Delayed Onset of Central Pontine Myelinolysis: A Rare Presentation Following Surgery for Severe Acute Necrotic Pancreatitis Complicating Infection

Introduction Central pontine myelinolysis (CPM) is a rare osmotic demyelination syndrome. Myelinolysis following patients with acute pancreatitis (AP) is extremely rare. To the best of our knowledge, only two cases have been reported in prior literatures. However, the associated mechanisms on patients with CPM secondary to AP have remained unclear. Patient concerns (1) A 58-year-old woman, with upper abdomen pain complicating nausea and vomiting for ten days, had a fever and abdominal pain (first hospitalization). (2) On second hospitalization, she was in abdominal pain and distension. (3) On third hospitalization, she was admitted because of "intense diarrhea for two days and drowsiness for half a day". On the eighth day, the patient deteriorated with onset of anisocoria. On the 12th hospital day, patient’s mental status became conscious but in a new-onset mutism. Diagnosis (1) Contrast-enhanced CT revealed a severe acute necrotic pancreatitis (first hospitalization). (2) On second hospitalization, laboratory tests showed a glucose of 12.3 mmol/L and a hyponatremia of 125.9 mmol/L. Follow-up CT showed the presence of abdominal infection. (3) On third hospitalization, laboratory findings included a hypokalemia of 2.4 mmol/L, a severe hypernatremia of 192 mmol/L and a severe hyperchloremia of 150 mmol/L, and a creatinine of 118.7umol/L. Brain MRI, performed 4.5 months after acute-onset, revealed the central pontine myelinolysis. Interventions (1) She received intravenous fluids and insulin treatment, initiated electrolyte corrections, and anti-infection (first hospitalization). (2) On second hospitalization, the operation including pancreatic abscess removal and cholecystectomy was performed around 2.5 months after AP onset. (3) On third hospitalization, she received potassium and fluid infusions, diuresis, and continuous renal replacement therapy. Electrolyte corrections were continuously proceeded. Outcomes When she was discharged from third hospitalization, the patient was in unconsciousness with a lethargy status. By means of telephone follow-up, the patient died five days after the third discharge. Conclusion It is important to raise the early diagnosis of CPM in AP patients (especially severe necrotic pancreatitis) if severe electrolyte disturbance and subsequently altered mental status or transient anisocoria occur. Based on high specificity imaging findings, MRI should be performed in time when delayed onset of CPM is suspected.