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Central pontine myelinolysis is most commonly associated with rapid correction of hyponatremia and has historically been associated with alcoholism. In this case report, 2 deaths with gross findings of central pontine lesions led to the possibility that CPM may have been a potential mechanism of death. Subsequent analysis revealed that these lesions were incidental findings. This case report discusses the importance of appropriate microscopic and immunohistochemical analysis of suspected CPM cases.

A 27-year-old man with a history of diabetes mellitus (DM) and asthma presented to the emergency department 1 month after the onset of dysarthria and ataxia. The symptoms were noted abruptly upon waking. He swayed on standing, fell easily, and noted tremor when manipulating objects. His speech was nearly unintelligible. He also had 1 month of mild distal paresthesias and a 30-pound unintentional weight loss. He denied diplopia, dysphagia, preceding illness, or other systemic symptoms. Over the course of the month, his dysarthria improved but his imbalance remained unchanged. His delay in seeking medical attention was due to lack of health insurance. The authors thank Michel J. Berg, MD, Department of Neurology, University of Rochester Medical Center, and Melissa Tsuboyama, MD, Department of Child Neurology, University of Rochester Medical Center, for reviewing the manuscript.

An 82-year-old man presented with altered mental status, withdrawal to pain, osmolality 405 mOsm/kg, and sodium >180 mEq/L, corrected at 8 mEq/L/d. Brain MRI on day 4 showed restricted diffusion within bilateral middle cerebellar peduncles and along the cortical spinal tracts (figure). Extrapontine osmotic demyelination was diagnosed. Classically described after rapid correction of hyponatremia, few cases have been reported in patients with severe hypernatremia. Extrapontine osmotic demyelination occurs after rapid increase in extracellular sodium causing cellular dehydration and cell death of astrocytes or oligodendrocytes provoking non-inflammatory demyelinating lesions in pontine or extrapontine regions. Isolated extrapontine lesions are seen in two-fifths of patients.1,2

Hyponatremia is associated with reduced survival in patients with cirrhosis awaiting orthotopic liver transplantation (OLT). However, data are sparse regarding the impact of hyponatremia on outcome following OLT. We investigated the effect of hyponatremia at the time of OLT on mortality and morbidity following the procedure. The study included 2,175 primary OLT recipients between 1990 and 2000. Serum sodium concentrations obtained immediately prior to OLT were correlated with subsequent survival using proportional hazards analysis. Morbidity associated with hyponatremia was assessed, including length of hospitalization, length of intensive care unit (ICU) admission, and occurrence of central pontine myelinolysis (CPM). Out of 2,175 subjects, 1,495 (68.7%) had normal serum sodium (>135 mEq/L) at OLT, whereas mild hyponatremia (125-134 mEq/L) was present in 615 (28.3%) and severe hyponatremia (

Hyponatremia is a frequent electrolyte disorder. A hyponatremia is called acute severe (115 mM) when the duration has been36 to 48 h. Such patients often have advanced symptoms as a result of brain edema. Acute severe hyponatremia is a medical emergency. It should be corrected rapidly to approximately 130 mM to prevent permanent brain damage. In contrast, in chronic severe hyponatremia (4 to 6 d), there is no brain edema and symptoms are usually mild. In such patients, a number of authors have recommended a correction rate0.5 mM/h to approximately 130 mM to minimize the risk of cerebral myelinolysis. Sometimes it is not possible to diagnose whether a severe hyponatremia is acute or chronic. In such cases, an initial imaging procedure is helpful in deciding whether rapid or slow correction should be prescribed. The modalities of treatment of severe hyponatremia have so far consisted of infusions of hypertonic saline plus fluid restriction. In the near future, vasopressin antagonists will become available. Preliminary experience has already demonstrated their efficiency of inducing a sustained water diuresis and a correction of hyponatremia.

Although the exact pathogenesis of central pontine myelinolysis (CPM) is unknown, correction of hyponatremia, thyreotropin releasing hormone, plasmapheresis, and corticosteroids seem to be effective. Assuming intravenous immunoglobulins (IVIG) to also be effective in CPM, 0.4 g/kg body weight/d immunoglobulins were applied to a 48-year-old patient who developed CPM with double vision, dysarthria, dysphagia, and left-sided hemiparesis 3 weeks after spontaneous normalization of hyponatremia. After 5 days of IVIG, his symptoms markedly improved, confirmed by improvement in the Norris score (42%), Frenchay score (19%), Kurtzke score (20%), Disability score (54%), vital capacity (26%), and peak torque (69%). The promising clinical effect of IVIG was assumed to be caused by the reduction of myelinotoxic substances, the development of antimyelin antibodies, and the promotion of remyelination. In conclusion, IVIG appear to be a promising therapeutic option in CPM.

In a recent series of 44 liver transplants we identified both extrapontine myelinolysis (EPM) - characteristic of cyclosporine neurotoxicity - and central pontine myelinolysis (CPM) in 5 recipients posttransplant. An additional 2 recipients had EPM only posttransplant. MRIs performed in 4 asymptomatic recipients were normal. Large perioperative shifts in serum sodium, hypomagnesemia, and high cyclosporine levels may play a role in the development of these lesions, although the evidence from this study is inconclusive. In addition to supportive care, dilantin was started in patients who had seizures; aggressive magnesium replacement was initiated for hypomagnesemia, and cyclosporine levels were reduced in all patients. All patients demonstrated a slow steady recovery and all but 2 are at home at the time of writing. CPM may be more prevalent than previously appreciated following liver transplantation, although its prognosis may not be as dismal.

Central pontine myelinolysis (CPM) is a neurological disorder with a variety of manifestations which may be fatal or result in permanent disabilities. Various factors, most commonly too rapid correction of serum sodium, have been implicated in the development of this osmotic demyelinating syndrome. The patient's survival depends on accurate assessment and prompt intervention by the neuroscience nurse. Optimal outcome depends on collaboration by all members of the health care team.

Too rapid correction of hyponatremia often causes osmotic myelinolysis. A rapid shift from normal to hypernatremia may also be dangerous. We report a hunger striker that developed an extreme serum sodium concentration followed by coma and radiologic abnormalities characteristic of osmotic myelinolysis. A 19-year-old Algerian asylum seeker started a hunger strike after his residence permit had been rejected. His medical history was unremarkable. He used no medications, including lithium. One month before fasting, he was placed in isolation because of behavioral disturbances. At this time, the weather was hot, and the patient refused sufficient intake of water and food. One day after he stopped eating and drinking, he became confused; after another 5 days, he became somnolent. He was transferred to a penitentiary hospital. On admission, his serum sodium level was 187 mmol/L, creatinine 213 μmol/L, and glucose 6.8 mmol/L. Urine osmolality was not measured. A feeding tube rehydration regimen was started with 2 L/day of water. His sodium level was 172 mmol/L the next day. …

A 76-year-old man developed general malaise and polyuria over a few days, and then became lethargic when he was brought into the hospital. He was oriented to self, but not to time or place. He had general motor weakness, but there was no laterality. Sensory disturbance was not noticed, except that he had been blind following a head injury 10 years ago. On admission, his serum sodium and potassium levels were 106 mEq/L and 3.6 mEq/L, and a CT scan of the brain demonstrated a large mass in the sella turcica extending anteriorly into the sphenoid sinus, which was accompanied with intratumoral bleeding. Under the diagnosis of pituitary apoplexy causing acute adrenocortical insufficiency, a series of treatments was started. Along with hormone replacement with 20 mg/day of …