A 29-year-old woman, G2P1A0, was brought to the emergency department (ED) in an unconscious state. She had a history of fever and decreased urine output for 4-5 days. She also had a recent history of a full-term normal vaginal delivery 9days before at a local hospital without any antenatal or intranatal complications. She did not receive any antibiotics during labor, and bleeding during delivery was approximately 500 mL. No partogram was available in the documents, and she had no history of postpartum hemorrhage. Her relatives explained that 4 days after the delivery, she started having episodes of fever (37.7 C-38.3 C) with loose stools (4-5 episodes per day). Subsequently, she was admitted to a government medical college and hospital where she delivered vaginally. She received paracetamol and fluids intravenously(the positive balance at the end of 2 days was 1500 ml). No other obstetrical postpartum complication, such as excessive bleeding, breast mastitis, or lactation problems, occurred. She was discharged home after 2 days of hospitalization, as her fever subsided, andresults of relevant tests such as complete blood count, renal function test, liver function test, and coagulation parameters were normal. She has advised tablet paracetamol and multivitamin syrup on discharge. However, on day 9 after the delivery, she was bought to the ED in an unconscious state, with complaints of fever and irrelevant talk for 1 day. According to her relatives, shehad excessive sweating and decreased intake of water in the last 2 days. There was no accurate record of fluid intake between days 4 and 8, but it was generally reduced because of the custom in thepatient's community.
On examination in the ED, her pupils were normal in size and reacting to light. Neck rigidity and limb hypotonicity were not observed, and her plantar response was flexor. She responded to painful stimuli by opening up her eyes, without a verbal response, and normally flexing her limbs. Her Glasgow coma scale (GCS) score was 7 (E2V1M4). She had a fever of 104.5 F (40.2 C), and her blood pressure was 100/68 mmHg, without any vasopressors, with a pulse rate of 144 beats per minute. She was intubated based on GCS of 7 and was placed on mechanical ventilation in the ED. Her provisional diagnosis was meningoencephalitis with a differential of tropical fever, and she was transferred shifted to the ICU for further management. During the first hospitalization, she did not receive any antibiotics, so we gave her ceftriaxone 2 gintravenously twice a day based on the provisional diagnosis.
Her CT of the brain was normal (Figure 1), following which a cerebrospinal fluid (CSF) was sent for examination. The laboratory evaluation showed severe hypernatremia with serum sodium (Na+) level of 182meq/L, chloride level of 148 mEq/L, plasma osmolality of 439 mOsmol/kg, urine osmolality of 782 mOsmol/kg, hemoglobin of 12.7 g/dL, hematocritof 47.8%, total white blood cell count of 16.68 x  103/muL, platelet count of 132 x 103/muL, blood urea of 171 mg/dL, and serum creatinine of 2.56 mg/dL. Other investigations including liver function test, coagulation parameters, and CSF biochemical report and cell counts were normal. All cultures were sterile. Dengue antibody and malaria rapid antigen were also negative.
Ultrasound screening of inferior vena cava showed collapsibility of >50%. Fluid resuscitation by intravenous administration of balanced crystalloids was started. A nasogastric tube was inserted, and free water replacement was started as the total free water deficit was calculated to be approximately 7.8 L. Nasogastric feeding was also started as per the ICU protocol, and glycemic control was maintained. Serial monitoring of serum sodium was conducted using arterial blood gas analysis (Figure 2). The rate of sodium correction was kept below 1 mEq/L/h, and her urine output was monitored (50-70 mL/h). She was kept on a ventilator, and her neurological status was assessed dailyduring ICU rounds. Over the next days, her serum sodium level dropped to 142 mEq/L, and her sensorium also improved. Sedation was stopped, and weaning trials were attempted. She could follow verbal commands by opening and closing her eyes and could identify her relatives by nodding her head. However, she was unable to move her limbs, and her power grade was between 1/5 to 2/5 in all four limbs. There was drooling of secretions from the angle of the mouth, which was suggestive of bulbar weakness. In view of her poor muscle power, neurology consultation was taken, and MRIof the brain and spine revealed symmetrical tbl2, and fluid-attenuated inversion recovery revealed hyperintense signal and restricted diffusion along the corticospinal tract involving the centrum semiovale, corona radiata, posterior limb of the internal capsule, and crus cerebri, appearing as "wine-glass" on the coronal image. Symmetrical signal changes also demonstrated involvement of the middle cerebellar peduncle and splenium of the corpus callosum. The gradient images showed microhemorrhages in the involved region. The imaging features were suggestive of postpartum hypernatremic encephalopathy with osmotic extrapontine myelinolysis (Figure 3). Following the MRI report, measurement of serum creatinine phosphokinase was advised, which was 475 IU, and her serum lactic dehydrogenase was 1229 IU/L. Her urine myoglobin was 1200 ng/mL. A final diagnosis of postpartum hypernatremic encephalopathy with osmotic EPM and rhabdomyolysis was made. MRI remains to be the chief diagnostic tool for ODS and EPM.   Her rhabdomyolysis resolved in a week with judicious fluid management. Considering bulbar involvement, it was difficult to extubate her, so percutaneous tracheostomy was performed on day 12 in the ICU. She was weaned from the ventilator after the PCT. As she was unable to swallow semisolids, gastroenterologists for advised percutaneous endoscopic gastrostomy for long-term feeding, which was performed by the gastroenterologists on the next day.
Her rehabilitation was started in the ICU. She was able to sit with support, and her power improved to grade 3/5 in the upper limbs and grade 2/5 in the lower limbs. She was then transferred to the ward for long-term rehabilitation under the follow-up of the department of physical medicine and rehabilitation.