Asymptomatic central pontine myelinolysis

Central pontine myelinolysis and the osmotic demyelination syndromes: an open and shut case?

Central pontine myelinolysis and extrapontine myelinolysis are collectively called the osmotic demyelination syndromes. Despite being described in 1959, there are several aspects of the disorder that remain an enigma. Animal models and neuroimaging techniques have allowed us to understand the condition better. From being a universally fatal disorder that was diagnosed post mortem, increased awareness, neuroimaging techniques and supportive care have enabled us to make the diagnosis ante-mortem. This has also led to a significant drop in associated mortality. The aim of this review is to highlight the clinical spectrum, neuroimaging findings, and recent developments.

Central pontine myelinolysis in advanced HIV infection with tuberculosis and multicentric Castleman's disease

Summary

We present a case of central pontine myelinolysis (CPM) in a patient with advanced HIV infection and miliary tuberculosis. While hospitalized the patient developed an unusual ataxic variant of CPM with full clinical recovery. Follow-up imaging revealed resolution of pontine lesions. To our knowledge, this is the first report of a clinical and radiological recovery from CPM in advanced HIV disease. Our report extends our knowledge of neurological presentations in patients with advanced HIV infection. It highlights the importance of considering CPM in patients with advanced HIV disease presenting with an ataxic syndrome, even in the absence of an electrolyte derangement.

Asymptomatic central pontine myelinolysis: a case report

Introduction

Central pontine myelinolysis (CPM) is an acquired demyelinating lesion of the basis pontis that typically occurs after rapid correction of hyponatremia. There are only a few reported cases of patients without symptoms that have demonstrated CPM on imaging.

Case Presentation

We report the case of a 26-year-old Hispanic male with history of alcohol abuse who was transferred to our medical center for acute onset diffuse abdominal pain. During his work up, a computed tomography scan demonstrated a large pancreatic mass. He underwent an endoscopic guided biopsy which demonstrated a rare and aggressive natural killer T cell lymphoma. His laboratory values were consistent with hyponatremia, which the medical team gently corrected. An MRI was performed for staging purposes which revealed findings consistent with CPM. A full neurological exam demonstrated no deficits.

Materials and Methods

We conducted a PubMed search using the following keywords: asymptomatic, central, pontine, and myelinolysis in order to find other case reports of asymptomatic CPM.

Results

Of the 29 results, only 6 previous case reports with English language abstracts of asymptomatic CPM were present since 1995.

Conclusion

Despite slow correction of hyponatremia, CPM can be an important consequence, especially in patients with chronic alcoholism. Although this patient did not demonstrate any neurological deficits, the fact that there were changes seen on MRI should caution physicians in aggressively treating hyponatremia. Furthermore, if there is a decision to treat, then fluid restriction and reversal of precipitating factors (i.e. diuretics) should be used initially, unless there is concern for hypovolemia.

Pontocerebellar volume deficits and ataxia in alcoholic men and women: no evidence for "telescoping"

INTRODUCTION

Brain volume shrinkage is common in treatment-seeking patients with alcohol use disorders. Whether women are more vulnerable to brain dysmorphology than men despite lower alcohol consumption levels or shorter dependency ("telescoping effect") remains controversial and has not been considered with respect to infratentorial structures or their potential contribution to ataxia.

METHODS

The 200 participants included 64 men and 31 women with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition alcohol dependence and 105 controls. An infratentorial region (pons, cerebellar hemispheres, vermis (anterior, posterior, and inferior sectors), fissures, cisterns, fourth ventricle) was quantified with atlas-based parcellation. To enable comparison of men and women, regional tissue volumes were expressed as ratios of tissue in the volume. Participants also completed quantitative ataxia testing.

RESULTS

Total infratentorial and vermian tissue ratios were significantly smaller in alcoholics than controls; alcoholic women did not show disproportionately greater volume deficits than alcoholic men. A re-analysis including alcoholic men and women matched in alcohol consumption, onset age, abstinence duration, and age revealed again that alcoholic women did not have disproportionately greater regional vermian volume deficits than alcoholic men. Alcoholic men and women were impaired in all measures of ataxia, which correlated with low infratentorial tissue ratios in men.

DISCUSSION

Alcoholic men showed deficits of pontocerebellar volume ratios, yet alcoholic women did not display signs of "telescoping". Further, alcoholic men and women both showed signs of ataxia of gait and balance, related to affected pontocerebellar systems in the men but not the women, suggesting the need to consider other neural substrates for ataxia in women.

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.

Central and Extrapontine Myelinolysis: Then…and Now

In this review, we emphasize neuropathologic and neurobehavioral aspects of central pontine and extrapontine myelinolysis (CPM/EPM), also known as the osmotic demyelination syndrome. The literature is reviewed from the time of the initial report in 1959 and from key developments that have occurred more recently. Particular consideration is given to pathogenic mechanisms as revealed by recent animal studies. The role of white matter pathology in neurobehavioral dysfunction is also considered. The "then" and "now" of CPM and EPM tell 2 different stories. Yet, in many respects, this expansion of information over the past nearly 50 years simply represents a continuum, as well as recognition, of the vast gaps that still persist in our understanding of this disorder.

Zentrale pontine Myelinolyse mit hyperintenser Läsion im diffusionsgewichteten MRT: Übersicht anhand eines Fallberichtes

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 etiology and pathogenesis of this disorder are still not fully understood. However, almost all cases of CPM are related to severe diseases or chronic alcoholism and occur in the setting of rapidly corrected serum hyponatremia and hypotonicity respectively. Depending on the involvement of other CNS structures, the clinical picture can vary considerably. Magnetic resonance imaging is the most sensitive investigation for the antemortem diagnosis of CPM, although the radiological findings lag behind and do not necessarily correlate with the clinical picture. Quite obviously diffusion-weighted imaging can be useful in the rapid diagnosis of CPM. This short review summarizes the current knowledge on the pathogenesis, clinical presentation, radiological findings, prognosis and therapeutic approaches of CPM. Characteristical clinical features and MR-findings including hyperintensity on diffusion-weighted images are illustrated by a typical case.

Myélinolyse centro-pontine révélée par une monoplégie supérieure gauche sans hyponatrémie ni dénutrition

Arising via an unidentified pathogenic mechanism, central pontine myelinolysis affects the central portion of the base of the pons. Rapid correction of hyponatremia is a frequent cause. The main symptoms are spastic tetraparesis, pseudobulbar paralysis and locked-in syndrome. We report a case of central pontine myelinolysis without hyponatremia, revealed by left upper monoplegia in a 40-Year-old female alcoholic patient without malnutrition symptom. Central pontine myelinolysis occurred consecutive to a suicide attempt with multiple drugs and alcohol. The diagnosis was confirmed by brain magnetic resonance imaging. This case illustrates the paucisymptomatic clinical characteristics of central ponine myelinolysis in patients without electrolyte and nutritional disorders.

Magnetic resonance imaging detection of a lesion compatible with central pontine myelinolysis in a pregnant patient with recurrent vomiting and confusion

The authors report a patient who presented with unexplained confusion. She was 15 weeks pregnant and had been having recurrent vomiting for several weeks. This was felt to possibly represent hyperemesis gravidarum, but she had several other possible contributing factors. Her serum sodium was 146 mmol/L, and her potassium was 2.6 mmol/L. She was alert but had disorientation, visual hallucinations, memory impairment, and confabulation despite being a college graduate with no history of illicit drug use or excessive alcohol consumption. Her initial magnetic resonance imaging (MRI) brain scan was interpreted as being normal. However, her follow-up MRI brain scan revealed typical findings of central pontine myelinolysis, which correlated with hyperreflexia and positive Babinski reflexes. This patient illustrates the constellation of signs and symptoms that can be seen with a demyelinating lesion of the pons. In addition, our case illustrates how this MRI scan finding can be quite nonspecific but may help to explain the clinical findings.

Osmotic demyelination disorders: central pontine and extrapontine myelinolysis

Focal symmetric demyelination in the central nervous system may be precipitated by aggressive correction of a hyper- or hypo-osmolar state and until recently has been associated with a high rate of morbidity and mortality. Specific anatomical locations are more susceptible to demyelination than others, although the mechanism of injury is unknown. Classic clinical and anatomical descriptions associated with a central pontine location have been supplemented by descriptions of patients with unusual symptoms associated with demyelinating lesions in extrapontine locations. The separation of patients with myelinolysis in central pontine and extrapontine locations is possible on the basis of clinical symptoms, and may direct specific pharmacological treatment. Patients at risk of central myelinolysis who are subjected to aggressive osmolar correction may be rescued with appropriate fluid management before brain injury has occurred; once injury is suspected on the basis of neurological symptoms, additional forms of intervention may still improve the outcome. Recent investigation of the molecular basis of the demyelinating process and the adaptive responses of the brain to dysosmolar challenge has allowed for the refinement of standard treatments and has made the osmotic demyelination syndrome a treatable condition with a better than expected prognosis.