Just diagnosed catatonia in a patient who became unresponsive and got intubated, got a CT, then a CT stroke protocol, CT angio chest, MRI, spinal tap, continuous EEG, flagrantly extensive metabolic and infectious workup. Negative findings. Final simple diagnosis for the altered mental status? Lorazepam 0.5mg IV: Pt became responsive and conversant within 5 minutes.
Sometimes you just have to go old school.