A case of parkinsonism due to pontine and extrapontine myelinolysis]

A 43-year-old man who presented parkinsonism due to pontine and extrapontine myelinolysis was reported. Late in February, 1990, the patient presented suffered from a flu-like illness and was seen at a community hospital. Physical finding showed the pigmentation on the whole body and hypotension, and laboratory examination revealed severe electrolyte imbalance (serum sodium 100 mEq/l, serum potassium 6.9 mEq/l, serum chloride 68 mEq/l) and hypoglycemia (postprandial serum glucose 78 mg/dl). Given these results, adrenal failure was strongly suspected. Prompt correction of electrocyte imbalance was performed by the infusion of sodium chloride, and four days later the serum sodium level reached 131 mEq/l. On the other hand, the patient was noticed lethargic and showed parkinsonism i.e., rest tremor, cog-wheel rigidity, and hypokinesia. Fourteen days after the onset of neurological abnormalities, the patient was referred to our hospital for further evaluation of parkinsonism. Additionally, neurological examination revealed dysphagia, mutism and positive pyramidal tract sign. On admission brain computed tomography was unremarkable, but on the 14th hospital day it showed low density area in the pons. Brain magnetic resonance imaging also showed a striking increase in T2-weighted signal from the pons, the midbrain, and the bilateral thalamus. Based on these findings, a diagnosis of parkinsonism due to pontine and extrapontine myelinolysis was made, and levodopa therapy was started. After the initiation of levodopa therapy, improvement of tremor, rigidity, and hypokinesia ensued with marked functional benefit, and the patient was discharged on the 49th hospital day. Levodopa was stopped three weeks after discharge but, all neurological abnormalities were not recurrent.(ABSTRACT TRUNCATED AT 250 WORDS)     

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: 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.     

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.     

Central pontine and extrapontine myelinolysis: a report of 58 cases

In 58 cases with central pontine myelinolysis (CPM) and/or extrapontine myelinolysis, systematic examination of the central nervous system was performed. The demyelinating disease occurred in three subtypes: (1) CPM, in which the lesion was confined to the pons, (2) CPM combined with extrapontine myelinolysis and (3) exclusively extrapontine myelinolysis. Type (1) was found in 27 cases, (2) in 18 cases and (3) in 13 cases. Cerebellum and lateral geniculate body were the most frequently affected extrapontine regions. One case with an extreme extension of the lesions is described in detail. Extrapontine lesions seem to be more frequent and widespread than has been hitherto reported in the literature.     

A case of central pontine and extra-pontine myelinolysis demonstrated by magnetic resonance imaging]

A 74-year-old woman was admitted because of disturbed consciousness due to iatrogenic hyponatremia. At admission, her serum level of sodium was 88 mEq/l. The hyponatremia was carefully corrected with physiologic saline for three days at a rate of 0.75 mEq/h until the serum sodium concentration of 135 mEq/l was achieved. Her neurologic state gradually improved to respond to painful stimuli with her left hand during the first week of treatment, but further improvement was not noted after that. On the 16th hospital day, seizure developed on her face and left upper extremity. Although abnormal lesions were not detected by MRI of the brain at admission, those performed on the 15th hospital day revealed multiple uncommon lesions with Tl and Gd enhanced images. On Tl images areas of low signal intensity were found in the central pons and left putamen, which were more clearly demonstrated by Gd enhanced MRI images. These lesions were considered to be consistent with central pontine and extra-pontine myelinolysis (CPEM). In addition, a part of the right temporal cortex was enhanced clearly by Gd-DTPA, which was also thought to be an extra-pontine myelinolysis. These lesions were responsible for the development of neurological signs due to CPEM. To our knowledge, this is the first case in which a lesion in the cerebral cortex was revealed as an extra-pontine myelinolysis by Gd enhanced MRI images. Gd enhanced MRI is useful for detecting the extra-pontine myelinolysis as well as central pontine myelinolysis.     

Osmotic demyelination syndromes: central and extrapontine myelinolysis.

Osmotic demyelination syndromes are often progressive disorders, with clinical features ranging from a mild tremor or dysarthria to a progressive quadraparesis. Although rapid correction of serum sodium is known to be a potent causative factor, additional pathogenic factors exist, which appear critical in predisposing pontine and extrapontine glia to osmotic stress. Interestingly, several cases of osmotic demyelination have emerged where serum sodium was found to be within normal limits and minimal or no correction of a hypo or hypernatraemic state was implemented. We describe two cases--one of extra pontine and another of central-pontine myelinolysis, both of which have occurred in the context of relatively normal serum sodium. The first case illustrates the association of extrapontine myelinolysis with the traditional risk factor of alcoholic cirrhosis and intravenous fluid resuscitation, while the second, more unusual case, describes a patient who developed central pontine myelinolysis possibly in association with alpha interferon therapy.     

Central pontine myelinolysis

Summary Thirty-seven cases of central pontine myelinolysis (CPM) with miscellaneous underlying disorders were found in 1,000 consecutive autopsies, of which 636 brains were examined. The incidence of CPM in this study was 5.8%. The frequent underlying disorders were malignant neoplasms (43%), chronic pulmonary disease (27%), and chronic renal failure cases under dialysis treatment (14%). Fatty liver cirrhosis due to alcohol abuse was recognized in only one CPM case. In the present study, 78% of the CPM cases revealed either electrolyte disturbances or abnormal blood gas data, such as marked deviation of base excess and/or of serum pH in 62.5%, hyper- or hypochloremia (above 115 mEq/l, below 95 mEq/l) in 47%, hyper- or hyponatremia (above 150 mEq/l, below 130 mEq/l) in 25%, marked hypoxemia (less than 40 mmHg) in 12.5% and hypokalemia (below 3.0 mEq/l) in 9% of the CPM cases. The myelinolytic changes were localized in the basis pontis in 14 of 37 CPM cases and in the basis pontis and the cerebral and/or cerebellar white matter (extrapontine myelinolysis) in the remaining 23 cases. The extrapontine changes were also closely related to the electrolyte disturbances or the abnormal blood gas data. The results of this study suggest that myclin and oligodendrocytes in the basis pontis and cerebral and cerebellar white matter are vulnerable to abnormal levels of serum electrolytes and also to marked changes of the acid-base balance.     

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.     

Central pontine and extra-pontine myelinolysis following rapid correction of hyponatremia--a case report

An autopsy case of central pontine and extrapontine myelinolysis following rapid correction of hyponatremia is reported. Hyponatremia was induced by massive devastation of adrenal cortex due to tuberculosis. Severe hyponatremia (approximately 100 mEq/l of serum sodium level) was rapidly corrected by infusion of hypertonic saline solution within two days. After transient regression of her consciousness, the patient developed decorticated state and then complete paralysis of all limbs. She died of pneumonia approximately one month after the last illness. The autopsy revealed myelynolysis in the center of the pontine basis. The nerve cells and axon cylinders were relatively well preserved. In addition, the similar lesions were seen in the subcortical gray matter and cerebral cortex. The thin white matter at the site characterized by an extensive admixture of gray and white matter was selectively involved. The pathogenesis of this disorder is briefly discussed.     

A case report of central pontine and extrapontine myelinolysis which occurred during pregnancy and was accompanied by choreic movement

A 25-year-old female in the 17th week of pregnancy was diagnosed by MRI as having central pontine and extrapontine myelinolysis. Serial observations with MR showed gradual disappearance of the lesions in the pons and striatum. Improvement of the symptoms took place shortly before disappearance of the lesions on MRI pictures. The initial symptoms were consciousness disturbance, cranial nerve palsy and tetraparesis. Before the latter disappeared seven months after occurrence of the disease, all other symptoms gradually improved. They were followed by delayed appearance of choreic movements, which was still remaining one year after discharge. It is rare for a pregnant woman to be attacked by central pontine myelinolysis. Moreover, very few symptoms caused by such extrapontine lesions have so far been reported. Also, a review of the relevant literature by the authors found no other case showing choreic movements. This report is of an extremely rare case of central pontine and extrapontine myelinolysis which occurred during pregnancy and is accompanied by choreic movements.     

Hyponatremia: cerebral symptoms and role in central pontine myelinolysis

Central nervous system symptoms due to hyponatremia is highly dependent on its acuteness and cause. Severe acute hyponatremia (serum sodium less than 125 mEq/l) often causes confusion, lethargy, seizures or frank coma due to brain oedema. If therapy is delayed, hyponatremia carries a high mortality rate, and risk of irreversible brain damage. Hyponatremia should probably be corrected to 125-130 mEq/l at a rate of 1.5-2.0 mEq/l/h. Malnourished alcoholic patients with hyponatremia may represent a special case with possible dangers of central pontine myelinolysis if a very low serum sodium is corrected acutely to normonatremic or hypernatremic levels. Mortality in this subgroup is high whatever the therapy.     

Central pontine myelinolysis following rapid correction of hyponatremia

Central pontine and extrapontine myelinolysis was experimentally produced in dogs by the rapid correction of severe, sustained, vasopressin-induced hyponatremia. Hyponatremia alone or slowly corrected hyponatremia did not produce the disease. Affected dogs showed rigid quadriparesis. The central pons, lateral aspects of the thalamus and adjacent internal capsules, deep layers of cerebral cortex and subjacent white matter, cerebellum, and other regions were symmetrically involved. Myelin and oligodendroglia were affected out of proportion to axons and neurons. Thus, the clinical features, the distribution of the lesions, and their histological features closely resemble the human disease. These experiments document an electrolyte manipulation that can cause permanent neuropathological lesions. Taken with the available clinical data on human patients, the experimental results indicate that human myelinolysis may be due to a rapid increase in serum sodium from previously low levels, and that rapid normalization of severe, sustained hyponatremia should therefore be avoided.     

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 a pediatric case of diabetic ketoacidosis and cerebral edema

Central pontine and extrapontine myelinolysis are characterized by symmetric demyelination following rapid shifts in serum osmolality, although in extrapontine myelinolysis, demyelination is confined to the supratentorial compartment. We present a case of extrapontine myelinolysis in a 17-year-old female that occurred in the setting of diabetic ketoacidosis, cerebral edema, mannitol therapy, and meningitis. The rate of correction of this patient's glucose and electrolyte levels was within well-accepted limits. Extrapontine myelinolysis is rare in pediatric patients: there are only 12 reports of extrapontine myelinolysis in children under age 20 years and no pediatric cases of extrapontine myelinolysis or central pontine myelinolysis associated with diabetic ketoacidosis. We review the published cases of extrapontine myelinolysis and examine the underlying etiologies and electrolyte disturbances that characterize these cases. This case expands the list of conditions in which extrapontine myelinolysis occurs to include pediatric patients with complicated diabetic ketoacidosis, emphasizing the importance of sudden osmolar shifts in the genesis of this disorder.     

脑桥中央和脑桥外髓鞘溶解症的临床分析和影像特点

目的:探讨脑桥中央和脑桥外髓鞘溶解症的临床及神经影像特点。方法:分析3例脑桥中央髓鞘溶解症和1例脑桥外髓鞘溶解症患者的临床特点,包括起病前诱因、临床表现、头颅MRI特点、治疗及预后情况。结果:4例患者均有慢性形成低钠血症后被快速纠正的病史,以意识改变、构音和吞咽困难、四肢瘫痪等为临床表现。3例脑桥中央髓鞘溶解症的MRI表现为脑桥部位对称性的T1加权低信号灶、T2加权高信号灶,呈环状分布;1例脑桥外髓鞘溶解症者在基底节区域有对称性的T1加权低信号、T2加权高信号病灶。4例患者总体预后良好。结论:提高髓鞘溶解症的认识对于本病的防治非常重要,缓慢纠正慢性形成的低钠血症是预防的关键。     

Central pontine myelinolysis after rapid correction of hyponatremia: a magnetic resonance imaging study

We describe a patient with severe hyponatremia (serum sodium 94 mmol/L) who developed encephalopathy and decorticate posturing after a 29 mmol/L rise in serum sodium concentration during the first 24 hours of correction. High-resolution computed tomography of the pons was normal during the first, second, and twelfth weeks of the illness. Subsequent magnetic resonance imaging revealed a pontine lesion consistent with central pontine myelinolysis.     

Central pontine and extrapontine myelinolysis owing to disequilibrium syndrome

Neurologic disorders can be seen in patients with end-stage renal failure owing to complications of hemodialysis or peritoneal dialysis. The disequilibrium syndrome can be seen, usually soon after or toward the end of dialysis. We report a patient with central pontine and extrapontine myelinolysis owing to disequilibrium syndrome. The patient had depressed consciousness, agitation, tremor, stupor and hyperactive deep tendon reflexes toward the end of the second peritoneal dialysis. A brain computed tomographic (CT) scan showed hypodense lesions in pontine and extrapontine locations without radiocontrast medium enhancement After 2 days, the patient had only minimal memory deficits. A control brain CT scan 1 week later showed a decrease of the lesions in central pontine and extrapontine locations. Central pontine and extrapontine myelinolysis should be suspected and investigated in the acute neurologic disorders of dialysis patients.     

Parkinsonism and dystonia in central pontine and extrapontine myelinolysis

Parkinsonism as well as dystonic signs are rarely seen incentral pontine myelinolysis and extrapontine myelinolysis. A 51yearold woman developed central pontine myelinolysis and extrapontine myelinolysis with parkinsonism after severe vomiting which followed alcohol and drug intake, even though marked hyponatraemia had beencorrected gradually over six days. Parkinsonism resolved four monthsafter onset, but she then exhibited persistent retrocollis, spasmodicdysphonia, and focal dystonia of her left hand. Although the medicalliterature documents three similar patients, this patient is differentas dystonic symptoms only developed four months after parkinsoniansigns had resolved.

     

Central pontine myelinolysis: delayed changes on neuroimaging.

The authors report two cases, a 44-year-old woman and a 6-year-old girl who had mental status changes and hyponatremia. Serum sodium levels in both of these cases were corrected quickly with further decline in their mental status, and the patients became quadriparetic. Magnetic resonance imaging (MRI) studies performed then did not reveal any abnormalities, whereas a repeat imaging study performed 10-14 days after the shift in serum sodium revealed evidence for central pontine myelinolysis and extrapontine demyelination. The clinical manifestations and distribution of lesions seen on the imaging studies demonstrated that the above presentation of neurologic illness is the result of hyponatremia and its correction. The authors conclude that imaging studies performed early during the illness may be unremarkable, but still a diagnosis of central pontine myelinolysis should be suspected and, most importantly, a repeat imaging study might be required in 10-14 days to establish the diagnosis of central pontine myelinolysis.