P2.L224: Dysphagia, bradypnea and bradycardia: Have you considered the cerebellum?

Introduction: Chiari malformation is an anatomic abnormality whereby part of the brain is displaced downwards, inappropriately occupying the spinal canal. The implications can be severe enough to require surgery. There are five identified subtypes with Chiari Type I being the most common with an estimated 0.5%-3.5% of the general population affected (though this number is likely an underestimate as it is often incidentally encountered with imaging). When symptoms are apparent, patients will experience changes in their posture, balance, muscle movements, speech and coordination, as expected with cerebellar involvement.

Case Description: This case pertains to a 9 m.o. F with frequent URI symptoms in the setting of chronic feeding difficulties leading to multiple outpatient/ED encounters where she was diagnosed with presumed viral infections and discharged to supportive care. When her symptoms were ongoing and a CXR revealed multifocal consolidations, she was admitted to the hospital for aspiration pneumonia. On review of provider documentation, the child's parents expressed concern that the infant was uncomfortable when placed prone, had worsening cough/choking-like episodes when taking a bottle supine and preferred to hold her head with her chin tucked to her chest. This history, and given that while inpatient the child had bradypnea (RR < 10), bradycardia (HR 70s), self-resolving desaturations (SpO2 80%), fussiness with neck extension and improved feeding tolerance in the side-lying position, a head US was ordered. The infant was found to have moderately enlarged ventricles warranting a follow-up MRI. Imaging of the brain and spine demonstrated significant Chiari 1 malformation with extension of cerebral tonsils through the foramen magnum, obstructive hydrocephalus and spinal cord edema with dilation from C2-C6. The patient required EVD placement, occipital craniectomy, C1 laminectomy, Chiari decompression and subsequent VP shunt placement.

Discussion: Though a Chiari malformation is more often congenital, it may not present itself until later in life. In patients with a confirmed malformation, routine examinations and diagnostic testing are recommended to monitor neurologic development. If left undiagnosed, side effects can include poor feeding with resulting malnutrition, motor delays with decreased muscle tone/strength, seizures, learning disabilities and in severe cases, acute deterioration and sudden death. As for the patient discussed, surgical correction allowed her to resume a regular diet with expected normal developmental outcomes.

Conclusion: An infant was admitted for evaluation of dysphagia and IV antibiotics for aspiration pneumonia but was found to have abnormal vital signs and head positioning. Imaging studies led to her diagnosis of Chiari malformation. Given the patient's significant brain and spinal cord edema, ventriculomegaly and brainstem compression, she required urgent neurosurgical intervention. Though pediatricians frequently encounter children with benign feeding difficulties that resolve with time, a thorough history and comprehensive physical examination are necessary to ensure no secondary cause.