Incidence of intracranial aneurysms in north-west Indian population.

One thousand human brains of both sexes were examined. Aneurysms were found in 10 specimens (1%). The incidence of aneurysms was 1.6% in females and 0.8% in males. All the aneurysms were saccular. The aneurysms varied in size. In 5 specimens the aneurysms were minute bulbous dilatations. In the rest of the cases it varied from 0.2 to 2.5 cm. In 7 specimens the aneurysms were present at the junction of anterior cerebral artery with the anterior communicating artery, in 2 on the anterior communicating artery and in one specimen it was seen at the origin of posterior communicating artery. The youngest subject with saccular aneurysm was an 18-years-old male and the oldest was a 55-years-old male. No aneurysm was found in the brains of 94 children (1-17 years).

Primary central nervous system lymphoma: experience of 46 cases with review of literature.

Primary central nervous system lymphomas (PCNSL) constitutes only 1.0 to 1.5% of all brain tumors. Their incidence has gone up over tenfold in the last 25 years. Though, there has been an association of PCNSL with acquired immune deficiency syndrome (AIDS), yet the increased incidence of PCNSL appears to be real and unrelated to AIDS and organ transplantation. This increased incidence could be because of improvement in diagnostic technology and practice. The outcome remains gloomy despite surgical resection, radiotherapy and intensive adjuvant chemotherapy regimens, as majority of the patients succumb to the disease, with only 30-40% survival in patients under 70 years of age.

Flowcytometric and histopathological correlation of primary intracranial neoplasms.

DNA ploidy and synthetic phase fraction (SPF) of 52 cases of primary intracranial neoplasms have been determined from fresh tissues and the data was correlated with histopathological typing and grading. Fresh tumour tissues from 52 random surgical biopsies (28 malignant and 24 benign) were obtained from neurosurgical operations during the period 1994-1996. The cells were analysed in Becton Dickinson flowcytometer fitted with Consort 30 programme and 'Sober' software. Percentage of diploid cells, proliferative cells and DNA aneuploidy were evaluated. The tumours were classified and graded according to WHO classification (1993). On histology, there were 28 malignant (grade II to IV) and 24 benign cases (grade I). All the histologically benign tumours in this study showed diploid DNA content with the exception of a pituitary adenoma which had a heterogeneous population of cells. The S phase fraction in all the benign cases was less than 10% except in the case of choroid plexus papilloma (S-phase 54%) and an atypical meningioma (S-phase 14%). Out of the 28 malignant tumours, 12 cases were aneuploid (43%) and the rest were diploid (57%). Among the 16 diploid tumours, SPF was more than 10% in eight cases. DNA aneuploidy and high SPF are more common in histologically malignant tumours than benign tumours. SPF is a reflection of proliferation potential of a tumour and may have some role in prognostication of brain tumours.

Suprasellar malignant mixed germ cell tumour presenting as craniopharyngioma.

A 15 year old boy presented with diminution in vision of both eyes, diabetes insipidus and hypopituitarism. MRI was suggestive of a large suprasellar and retrosellar craniopharyngioma with stretching of the optic chiasma. Histopathological findings on the first surgical specimen were interpreted as a craniopharyngioma. He was reoperated on account of clinical deterioration and increase in tumour size. Histological examination this time revealed derivatives of all three germ cell lineages along with areas of embryonal carcinoma, and yolk sac tumour besides squamous cysts, establishing the diagnosis of malignant mixed germ cell tumour. Serum and CSF were strongly positive for alpha foetoproteins.

Clinically and biochemically silent thyrotroph adenoma with oncocytic change.

A case of clinically and biochemically silent pituitary tumour with ultrastructural and immunohistochemical evidence of thyroid stimulating hormone secretion is presented. Significance of recognition of such silent tumours is discussed.

Ideal ward round making in neurosurgical practice.

The success of a perfect ward round lies in the role of the consultant leading the 'round making group' (RMG) as well as the hallmark of effective questioning and participation of each member. Twelve senior consultants with more than 10 years' experience in neurosurgical practice at three different university hospitals were observed during round making by a participant observer. Observations were made on the group climate of the RMG, the leadership pattern and language expressed by the clinician conducting the round and the effectiveness in his performance as a leader during clinical discussions. The group climate showed evidence of good productivity and flexibility with 92% and 75% consultants, pleasantness of climate was above average with only 50% (6/12) and poor objectivity with 42% (5/12) consultants. Forty two percent of the consultants were not always very well comprehensible, while only 50% (6/12) spoke exactly fitting the occasion. Only 33% (4/12) of the consultants used humour effectively, while 42% (5/12) spoke unnecessarily in between discussion and were poor in introducing the problems of patient to the round making group. Ward round making in neurosurgical practice needs a holistic approach with motivation, planning, leadership skills and structured curriculum to fulfill its objectives.

Pituitary adenoma and parasagittal meningioma: an unusual association.

Simultaneous detection of an intracranial meningioma with a pituitary tumour prior to radiotherapy is an extremely uncommon occurrence. Authors have managed an elderly acromegalic lady with an acidophilic pituitary adenoma, who also harboured an asymptomatic anterior third parasagittal meningioma. There were no features of neurofibromatosis. Both tumours were concurrently excised.

A mathematical outcome prediction model in severe head injury: a pilot study.

103 patients of head injury, with a Glasgow coma scale (GCS) score of 8 or less, were studied prospectively. GCS score, brain stem reflexes, motor score, reaction level scale, and Glasgow Liege scale were evaluated as prognostic variables. Linear logistic regression analysis was used to obtain coefficients of these variables and mathematical formulae developed to predict outcome in individual patients.

Midline and far lateral approaches to foramen magnum lesions.

Twenty patients with foramen magnum lesions were operated upon in the last 5 years at Postgraduate Institute of Medical Education and Research, Chandigarh. The common presenting features were quadriparesis, quadriplegia, diminished sensations, neck pain and respiratory insufficiency. The lesions encountered were meningiomas, neurofibromas, posterior inferior cerebellar artery aneurysms, neurenteric cyst and chordoma. Patients with posterior or posterolaterally placed lesions were operated by the midline posterior approach while those with anterior or anterolateral lesions were managed by the far lateral approach. All mass lesions were excised completely and the aneurysms were clipped. Seventeen patients made good neurological recovery while three died. The latter three patients presented very late. The merits of various surgical approaches to the foramen magnum are discussed.

Suprasellar arachnoid cyst presenting with precocious puberty : report of two cases.

Suprasellar arachnoid cysts (SSAC) are uncommon intracranial lesions. Two patients of SSAC presenting with precocious puberty are described. In both the cases partial excision of the cyst wall, through a pterional craniotomy, establishing communication with the basal subarachnoid spaces was carried out. The endocrinological symptoms regressed after surgery. The clinical presentations of SSAC and the treatment options available are reviewed.

Intracranial pressure changes with different doses of lignocaine under general anaesthesia.

The effect of intravenous lignocaine on intracranial pressure (ICP) was studied on thirty patients of either sex, aged above 5 years and scheduled for elective ventriculoperitoneal shunt surgery. The patients were randomly divided into 3 groups, which received intravenous lignocaine in the dose of 1 mg, 1.5 mg and 2 mg/kg body weight respectively. Intracranial pressure, heart rate, ECG, arterial pressure and arterial blood gases were monitored at various intervals for a period of 30 minutes. Maximum decrease in ICP was seen at 2 minutes after IV lignocaine in all the three groups (p<0. 001). The fall in ICP was significantly more in group II and group III (35.65% and 37.5% respectively) as compared to group I (17.47%) (p<0.001). This fall in ICP in all the three groups persisted below the basal level, throughout the study period. None of the groups showed any significant change in the heart rate, but a statistically significant fall in arterial pressure was observed in group III (p<0. 05). In conclusion intravenous lignocaine, in a dose of 1.5 mg/kg, causes significant fall in ICP without causing any untoward cardiovascular effects and is recommended for routine clinical use.

Choroid plexus tumours--an immunohistochemical analysis with review of literature.

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.

Multicentric gliomas: report of 2 cases.

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.

Meningeal melanocytoma: report of two cases.

Two cases meningeal melanocytoma, one each at cranial and spinal location, are described. Neurological deficits in both cases improved following surgery. Pathological features of this rare tumour are discussed.