Functional Neurosurgery modifies CNS circuits to effect change within or outside the nervous system. Most commonly, Functional procedures are performed to treat movement disorders, chronic pain, spasticity and epilepsy. Whilst regarded as a predominantly elective subspecialty, emergent scenarios are encountered. The combination of their relative rarity couple with the niche nature of the subspecialty may engender anxiety amongst neurosurgery trainees. This Element overviews some more common emergency scenarios which may be encountered comprising suspected malfunction of intra-thecal drug delivery devices, deep brain and spinal cord stimulators. Status Trigeminus and an approach to investigations with a neuromodulation device in situ are also covered.