Neurosurgery is a medical speciality that focuses on the prevention, diagnosis, treatment, and rehabilitation of disorders affecting the nervous system, which includes the brain, spinal cord, and the peripheral nerves. The field deals with all manners of pathology including congenital, acquired, trauma, infection-related, and degenerative. One example of a congenital condition is hydrocephalus while infection-related cases include meningitis and myelomeningocele; both are very common among paediatric patients. Traumatic neurological conditions include head or spine trauma that may cause internal bleeding, which are very common among adults while degenerative diseases include aneurysms and Parkinson's disease and are more common among older patients.

Due to its expansive nature, neurosurgery is divided into different categories, including general neurosurgery and a host of specialized branches.

General neurosurgery – General neurosurgery is involved with most conditions that are of neurological in nature particularly neurological trauma and neurological emergencies, one example of which is intracranial haemorrhage.

Vascular and endovascular neurosurgery – This involves the diagnosis and treatment of aneurysms, carotid stenosis, strokes, vasospasms, and spinal malformations. Surgical treatments of such conditions are now conducted using minimally invasive techniques such as angioplasty, stenting, and embolization.

Spine neurosurgery – This involves the treatment of disorders affecting the cervical, thoracic, and lumbar spines; these problems include arthritis in the spinal discs, spinal cord compression caused by trauma, or spondylosis. Symptoms of spinal problems include balance deficiency, numbness and tingling in the hands and the feet.

Peripheral nerve surgery – Common peripheral nerve surgeries include carpal tunnel decompression for the treatment of carpal tunnel syndrome as well as peripheral nerve transposition; this branch of neurosurgery is responsible for the treatment of nerve entrapment conditions.

Stereotactic, functional, and epilepsy neurosurgery

Oncological neurosurgery

Skull base surgery

Paediatric neurosurgery

Aside from these specialized branches, neurosurgery also involves the use of different surgical methods for diagnosing and treating neurological conditions. In recent years, there has been a shift from conventional neurosurgical methods to more modern alternatives. While the conventional method requires open surgery where the surgeon opens up the skull to access the brain, newly developed methods now allow specialists to surgically treat neurological conditions through smaller openings. These methods make use of microscopes, endoscopes, and most recently, neuroradiology methods. Open surgery techniques are now usually reserved for traumatic cases or emergencies.

Microsurgery, or microscopic neurosurgery, makes use of microscopic technology to enable surgeons to treat affected areas of the brain through a smaller opening, simply by magnifying the treatment area. Nowadays, even complex procedures such as clipping an aneurysm or complex spine surgeries such as microdiscectomy and laminectomy can be performed through microscopic surgery, making neurosurgical treatment less invasive.

Endoscopic neurosurgery is also widely in use today in the treatment of pituitary tumours, cerebrospinal fluid leakage, hydrocephalus, colloid cysts, and many others.

Neuroradiology has lately become synonymous with modern neurosurgery and now plays a huge role in both the diagnosis and treatment of neurological conditions. Neuroradiology technologies include:

Computer-assisted imaging computed tomography, or more popularly known as a CT scan

Magnetic resonance imaging or MRI

Positron emission tomography or PET

Magnetoencephalography or MEG

Stereotactic radiosurgery