Neurosurgery has played an important role in the development of neuroscience and the science of consciousness. In this paper, the authors reflect on some of the historical contributions of neurosurgeons to the science of consciousness and discuss the ways in which clinical neurosurgery can contribute to the science of consciousness in the 21st century. An approach to the “hard problem” is proposed based on the principles of psychophysics, and the opportunities offered by intracranial recording and stimulation in patients capable of reporting changes in subjective experience are discussed. Such an approach will allow the systematic study and description of the bridging relationships between neurobiology and conscious experience.
Harutomo Hasegawa, Graham A. Jamieson, and Keyoumars Ashkan
Keyoumars Ashkan and Anne J. Moore
Francesco Marchi, Francesco Vergani, Iacopo Chiavacci, Richard Gullan, and Keyoumars Ashkan
This paper retraces the fundamental achievements of Geoffrey Knight (1906–1994), a British neurosurgeon and a pioneer in the field of psychosurgery. His career developed in the 1950s and 1960s, when—following the unregulated practice of frontal lobotomies—strong criticism arose in the medical community and in the general public against psychosurgery. Geoffrey Knight's clinical research focused on identifying new, selective targets to limit the side effects of psychosurgery while improving the outcome of patients affected by mental disorders. Following the example of William Beecher Scoville, he initially developed restricted orbital undercutting as a less invasive alternative to standard frontal lobotomy. He then developed stereotactic subcaudate tractotomy, with the use of an original stereotactic device. Knight stressed the importance of the anatomy and neurophysiology of the structures targeted in subcaudate tractotomy, with particular regard to the fibers connecting the anterior cingulate region, the amygdala, the orbitofrontal cortex, and the hypothalamus. Of interest, the role of these white matter connections has been recently recognized in deep brain stimulation for major depression and anorexia nervosa. This is perhaps the most enduring legacy of Knight to the field of psychosurgery. He refined frontal leucotomies by selecting a restricted target at the center of a network that plays a crucial role in controlling mood disorders. He then developed a safe, minimally invasive stereotactic operation to reach this target. His work, well ahead of his time, still represents a valid reference on which to build future clinical experience in the modern era of neuromodulation for psychiatric diseases.
José Pedro Lavrador, Prajwal Ghimire, Richard Gullan, Keyoumars Ashkan, Francesco Vergani, and Ranjeev Singh Bhangoo
José P. Lavrador, Graeme Pang, Francesco Vergani, Ranjeev Bhangoo, Richard Gullan, and Keyoumars Ashkan
José Pedro Lavrador, Shami Acharya, Anastasios Giamouriadis, Francesco Vergani, Keyoumars Ashkan, and Ranjeev Bhangoo
Anmol Pandey, Bhaskar Thakur, Florence Hogg, Christian Brogna, Jamie Logan, Roopen Arya, Richard Gullan, Ranjeev Bhangoo, and Keyoumars Ashkan
Venous thromboembolism (VTE) is a major cause of morbidity in patients undergoing neurosurgical intervention. The authors postulate that the introduction of a routine preoperative deep vein thrombosis (DVT) screening protocol for patients undergoing neurosurgical intervention for brain tumors would result in a more effective diagnosis of DVT in this high-risk subgroup, and subsequent appropriate management of the condition would reduce pulmonary embolism (PE) rates and improve patient outcomes.
The authors conducted a prospective study of 115 adult patients who were undergoing surgical intervention for a brain tumor. All patients underwent preoperative lower-limb Doppler ultrasonography scanning for DVT screening. Patients with confirmed DVT underwent a period of anticoagulation therapy, which was stopped prior to surgery. An inferior vena cava (IVC) filter was inserted to cover the perioperative period during which anticoagulation therapy was avoided due to bleeding risk before restarting the therapy at a later date. Patients underwent follow-up performed by a neurooncology multidisciplinary team, and subsequent complications and outcomes were recorded.
Seven (6%) of the 115 screened patients had DVT. Of these patients, one developed postoperative PE, and another had bilateral DVT postoperatively. None of the patients without preoperative DVT developed VTE postoperatively. Age, symptoms of DVT, and previous history of VTE were significantly higher in the group with preoperative DVT. There were no deaths and no complications from the anticoagulation or IVC filter insertion.
Preoperative screening for DVT is a worthwhile endeavor in patients undergoing neurosurgical intervention. A multidisciplinary approach in management of anticoagulation and IVC filter insertion is safe and can minimize further VTE in such patients.
Santo Chakraborti, Harutomo Hasegawa, Daniel E. Lumsden, Wisam Ali, Margaret Kaminska, Jean-Pierre Lin, and Keyoumars Ashkan
The methylmalonic acidemias (MMAs) are a group of inborn errors of metabolism resulting in the accumulation of methylmalonic acid in body tissues and fluids. A recognized complication of MMA is bilateral liquefaction of the globus pallidi, resulting in a fulminant total body dystonia of childhood often refractory to medical treatment. This case of total body dystonia due to MMA in a 4-year-old boy had been medically refractory for 15 months. Complete metabolic destructive liquefaction of the pallidi, that is, autopallidotomy, necessitated an alternative, bilateral subthalamic nucleus (STN) target for deep brain stimulation (DBS) with a marked improvement in dystonia and reduction in pain. The case illustrates the efficacy of STN DBS in this condition and the technical challenges in targeting the STN in a small child.