-dictionary.thefreedictionary.com]

  Although neurological sequelae of ODS — including quadriparesis, cognitive changes, tremor and weakness — may be persistent, the few reported cases involving hyperosmolar stress seem to have had relatively good outcomes. [thepoisonreview.com]

  He was given symptomatic treatment for rigidly and tremor. His sensorium gradually improved but patient had quadripareisis with muteness, cogwheel rigidity and rest tremor predominantly involving upper limbs. [omicsonline.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]

  We report a case of osmotic demyelination syndrome in a 55-year-old female, with a past medical history of arterial hypertension and multi-level cervical spondylosis, hospitalized for acute altered mental status complicating an array of acute gastroenteritis [scienceopen.com]

  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]

• Lethargy

  A 26-year-old man with a history of chronic alcohol abuse presented with dysarthria, lethargy, and horizontal nystagmus. [dx.doi.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]

  Our patient presented initially with the symptoms of CPM, exhibiting lethargy, quadriparesis, and dysarthria. [movementdisorders.org]

  Radiation treatment of the brain Severe nausea and vomiting during pregnancy Symptoms Symptoms may include any of the following: Confusion, delirium, hallucinations Balance problems, tremor Problem swallowing Reduced alertness, drowsiness or sleepiness, lethargy [leehealth.org]

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.

Central pontine myelinolysis occurs most often as a complication of treatment of patients with profound, life-threatenin-g hyponatremia (low sodium) and is a consequence of a rapid rise in serum tonicity following treatment in individuals with chronic [physio-pedia.com]

The aetiology is not clear, and there is no evidence regarding the optimal treatment or prognosis of CPM. [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. [dx.doi.org]

We cannot explain the reason and mechanism of the poor prognosis in this case, although we could predict a poor prognosis from the serial MRIs. [alcalc.oxfordjournals.org]

When an uncommon etiology for CPM is suspected, exhaustive workup, including evaluation for autoimmune etiologies, should occur and guide management prior to prognostication. These patients may be responsive to steroids. [hoajonline.com]

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

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]

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 [dx.doi.org]

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]

The pathophysiology of CPM has not been well understood. [ajnr.org]

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]

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]

The appropriate administration of thiamine may prevent poor outcomes. [ncbi.nlm.nih.gov]

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]

Prevention and treatment of pontine myelinolysis Several options surround the prevention and treatment of PM. A hallmark of prevention is proper management of hyponatremia post-absorption of irrigation fluid. [transbiomedicine.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.