A 3-year-old boy with DiGeorge syndrome is brought to the emergency department after a 5-minute, generalized tonic-clonic seizure. For the past week, the patient has been increasingly tired and has had severe morning headaches, which have not been relieved by acetaminophen or ibuprofen. He has been dragging his right leg for several days while walking. His appetite has decreased, and he has been vomiting after waking up in the morning. The patient's family recently emigrated from a developing country to obtain care for his unrepaired tetralogy of Fallot. The patient has speech delay and a history of recurrent pneumonias and sinus infections. Temperature is 38.3 C (101 F). Physical examination shows a tired-appearing child with dysmorphic facial features. The right lower extremity exhibits decreased strength and the ankle deep tendon reflex is hyperreflexic; the left lower extremity is normal. There is no truncal ataxia. Which of the following is the most likely cause of this patient's symptoms?
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This patient's fever, morning headache and vomiting, and focal neurologic deficits are concerning for a brain abscess. Children with cyanotic congenital heart disease (tetralogy of Fallot) are at increased risk for brain abscess due to hematogenous spread of bacteria. The right-to-left shunting of venous blood through a ventricular septal defect allows bacteria to bypass the pulmonary circulation, where they are typically filtered and removed by phagocytosis, and spread to the brain.
Headache that is severe and nonresponsive to over-the-counter pain medications is the most common presenting symptom in patients with brain abscess. In addition, vomiting, particularly in the early morning, can be a sign of increased intracranial pressure. Fever and focal neurologic changes (eg, leg weakness, hyperreflexia) are present in about half of patients, and seizure occurs in about 25% of patients. Brain imaging is the next step in diagnostic workup.
(Choice A) Bacterial meningitis can present with acute fever, headache, and vomiting. However, meningeal signs (eg, nuchal rigidity) are often present on examination. This patient's focal right leg weakness and hyperreflexia make brain abscess more likely.
(Choice C) Hypocalcemia is a common feature of DiGeorge syndrome resulting from underdeveloped parathyroid glands. Severe hypocalcemia can cause tetany and seizures; however, hypocalcemia would not explain this patient's fever and several days of unilateral weakness.
(Choices D and E) Hypoglycemia and hyponatremia can cause seizures but are not features of DiGeorge syndrome and would not explain this patient's fever and focal neurologic deficits.
(Choice F) Medulloblastoma is a pediatric tumor most commonly found in the cerebellum that can present with nocturnal or morning headaches and vomiting. However, cerebellar dysfunction manifests as incoordination and/or ataxia, and is unlikely in this patient given no truncal ataxia.
(Choice G) Patients with unrepaired tetralogy of Fallot are at risk for embolic stroke as venous clots (typically filtered in the lungs) can cross the ventricular septal defect into the systemic arterial system. Patients have acute, focal neurologic deficits rather than the indolent headache and neurologic changes seen in this patient. In addition, this patient's fever suggests an infectious process rather than a stroke.
Educational objective:
Brain abscess in children frequently presents with headache, fever, focal neurologic deficits, and seizure. Cyanotic congenital heart disease is a risk factor for brain abscess due to hematogenous spread of bacteria.