A woman with focal neurological deficit following treatment for cholera

A 41-year old woman was treated for cholera at one of the health centers in Blantyre. Two days after discharge from the treatment unit, she developed weakness of all 4 limbs and difficulties with speech. She was referred to the Queen Elizabeth Central Hospital. A CT scan of the brain showed hypodense lesions in the pons. A diagnosis of central pontine myelinolysis was made. She recovered slowly and was discharged from hospital 17 days after admission.

Pituitary tumor apoplexy associated with extrapontine myelinolysis during pregnancy: A case report

RATIONALE

Pituitary tumor apoplexy (PTA) is a rare clinical syndrome which requires urgent diagnosis and treatment due to its life-threatening consequences. Management of undiagnosed pituitary tumor before pregnancy is a problem during pregnancy.

PATIENT CONCERNS

We reported a case with PTA which was not diagnosed before pregnancy presenting with vomiting associated with hyponatremia during the third trimester. After supplying the sodium the patient presented with dysarthria and hemiplegia.

DIAGNOSES

MRI examination showed PTA accompanied with extrapontine myelinolysis (EPM).

INTERVENTIONS

The patient was given hydrocortisone according to the symptoms gradually to taper off dose, at the same times oral levothyroxine therapy (25μg/day) was given.

OUTCOMES

The patient delivered a healthy baby via cesarean section at hospital at 38 + 1 week of gestation. We performed MRI examination regularly and the tumor regressed significantly 8 months postpartum.

LESSONS

We reported a case as PTA associated with EPM. Headache during pregnancy is often nonspecific, so careful medical history inquiry is very important.

[Central pontine myelinolysis during qualified alcohol withdrawal therapy. A case report]

Central pontine myelinolysis is a rare but severe disease that often occurs in alcohol-dependent and malnourished patients. One pathological mechanism is the rapid correction of chronic hyponatremia, even though the disease can occur independently of decreased serum sodium levels. Here, we present a patient suffering from malnutrition, alcohol dependency, and a severe depressive disorder, who presented himself to our clinic wishing for qualified withdrawal treatment. Because the patient reported significant weight loss and nocturnal sweating without fever, we performed different diagnostic investigations and examinations. Cranial MRI revealed the presence of a central pontine myelinolysis. In the clinical neurological examination, the patient only showed slight gait ataxia. The depressive symptoms had improved while the patient now showed problems in his short-term memory. At presentation, only slight hyponatremia was present, while no rapid correction occurred throughout treatment. The presented case reveals the importance of considering osmotic demyelination disorders as a differential diagnosis in patients suffering from neurological symptoms during alcohol withdrawal therapy. This is important independently of hyponatremia.

Syndrome de démyélinisation osmotique compliquant la correction rapide d’une hyponatrémie sévère associée à une hypokaliémie

Le syndrome de démyélinisation osmotique correspond à une démyélinisation du centre de la protubérance ou d'autres parties du cerveau. Nous rapportons un cas de syndrome de démyélinisation osmotique chez une patiente âgée de 55 ans, connue hypertendue, suivie pour cervicarthrose étagée, hospitalisée pour coma non fébrile d'installation brutale compliquant un tableau de gastroentérite aigue. L'évolution a été marquée par l'aggravation neurologique avec confusion, aphasie, tétraplégie et aréflexie ostéotendineuse. Le diagnostic de myélinolyse centropontine et extrapontine a été confirmé par une imagerie par résonance magnétique cérébrale faite 20 jours après une première qui n’a pas montré d'anomalies spécifiques. La correction rapide de l'hyponatrémie était la cause principale de ce syndrome, sans négliger le rôle favorisant très probable de l'hypokaliémie associée. L'évolution de la myélinolyse centropontine (MCP) et myélinolyse extrapontine (MEP) est variable. Le traitement est principalement préventif basé sur la correction prudente des hyponatrémies sévères et des facteurs favorisants.

Extrapontine myelinolysis manifested selectively by acute severe parkinsonian syndrome. Case Report

OBJECTIVES

Osmotic demyelination syndrome (ODMS) is a rare and serious neurologic disorder with acute myelin disintegration, usually in the pontine area (central pontine myelinolysis) and to a lesser extent, even in other areas of the central nervous system (extrapontine myelinolysis). The main underlying mechanism is the change of serum osmolality with quick correction of low mineral levels, mainly hyponatraemia. Clinical manifestation is various and depends on the localization.

DESIGN

We describe an acute isolated extrapontine myelinolysis causing acute onset of parkinsonism in a 61-year-old man who developed quickly progressing parkinsonian syndrome after the rapid correction of hyponatraemia.

RESULTS

Brain MRI revealed lesions only in the striatum, sparing the globus pallidus. Substitution therapy with high doses of levodopa significantly improved his clinical condition.

CONCLUSION

Extrapontine myelinolysis with isolated affection of basal ganglia is extremely rare. In such case, clinical manifestation of acute severe parkinsonism could be successfully treated by high dose of levodopa.

Osmotic Demyelination and Hypertonic Dehydration in a 9-Year-Old Girl: Changes in Cerebrospinal Fluid Myelin Basic Protein

A 9-year-old girl was admitted for the treatment of hyper-natremic dehydration. Her history was significant for psychogenic polydipsia, hyponatremia, and a renal concentrating defect. She presented with a 2-day history of altered mental status, ataxia, lethargy, fever, nausea, vomiting, and diarrhea. Meningitis was ruled out. Over the course of her illness, slow rehydration was maintained with a gradual decrease (10 mEq per 24 hours) of the serum sodium. Despite this care, she developed quadriparesis, and magnetic resonance imaging performed on day 6 of her illness was consistent with osmotic demyelination (central pontine myelinolysis). To rule out an excessively rapid correction of hypernatremia as the etiology of the problem, a myelin basic protein was measured in the cerebrospinal fluid that had been obtained on hospital day 1. The myelin basic protein was 649.50 ng/mL (normal, 0.07-4.10 ng/mL). The current literature is presented regarding the postulated pathogenesis of central pontine myelinolysis and suggested therapies, previous reports of central pontine myelinolysis in children are reviewed, and the potential role of myelin basic protein in its diagnosis is discussed.

Urinary incontinence a first presentation of central pontine myelinolysis: a case report

An 84-year-old lady was treated for hyperosmolar hyperglycaemia with IV insulin, fluids and catheterisation for fluid balance monitoring. Trial without catheter failed as the patient complained of new-onset urinary incontinence and lack of awareness of bladder filling. In light of her breast cancer history, we excluded cauda equina. Ultrasound KUB showed an enlarged bladder. Whole-body MRI revealed a lesion in the pons which was highly suggestive of central pontine myelinolysis (CPM). Her electrolytes were normal throughout her admission; thus, the rapid fluctuation in osmolality, secondary to her hyperglycaemic state, was the likely cause of CPM. CPM has been reported secondary to hyperglycaemia; however, this is the first reported case of CPM presenting as urinary incontinence and loss of bladder sensation.

Extrapontine Myelinolysis in a patient with Primary Adrenal Insufficiency

PURPOSE

To report the development of estrapontine myelinolysis (EPM) in a patient with adrenal insufficiency and review similar in the literature.

CASE REPORT

A 49-year-old female with insufficiency presented with acute dysarthria, stuttering, and parkinsonism. She received isotonic saline hydration for adrenal crisis and hyponatremia 18 days before the onset of symtoms. The brain MRI and MRS showed demyelination at bilateral basal ganglia and the thalamus, which was compatible with EPM and resolved within 3 months after steroid treatment.

CONCLUSION

Development of acute parkinsonism after rapid correction of hyponatremia may indicate the occurrence of EPM and underlying adrenal insufficiency should be excluded in these patients.

Osmotic demyelination syndrome

Formerly known as central pontine myelinolysis, osmotic demyelination syndrome (ODS) is defined by a symmetrical destruction of myelin sheaths involving mainly the central portion of the basis pontis without evidence of vascular involvement. We report the case of a 60-year-old man who presented to the emergency department with a 2-week history of progressive confusion, memory loss, and lower extremity weakness with limited ambulation. A computed tomography scan of the head revealed areas of low attenuation within the pons, and brain magnetic resonance imaging (MRI) confirmed the changes as compatible with ODS.

[A case of central pontine and extrapontine myelinolysis, without hyponatremia, during alcohol withdrawal with favorable outcome]

Central pontine and extra-pontine myelinolysis (CPM/EPM) is a rare neurological disorder, well documented for more than 50 years but whose pathogenesis remains obscure. The existence of predisposing factors occurs in the most cases; chronic alcohol abuse is one of the most commonly encountered, among many others. Alcohol withdrawal represents an additional vulnerability factor, being responsible for electrolyte imbalances which are not always demonstrable but are certainly involved in the development of CPM and/or EPM. CPM/EPM may be responsible for severe morbidity and is potentially life-threatening. The diagnosis of CPM/ EPM remains mostly clinical and is confirmed by magnetic resonance imaging of the brain. It should be considered in the setting of any unexplained neurological symptoms during the course of alcohol withdrawal or for any patient with chronic alcohol abuse, as promptly as possible, given the potentially fatal outcome.

[Central pontine myelinolysis developed during alcohol withdrawal in a chronic alcoholic with hyperosmolar hyperglycemic state]

We present a 46-year-old man with central pontine myelinolysis (CPM). He had been diagnosed with diabetes mellitus and chronic pancreatitis. He had drunk more than 1.2 l of Japanese sake daily for 20 years and more. He developed slight reduction of consciousness, dysarthria and truncal ataxia 7 days after he stopped drinking. The laboratory data on admission showed hyperosmolar hyperglycemic state, according to the following findings; glucose 1,058 mg/dl, serum osmolality 328 mOsm/l and serum sodium 119 mEq/l. According as administration of acetic Ringer's solution and insulin injection, the laboratory data 14 hours after admission showed glucose 235 mg/dl, serum osmolality 290 mOsm/l and serum sodium 131 mEq/l. The initial diffusion weighted images (DWI) on MRI revealed a small high signal intensity spot in the pons. The second DWI after 14 days revealed a trident-shaped hyperintensity in the pons that was compatible with CPM. His symptoms showed no remarkable changes, but susceptibility weighted images of MRI after 4 months revealed low signal intensity area in the CPM lesion that indicated pontine hemorrhage. We speculate that marked fluctuation of serum osmotic pressure associated with the rapid change of the serum glucose had a significant role in the pathogenesis of the present case. Therefore, we recommend gradual correction of serum glucose and serum osmolality to maintain less than 12 mEq/l/day as correction of chronic hyponatremia in to prevent and ameliorate pathologic condition of CPM.

[Development of central pontin myelinolysis in a patient with light hyponatraemia]

Central pontin myelinolysis has since the 1970s been correlated with hyponatraemia. A 56-year-old woman was admitted to hospital after a few days of diminished capacity and acute disorientation and respiratory distress. Initially, her alcohol overconsumption was not recognised. She presented with only a light hyponatraemia and sepsis. Following fluid resuscitation she developed hypernatraemia and was later diagnosed with osmotic demyelination syndrome. Despite several weeks of therapy the outcome was fatal.

[Central pontin myelinolysis]

Initially central pontin myelinolysis was associated with alcoholism and later with hyponatraemia and particularly the correction rate. The diagnosis is made by characteristic symptoms and cerebral MRI with areas of hyperintensity on T2-weighted images. Outcome varies, mortality is high and most survivors have some degree of neurological deficit. There is no treatment and supportive therapy remains the only option with possible recovery within 6-8 weeks. Hyponatraemia can safely be corrected at a rate of no more than 10 mmol/l within the first 24 hours and 18 mmol/l within 48 hours.

Central pontine myelinolysis in the hyperosmolar hyperglycaemic state

OBJECTIVE

To report a rare association of central pontine myelinolysis (CPM) with hyperosmolar hyperglycaemic state (HHS).

CLINICAL PRESENTATION AND INTERVENTION

A diabetic female presented with HHS and prolonged severe hypernatraemia. The metabolic derangement was adequately treated with proper correction of both hyperglycaemia and hypernatraemia. Lack of improvement in the presenting confusional state and the development of a fresh neurological deterioration led to the suspicion of CPM that was confirmed with magnetic resonance imaging. She fully recovered after 4 weeks with no specific medical treatment.

CONCLUSION

This case report showed that osmotic demyelination was linked to hypernatraemia and that CPM could result from severe hypernatraemia of HHS.

Rapid development of central pontine myelinolysis after recovery from Wernicke encephalopathy: a non-alcoholic case without hyponatremia

We describe a non-alcoholic diabetic patient with central pontine myelinolysis (CPM) and Wernicke encephalopathy (WE). A 69-year-old man developed consciousness disturbance after parenteral hyperalimentation for liver abscess and sepsis. Neurological examination revealed drowsiness and no articulation. MRI disclosed T2-hyperintense lesions in the dorsal medulla oblongata and dentate nuclei, and symmetric enhancement in the inferior colliculus. Thiamine treatment (1,000 mg/day, div) attenuated neurological deficits. Seven days later, WE-related lesions were markedly regressed and a central pontine T2-hyperintensity lesion appeared. Serum sodium levels were normal. Physicians should pay more attention to rapid development of normonatremic CPM under thiamine supplementation in non-alcoholic WE patients.

Clinical and radiologic correlations of central pontine myelinolysis syndrome

OBJECTIVE

To characterize clinical and radiologic features of patients with central pontine myelinolysis (CPM) and identify variables that predict outcome.

PATIENTS AND METHODS

We retrospectively studied patients diagnosed as having CPM identified by a search of Mayo Clinic medical records from January 1, 1999, through December 31, 2010. Diagnosis was made by clinical and radiologic features. Favorable outcome was defined by a modified Rankin Scale score of 2 or lower. Volume of signal abnormality on brain magnetic resonance imaging (MRI) was quantified by a neuroradiologist blinded to outcomes. Wilcoxon rank sum tests were used to assess association between volume of signal abnormality and outcomes at discharge and last follow-up.

RESULTS

Of 24 patients, 14 (58%) had only CPM, and 10 (42%) had extrapontine involvement. Hyponatremia was documented in 18 patients (75%), with median sodium nadir of 114 mmol/L. Eighteen patients (75%) had alcoholism, and malnutrition was documented in 12 (50%). Presenting symptoms included encephalopathy (n=18 [75%]), ataxia (n=11 [46%]), dysarthria (n=7 [29%]), eye movement abnormalities (n=6 [25%]), and seizures (n=5 [21%]). Favorable outcome was seen in 15 patients (63%) at last follow-up. Findings on initial brain MRI were normal in 5 patients, but all MRI scans were abnormal with serial imaging. The volume of radiologic signal abnormality was not associated with outcome at discharge or last follow-up (P=.67 and P=.37, respectively).

CONCLUSION

Clinical outcome in patients with CPM is not predicted by the volume of radiologic T2 signal abnormality on MRI or the severity of hyponatremia. Serial brain imaging is of value because a substantial proportion of patients have normal findings on initial MRI.

Complete clinical recovery of a central pontine and extrapontine myelinolysis delayed onset in a child with acute myeloblastic leukemia

Central pontine myelinolysis (CPM) is a demyelinating disease of the pons often associated with the demyelination of extrapontine areas of the central nervous system. It typically occurs 0.5-7 days after a rapid increment in serum Na level in hyponatremic patients and may lead to death. A 2.5-year-old child with a diagnosis of acute myeloblastic leukemia developed febril neutropenia, diarrhea, gastrointestinal hemorrhage followed by pulmonary aspergillosis. He could not tolerate enteral nutrition. He was given broad spectrum antibiotics and antifungal treatment. Laboratory tests showed electrolyte abnormalities including hyponatremia, hypokalemia and hypophosphatemia in a chronic course. Twenty three days after a rapid correction of hyponatremia (16 mEq/L/24 h) he revealed flask quadriparesis, disphagia, mutism, irregular respiratory pattern and loss of cough and gag reflex. Cranial magnetic resonance showed central pontine and extrapontine myelinolysis. He required mechanical ventilation and then he regained his neurologic functions. He completed chemotherapy protocol and underwent hematopoietic stem cell transplantation. After 2.5 years of the occurrence of CPM he is in completely normal physical and neurological status. CPM is a very severe but rare disorder in children with underlying disease. In the presence of multiple etiologic factors it may reveal a delayed onset and optimum outcome can be seen even in the severe clinical presentation with adequate intensive support.

Central pontine myelinolysis after orthotopic liver transplant-a rare complication

Central pontine myelinolysis is a rare but devastating cause of morbidity and mortality after orthotopic liver transplant. The exact cause of central pontine myelinolysis is uncertain. However, rapid correction of hyponatremia has been described as a major factor. We describe a patient with central pontine myelinolysis after orthotopic liver transplant in the absence of significant hyponatremia. Although rapid correction of hypernatremia has been reported in association with central pontine myelinolysis, to our knowledge, in this case, where the serum sodium went from normal to hypernatremic, later diagnosis of central pontine myelinolysis in a postliver transplant setting is unique. We also discuss factors that may contribute to the development of central pontine myelinolysis after orthotopic liver transplant and its pathophysiology.

[Central pontine myelinolysis after liver transplantation. Report of five cases]

BACKGROUND

Central Pontine Myelinolysis (CPM) is the most severe neurological complication after liver transplantation and apparently is not related to changes in osmolarity.

AIM

To report five transplanted patients with CPM.

PATIENTS AND METHODS

In a series of 27 patients subjected to liver transplantation between 2005 and 2008, we found five patients who developed CPM.

RESULTS

All patients presented a severe hepatic encephalopathy. In the absence of alterations in osmolality, they developed, between the second to seventh day after transplantation, a central quadriplegia, hyperreflexia and Babinski sign, with preservation of sensorium. Magnetic resonance imaging showed demyelination of the motor pathway only in the protuberance. Motor recovery first began in the fingers and hands, followed by forearms, toes, feet, arms and finally the legs, defining a somatotopic recovery of the cortico-spinal pathway.

CONCLUSIONS

This form of regaining motility shows that the selective involvement of the pyramidal tract in CPM, is according to its location in the pons and suggests a local entrapment. It is due to the structural rigidity of the protuberance that limits the expansive requirements of cytotoxic and vasogenic edema, and only affects the long fibers of cortico-spinal tracts, sensitized by encephalopathy. The entrapment syndromes generally preserve the axons, injure myelin and have no inflammatory reactions.

Extrapontine myelinolysis in a child with nephrotic syndrome

Extrapontine myelinolysis is rare in children. We describe a 6-year-old girl with nephrotic syndrome who presented with symptomatic hyponatremia, and who developed acute quadriparesis with pseudobulbar palsy during rapid correction of the hyponatremia. Cranial magnetic resonance imaging demonstrated bilateral, symmetric basal ganglia lesions (extrapontine myelinolysis). The extrapontine myelinolysis was caused by rapid correction of severe and prolonged hyponatremia with intravenous 3% sodium chloride. The child demonstrated complete neurologic recovery. Prevention of this rare condition involves recognizing patients at risk for the disorder, and avoiding rapid correction of severe and prolonged hyponatremia. To the best of our knowledge, this is the first case report of extrapontine myelinolysis in a child with nephrotic syndrome.

[Pontine and extrapontine myelinolysis]

INTRODUCTION

Myelinolysis is defined as acute demyelinating disorder, associated with flaccid quadriplegia, speech and swallowing impairment. The pathogenesis is usually related to hydroelectrolytic imbalance, particularly with severe hyponatremia and its rapid correction. The imagiologic diagnostic is commonly done by magnetic resonance imaging.

AIM

The authors present a clinical case focusing on the follow up, rehabilitation program, and giving importance to functionality gains. The main clinical intercurrences related to the late diagnosis are also reported.

CLINICAL CASE

A female patient with documented past psychiatric history and polidipsia was admitted with repeated seizures unsuccessfully controlled by drugs. Hyponatremia was identified and corrected. After the correction, a quadriplegia and a generalized hypotonia were noticed and the patient underwent magnetic resonance imaging. The imaging findings were consistent with the diagnosis of central pontine and extrapontine myelinolysis.

[Central pontine myelinolysis--etiological, clinical and prognostic variety]

Central pontine myelinolysis (CPM) is a neurologic disorder that the most often is related to rapid correction of hyponatremia. It is concentrated, frequently symmetric, noninflammatory demyelination within the base of the pons with a relative sparing of the axons and the nerve cells. Focal demyelination can occur outside the pons (extrapontine myelinolysis--EPM). Clinical symptoms have various manifestations and the prognosis can be different. In the diagnosis of CPM the most useful is magnetic resonance imaging (MRI), that is more sensitive than computed tomography (CT). The authors present two cases of CPM with different aetiology, clinical features and course of the disease.

Central pontine and extrapontine myelinolysis that developed during alcohol withdrawal, without hyponatremia, in a chronic alcoholic

Central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) are osmotic demyelination syndrome. A 45-year-old man with a history of alcoholism visited the ER with dysarthria and dysphagia for 2 days. These symptoms occurred 3 days after he had stopped drinking alcohol. The neurological symptoms progressed to anarthria, pseudobulbar palsy and gait disturbance. During admission, the electrolyte studies were within the normal range. Diffusion-weighted images revealed high signal intensities in the pons, thalamus and basal ganglia. Apparent diffusion coefficient image showed low signal intensities in the pontine lesion, but isosignal intensities in the extrapontine lesion. The symptoms gradually improved after 1 month with only conservative treatment. The 1 month-follow-up MRI showed significant reduction of the previous extrapontine lesions. These findings suggest that cytotoxic edema is central to the pathogenesis of CPM, but vasogenic edema plays an important role in the pathogenesis of EPM occurring during alcohol withdrawal.

Extrapontine myelinolysis in preoperative sellar region tumor: report of two cases

Osmotic demyelination syndrome (ODS) is a well-known disorder caused by rapid correction of serum sodium. Many conditions including hormonal abnormality are associated with this syndrome. The authors describe two cases of preoperative sellar region tumor associated with hypopituitarism and secondary adrenal insufficiency. These two patients had hyponatremia. Neurological manifestations in both of them were generalized dystonia. Magnetic resonance imaging (MRI) revealed a characteristic extrapontine myelinolysis (EPM). The first case was a 35-year-old man with craniopharyngioma who developed generalized dystonia after rapid correction of hyponatremia. The second case was a 24-year-old man with gonadotroph pituitary adenoma who developed generalized dystonia, dysarthria, and dysphagia in the course of hyponatremia. Hormonal changes will cause fluctuation in hyponatremia and correction of hyponatremia, even if the recommended rate may be hazardous and will promote ODS. Patients with sellar region tumors are at risk of developing ODS and correction of hyponatremia in these cases should be closely monitored.

[Ethanol, water, salt and coma]

We report on a 52-year-old woman with liver cirrhosis who suddenly fell into deep coma after correction of an intercurrent hyponatremia. After exclusion of the commonest causes of coma, the MRI showed a symmetrical osmotic demyelination of both thalami. The newest epidemiological data, the pathophysiology of osmotic demyelination, the threats of the treatment of a prolonged severe hyponatremia as well as the therapeutic options in face of osmotic demyelination are discussed.

[Intoxication with lithium]

We report a case of a 75-year-old male patient who presented to the emergency room with arterial hypotension and impaired vigilance. The patient was on lithium therapy due to mood disorder. One month earlier medication with a betablocker, a loop-diuretic and an ACE-inhibitor had been started due to heart failure. Findings at admission included renal insufficiency, pneumonia and a slightly increased serum level of lithium. Three days later his Glasgow Coma Scale Score was 7, he showed gaze deviation, increased muscle tonus and cloni. The patient fully recovered after volume substitution and normalization of his renal function. Diagnosis of chronic intoxication with lithium was made due to the clinical picture and after exclusion of neurological pathologies. The pharmacokinetic characteristics of lithium is described and the risk factors leading to lithium intoxication and treatment of intoxication are discussed.

[Alcoholism and possible consequences for the central nerval system - pontine and extrapontine myelinolysis]

The central pontine and extrapontine myelinolysis is an important entity in the neurology disorders in the context with alcohol abuse. Though often first based on clinical characteristics, the diagnosis can be often supported with radiologic imaging.

Pontine Myelinolysis in a Child with Carbamate Poisoning

Carbamate and organophosphate pesticides are widely used all over the world. Poisoning with these substances may produce both immediate and delayed neurotoxic effects. We report the case of a 4-year-old boy who was admitted to the Pediatric Department of the Second University of Naples for evaluation of stupor, lethargy, severe hypotonia, generalized weakness of his arms and legs, ataxia, dysmetria, miosis, excessive salivation and tearing. The pesticide carbaryl (1-naphthyl-N-methylcarbamate) was identified in blood and urine samples. On admission, magnetic resonance imaging (MRI) was unremarkable; on day 11, MRI showed central pontine myelinolysis. The demyelination improved after 4 months and disappeared after 2 years. Various underlying and concomitant diseases have been described in children with central pontine myelinolysis but, to our knowledge, the finding of pontine myelinolysis after carbamate poisoning has not yet been described.

[Central pontine myelinolysis after living donor liver transplantation]

Central pontine myelinolysis (CPM) is the most serious central nervous system complication that could be seen after liver transplantation and represents an important source of mortality early after liver transplantation. CPM following liver transplantation was reported more and more in literatures, but the true incidence of CPM after living related liver transplantation (LDLT) remains unknown. However, with the introduction of magnetic resonance imaging (MRI), early recognition has become possible. In this report, we present a case of rapid resolution of CPM followed by MRI examinations.

Central pontine lesions observed with MRI in four diabetic patients

We report four diabetic patients with a central pontine lesion on magnetic resonance imaging (MRI). All patients also had hypertension, diabetic neuropathy and nephropathy, and three had chronic hepatitis C. Their neurological symptoms were disproportionately mild compared with the MRI features, which were of high intensity on T2-weighted images, but were less prominent on T1- and diffusion-weighted images. A subclinical pontine lesion was found in two patients who had undergone MRI previously. We consider that diabetes mellitus is an important factor for developing a pontine lesion with or without symptoms, probably in association with hepato-renal problems and hypertension.

Central myelinolysis in a patient with hyponatraemia

We present a case of a 50-year old man who developed mutism and a flaccid quadriparesis within 48 hours of presentation to hospital with severe hyponatraemia. A diagnosis of central pontine myelinolysis was made based on the clinical features and typical appearances on magnetic resonance imaging.

Osmotic demyelination syndrome in a 40-day-old infant

Osmotic demyelination syndrome refers to the myelin destruction of various brain structures that follows osmotic stress. It affects myelinated brain; therefore, it is very rare in babies and it has not been reported in patients younger than 10 months of age. Herein, we present a 40-day-old infant with osmotic demyelination syndrome, along with imaging findings. Her pontine and thalamic lesions regressed during the 10-day treatment course, whereas demyelinated areas in the lentiform nucleus persisted. Magnetic resonance spectroscopy of the latter revealed decreased levels of all major metabolites. Imaging findings remained unchanged after that phase.

[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.