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.     

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.     

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。     

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.     

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.     

Central pontine myelinolysis in alcoholism. Clinical aspects, neurophysiology, computerized tomography and nuclear magnetic resonance tomography in a patient who survived

A case of central pontine myelinolysis in a 38-year-old alcoholic is reported. The findings initially and over a course of almost 2 years, including clinical data, magnetic resonance imaging (MRI), cranial computerized tomography (CCT), evoked potentials (BAEP, VEP, SEP), EEG and EMG/ENG are presented and discussed in relation to other recent case reports, with special regard to the CCT findings. The important role of CCT is emphasized, although negative CCT findings probably do not allow exclusion of the diagnosis. MRI can be expected to play an important part in the detection of central pontine myelinolysis. The importance of BAEP as a possible method for monitoring must be clarified by further research.     

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.     

Movement disorders as sequelae of central pontine myelinolysis: report of three cases.

In three survivors of central pontine myelinolysis, dystonia (in two patients) and rest tremor (in one) were sequelae. The onset of these movements occurred 3 weeks to 5 months after the initial presentation with central pontine myelinolysis. Magnetic resonance imaging revealed basal ganglia lesions suggestive of extra-pontine myelinolysis in all three patients. We propose that the movement disorders seen in our cases are clinical correlates of extra-pontine myelinolysis.     

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.     

Asymptomatic pontine myelinolysis

A 43-year-old lady presented with bilateral foot drop due to alcohol-related peripheral neuropathy. There was no history of electrolyte disturbance or altered consciousness. Cranial nerve, bulbar and pyramidal symptoms and signs were absent. Nerve conduction studies confirmed the neuropathy. Inadvertently requested neuroimaging of brain demonstrated signal change typical of central pontine myelinolysis. Asymptomatic pontine myelinolysis occurs rarely in alcoholics in the absence of bulbar dysfunction. It is important for physicians to be aware of the clinical entity of asymptomatic pontine myelinolysis to avoid misinterpretation of abnormalities detected on cerebral imaging in alcoholic individuals.     

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.     

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.     

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.     

Parkinsonism and recovery in central and extrapontine myelinolysis

Central pontine myelinolysis is a demyelinating affection of central pons diagnosed on the basis of characteristic MRI finding in an appropriate clinical setting. The condition has been described as universally fatal; however, recent reports of recovery have been documented. We report a case of central pontine and extra pontine myelinolysis, which presented with parkinsonian features apart from bulbar symptoms and made a remarkable recovery. A short review of the literature follows.     

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.     

The corticobasal syndrome triggered by central pontine myelinolysis

Single case reports have described movement disorders including parkinsonism, dystonia and chorea, but not corticobasal syndrome as a consequence of central pontine and extrapontine myelinolysis. We report a case of a 61-year-old woman who developed progressive asymmetric parkinsonism with ideomotor apraxia and cortical sensory deficits following 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.

     

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.     

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.     

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.