Neurological surgery was recognized as a specialty in the beginning of the 20th century. The introduction of ventriculography, pneumoencephalography, and angiography in the second and third decade led to the indirect diagnosis of brain tumours and vascular pathologies. However, the mortality and morbidity of neurosurgical disease was profoundly high due to crude diagnostic and operative techniques and a lack of skilled neuro-anaesthesia. Neurosurgeons would then operate on the lesion in the most hostile environment, marred by lack of microsurgical instruments and inadequate knowledge regarding control and maintenance of intracranial pressure during surgery. Advent of the Computed Tomography (CT) scan in the early 1970s helped to delineate brain lesions in a better manner. The invention of cerebrospinal fluid diversion procedures for hydrocephalus was a significant advance in the management of raised intracranial pressure. The introduction of magnetic resonance imaging (MRI) in the 1990s and invention of the high magnification surgical microscope provided a giant leap forward in the surgical resection of brain tumours. This along with progress in neuro-anaesthesia techniques and management of intracranial pressure which helped the neurosurgeon to operate on a relaxed brain, thereby promoting a safe maximal resection of the brain tumour, as well management of vascular lesions. The enhanced magnification provided by the surgical microscope improved the understanding of micro-surgical anatomy. In 1950s and 1960s, discovery of radiation treatment and chemotherapy as an adjuvant therapy for malignant brain tumours, provided a further boost to reduce mortality and morbidity. Broad spectrum antibiotics and steroids in the treatment of central nervous system infections have made a significant impact on reducing central nervous system infections and the incidence of brain abscesses. In the last 20 years of the 20th century, endovascular procedures have been a good adjunct for treatment of vascular diseases of brain.
The 21st century brings with it multiple challenges and opportunities in view of the explosion in information technology, as well as major advances in molecular biology and genetics. Computers in medicine have revolutionised the investigative modalities, as well as diagnosis and treatment paradigms. Neuro-imaging, intra-operative neuro-monitoring, neuronavigation, and neuro-modulation are computer-based applications which are now routinely used in standard neurosurgical practice. A 64-slice CT scan with 3D imaging capability is used for vascular reconstructions during aneurysm surgery and for detailed anatomicopathological demonstration for brain tumour surgery. Functional neuro-imaging is being studied for epilepsy surgery. MRI spectroscopy (metabolic neuro-imaging) is being used to differentiate brain tumours from infections and metastasis. Intraoperative MRI imaging is nowadays being used for rendering maximal safe resection of the brain tumours such as gliomas and pituitary adenomas. Neuromodulation with stem cells for neurological functional restoration is currently being utilized for selected patients with spinal cord injury and certain degenerative neurological diseases. Although the results are modest, they offer some hope for these debilitated patients. The use of stereotaxy has opened up the field of neurosurgery to robotics. Robots have been in use for the past almost two decades in neurosurgery, but largely remain unknown due to limitations in current robotic systems.
The real challenge for the 21st century neurosurgeon will be to assimilate the tremendous advances in neuroscience that have occurred over the last century and then integrate this into the current practice paradigms. Advances in computer technology should help create large, central databases of neurological ailments which will then provide a reference model for investigation, therapeutics, and further research into the subject. Intraoperative image guidance systems provide real-time images, which could increase surgical accuracy. Image guidance navigation in pituitary surgery provides continuous three-dimensional (3D) information regarding anatomical variations of the sphenoid sinus and relationship of tumors to the internal carotid arteries. However, the equipment is expensive and requires specific training for the operating room personnel. Stereotactic radiosurgery for primary and metastatic lesions, as well as arteriovenous malformations, can be performed using linear accelerators and refined systems for visualization and guidance. They can allow effective and safe treatment of radioresistant neoplasms. The advances in molecular biology and genetics should also change the way a brain tumour, or a degenerative neurological disease, would be treated. Genetic microarray would be able to diagnose the type of brain tumour and then suggest relevant molecular targeted therapies. Detection of genetic abnormalities in utero would help the mother to make an informed decision about the future of her pregnancy. Myelomeningocele has been corrected in utero, so-called foetal neurosurgery, although it has been done in an experimental setting. However, its inclusion into routine clinical practice is yet to be accepted worldwide. Infusion of chemotherapeutic agents directly into the tumour bed using nano-technology would be a major advance in this century. The applications of nanotechnology in neurosciences include nerve nano-repair, nano-imaging with nano-particles and quantum dots and nano-manipulation of the CNS with surgical nanobots.The modern-day neurosurgeon will have to integrate the information technology along with the advances in molecular biology and genetics. Surgery is more likely to become minimally invasive until molecular and genetic targeted options provide solutions to major diseases. Clinical neurology will continue to have its own importance in decision making for surgery, however, technology will help refine techniques, achieve precision, and perfection. Neurosurgeons will have to work in conjunction with other specialities including neurologists, psychiatrists, neuro-radiologists, and basic scientists. Epilepsy surgery is one such example where close collaboration between neurosurgeons, epileptologists and neuro-psychologists is required. As such, the neurosurgeon will have to be a leader and adaptable to suggestions, since treatments for most neurosurgical diseases have become multimodal. They need to be well versed with computational neurobiology and telemedicine since future consultations and operative surgery will use digital technology.