Acute subdural haematoma : a reappraisal.

Acute subdural haematoma is a well-entrenched nosological entity implying subdural collection of blood following acute head injury. Pathologically, it is usually associated with or, for that matter, secondary to cerebral contusion and laceration. Based on cumulated experience, clinical and pathological studies it is proposed that, for too long the neurosurgeons have put emphasis on the clot rather than the totality of the pathological anatomy and that they have focused their therapeutic strategy on removal of the accumulated blood, unmindful of the associated parenchymatous lesion. Not surprisingly, such attempts have been associated with a very high mortality. On the basis of nearly four decades of personal experience and critical review of the literature, evidence has been provided that to reduce the mortality associated with this condition, it is necessary to evolve a strategy, not only to evacuate the blood but comprehensively deal with the associated parenchymatous lesions and the cascade of secondary insult to the underlying brain.

Epileptic seizures in supratentorial gliomas.

Two hundred patients with supratentorial glioma; astrocytoma (pilocytic, fibrillary, gemistocytic) 82, mixed glioma (oligoastrocytoma) 46, oligodendroglioma 8, malignant (anaplastic) astrocytoma 33 and glioblastoma multiforme 31, surgically treated for the tumours and followed up for one to sixteen years, were retrospectively analysed for the incidence of pre and postoperative epileptic seizures. 122 patients (61%) had seizures preoperatively. 62 (50.8%) of them had at least one or more seizures during follow up. Seizures were persistent in 22 patients. Doubtful, or one or two minor seizures occurred in 19 cases. Six patients in this group had seizure only at the time of CT confirmed recurrence, after a seizure free interval of one to nine years. Amongst 78 patients who did not have seizures preoperatively, 24 (30.6%) developed seizures during the postoperative follow up period. Recurrent attacks were reported only by 5 patients while 15 patients had seizure(s) only at the time of recurrence of tumour. Two patients had a few seizures in the early postoperative period and none thereafter, while doubtful seizures were reported by two patients.

The decade of the brain: a brief review.

Recognising the huge burden of neurological and psychiatric disorders and prompted by the potentials of new techniques of molecular biology, biotechnology, genetics and imaging to study these, the 1990s were declared the 'decade of the brain'. This stimulated global scientific efforts to understand the human brain in health and disease. This review summarises some of the major research achievements during the decade. While it is impossible to provide a comprehensive summary of the voluminous data that has been generated, it was decided to provide a bird's eye view of the recent advances in the fields of developmental neurobiology, neurogenetics, neurochemistry and imaging of the brain, which have direct relevance for the clinicians.

Development of neurogenic pulmonary edema at different grades of intracranial pressure in cats.

Development of neurogenic pulmonary edema (NPE) subsequent to increased intracranial pressure (ICP) was evaluated in an experimental model in cats. Experiments were conducted in chloralose anaesthetised animals, either on spontaneous respiration or on intermittent positive pressure ventilation. Hemodynamic parameters i.e., mean arterial pressure (MAP) and heart rate (HR) were continuously monitored. Pulmonary artery/right ventricular systolic pressure was recorded in cats on spontaneous respiration. Increase in ICP for 180 minutes caused an increase in extravascular lung water (EVLW) content in both spontaneously breathing and artificially ventilated animals. In spontaneously breathing animals EVLW to blood free dry weight ratio (EVLW/BFDW) was 3.95 +/- 0.16 and 4.96 +/- 0.16 at ICP 40 and 80 mm Hg respectively while in animals on artificial ventilation, at 40, 60, 80 and 100 mm Hg ICP, it was 3.88 +/- 0.11, 4.09 +/- 0.10, 4.50 +/- 0.13 and 5.03 +/- 0.17 respectively. These values were significantly greater (P < 0.05) as compared to that in sham operated animals (3.43 +/- 0.10). This was accompanied by rise in MAP, HR and pulmonary artery pressure. The study establishes the graded development of NPE, the severity of which is proportional to the levels of ICP.

Ultrastructural study of mixed growth hormone & prolactin secreting pituitary adenomas.

An ultrastructural study was done on 15 mixed growth hormone (GH) and prolactin (PRL)-secreting pituitary adenomas surgically removed from acromegalic patients with hyper-prolactinaemia, in order to see whether the 2 hormones were present in the same cell or in different cells. Double labelling immunogold technique was used for simultaneous ultrastructural localization of GH and PRL. It was found that each neoplastic cell in these 15 tumours (30 to 50 cells were studied in each case) contained 4 populations of granules viz., (i) granules positive for only GH; (ii) granules positive for only PRL; (iii) granules positive for both GH and PRL; and (iv) granules negative for both GH and PRL (unlabelled). Though the relative percentage of these 4 types of granules varied from cell to cell even within the same tumour, the major population (49.9 to 96%) was constituted by the mixed granules showing labelling for both GH and PRL. Almost all the cells examined from each tumour appeared to be mammosomatotrophs. Thus, the study indicated that mammosomatotroph adenomas are perhaps more common among mixed GH and PRL--secreting pituitary adenomas than previously believed. It could be important to recognize these tumours from the therapeutic point of view.

A clinico-pathologic study of pituitary adenomas.

One hundred patients of pituitary adenoma were studied using light microscopy, electron microscopy, immunohistochemistry and serum hormone estimation. Depending on the absence or presence of clinical endocrine manifestation they were divided into 2 groups 'non-functioning' (group I -48 patients) and 'hyper-functioning' (group II- 52 patients). Tumours in group I were chromophobes, some of which (group IA) had no hormone increase in serum nor detection in tissues and ultrastructurally they consisted of secretorily inactive cells (null cell adenomas) while others (group IB) were composed of secretorily active cells with prolactin consistently increased in serum and localized in tissue (lactotroph adenomas). Tumours in group II were chromophobe, acidophil, basophil or mixed adenomas with varying number of secretorily active cells in all. The hormone responsible for the hyperfunction was always raised in serum and localized in tissue. Thus growth hormone was demonstrated in all tumours from patients with acromegaly (somatotroph adenomas), prolactin in all tumours from patients with galactorrhea (lactotroph adenomas) and ACTH in all tumours from patients with Cushing's syndrome (corticotroph adenomas). It was observed, however, that 40 per cent of tumours were pleurihormonal, growth hormone and prolactin being the commonest combination. Interestingly, not all the hormones localized by immunohistochemistry in pleurihormonal adenomas were detected in serum and/or reflected in the clinical picture.

Primitive neuroectodermal tumours of the central nervous system--an electron microscopic & immunohistochemical study.

A series of 75 poorly differentiated neoplasms of the central nervous system viz., medullo-blastoma, cerebral neuroblastoma, pineoblastoma and ependymoblastoma were studied by light microscopy (LM), electron microscopy (EM) and immunohistochemistry (IH). Although the predominant cells constituting these tumours appeared to be undifferentiated cells by LM and EM, many others showed evidence of differentiation into glial, neuronal or ependymal cell lines by EM and IH. It is therefore, concluded that all these neoplasms are best considered as primitive neuroectodermal tumours and these may be classified as such in neuro-oncology. They may be subclassified further on the basis of differentiation into one or more cell lines.