Clinical Analysis Of 20 Cases With Osmotic Demyelination Syndrome

Background and ObjectiveOsmotic demyelination syndrome(ODS)is an acute,non-inflammatory,secondary demyelinating disease,which includes central cerebral myelinolysis(CPM)as well as extrapontine myelinolysis(EPM).If the demyelination is located in the base of the pons,it can be called CPM.While,if the demyelination is situated at other places apart from the pons,such as the bilaterally symmetrical basal ganglia,the thalamus,and the deep part of the cerebral cortex,we can call it EPM.Osmotic demyelination syndrome is often secondary to other underlying diseases such as rapid correction of chronic hyponatremia,malnutrition,chronic alcoholism,liver transplantation,kidney disease,hypophysoma and so on.The pathogenesis of the disease is still unknown.The more accepted hypothesis is that the rapid correction of chronic hyponatremia causes brain cell dehydration and secondary nerve damage.Osmotic demyelination syndrome shows a variety of clinical symptoms depending on the region of the involvement,and can present paralysis,coma,dysphagia,dysarthria,parkinsonism,chorea,dystonia and so forth.Osmotic demyelination syndrome is rare,and the incidence is unclear.Due to its a variety of secondary diseases and various clinical manifestations,it can be found in many clinical departments,which may be misdiagnosed and mistreated.With the application of magnetic resonance technology,the diagnosis rate of the disease has been increased.At present,the available literature on the disease is mainly concentrated in case reports.This study retrospectively analyzed the age,gender,underlying disease,clinical manifestations,serological electrolyte,cerebrospinal fluid,magnetic resonance characteristics,treatment and prognosis of 20 patients with osmotic demyelinating syndrome admitted to the author's hospital in order to explore the etiology,clinical manifestations,imaging,treatment and prognosis of the disease,so it may improve the clinicians' understanding of the disease.Materials and MethodsClinical data of 20 patients with osmotic demyelinating syndrome admitted to the Department of Neurology,the First Affiliated Hospital of Zhengzhou University from March 2011 to February 2019 were collected.Inclusion criteria:(1)Underlying diseases such as malnutrition,chronic alcoholism,liver transplantation,kidney disease,hypophysoma or rapid correction of chronic hyponatremia;(2)sudden neurological symptoms,such as paralysis,coma,dysphagia,dysarthria,parkinsonism,chorea,dystonia and so on;(3)brain magnetic resonance imaging with central cerebral and(or)extrapontine symmetry demyelination such as bilaterally symmetrical basal ganglia or other parts,early onset of brain magnetic resonance imaging may be normal.Exclusion criteria:(1)other diseases that cause the above symptoms,such as reversible posterior leukoencephalopathy syndrome,cerebral infarction,parkinsonism caused by other clear causes,multiple sclerosis,etc;(2)patients who were unable or unwilling to take magnetic resonance imaging examination,such as many dentures,with a heart pacemaker,cardiac stent surgery and intracranial vascular stent surgery.The data of 20 patients with osmotic demyelination syndrome were summarized,analyzed and discussed.Including: age,gender,etiology,onset to diagnosis time,clinical manifestations,serological electrolyte,cerebrospinal fluid examination,electroencephalogram,brain magnetic resonance image,treatment,prognosis,etc.Results1.Among the 20 patients,13 were female and 7 were male.The youngest was 25 years old and the oldest was 69 years old.The median age was 54.5.The high incidence age ranged from 50 to 69 years.2.Among the 20 patients,there were 16 patients(80%)with serological electrolyte disorders,13 patients(65%)had hyponatremia,11 patients(55%)had hypokalemia,2 patients(10%)had hypernatremia and 1 patient(5%)had hypochloritemia.Two patients(10%)had unknown serum electrolyte status.Serum electrolytes were normal in 2 patients(10%).Incidence factors included early pregnancy reaction in 1 case(5%),dizziness and frequent vomiting in 3 cases(15%),nausea in 4 cases(20%),pituitrin application in 2 cases(10%),indapamide application in 1 case(5%),hypophysoma in 3 cases(15%),tacrolimus application in 3 cases after liver transplantation(15%),diabetes mellitus with cirrhosis in 1 case(5%),splenectomy in 1 case(5%),chronic alcoholism with malnutrition in 1 case(5%).3.Among the 20 patients,7 patients(35%)had different degrees of disturbance of consciousness,10 patients(50%)had limb weakness,13 patients(66.7%)had different degrees of dysphonia,8 patients(40%)had dysphagia,6 patients(30%)had mutism,5 patients(25%)had bradykinesia,2 patients(10%)had tremor,1 patient had athetosis,and 3 patients(15%)had urinary dysfunction.4 patients(20%)had mental behaviors,2 patients(10%)had seizures and 1 patient(5%)had unstable gait.Physical examination revealed that 12 patients(60%)had rigidity and 5 patients(25%)had positive pathological reflexes.4.Among the 20 patients,16 patients underwent cerebrospinal fluid examination.16 cases(100%)of cerebrospinal fluid leukocyte content,sugar,chloride were normal,1 case(6.3%)of cerebrospinal fluid pressure was slightly increased,and 3 cases(18.8%)of white blood cell classification were abnormal.10 patients underwent cerebrospinal fluid autoimmune encephalitis related antibodies,all of them(100%)were negative.5.Among the 20 patients,6 patients underwent EEG.2 case(33.3%)showed no obvious abnormalities,1 case(16.7%)had mild diffuse abnormality,and 3 cases(50%)had diffuse slow wave.6.All of the 20 patients underwent brain magnetic resonance imaging.No abnormalities were found in 2 of these cases(10%).For the rest,only 2 cases(10%)had pontine involvement,4 cases(20%)had extrapontine involvement,and 12 cases(60%)had both extrapontine involvement and pontine involvement.Among the 20 patients,14 patients(70%)had pons demyelination,13 patients(65%)had bilateral basal ganglia involvement,8 patients(40%)had bilateral thalamic involvement,3 cases(15%)were involved in bilateral midbrain,2 patients(10%)had cerebral peduncle involvement,2 patients had cortex involvement.Bilateral lateral ventricle,bilateral cerebral hemisphere,bilateral cerebellar hemisphere and hippocampus were all involved in one case.Three patients who underwent brain MRI found an expanded range of intracranial demyelination.7.Among the 20 patients,from the onset to the time of diagnosis,the average time for diagnosis of all patients was about 15 days.The average time from neurological symptoms to abnormal brain MRI was about 5.7 days.8.20 patients with ODS in this group were followed up by telephone.5 patients(25%)recovered completely and 13 patients(65%)had some neurological sequela.2 patients were(10%)dead.Among the 3 cases of liver transplantation,1 case were dead,1 case had persistent vegetative state and 1 case could not take care of himself.Conclusion1.The most common cause of ODS is the rapid correction of chornic hyponatremia.2.Intracranial demyelination in ODS patients first appears in the bilateral basal ganglia,then in the pons.3.Most of the patients with ODS have poor prognosis.Early diagnosis and treatment may improve the prognosis.