Biomedical subjects
Publications and source records attributed to V K Kak.
Intercranial epidermoid tumours are benign lesions of congenital origin that are potentially curable. Although computerized axial tomography (CT) and magnetic resonance imaging (MRI) are usually diagnostic, a few atypical features sometimes make pre-operative diagnosis difficult. Two cases of cystic epidermoids with peripheral ring enhancement are reported. Relevant literature has been reviewed.
Thirty eight patients with multiple pyogenic brain abscesses constituted 11% of all the brain abscesses treated during a 12 year period. Sixty per cent (23) of the patients were in the first two decades of life, including 9 (24%) infants. The clinical presentation was similar to brain abscess in general. 21 patients had altered "sensorium" at the time of admission. Otogenic brain abscesses were the commonest (26%), followed by those associated with congenital cyanotic heart disease (18%). The abscesses were invariably large in size. The pus was sterile on culture in 11 (29%) patients, while Staphylococcus aureus was the commonest organism grown in 9 (24%) patients. Aspiration of the pus was required as a life saving measure, to control raised intracranial pressure, in 29 (76%) patients. Twelve (32%) of these patients underwent secondary excision of the abscess capsule. The overall mortality was 32% with failure to control intracranial and systemic infection as the major causes of mortality. Level of consciousness at the time of admission was the most significant factor affecting the outcome. Surgery has a definite therapeutic and life saving role in the management of multiple pyogenic brain abscesses. A systematic treatment plan for multiple abscesses is proposed.
Three hundred and ninety-six paediatric (below 15 years of age) patients with brain tumours were treated at our institute in the last 4 years. Eighty-two of the tumours were located supratentorially. These 82 patients included 14 infants (below 1 year of age), who made up 3.5% of all paediatric patients with brain tumours and 17% and those with brain tumours in a supratentorial location. There was a male preponderance, and two-thirds of the 14 patients were within their first 6 months of life. Increasing head size, vomiting and failure to thrive were the common presenting features. One infant presented with asymmetric skull growth. The tumours tended to be large, occupying almost the entire affected cerebral hemisphere; histological types included astrocytomas, malignant astrocytomas, glioblastoma multiforme, primitive neuroectodermal tumours, malignant choroid plexus papillomas and malignant teratomas. Two children had congenital tumours and another two tumours, in children with associated lobar agenesis, were thought to be congenital in origin. Associated hydrocephalus was present in seven patients, but precraniotomy shunt was required in only two patients. The perioperative (within 1 month) mortality was 57%. Only 30% of the patients survived for more than 1 year after surgery and chemotherapy. The longest survival was 20 months. Delay in diagnosis, poor general condition prior to surgery, and the high vascularity and malignant nature of these tumours accounted for the poor results.
Aneurysmal bone cysts are uncommon bony lesions of the spine. Two such patients are reported in the study. The first patient had involvement of first and second thoracic vertebrae, and a preoperative diagnosis was made possible due to the typical magnetic resonance imaging appearances. A total removal was achieved in two stages. In the second patient the C2 spinous process was involved, and this patient presented as atantoaxial dislocation. Removal of the abnormal tissue and posterior fusion was done. Both the patients showed neurologic improvement. The relevant literature is reviewed.
A rare case of metastasis to the brain from an urachal carcinoma is reported. Metastasis in the brain developed 7 months after partial cystectomy and radiation therapy. Cranial computed tomography showed a ring-enhancing mass lesion that was excised. A month later, the patient died of distant metastasis.
Forty-five patients with brain tumours were studied for evidence of any haemostatic abnormalities in the preoperative and intraoperative period. An abnormality was found in 44 of the patients in the preoperative period and in all the patients during the operation. One patient developed acute disseminated intravascular coagulation. A change in the haemostatic abnormality from the preoperative to the intraoperative period was demonstrated in 9 of the patients. The histological nature of the tumour did not influence the haemostatic derangement. A shortened euglobulin lysis time, prolonged thrombin time, increased fibrin degradation products and abnormal fibrinogen levels were the common isolated abnormalities. When considered together, chronic disseminated intravascular coagulation (DIC) with or without fibrinolysis and fibrinolysis with or without DIC were the commonest abnormalities. Although some degree of haemostatic derangement is found in a high proportion of patients with brain tumours, clinically relevant abnormalities are rare.
Immunohistochemical analysis of 9 choroid plexus papillomas (CPPs) and 3 choroid plexus carcinomas (CPCs) using a panel of antibodies against glial fibrillary acidic protein (GFAP), cytokeratin (CK), epithelial membrane antigen (EMA), S-100 protein, vimentin (vim), and neuron specific enolase (NSE) is presented. Focal positivity was observed for GFAP in 11, vimentin in 7, cytokeratin in 2 and EMA in 3 cases. Diffuse and intense immunoreactivity for S-100 protein was seen in all papillomas, however, unreactive areas were noted in carcinomas. All cases exhibited focal to diffuse NSE positivity. Location and type of the tumour and age of the patient did not influence the staining pattern except for predominant S-100 positivity in papillomas. The significance of these findings is discussed in relation to the differential diagnosis or immunoreactivity patterns of these tumours.
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Seventy children with posterior fossa tumours treated over a period of 6 1/2 years were studied. Most patients presented in the late stage of disease. Sixty-four required insertion of a precraniotomy shunt for one or more of the following: persistent vomiting, severe headache, dehydration, poor general condition, failing vision, altered sensorium, marked periventricular lucency, and brain stem involvement deferring total removal of the tumour. Insertion of precraniotomy shunt improved the general condition and signs and symptoms of increased intracranial pressure. It also provided a lax brain during definitive surgery and a smooth postoperative course. Shunt-related complications, consisting of block and/or infection, were observed in 21 patients. It was concluded that precraniotomy shunt is important in the management of children with posterior fossa tumours in developing countries where these patients present in the late stage of disease.
Spontaneous haemorrhage in association with a brain abscess is a very rare occurrence and may confuse the CT diagnosis. A case of cerebral abscess with haemorrhage into the abscess cavity, the surrounding brain parenchyma, the subarachnoid space and the ventricular system is reported. The differential diagnosis, pathogenesis and the management of such a case are discussed and the literature reviewed.
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Two cases of multicentric gliomas with long survival are reported. One patient underwent multiple surgical procedures while another had two separate surgical procedures at the same time. Presence of calcification of CT scan in one case raised suspicion for a preoperative diagnosis of oligodendroglioma. Lack of direct continuity or subarachnoid enhancement on CT scan and low histological grade of the tumours suggested their primary multicentric origin. The incidence of multicentric gliomas in our experience is 0.4% amongst 500 glial tumours over a period of eight years.
Twenty-four cases of posterior fossa extradural haematoma constituted 4.16% of all extradural haematomas (576) and 1.12% of all craniocerebral trauma requiring surgery (2150). Five cases were excluded from this study. Of the remaining nineteen cases (the study group), lucid interval was present in eight (42.10%) cases. In half of the cases, the clinical course was acute. Neck stiffness and drowsiness were the commonest clinical signs. Occipital bone fracture was present in 57.89% cases. CT scan was the most valuable investigation in the diagnosis and detection of the associated intracranial injury in 18 cases. Associated intracranial injury was present in seven (36.84%) of these cases. Two (11.1%) of these patients died despite emergency surgery. The Glasgow Coma Scale prior to operation and the presence of associated supratentorial injuries were important prognostic factors. It is concluded that posterior fossa extradural haematoma should be suspected in the presence of a fall on the back of the head, drowsiness, neck stiffness or an occipital bone fracture.
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A thoracic intradural extramedullary enterogenous cyst in association with a syringomeningomyelocele in a 5-year-old boy is presented. The pathogenesis of this rare association is discussed and the pertinent literature reviewed.
An 11-year-old boy presented with pain in the back, urinary retention, paraplegia and loss of sensations below L1. Investigations revealed an intramedullary lesion. An intramedullary spinal cord abscess was found at surgery. The pus was evacuated and abscess was excised. Minimal recovery was seen following surgery. Early intervention and a high index of suspicion is required in such cases.
Three young children who presented with acute backache and rapidly progressive neurological deterioration were investigated and found to have spontaneous spinal extradural hematoma (SSEDH). They were operated on soon after the diagnosis had been confirmed. The present report highlights the fact that in children progressive weakness of nontraumatic origin should be investigated thoroughly and as early as possible. Patients with SSEDH should be operated on immediately, as this is a curable condition. The pertinent literature has been reviewed.
Cranial chordomas are extremely rare in childhood with only 25 cases having been reported in the first decade of life. A 6-year-old female child with cranial chordoma is reported. Literature on the subject is reviewed, with special reference to the management, histopathological features and prognosis in childhood chordomas as compared to the adult variety.