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.     

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。     

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。     

Dystonia in central pontine myelinolysis without evidence of extrapontine myelinolysis.

A 44-year-old female is described who developed persistent upper extremity and orolingual dystonia several weeks after suspected onset of central pontine myelinolysis (CPM), later confirmed by characteristic pontine lesions on MRI. No foci of the extrapontine myelinolysis were evident. This case confirms that dystonia may be a late and persistent sequela of CPM and may occur in the absence of visible lesions outside the brainstem.     

Central pontine myelinolysis.

Central pontine myelinolysis (CPM) is a demyelinating disease of the pons often associated with demyelination of other areas of the central nervous system (CNS). The term 'osmotic demyelinization syndrome' is used for pontine and extrapontine myelinolysis. In this paper, we are concerned with CPM although the extrapontine one is based on the same pathogenesis. 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. Chronic alcoholism is still the most common underlying condition of CPM patients. In the literature, 174 cases of CPM have been reported in alcoholics since 1986, which is equivalent to an incidence of 39.4%. Likewise, 95 cases of CPM following the correction of hyponatremia have been documented since 1986 (21.5%). The role of hyponatremia and its correction will be outlined in the discussion of the pathogenesis of CPM. The third largest group of CPM cases are liver transplant patients (17.4%), with the development of CPM being attributed to the immunosuppressive agent cyclosporine in particular. Depending on the involvement of other CNS structures, the clinical picture can vary considerably. The large-scale introduction of magnetic resonance imaging has increasingly facilitated the antemortem diagnosis of CPM, although the radiological findings lag behind and do not necessarily correlate with the clinical picture. As yet, there is no specific therapy of choice. A number of therapeutic approaches have been tested and although they have not been compared with regard to their rate of success, they have all led to a substantial improvement in the prognosis of CPM.     

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.     

Belly dancer's syndrome following central pontine and extrapontine myelinolysis.

We report on a woman with delayed-onset of belly dancer's syndrome 5 months after central pontine and extrapontine myelinolysis (CPM/EPM) and severe hyponatriemia. This case demonstrates that basal ganglia lesions in EPM can be the underlying pathoanatomic substrate for the rarely observed belly dancer's syndrome. The sequential appearance of extrapyramidal symptoms might reflect an ongoing but ineffective or deficient remyelination process. The presence of CPM/EPM should be considered in patients with involuntary dyskinesias of the abdominal wall.     

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.     

Overlapping features of extrapontine myelinolysis and acquired chronic (non-Wilsonian) hepatocerebral degeneration

Central pontine myelinolysis (CPM, osmotic demyelination syndrome) and acquired chronic hepatocerebral degeneration (ACHD) both occur in patients with liver failure, but are not thought to be caused by similar etiopathogenic mechanisms despite the fact that occasional patients exhibit both disorders. In our autopsy practice we have recently encountered three patients with the pontine lesions of acute or subacute osmotic demyelination syndrome, coupled with superimposed non-Wilsonian ACHD. All three patients had well-documented rapid elevations in serum sodium proximate to their demise, as well as terminal liver failure. A close intermingling and juxtaposition of lesions with severe demyelination and macrophage breakdown [thought to represent extrapontine myelinolysis (EPM)] to those with vacuolization of myelin but no cellular reaction or myelin loss (ACHD) was noted within some of the same anatomic areas. Particular overlap was seen in lesions at the cerebral cortical gray–white junction and in pencil fibers of the striatum. In these areas it was difficult to be certain whether the lesions were due to EPM or ACHD. We concluded that there was a synergism between the two disorders and raise the possibility that there may be factors common to both disorders that lead to similar anatomic sites for involvement.Presented (in abstract format) at XVIth International Congress of Neuropathology, San Francisco, Sept 10–15, 2006.     

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 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.     

Central pontine myelinolysis after liver transplantation

Eight adults and 3 children out of 85 patients who had neuropathologic examination after death following orthotopic liver transplantation showed central pontine myelinolysis (CPM). Four patients also had extrapontine myelinolysis. Eight patients had significant serum sodium changes. In 5, the fluctuation occurred perioperatively and 4 had a clinical picture consistent with CPM, although no patient had this as an antemortem diagnosis. We emphasize the role of hepatic dysfunction as a cause of CPM and recommend careful monitoring of electrolytes in the perioperative period of patients undergoing liver transplantation.     

Central pontine myelinolysis, an update

Central pontine myelinolysis (CPM) can be regarded as one of the demyelinating syndromes. First described by Adams et al. in 1959 in their chronic alcoholic patients, it has now been described in the malnourished, the chronically debilitated, the renal, the hepatic and the transplant patient among others. Pathologically, it is defined as a symmetric area of myelin disruption in the center of the basis pontis, although similar symmetric lesions have also been described occurring with CPM as well as independently in other brain areas (extrapontine myelinolysis or EPM) including the cerebellar and neocortical white/gray junctional areas, thalamus and striatum. Possible mechanisms include a hyperosmotically induced demyelination process resulting from rapid intracellular/ extracellular to intravascular water shifts producing relative glial dehydration and myelin degradation and/or oligodendroglial apoptosis. The process most often occurs during rapid rebalancing of the electrolyte parameters in the hyponatremic patient. Avoidance of CPM/EPM is dependent upon recognizing those patients with conditions pre-disposing them to osmotic myelinolysis and then moderating the rate of normalization of the electrolyte imbalance. 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.     

渗透性脱髓鞘综合征的临床和影像学研究(附四例报道)

目的 探讨渗透性脱髓鞘综合征的临床和神经影像特点.方法 对4例渗透性脱髓鞘综合征患者的临床演变过程、CSF、头颅CT和MRI、EEG动态变化特点、治疗及预后进行分析.结果 4例患者均存在低钠血症,纠正后出现精神意识改变、构音和吞咽困难、四肢瘫痪、肌张力障碍等症状,临床过程有双相性.EEG出现一过性的重度异常.头颅CT及CSF均未见异常.MRI特征性影像晚于临床表现10 d以后出现,4例患者首次MRI均为阴性,7～13 d后复查才显示病灶.MRI示4例患者均存在脑桥外髓鞘溶解症病灶,T1WI加权低信号,T2WI加权高信号,对称性地累及双侧尾状核、豆状核、丘脑、脑岛叶皮质、海马头部等部位,其中3例同时存在脑桥中央髓鞘溶解症改变,呈脑桥基底部位对称性T1低、T2高信号的蝶形病灶;Flair加权异常信号更清楚.3例有好转或痊愈,其中1例遗留明显肌张力障碍.结论 渗透性脱髓鞘综合征与慢性低钠血症有关,合并低血钾、低血氯时可能更易发生.治疗时应尽量避免过快纠正,临床病程具有双相性.MRI的特征性改变出现较迟,复查MRI是非常必要的.     

渗透性脱髓鞘综合征的临床和影像学研究(附四例报道)

目的 探讨渗透性脱髓鞘综合征的临床和神经影像特点.方法 对4例渗透性脱髓鞘综合征患者的临床演变过程、CSF、头颅CT和MRI、EEG动态变化特点、治疗及预后进行分析.结果 4例患者均存在低钠血症,纠正后出现精神意识改变、构音和吞咽困难、四肢瘫痪、肌张力障碍等症状,临床过程有双相性.EEG出现一过性的重度异常.头颅CT及CSF均未见异常.MRI特征性影像晚于临床表现10 d以后出现,4例患者首次MRI均为阴性,7～13 d后复查才显示病灶.MRI示4例患者均存在脑桥外髓鞘溶解症病灶,T1WI加权低信号,T2WI加权高信号,对称性地累及双侧尾状核、豆状核、丘脑、脑岛叶皮质、海马头部等部位,其中3例同时存在脑桥中央髓鞘溶解症改变,呈脑桥基底部位对称性T1低、T2高信号的蝶形病灶;Flair加权异常信号更清楚.3例有好转或痊愈,其中1例遗留明显肌张力障碍.结论 渗透性脱髓鞘综合征与慢性低钠血症有关,合并低血钾、低血氯时可能更易发生.治疗时应尽量避免过快纠正,临床病程具有双相性.MRI的特征性改变出现较迟,复查MRI是非常必要的.     

渗透性脱髓鞘综合征的临床和影像学研究(附四例报道)

目的 探讨渗透性脱髓鞘综合征的临床和神经影像特点.方法 对4例渗透性脱髓鞘综合征患者的临床演变过程、CSF、头颅CT和MRI、EEG动态变化特点、治疗及预后进行分析.结果 4例患者均存在低钠血症,纠正后出现精神意识改变、构音和吞咽困难、四肢瘫痪、肌张力障碍等症状,临床过程有双相性.EEG出现一过性的重度异常.头颅CT及CSF均未见异常.MRI特征性影像晚于临床表现10 d以后出现,4例患者首次MRI均为阴性,7～13 d后复查才显示病灶.MRI示4例患者均存在脑桥外髓鞘溶解症病灶,T1WI加权低信号,T2WI加权高信号,对称性地累及双侧尾状核、豆状核、丘脑、脑岛叶皮质、海马头部等部位,其中3例同时存在脑桥中央髓鞘溶解症改变,呈脑桥基底部位对称性T1低、T2高信号的蝶形病灶;Flair加权异常信号更清楚.3例有好转或痊愈,其中1例遗留明显肌张力障碍.结论 渗透性脱髓鞘综合征与慢性低钠血症有关,合并低血钾、低血氯时可能更易发生.治疗时应尽量避免过快纠正,临床病程具有双相性.MRI的特征性改变出现较迟,复查MRI是非常必要的.     

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.     

A case of alcoholic with vitamin B12 deficiency presenting central pontine and extrapontine myelinolysis on MRI]

A 55-year-old man with chronic alcoholism was first referred to us in 1992 because of spastic quadriparesis. T2-weighted images of MRI showed pontine and extracapsule lesions as central pontine and extrapontine myelinolysis (CPM/EPM). He had macrocytic anemia with normal serum level of vitamin B12 (B12). Gait disturbance was progressively worsened from the end of 2004 and dysuria appeared from June, 2005. Neurological examination on admission in November, 2005, showed mild impairment of recent memory, spastic paraparesis with hyperreflexia in all limbs, loss of deep sensations in lower limbs and urinary disturbance. The low serum level of B12 with marked macrocytic anemia was noted. On MRI. the pontine lesion extended to the midbrain but no abnormality was found in the spinal cord. We intramuscularly administered B12, resulting in marked improvement of both anemia and neurological symptoms. The brainstem lesion on MRI, however, was unchanged. We assume that B12 deficiency was involved in the formation of CPM/EPM and the neurological symptoms in our patient.     

Magnetic resonance imaging in central pontine myelinolysis.

Magnetic resonance imaging (MRI) was performed in two patients in whom a clinical diagnosis of central pontine myelinolysis (CPM) had been made. MRI showed lesions in the pons in both cases about 2 years after the illness, at a time when the spastic quadriparesis and pseudobulbar palsy had recovered. The persisting abnormal signals in CPM are likely to be due to fibrillary gliosis. Persistence of lesions on MRI means that the diagnosis of CPM may be electively, after the acute illness has resolved.     

Subclinical central pontine myelinolysis following liver transplantation

Central pontine myelinolysis (CPM) is a demyelinating disorder of unknown origin that almost exclusively affects the central portion of the basis pontis, and is one of the fatal neurological complications after liver transplantation. We describe two children with CPM detected incidentally after liver transplantation. To our knowledge, this is the first report of CPM diagnosed antemortem in children who had undergone liver transplantation. In our patients, there were no clinical manifestations associated with CPM. We conclude that, including silent cases such as our patients, CPM may be more prevalent than previously appreciated following liver transplantation.