Improvement of central pontine myelinolysis as demonstrated by repeated magnetic resonance imaging in a patient without evidence of hyponatremia.

Central pontine myelinolysis is usually associated with hyponatremia or rapid correction of this condition. 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. The initial magnetic resonance (MR)-imaging showed a marked lesion in the central pontine area, sequential MR-imaging revealed progressive reduction of this defect over the following months. This reduction was accompanied by excellent clinical recovery. This case report demonstrates that central pontine myelinolysis is not always associated with hyponatremia and illustrates that, although in general the prognosis is bad, some patients may recover with improvement of the abnormalities on the MR-images.     

Delayed onset movement disorders as a complication of central pontine myelinolysis

This report describes a case of central pontine myelinolysis occurring after a rapid correction of profound hyponatremia. Delayed-onset generalized dystonia and choreoathetosis then appeared. A small pontine myelinolysis was demonstrated by magnetic resonance images, but striatal myelinolysis could not be established. Aspects of movement disorders associated with the osmotic demyelination syndrome are briefly reviewed and discussed.     

Parkinsonism after correction of hyponatremia with radiological central pontine myelinolysis and changes in the basal ganglia.

Parkinsonism has been rarely described following central pontine and extrapontine myelinolysis. We report a case of parkinsonism developing following rapid correction of hyponatremia with radiological evidence of central pontine myelinolysis and changes in the basal ganglia. A 56-year-old man developed drooling and bilateral hand tremors 3 weeks after correction of hyponatremia from 103 to 125 mmol/L over 14 h. He had a prominent 6 Hz resting tremor which worsened with action and mild cogwheel rigidity. Magnetic resonance imaging (MRI) showed changes consistent with central pontine myelinolysis and increased signal on T1-weighted images in the putamen bilaterally. His tremor responded well to L-dopa therapy. There have been several other cases of parkinsonism developing after central pontine/extrapontine myelinolysis. Increased signal in the basal ganglia on T1-weighted images has been described in another case of central pontine myelinolysis imaged about the same time after sodium correction as our case.     

Extrapontine myelinolysis in infancy: report of a case

Osmotic myelinolysis is a rare, acute, demyelinating process that involves the pons (central pontine myelinolysis) and other locations of the central nervous system (extrapontine myelinolysis). Central pontine myelinolysis is described in children, usually associated with rapid correction of hyponatremia. Other conditions, such as hypernatremia and hyperglycemia, have also been reported as being responsible for pontine myelinolysis. Extrapontine myelinolysis in childhood is very rare and presents in a wide variety of locations. We report a patient who developed extrapontine myelinolysis in the cerebellum during treatment of hyponatremic dehydration. This is the first case reported during infancy.     

Central pontine and extrapontine myelinolysis associated with acute hepatic dysfunction

Central pontine myelinolysis and extrapontine myelinolysis are rare demyelinating diseases of the central nervous system. These diseases are related frequently to rapid correction of hyponatremia. They have also been described in association with other underlying conditions such as alcoholism and malnutrition. In the present study, we report a case of central pontine and extrapontine myelinolysis with acute hepatic dysfunction. The patient had no apparent evidence of hyponatremia and no history of alcohol abuse. On admission, the patient was lethargic; dysphagia, dysarthria, and quadriplegia were noted. Laboratory examination showed significantly increased transaminase without hyponatremia. Magnetic resonance imaging revealed abnormal signal intensities in the pons and thalamus. Consciousness level and clinical symptoms improved gradually within a week. We suggest that acute hepatic dysfunction may play an important role in the development of central pontine myelinolysis and extrapontine myelinolysis.     

Osmotic myelinolysis in a normonatremic patient

Osmotic demyelination syndrome is usually associated with hyponatremia or rapid correction of this condition. The prognosis is usually fatal. We treated a 34-year-old chronic renal failure patient who did not have hyponatremia but developed severe pontine myelinolysis demonstrated with MRI. Serial MRI revealed gradual reduction of the lesions over 2 months. This case demonstrates that osmotic demyelination syndrome is not always associated with hyponatremia, and that, although the prognosis is usually poor, some patients recover.     

Central pontine myelinolysis following ‘slow’ correction of hyponatremia

Two patients with central pontine myelinolysis are described for the peculiar mode of development. Both patients were in chronic renal failure and admitted in a stuporous state due to hyponatremia. Both developed central pontine myelinolysis during the hospital stay following slow and judicious correction of hyponatremia. The role of chronicity of hyponatremia prior to its correction, in the genesis of central pontine myelinolysis, particularly in the patients who have chronic debilitating illness, septicemia or malnutrition, is highlighted.     

Central pontine and extra-pontine myelinolysis in an alcoholic patient without hydro-electrolyte disturbances: case report

Central pontine myelinolysis (CPM) and extra-pontine myelinolysis (EPM) are different presentations of a demyelinating disorder of the brain more commonly associated with rapid correction of hyponatremia, spastic tetraparesia and pseudo-bulbar palsy. There are in the literature a few cases of CPM/EPM in patients without electrolyte disturbances. We report the case of a 39 year-old man with severe alcoholism, who presented with spastic tetraparesis and palsy of several cranial nerves, associated with lesions in the magnetic resonance compatible with CPM/EPM. The patient had a good follow-up after pulse therapy with corticosteroids.     

"Man-in-the-barrel" syndrome as delayed manifestation of extrapontine and central pontine myelinolysis: beneficial effect of intravenous immunoglobulin

"Man-in-the-barrel" syndrome has been rarely described following osmotic myelinolysis. We report a case of a 45-year-old woman admitted with septicemia and severe hyponatremia. She presented with a "man-in-the-barrel" syndrome which developed more than 10 days after rapid correction of the hyponatremia. There was radiological evidence of central pontine and extrapontine myelinolysis. Three days after completing a course of intravenous immunoglobulin therapy (0.4 g/kg body weight/day for 5 days) there was considerable improvement (Expanded Disability Status Scale score improved 30%). This case, reported for its peculiar mode of development, unusual presentation and challenging therapeutic response to intravenous immunoglobulin, highlights the enigmatic and unpredictable aspects of osmotic myelinolysis.     

Psychotic disorder in a patient with central and extrapontine myelinolysis

Central pontine and extrapontine myelinolysis (CPEM) are rare conditions usually associated with rapid correction of hyponatremia. Neurologic complications are the usual sequelae although neuropsychiatric features are rare. Described herein are unusual psychotic symptoms following CPEM and discussion of the likely pathogenesis and implications for treatment.     

Central pontine and extrapontine myelinolysis: report of an autopsied case and review of the literature

An autopsied case of central pontine and extrapontine myelinolysis in a 16-year-old diabetic girl is described. Due to dehydration she was treated vigorously with daily intravenous isotonic saline, from the first day of hospitalization. In the first three days the serum sodium level increased by more than 30 mEq/l when compared with the initial level. By the next days the serum sodium level, after a mild drop, rose again and was maintained above normal range for a further 12 days. On the sixth day of this new and sustained serum sodium increase, the patient presented progressive neurological manifestations that remained until her death, characterized by mutism, inability to eat, to move her head, trunk, and members and, in addition, retention of respiratory secretions. The neuropathological examination showed massive central pontine myelinolysis and similar myelinolytic lesions in the subcortical white matter of the temporal lobe, the right optic tract, the external and extreme capsules to the right, the main mammillary tract and the subcortical white matter of the left cerebellar hemisphere. The review of the literature on central pontine and extrapontine myelinolysis shows that the present case is the 30th of such condition. The clinical picture and the etiopathogenesis of central pontine and extrapontine myelinolysis are commented upon. It is suggested, as possible causative factors, the persistent and rapid correction of serum sodium concentration as well as its fluctuation in patients with hyponatremia and/or dehydration.     

Cerebellar peduncular myelinolysis in a patient receiving hemodialysis

Here, we report the observation of extrapontine lesions, in addition to the pontine lesions previously documented in a diagnosed case of hemodialysis-associated osmotic demyelination syndrome due to end-stage renal disease. The patient exhibited lesions on bilateral middle cerebellar peduncles, and had been receiving regular hemodialysis as treatment for end-stage renal disease. He presented with progressive gait disturbance and postural instability. Accompanying symptoms included peduncular hallucinations and mild cognitive dysfunction. Brain MRI revealed high signal intensity in the area of bilateral cerebellar peduncles on the diffusion and T2-weighted images, with a decreased signal intensity noted on the ADC map. The ataxic form of osmotic myelinolysis syndrome is quite rare. The involvement of the cerebellar peduncles in extrapontine myelinolysis in a patient with end stage renal disease has not, to our knowledge, been previously reported. Here, we describe the MRI findings and clinical features associated with this unique case, and include a review of the relevant literature.     

Lateral pontine and extrapontine myelinolysis associated with hypernatremia and hyperglycemia

Efforts to understand and prevent pontine and extrapontine myelinolysis have focused on the correction of hyponatremia, but controversy persists. We report a woman who presented in hyperosmolar diabetic coma with hypernatremia (169 mEq/l) and hyperglycemia (954 mg/dl). Plasma sodium rapidly increased to 188 mEq/l before gradually returning to normal. She remained obtunded and died 21 days later. Autopsy showed widespread, symmetrical demyelination involving the subcortical white matter, corpus callosum, anterior commissure, extreme, external, and internal capsules, fornix, thalamus, cerebellum, and lateral pons. The central pons and lateral geniculate nuclei were uninvolved. This case illustrates that lateral pontine and extrapontine myelinolysis can be associated with hypernatremia and hyperosmolality. In both hypo- and hypernatremic states, the significant event may be an increase in serum sodium or serum osmolality of sufficient rapidity and magnitude.     

Akinetic-rigid syndrome due to extrapontine and pontine myelinolysis following appropriate correction of hyponatraemia

Extrapontine myelinolysis in association with the more common central pontine variety is increasingly reported. Although typically associated with rapid correction of hyponatraemia, myelinolysis is also seen when sodium correction occurs at recommended rates. We present a 60-year-old man who developed hyponatraemia and hypokalaemia due to repeated vomiting. An acute symmetric akinetic-rigid syndrome followed correction of hyponatraemia, performed in line with current guidelines. There were no clinical features of pontine involvement even though a typical lesion was seen on MRI. Bilateral putaminal and caudate lesions were seen. He recovered well with only symptomatic treatment. Myelinolysis can present with features of extrapontine involvement with the pontine lesions remaining asymptomatic. Current guidelines for the correction of hyponatraemia do not prevent development of myelinolysis in all instances. In contrast to the generally expected poor outcome in this condition, patients do make a good recovery with symptomatic treatment and good nursing care.     

脑桥中央髓鞘溶解症和脑桥外髓鞘溶解症5例临床分析

目的　探讨脑桥中央髓鞘溶解症 (CPM)和 /或脑桥外髓鞘溶解症 (EPM)的发病机制及早期预防和诊治原则。方法　对 5例CPM/EPM患者的临床表现、影像学资料及治疗转归进行分析。结果　临床观察发现 :(1)5例患者均存在严重的基础疾病 ,特别是严重的电解质紊乱 (低钠血症 ) ,不同程度的意识障碍 ,吞咽困难 ,构音障碍。 (2 ) 3例有四肢瘫 ,锥体束征阳性 ;1例表现为帕金森综合征。 (3) 5例头颅MRI均阳性。 (4) 5例均临床好转出院 ,生活自理。结论　 (1)CPM和 /或EPM的发生与低钠血症及快速纠正低钠血症有关。 (2 )CPM和 /或EPM并非致死性疾病 ,无论病情多严重 ,均不应放弃治疗。     

Chronicity of hyponatremia as a factor in experimental myelinolysis

A recent analysis of hyponatremic patients disclosed that those who were chronically hyponatremic prior to rapid correction subsequently developed central pontine myelinolysis. To test the view that chronicity of hyponatremia is a factor in myelinolysis, we studied a group of rats that were hyponatremic for 1 day and compared it with another group of animals maintained in a hyponatremic state for 3 days prior to the administration of hypertonic saline solution. The 3-day hyponatremic rats developed more numerous and more severe demyelinative lesions than the 1-day rats. The findings support the view that duration of hyponatremia is a factor in myelinolysis and that the electrolyte disturbance of chronically hyponatremic patients should be corrected cautiously and relatively slowly.     

Extrapontine myelinolysis with involvement of the hippocampus in three children with severe hypernatremia

Central pontine myelinolysis is a disorder of unknown etiology linked to overly aggressive correction of hyponatremia. In addition to the typical location of demyelination with preservation of neurons and axon cylinders in the basis pontis, similar lesions have been described in extrapontine locations. Central pontine myelinolysis and extrapontine myelinolysis usually occur together, and are identified at autopsy rather than in life because symptoms of extrapontine myelinolysis are often masked in the critically ill patient. Central pontine myelinolysis is described in children, usually in the clinical setting of hyponatremic dehydration. Extrapontine myelinolysis has not been described in children previously. We report three children with severe hypernatremia and extrapontine myelinolysis involving various combinations of thalamus, basal ganglia, external and extreme capsules, and cerebellar vermis. All three had additional involvement of the hippocampus seen on T2-weighted magnetic resonance imaging. None of the three had detectable pontine lesions. Clinical features of the three cases were dehydration in a 28-month-old girl, respiratory syncytial virus bronchiolitis in a 14-month-old girl, and acute respiratory failure due to anaphylaxis after consumption of walnuts in a 3-year-old boy. Peak sodium values in each child were 195, 168, and 177 mmol/L, respectively; each received aggressive treatment for hypernatremia. We believe this to be the first report of extrapontine myelinolysis in children, the first report of extrapontine myelinolysis without central pontine myelinolysis in children, and the first report in children of hippocampal formation involvement. The pathogenesis of the central and extrapontine myelinolysis complex in children is more complicated than previously believed, and might differ significantly from that of adults.     

Behavioral manifestations of central pontine myelinolysis

A young woman with a clinical history and magnetic resonance imaging scan consistent with central pontine myelinolysis came to medical attention because of prominent behavioral symptoms. Marked clinical recovery occurred despite persistent radiologic abnormalities. Rapid correction of hyponatremia was probably related to the development of the central pontine myelinolysis. A normal computed tomographic scan and the absence of brain-stem signs delayed accurate diagnosis.     

Central pontine myelinolysis following correction of hyponatremia: MRI diagnosis

A 37-year-old woman with hepatic failure developed a locked-in syndrome after correction of a severe symptomatic hyponatremia. Magnetic resonance imaging showed a lesion involving the basis pontis and extending into the midbrain, consistent with central pontine myelinolysis. In this patient the rate of correction of hyponatremia was within the range considered sure by several authors, but factors such as hepatic encephalopathy, a single generalized seizure and correction of hyponatremia in 42 h with a change in serum sodium concentration of 34 mmol/l were present, and they could have been etiologically relevant. This case, like other recent reports, suggests new views about the pathogenesis of cerebral demyelinating lesions in patients with hyponatremia.     

Protective effect of steroids in electrolyte-induced demyelination

Electrolyte-induced demyelination (EID), an experimental model for central pontine myelinolysis was produced in rats by inducing hyponatremia followed by hypernatremia. There was a marked reduction in the number and size of lesions developing in animals that were bled repeatedly by tail transection during induction of the disease. Subsequently a similar protective effect was produced in animals by injecting a single dose of dexamethasone, one hour before the induction of hypernatremia. These findings suggest that steroids may be useful in preventing central pontine myelinolysis from developing in high risk patients requiring urgent correction of hyponatremia.