Posttraumatic total dislocation of the upper thoracic spine.

BACKGROUND: Difficulty in proper visualization of the upper thoracic spine in plain radiographs allows for injuries at this level to be missed, especially in a busy trauma center. This window of error is increased when the patient presents with no symptoms or signs of neurologic or spinal involvement, as upper thoracic dislocations commonly present early. CASE DESCRIPTION: The authors report a 19-year-old girl who developed progressive paraparesis 18 hours following initial presentation with a scalp avulsion injury. Imaging revealed a complete dislocation at T1-T2, with cord compression. Emergency surgical decompression and reconstruction of her spinal column was performed with a 360-degree stabilization. There was immediate neurologic improvement and on follow-up the patient is neurologically normal. CONCLUSIONS: The case highlights the difficulty in visualization of the upper thoracic spine in routine radiographs taken in a casualty setting. Treating physicians should have a low threshold for investigation of cervico-thoracic dislocations. The possibility of a delayed progressive dislocation should be kept in mind when dealing with injuries with a potential for spinal injury.

Appropriate technology for neurosurgery.

Though more than 50 years have elapsed since neurosurgery has come to the developing countries, vast areas of the population do not have neurosurgical facilities available to them. This is due not only to the economic status of the country but also as a result of the training that the neurosurgical trainee receives. It is proposed in this article that while the young neurosurgeon must, without doubt, be very well trained in the latest technology, at the same time he must be taught to work with confidence with whatever facilities are available without any feeling of inferiority. The locally available appropriate technology should be fully utilized. The neurosurgeon at the periphery must be provided with the minimum essential neurosurgical equipment and also with good compensation. The concerned governments, the public, neurosurgical teachers, and neurosurgical societies and journals have a great role to play in this difficult task.

Spatiotemporal dynamics of charged species in the afterglow of plasmas containing negative ions.

The spatiotemporal evolution of charged species densities and wall fluxes during the afterglow of an electronegative discharge has been investigated. The decay of a plasma with negative ions consists of two stages. During the first stage of the afterglow, electrons dominate plasma diffusion and negative ions are trapped inside the vessel by the static electric field; the flux of negative ions to the walls is nearly zero. During this stage, the electron escape frequency increases considerably in the presence of negative ions, and can eventually approach free electron diffusion. During the second stage of the afterglow, electrons have disappeared, and positive and negative ions diffuse to the walls with the ion-ion ambipolar diffusion coefficient. Theories for plasma decay have been developed for equal and strongly different ion (T(i)) and electron (T(e)) temperatures. In the case T(i)=T(e), the species spatial profiles are similar and an analytic solution exists. When detachment is important in the afterglow (weakly electronegative gases, e.g., oxygen) the plasma decay crucially depends on the product of negative ion detachment frequency (gamma(d)) and diffusion time (tau(d)). If gamma(d)tau(d)>2, negative ions convert to electrons during their diffusion towards the walls. The presence of detached electrons results in "self-trapping" of the negative ions, due to emerging electric fields, and the negative ion flux to the walls is extremely small. In the case T(i)<

Surgery for ossification of the posterior longitudinal ligament of the cervical spine.

The authors present their surgical experience with fifty seven cases of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine, operated between January 1992 and January 1999. Continuous OPLL was seen in the majority of patients (40/57). Posterior decompressive surgery was performed in 18 patients, a median corpectomy and excision of the OPLL in 28 and anterior segmental decompression in 11 patients. One patient had a transient weakness of muscles supplied by the C5 myotome following a C4-C5 corpectomy. 84.2% of the patients showed improvement by at least one grade at the time of discharge. 92.8% of patients who underwent a corpectomy improved in the immediate post-operative period as compared to 90.9% of those who underwent an anterior segmental decompression and 83.3% of those who underwent a posterior decompressive procedure. 97.7% of the 44 patients followed-up between one and five years showed neurological improvement. Thirty-two patients (72.7 %) had regained normal or near normal neurological function and returned to their jobs. Good results were obtained when the surgical approach and the procedure adopted were individualised.

Giant invasive spinal schwannomas: definition and surgical management.

OBJECT: Confusion exists regarding the term giant spinal schwannoma. There are a variety of nerve sheath tumors that, because of their size and extent, justify the label "giant schwannoma." The authors propose a classification system for spinal schwannomas as a means to define these giant lesions. The classification is confined to tumors that are essentially intraspinal, with or without extraspinal components. Lesions that erode the vertebral bodies (VBs) and extend posteriorly and laterally into the myofascial planes are classified as giant "invasive" spinal schwannomas. METHODS: The records of patients with giant invasive spinal schwannoma were analyzed. The radiological features, operative approaches, and intraoperative findings were noted. Ten patients with giant invasive tumors were surgically treated over the last 8 years. Six patients were male. Erosion of the posterior surface of the VBs was the diagnostic finding demonstrated on plain x-ray films. Magnetic resonance imaging delineated the extent of the tumors and helped in preoperative planning. Radical excision of the tumors in multiple stages was possible in eight of the 10 patients. Dural reconstruction was required in four patients. All patients required fusion, and an additional stabilization procedure was undertaken in three patients. CONCLUSIONS: The authors conclude that giant invasive schwannomas are uncommon lesions and propose a new classification system. Because of their locally "invasive" nature and extension in all directions, careful preoperative planning of the surgical approach is very important. Although radical excision is possible and promises good results, recurrences may occur and multiple surgical procedures may be required.

Stereotactic surgery in India: the past, present and the future.

The achievements of Indian neurosurgeons in different fields of stereotactic surgery over the past decades have been discussed. This covers diverse areas like Parkinson's disease, abnormal movements, cerebral palsy, spasticity, pain relief, and sedative and functional neurosurgery. Recently, technological advances have made stereotactic surgery useful in many fields like deep biopsies, minimally invasive surgery and radiosurgery. Apart from these areas, there is still a big scope for revival of surgery on deep structures of the brain, as was practised earlier. This will lead to newer knowledge about brain function and also give relief to many patients. The future is bright, provided Indian neurosurgeons show a paradigm shift in their thinking and bring out new ideas. Interaction with other scientific disciplines is necessary in the future if new knowledge has to be added or new techniques have to be devised.

Magnetic resonance imaging artifact following acoustic neurofibroma surgery--case report.

Metallic artifacts in magnetic resonance (MR) imaging occur mostly in patients who have received an implant at surgery. Similar artifacts are now increasingly recognized in patients in whom high-speed drills have been used. A 15-year-old male with neurofibromatosis 2 had undergone excision of acoustic neurofibroma on the left 1.5 years prior to the present admission. MR imaging to evaluate the acoustic neurofibroma on the right showed a metallic artifact at the site of the previous surgery. Computed tomography did not show any evidence of metal debris. The artifact was probably caused by metallic dust or debris from a high-speed drill during the first surgery. We suggest that care should be taken to prevent deposition of such debris in the operative field to prevent this complication.

Limited unilateral approach for extramedullary spinal tumours.

Traditionally, spinal extramedullary tumours are approached by a wide multilevel laminectomy and a midline dural incision. This exposure may result in immediate or delayed instability of the spine, and exposes the spinal cord to the possibility of inadvertent injury during surgery. To avoid these complications the authors have, in 27 patients, used a limited unilateral approach to remove extramedullary tumours. The approach entails bone removal which is limited to the lateral half of the lamina on the side of the tumour and may or may not include the medial part of the facet joint. A lateral dural flap exposes the tumour without exposing the cord. Extraspinal extensions of the lesion may be approached by extending the laminectomy further laterally to the facet joint. This technique has been used in the cervical, thoracic and the lumbar spine to radically remove the lesion in all cases. There were no complications. The authors conclude that extramedullary lesions of the spine can be removed radically by this approach which allows direct access without cord or root retraction, and with little disturbance to the normal anatomy.

The fourth state of consciousness: the Thuriya Avastha.

Present day neurophysiology stops with attributing thinking processes as the highest level of function of the brain. It has been common knowledge to oriental thinkers for many centuries, that there are many further states of the human mind, culminating in the state of thoughtless awareness; the fourth state of consciousness. This state must have a physiological basis. The complicated structure of the brain, the extravagant abundance of neural and glial elements in the brain, the infinite possibilities of synaptic junctions and synaptic transmission, and the multitude of neurotransmitters and neuromodulators; all these point to the definite possibility of a much greater level of performance and achievement for the human brain than has been apparent so far. Not only the theories but also the experience of Eastern seers have shown that the brain can transcend the boundaries of logic and reason, and experience states of awareness, commonly unrecognized. In the past few decades, knowledge about the functioning of the human brain has been growing exponentially and scientists of diverse disciplines are concentrating on unraveling its mysteries. It is necessary for scientists to investigate this state with all available tools and find the neurophysiological basis of this state.

Cystic meningiomas.

BACKGROUND: Meningiomas are generally solid tumors and are easily diagnosed by CT scans and MRI scans. Rarely are these tumors associated with cysts that can cause a confusion in the pre- and intraoperative diagnosis. Cysts associated with meningiomas may be intratumoral or peritumoral. METHODS: The authors conducted a retrospective study of the seventeen meningiomas, out of a total number of 232, which were associated with cysts. The cysts were classified based on their relationship to the tumor. The patients' sex, age group, location of the tumor, and pathological type of tumor were also analyzed. RESULTS: The 17 cases of cystic meningioma formed 7.3% of the meningiomas seen between 1984 and 1993. Eleven of these were intratumoral and 6 peritumoral. One case had both intra- and peritumoral cysts. The tumors were found mostly in the fourth and fifth decades of life. Histologically, all the peritumoral cysts except one were associated with meningotheliomatous meningiomas. Tumors with peritumoral cysts were more common in males. Intratumoral cysts, more common in females, were angioblastic or meningotheliomatous on histopathology. Only one case was an anaplastic meningioma. CONCLUSION: Cysts associated with meningiomas, although uncommon, are certainly not rare. The peritumoral and the intratumoral cysts form distinct subtypes needing separate consideration. Cystic meningiomas are only rarely malignant.

The continuing challenge of acoustic neurinomas (1949-1993).

Experience gained in the treatment of acoustic neurinomas over a period of 43 years is presented. This is divided into three eras based on the prevailing knowledge and techniques. Advances in diagnosis, anaesthesia and microsurgical techniques have reduced the mortality to 4% in large tumours and to less than 1% in small tumours. With large tumours, facial nerve preservation has been possible only in 20% of patients. Large tumours continue to predominate, thus providing a formidable challenge. Saving life and the functions of the lower cranial nerves still form the main goal in the majority of patients who come with large tumours.

Mentality and behaviour in India.

Based on a historical survey of the origins and development of the Hindu religion and its absorption of Buddhism the author outlines that tolerance, gentle behaviour, profound optimism and a lack of obsession with time are the main features of Indian mentality and behaviour. But with industrial revolution, urbanisation and population explosion many old values have been eroded and even aggression of different degrees found its way into the Indian psyche.