Index of Suspicion

Case 1 Presentation

An 8-month-old girl presents with a 2-day history of progressive weakness, which was first noted yesterday morning, when she appeared to be crawling with her legs only and was unable to support her upper body. Last evening, her eyes appeared crossed, and this morning her cry sounded weaker. She recently had an upper respiratory tract infection, but has had no exposure to medications, insects, insecticides, honey, or canned foods.

On physical examination, the infant appears hypotonic but is alert and in no apparent distress. Her vital signs are normal. She has a dysconjugate gaze, but her gag reflex is present. She moves all extremities and can grasp objects. She exhibits extreme head lag on a pull-to-sit maneuver, and she is unable to sit or stand independently. Her distal muscle strength is 3/5 and proximal muscle strength is 4/5. No deep tendon reflexes can be elicited. Her remaining physical findings are normal.

Her laboratory test results include a normal CBC and complete metabolic panel, ESR of 1 mm/h, creatine kinase of 171 IU/L, and a negative urine toxicology screen. Lumbar puncture shows clear fluid, glucose concentration of 67 mg/dL (3.7 mmol/L), total protein concentration of 26 mg/dL, and 2 WBCs (1 lymphocyte, 1 monocyte)/mm³. CT and MRI of the brain and cervical spine yield normal results. The following day, the patient is unable to move her extremities, is incapable of clearing her secretions, and requires intubation. An additional test leads to the correct diagnosis.

Case 2 Presentation

A 3-month-old boy is admitted to the hospital in February because of wheezing and stridor. Viral croup and possible bronchiolitis are diagnosed, and he improves with epinephrine and albuterol nebulizers. The stridor and wheezing are most pronounced with activity and immediately after feedings. The baby has had intermittent stridor since birth as well as “noisy …