An Instructive Case of Intussusception Secondary to Rotavirus Infection Presenting with Encephalopathy

To the Editors: Intussusception is the invagination of 1 segment of the intestine into another segment.1 It is the most common cause of abdominal emergencies in early childhood, particularly in children under 2 years of age.2 In approximately 95% of pediatric cases, no underlying cause is identified.3 The incidence of intussusception exhibits seasonal variability, often coinciding with peaks of viral gastroenteritis.3 The male-to-female ratio is approximately 2:1.3 Anatomically, 90% of cases are classified as ileocolic intussusception.3 The classic clinical presentation includes sudden onset, intermittent, severe, cramp-like abdominal pain occurring every 15–20 minutes, accompanied by inconsolable crying and drawing up of the legs toward the abdomen.4 Rarely, the initial presentation may involve only lethargy or altered consciousness.4 A 21-month-old male child presented with a history of diarrhea twice and subsequently became unresponsive and refused feeding approximately 5 hours before admission. Detailed history revealed head trauma 2 days prior due to hitting furniture, with no initial changes in general condition and no medical consultation. The patient was referred from an external center due to the need for intensive care. On admission: Glasgow Coma Scale score of 10 (E2, M4, V4), bilateral light reflexes present, no rash, capillary refill time under 2 seconds, temperature: 36.8 °C, blood pressure: 104/65 mm Hg, heart rate: 120 bpm, oxygen saturation: 98% (on room air), respiratory rate: 28/min. The patient was monitored, supported with a reservoir oxygen mask, oral intake was stopped, and maintenance fluids were initiated. A cranial computed tomography scan was performed and found to be normal. Laboratory results were: blood glucose normal, white blood cell count 10.28 × 10³/µL, hemoglobin 10.6 g/dL, hematocrit 30.6%, platelets 306,000 × 10³/µL, aspartate aminotransferase 36.6 U/L, alanine aminotransferase 10.7 U/L, sodium 137 mmol/L, potassium 4.09 mmol/L, blood urea nitrogen 7 mg/dL, creatinine 0.21 mg/dL, C-reactive protein 0.49 mg/dL, chloride 106 mmol/L, pH 7.38, base excess −8.7, bicarbonate 17.9 mmol/L, partial pressure of carbon dioxide 26.5 mm Hg, and lactate 1.2 mmol/L. The patient received a saline bolus of 10 cc/kg. Blood cultures were obtained, and antibiotics were initiated at CNS infection doses. The patient showed fluctuating GCS levels over time. Within an hour, 2 vomiting episodes occurred. Abdominal ultrasound was performed for suspected intussusception and revealed bowel loops forming a pseudokidney appearance in the right upper quadrant, measuring approximately 3 cm. Stool microscopy showed abundant leukocytes; rotavirus antigen was positive. The patient was consulted to pediatric surgery and was hospitalized in the pediatric ward. On the second day of hospitalization, the patient's condition improved, with normal passage of gas and stool and was discharged with recommendations. Intussusception typically occurs between 6 and 36 months of age and is the most common cause of intestinal obstruction in this age group.1 However, clinicians must also consider intussusception outside of this age range. Vomiting is usually a prominent symptom and commonly follows the initial attacks of abdominal pain.2 Initially, vomiting may be nonbilious but can become bilious as the obstruction progresses.2 A sausage-shaped palpable mass may be detected in the right abdomen. Currant jelly stools, consisting of blood and mucus, are a late finding and occur in only a small percentage of patients.2 Consequently, initial presentation can often mimic gastroenteritis. The classic triad of abdominal pain, palpable sausage-shaped abdominal mass, and currant jelly stool is observed in fewer than 15% of patients at presentation.3 Approximately 20% of infants exhibit no apparent abdominal pain, and nearly one-third of patients have neither visible blood/mucus in stool nor a palpable mass.2,4 Many older children may present with isolated abdominal pain without other signs or symptoms. Rarely, lethargy or altered consciousness may be the first presenting feature, more frequently observed in infants and often misinterpreted as sepsis. Three hypotheses have been proposed for this encephalopathy: The first, suggested by Singer, involves systemic effects of toxic metabolites released from ischemic bowel suppressing the central nervous system.5 The second proposes endogenous opioid intoxication due to intense endorphin release during pain episodes.6,7 Schwartz et al7 found no significant difference in plasma beta-endorphin levels between intussusception patients and controls.8,9 The third hypothesis suggests that acute abdominal pathology leads to electrolyte imbalance, subsequently resulting in metabolic encephalopathy.10,11