Neurosciences - A neurosurgeon's perspective.
The advancements in the field of science in the past fifty years have highlighted the need to integrate all fields of human endeavours and have emphasised interdependency of various disciplines. The separation of humanities, therefore, from neurosciences is a preposterous practical joke on all thinking men. With the human genome project on the anvil, biotechnology is making significant headway holding out promise for organ regeneration. Macro evolution is over, but micro-evolution continues in the brain. Neural Darwinism thus, continues to evolve as long as individual remains conscious and has memory. In the milieu of widely varying internal physiological mechanisms and external stimuli, an alternative theory to preprogrammed directionalism is proposed by three mechanisms namely developmental variation and selection, experiential selections and reentrant signalling. Reentrant signalling reorients and correlates the external inputs leading to psychic development preceding the development of consciousness. The cholinergic and aminergic neuro-modelling systems are well suited to serve as value systems. The main achievement of consciousness is to bring together the many categorizations involved in perceptions into a SCENE. Another part of evolution involved capacity of reentrant signalling to be guided by a value system where it is provided with a lot of choices. With 10(13) neurons and 10(16) connections, freedom of choice may manifest into a 'Buddha' or a 'Hitler'. As part of the evolutionary process, it was interesting how capacity to categorize the need to worship by referring to environment outside evolved into a search within our minds. As the next stage of evolution, neuroscience may, thus, serve as the next gateway to understanding the mind and soul. (+info)
Extreme lateral transcondylar approach to the skull base.
In this study, the authors present their experience of using extreme later transcondylar approach (ELTC) for treating 7 patients with lesions in the anterolateral foramen magnum, upper cervical spine and cerebellopontine angle reaching upto jugular foramen. The tumours included meningiomas, neurofibromas (2 cases each), chondrosarcoma, epidermoid and aneurysmal bone cyst (one case each). The approach was used alone, in combination with retrolabyrinthine presigmoid approach in a patient with lower cranial nerve neurofibroma extending extracranially through the jugular foramen, or in combination with partial C1-C3 laminectomy in two patients with meningiomas situated anterolateral to the cord from the foramen magnum to C3. In two patients with extradural vertebral artery (VA) entrapment by a chondrosarcoma and aneurysmal bone cyst respectively, the vertebral artery was ligated distal to the tumour. The tumours were totally excised in five cases and partially in two. There was no preoperative mortality. The major complications included cerebrospinal fluid leak from the wound (3 cases) and increase in lower cranial nerve paresis (2 cases). At follow up, ranging from 6 months to 2 years, 5 patients showed no tumour recurrence. There was improvement in neurological status. One patient, with a partially excised aneurysmal bone cyst, showed no added deficits or increase in the tumour size. However, there was a massive regrowth in the patient with chondrosarcoma after 6 months. This technique provided a wide surgical exposure with direct visualization of the tumour-anterior cord interface, early proximal control of the VA and preservation of lower cranial nerves. (+info)
Teleradiology in the operating room of the future.
Recent advances in magnetic resonance imaging (MRI) are rapidly making this modality the imaging method of choice for image-guided neurosurgical operations. However, to be ready for its prime time in the operating room (OR), utilization of MRI in the OR requires development of better techniques for image-guided navigation, as well as interactive real-time teleradiologic methods that will allow tele-collaboration between the surgeon and the radiologist. This presentation describes our work in progress toward achievement of teleradiology in the OR. (+info)
Retrolabyrinthine presigmoid transpetrosal approach for selective subtemporal amygdalohippocampectomy.
The retrolabyrinthine presigmoid transpetrosal approach is a modification of the subtemporal approach which is suitable for complete amygdalectomy. By drilling away the retrolabyrinthine presigmoid petrosal bone, at least 1 cm more space below and 1 cm more space medially is obtained than in the subtemporal approach, and temporal retraction pressure is diminished when approaching from below. Operative results according to the Engel's classification of seizure control, and pre- and postoperative Wechsler Adult Intelligence Scale (WAIS), revised WAIS, and Wechsler Intelligence Scale for Children scores were measured in 16 patients treated by normal or modified subtemporal amygdalohippocampectomy. Postoperative follow-up ranged from 8 to 79 months. There has been no morbidity or mortality among these 16 patients, and postoperative seizure frequency has been diminished to less than 10% of the preoperative level in 15 of the 16. In eight patients, seizures have been eliminated totally. Subtemporal amygdalohippocampectomy achieved significantly increased performance and full scale intelligence quotient within 2 months after surgery, compared to preoperative levels. Subtemporal amygdalohippocampectomy is an alternative to the transsylvian approach, but is less invasive. (+info)
The North American Symptomatic Carotid Endarterectomy Trial : surgical results in 1415 patients.
BACKGROUND AND PURPOSE: This study reports the surgical results in those patients who underwent carotid endarterectomy in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). METHODS: The rates of perioperative stroke and death at 30 days and the final assessment of stroke severity at 90 days were calculated. Regression modeling was used to identify variables that increased or decreased perioperative risk. Nonoutcome surgical complications were summarized. The durability of carotid endarterectomy was examined. RESULTS: In 1415 patients there were 92 perioperative outcome events, for an overall rate of 6.5%. At 30 days the results were as follows: death, 1.1%; disabling stroke, 1.8%; and nondisabling stroke, 3.7%. At 90 days, because of improvement in the neurological status of patients judged to have been disabled at 30 days, the results were as follows: death, 1.1%; disabling stroke, 0.9%; and nondisabling stroke, 4.5%. Thirty events occurred intraoperatively; 62 were delayed. Most strokes resulted from thromboembolism. Five baseline variables were predictive of increased surgical risk: hemispheric versus retinal transient ischemic attack as the qualifying event, left-sided procedure, contralateral carotid occlusion, ipsilateral ischemic lesion on CT scan, and irregular or ulcerated ipsilateral plaque. History of coronary artery disease with prior cardiac procedure was associated with reduced risk. The risk of perioperative wound complications was 9.3%, and that of cranial nerve injuries was 8.6%; most were of mild severity. At 8 years, the risk of disabling ipsilateral stroke was 5.7%, and that of any ipsilateral stroke was 17.1%. CONCLUSIONS: The overall rate of perioperative stroke and death was 6.5%, but the rate of permanently disabling stroke and death was only 2.0%. Other surgical complications were rarely clinically important. Carotid endarterectomy is a durable procedure. (+info)
Outcome of surgery for acromegaly--the experience of a dedicated pituitary surgeon.
Previous large series of outcome following pituitary surgery for acromegaly, including our own, have demonstrated poor results, with cure, defined as GH <5 mU/l, achieved in only 33-42% of patients. In our previous series, surgery was performed by one of eight different surgeons. Largely based on the disappointing results of this previous audit of outcome, our practice since 1990 has been, whenever possible, to refer all patients with acromegaly to a dedicated pituitary surgeon (APJ). The objective of the current study was to re-analyse the outcome of surgical treatment for acromegaly since instituting this change. Tumour size and extension was determined on CT/MRI scanning. Biochemical cure was defined as a basal GH <5 mU/l or a nadir GH of <2 mU/l across an OGTT following initial pituitary surgery. Surgery was performed on 66 patients and 42 (64%) were cured, compared with 26/78 (33%) in our previous study (p<0.0005, chi (2) test). The cure rate for microadenomas (n=22) was 86%, and for macroadenomas 52%, compared with 54% (p<0.05, chi (2) test) and 30% (p<0.05, chi (2) test) respectively, in our previous study. We conclude that surgical outcome for acromegaly is enhanced if patients are operated on by a single experienced surgeon. (+info)
Telemedicine in neurosurgery using international digital telephone services between Japan and Malaysia--technical note.
A new image transmission and teleconference system using international digital telephone services was established between Japan and Malaysia. This new system consists of an ordinary personal computer, image scanner, and terminal adapter for digital telephone lines. The quality of images transferred using this system was high enough for diagnosis and discussion except for images such as radiographs requiring huge data transfer. Transmission of one image took approximately 20 seconds. The cost performance was almost equal to the conventional mailing system. The most remarkable advantage of this new system is the high quality of transferred images, the cost and time performance, and security of the medical information. New communication systems using international digital networks including the internet may allow re-distribution of medical resources between advanced countries and developing countries in neurosurgery. (+info)
Snapshot view of emergency neurosurgical head injury care in Great Britain and Ireland.
OBJECTIVES: To study the availability of neurosurgical intensive care for the traumatically brain injured in all 36 neurosurgical centres in the United Kingdom and Ireland receiving head injuries, the response times to referral, and the advice given to the referring hospitals. METHODS: Telephone survey of receiving neurosurgeons regarding their bed status and their advice on three hypothetical case scenarios. Outcome measures included response times for an acute head injury to be accepted to a neurosurgical centre; the intensive care bed status; variations in advice given to the referring hospitals with regard to ventilation, use of mannitol, steroids, anticonvulsants, and antibiotics. RESULTS: There were 43 neurosurgical intensive care beds available for an overall estimated population of 63.6 million. There were 1.8 beds available/million of the population for non-ventilated patients, 0.64 beds available/million for ventilated patients, and 0.55 beds available/million for ventilated paediatric patients. London had a shortage of beds with 0.19 adult beds for ventilation/million north of the Thames and 0.14 adult beds for ventilation/million south of the Thames. The median response time for a patient with an extradural haematoma to be accepted for transfer was 6 minutes and 89% of such a referral was accepted within 30 minutes. Clinically significant delays in receiving referrals (over 30 minutes) occurred in four units. Practices regarding the use of hyperventilation, mannitol, anticonvulsants, and antibiotics showed little conformity and in some cases were against the available evidence and advice given by published guidelines. CONCLUSIONS: There is a severe shortage of available emergency neurosurgical beds especially in the south east of England. The lack of immediately available neurosurgical intensive care beds results in delays of transfer that could adversely affect the outcome of surgery for traumatic intracranial haematoma. Advice given to the referring units by the receiving doctors is very variable. (+info)