Diagnostic Challenges

One aspect of neurology I really enjoyed was the diagnostic challenge. We had several people on our service over the month that defied diagnosis despite impressive attempts at tracking down the cause of dementia or coma or other clinical presentations. Most recently, we had a man in his 40s come in with a month history of headache and dizziness. On CT scan, he had a rim-enhancing mass in his cerebellum suggestive of tumor or infection. But a chest X-ray showed an impressive reticular opacification (ground-glass) of bilateral lungs, mostly in the periphery. This became the topic of discussion among neurology, pulmonology, and radiology. Occam's (Ockham's) razor dictates that one cause must be causing both conditions. The patient only had mild dyspnea and cough; he otherwise looked pretty healthy. It was fun seeing how excited everyone got with this diagnostic mystery and the responses of the audience at neuroradiology conference. In the end, the pulmonary consult team guessed that this was a rare manifestation of an atypical infection in an immunocompetent host: Nocardia spreading to the brain.