Most neurosurgeons have been trained and practice all facets of neurological surgery. However, within the large academic neurosurgical departments of developed countries there is a trend towards subspecialisation. Indeed, paediatric neurosurgery in the United States now has its own board, which requires its members to have at least 12 months of fellowship training and to pass a separate board exam. Similarly, the disciplines of vascular, functional, spinal, oncological and skull base neurosurgery are becoming more defined and complex often necessitating fellowship training.
The concept of minimally invasive neurosurgery originated with the keyhole craniotomy for intracranial pathology. Complications from the approach alone seemed unacceptable and from the desire to reduce the risk of craniotomy came this new discipline. Arguably the greatest breakthrough in minimally invasive techniques was the application of endoscopy to neurosurgery. The endoscope has revolutionised the treatment of patients with hydrocephalus, brain tumours, aneurysms, pituitary tumours and any intraventricular pathology. The 2 subspecialties of neuroendoscopy and paediatric neurosurgery are intimately related because more than 30% of paediatric cases involve conditions of cerebrospinal fluid dynamics or intraventricular pathology. Indeed, in order to practice contemporary paediatric neurosurgery one must be comfortable with all the aspects of endoscopy.
Other tools that have made neurosurgery less invasive and equally, or more, effective are radiosurgery, frame-based and frameless stereotaxy and advances in technology such as ultrasonic aspirators, laser fibres and microsurgical instrumentation.
