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.     

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.     

Central Pontine Signal Changes in Wilson's Disease: Distinct MRI Morphology and Sequential Changes with De-Coppering Therapy

BACKGROUND AND PURPOSE: Reports of central pontine myelinolysis (CPM)-like changes in Wilson's disease (WD) and its sequential changes are exceptional. The aim was to study the MRI characteristics of CPM-like changes in WD and the serial changes. METHODS: Among the 121 patients of WD, twenty (M:F:9:11, age at onset: 14.2 +/- 4.6 years) had features similar to CPM. All had progressive neuropsychiatric form of WD. All except five were on de-coppering treatment. None had acute deterioration or hepatic failure. Ten patients underwent repeat studies. RESULTS: Twenty patients with CPM-like changes manifested with characteristic phenotype of WD. Three distinct patterns of CPM-like changes were observed: (a) characteristic round shape -7, (b) "bisected" -9, and (c) "trisected" -4. Only one had signal changes suggesting extra-pontine myelinolysis. All patients had contiguous involvement of midbrain. Serial MRI evaluation in 10 patients, at mean interval period of 17.4 +/- 13.2 months, revealed complete reversal in one, partial improvement in five, and no change in three. Clinical and MRI improvement occurred pari passu, except in one. CONCLUSIONS: CPM-like changes in WD are perhaps under-recognized and are distinct from the commonly known "osmotic demyelination." It is potentially reversible similar to other MRI features of WD.     

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 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.     

Morel's laminar necrosis like findings on MRI in a case of extra-pontine myelinolysis

A 39-year-old man developed disturbance of consciousness with hyponatremia during the treatment of schizophrenia in another hospital. He became alert after the correction of hyponatremia. But his consciousness deteriorated one day later in spite of normal serum sodium level, then he was referred to our hospital. The disturbance of consciousness, quadriparesis and rigidity were persisted even 4 months later. MRI (T2WI) showed well defined high intensity areas along the deep layer of the cerebral cortex and in the bilateral basal ganglia. But there were no lesions in the pons on MRI. Therefore, the diagnosis was made as extra-pontine myelinolysis (EPM) without apparent central pontine myelinolysis (CPM) according to the MRI findings. Recently, the EPM without CPM has been reported in 3 patients. Two cases were examined pathologically, findings of which were characterized by Morel's laminar necrosis at the deep layer of the cerebral cortex. But there is no report in the literature describing the detection of Morel's laminar necrosis on antemortem MRI. It seemed that the MRI findings of our case indicated Morel's laminar necrosis. Our case is suggestive in relation to the pathogenesis of EPM and CPM.     

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.     

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.     

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 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 myelinolysis associated with low potassium levels in alcoholism

Summary Two patients with chronic alcohol abuse and central pontine myelinolysis are described. One developed a Korsakoff syndrome 2 days before admission to our hospital and the other showed signs of a incipient delirium without Korsakoff syndrome. Diagnosis of incipient central pontine myelinolysis was based on acute brain-stem dysfunction, serum electrolyte disturbances, malnutrition with vitamin B₁ (thiamine), B₆ (pyridoxine) and B₁₂ (cyanocobalamine) deficiency in combination with typical neuroradiological findings. Hypokalaemia but no disturbance in serum sodium levels was found in both patients. After correction of hypokalaemia and vitamin deficiency the patients showed complete recovery of neurological and neuropsychological function. The findings are interpreted as suggesting that disturbances in serum potassium levels as well as rapid correction of hyponatraemia may be associated with pontine swelling and dysfunction which, if undetected, leads to central pontine myelinolysis.     

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 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.     

Central pontine and extra-pontine myelinolysis: a complication of lithium toxicity in a pregnant woman

Osmotic demyelinating syndromes consisting of central pontine and extra-pontine demyelination are very uncommon disorders characterized by non-inflammatory lesions involving the pons and sometimes spreading to other areas. Rapid changes in serum sodium concentration are usually regarded as the main pathophysiological mechanism. We report herein the case of a 23-year-old woman in the 24th week of pregnancy, who demonstrated both central pontine and extra-pontine demyelination occurring at the time of a recently introduced treatment with lithium. The disorder was related to the rapid correction of pregnancy-related hyponatremia, as a consequence of lithium-induced diabetes insipidus. Hence, lithium toxicity is a rare cause of osmotic demyelinating syndromes and appears to correlate with disturbances in sodium homeostasia.     

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.     

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.     

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.     

Computerized tomography in central pontine myelinolysis

We describe an autopsy-proven case of central pontine myelinolysis (CPM) with premortem computerized tomographic (CT) visualization of the lesion on two scans, performed with an interval of 2 weeks. This case demonstrates the capability of CT to support the clinical diagnosis of central pontine myelinolysis. Identification of the condition should facilitate prompt initiation of aggressive supportive care.     

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.     

Ocular bobbing and myoclonus in central pontine myelinolysis.

Ocular bobbing and myoclonus were unusual findings in a patient with central pontine myelinolysis. Pathological findings confirmed the diagnosis of pontine and extrapontine myelinolysis.