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Biomedical subjects

A K Banerji

Publications and source records attributed to A K Banerji.

At least 19 recordsLinked to original sources

Risk factors in postoperative neurosurgical infection. A prospective study.

Four hundred and seventy patients who had undergone neurosurgical operations were studied prospectively. After defining post-operative infection so that is included all the infective complications irrespective of location occurring after surgery, the overall infection rate was 17%. The infection rate in 413 cases without pre-existing infection was 15%. Wound infection was recorded in 5% and meningitis in 6%. Risk factors which lead to a significant increase in the incidence of postoperative infection were found to be altered sensorium, multiple operations, pre-existing infection, emergency surgery, duration of surgery more than 4 hours, urinary catheterisation, cerebrospinal fluid leak, and ventilatory support.

Administration, Oral

Elastomechanical characterization of brain tissues.

The fluid-induced changes in the intracranial pressure which have important clinical implications are believed to be largely determined by the elastomechanical properties of the brain tissues. To define and evaluate the elastomechanical characteristics of the brain tissues a nonlinear hyperelastic hollow spherical shell has been employed to model the craniospinal complex for its fluid-induced intracranial pressure volume changes. The strain energy function proposed by Hart-Smith has been used to derive the constitutive equations. In 10 dogs, fluid has been infused in the lateral ventricle of the brain. The resulting changes in the ventricular fluid pressure (VFP) and the epidural pressure (EDP) have been recorded. The plot of pressure as a function of volume increases first, reaches a maximum, decreases, reaches a minimum and increases monotonously. The values of maximum and minimum pressures (pv max and pv min) due to fluid infusion are found to be, respectively, 42.4 +/- 15.4 mmHg and 33.1 +/- 12.2 mmHg. The pressure achieved the maximum and minimum values with infusion of 0.19 +/- 0.09 ml and 0.51 +/- 0.15 ml of fluid, respectively. The elastomechanical parameters of the Hart-Smith function that characterize the brain tissues have been evaluated by matching the experimentally obtained pressure-volume curves with the corresponding model generated curves. It is found that the agreement between the experimentally obtained pressure-volume curves and the corresponding Hart-Smith profile is satisfactory at a high inflation level but less so at the lower inflation level.

Animals

Giant lumbosacral nerve sheath tumors.

Cauda equina nerve sheath tumors are usually small, well-encapsulated tumors. Sometimes they may attain very large proportions, cause extensive bony changes, and resemble ependymomas in the cauda equina. They may also infiltrate into adjacent soft tissue planes and retroperitoneal spaces and yet be histologically benign. An awareness of this entity ensures aggressive surgical removal at the time of exploration. Primary neuro-fibrosarcomas or malignant changes in primary nerve sheath tumors of the cauda equina are seen in patients with neurofibromatosis.

Adolescent

Collet-Sicard syndrome resulting from closed head injury: case report.

A 67-year-old man developed paralysis of the right ninth, tenth, eleventh, and twelfth cranial nerves (Collet-Sicard syndrome) after sustaining a closed head injury. Plain x-ray films of the skull revealed two linear fractures of the occipital bone (one of them probably traversing through the right occipital condyle) and a prominent soft-tissue shadow in the region of the nasopharynx, suggestive of a skull base fracture. The patient was managed conservatively. This is the only case of unilateral multiple caudal cranial nerve palsies (IX through XII), seen by us over a 20-year period, from among more than 5,000 moderate to significant head injuries.

Accessory Nerve

Relation between epidural and ventricular pressures in canine brain: an experimental study.

Complications of epidural pressure (EDP) monitoring are much less severe than those of ventricular fluid pressure (VFP) monitoring. Hence, an insight into the relationship between the epidural and the ventricular pressures is of clinical importance. The pressure volume response as obtained during infusion tests performed on dogs can be categorized into two phases: (i) the latent phase and (ii) the monotonic rise phase. During the latent phase the VFP first rises to a maximum and then falls to a minimum, but these changes in VFP are not reflected in EDP. The latent phase is followed by the monotonic rise phase during which both VFP and EDP rise simultaneously and monotonically. Although the changes in VFP and EDP are similar the epidural pressure remains consistently less than the ventricular fluid pressure. Hence, changes in VFP can be estimated by monitoring EDP during the monotonic rise phase but not during the latent phase.

Animals

Intracranial pressure-volume response in dog subjected to repeated infusion tests: an experimental study.

Several experimental studies have been made in the past to try to understand the nature of the fluid-induced changes in the intracranial pressures of the animals by infusing fluid into their craniospinal complex. The objective of the present investigation was to study the changes in the characteristics of the ventricular and epidural pressure-volume curves when a dog was subjected to repeated fluid infusion tests. The animals were subjected to three cycles of infusion tests with a time interval of either 10 min or 2 h between any two successive tests. An infusion test repeated 10 min after the preceding test exhibited a significant change in the characteristics of the ventricular fluid pressure (VFP) response but not in the epidural pressure (EDP) response. However, in the case of an infusion test which was repeated 2 h after the preceding test, it was observed that both the VFP and EDP responses remained the same as those found in the first infusion test.

Animals

Complications related to pre-craniotomy shunts in posterior fossa tumours.

Among 344 patients with posterior fossa tumours treated from 1979 to 1986 a ventriculoperitoneal, or, less commonly, a ventriculatrial shunt was inserted in 164 cases pre-operatively. Haematoma following the insertion of a shunt was found to be an important cause of deterioration. While the occurrence of cerebrospinal fluid leak (p less than 0.3) and pseudomeningocele (p less than 0.01) was more frequent in the non-shunted cases, seizures (p less than 0.01) were found to occur more frequently in the shunted cases.

Brain Neoplasms

MR evaluation of brachial plexus injuries.

Ten cases of brachial plexus injury were subjected to magnetic resonance (MR) to demonstrate the roots, trunks, divisions or cord abnormalities. Both normal and abnormal brachial plexuses were imaged in sagittal, axial, coronal and axial oblique planes. Myelography, using water soluble contrast agents, was performed in seven cases. MR demonstrated one traumatic meningocele, one extradural cerebrospinal fluid (CSF) collection, trunk and/or root neuromas in four, focal root fibrosis in two and diffuse fibrosis in the remaining two cases. Results of MR were confirmed at surgery in four cases with neuromas, while myelography was normal in two and was not carried out in the remaining two. In two cases, where MR demonstrated diffuse fibrosis of the brachial plexus, myelography showed C7 and T1 traumatic meningocele in one and was normal in the other. Both these patients showed excellent clinical and electrophysiological correlation with MR findings and in one of them surgical confirmation was also obtained. In the other two cases with focal nerve root fibrosis, myelography was normal in one and showed a traumatic meningocele in another. Operative findings in these cases confirmed focal root fibrosis but no root avulsion was observed although seen on one myelogram. Focal fibrosis, however, was noted at operation in more roots than was observed with MR. Initial experience suggests that MR may be the diagnostic procedure of choice for complete evaluation of brachial plexus injuries.

Adolescent

Multiple pyogenic brain abscesses: an analysis of 21 patients.

Multiple pyogenic brain abscesses constituted 11.7% (21 patients) of a series of 179 consecutive patients with brain abscess treated from 1976 to 1984. The commonest cause of these abscesses was congenital cyanotic heart disease (38%), followed by middle ear infection (19%). Two thirds of these patients were in the first two decades of life. The clinical presentation was similar to brain abscesses in general, there being no clinical features suggestive of multiple lesions. In 85% the abscesses were supratentorial. Infratentorial abscesses alone or in association with supratentorial abscesses were invariably otogenic in origin. Aspiration of the largest abscesses supplemented with appropriate antibiotics was the treatment of choice in 16 patients; secondary excision of the largest abscesses was required in six patients. Primary excision was performed in three patients when the abscesses were in close proximity to each other. Two patients were managed with antibiotics alone. The overall mortality was 23.8%.

Adolescent

Acute effect of anhydrous glycerol on peripheral nerve: an experimental study.

Percutaneous retrogasserian glycerol rhizotomy has shown encouraging results in the treatment of trigeminal neuralgia. An experimental study was undertaken using a rat sciatic nerve model to elucidate the mechanism of action of anhydrous glycerol and to study the acute changes which develop within one week. Extraneural glycerol was applied in 20 adult Wistar rats. Groups of five animals were sacrificed at days 1, 3, 5 and 7 respectively. The sciatic nerve of the opposite limb in the same animals was used as a control. The nerve were examined with light and electron microscopy including a morphometric study to assess the type of fibres affected. The specific pattern of involvement of larger and medium sized myelinated fibres with relative preservation of unmyelinated fibres was noted.

Animals

Transfusion malaria amongst operated neurosurgical patients--a prospective study of 22 cases.

Twenty two patients with transfusion malaria were studied over a one year period. They constituted 75% of all neurosurgical patients receiving blood transfusions during surgery or in the immediate postoperative period. Malaria parasites could be demonstrated in the peripheral blood smears of only eight patients, and the rest (14) were diagnosed on clinical grounds, further supported by their prompt response to chloroquine therapy. In all the patients, investigations for local and systemic infections were normal. Cerebrospinal fluid examination did not reveal any abnormality. Patients under 30 years of age had significantly higher incidence.

Adolescent

Temporal lobe lesions in head injury.

In cases of closed head injury temporal lobe lesions e.g. contusion, laceration, pulping, or intracerebral haematoma frequently result in an expanding process. These are frequently associated with an overlying subdural haematoma. Eighty five cases of such lesions from a consecutive series of 1,000 cases of head injury have been analyzed. The lesions are caused by severe injury resulting in loss of consciousness and skull fracture. Most of them are contre-coup lesions. Clinically they manifest themselves like any other acute or subacute intracranial hematoma. The majority of the patients have contralateral hemiparesis and pupillary abnormalities. Carotid angiography is valuable for diagnosis. These lesions are likely to be missed when exploratory burr holes are made or, are erroneously diagnosed as acute subdural haematoma or brain oedema. Smaller lesions, not showing progressive deterioration, may respond to conservative treatment. However, surgical decompression is essential in most cases A frontotemporal osteoplastic craniotomy or a large Scoville trephine hole is essential to deal with these lesions adequately.

Accidents, Traffic

Haemorrhage into pituitary adenomas.

Seventy cases of pituitary adenoma were analysed for evidence of haemorrhage. It was present in 18 cases. These are classified into four groups, acute, acute on chronic, chronic, and late sequelae of pituitary apoplexy, and an example of a patient in each group is given. The diagnosis and management are discussed.

Adenoma

Brain abscess and congenital heart disease.

The clinical features and management of 18 patients with congenital heart disease and a brain abscess are reviewed. Except for one patient all had cyanosis. All abscesses were large, containing at least 50-60 ml of pus, and mostly unilocular. Bilocular and multilocular abscesses were also encountered. The organisms cultured from the pus had little relation to the mortality. Tapping may be the final investigation, and is also the treatment of choice. The high mortality (50%) is attributed to the delay in referral of these patients to a neurosurgical unit.

Adolescent