Morphology and comparative anatomy of circulus arteriosus cerebri in mammals.

The normal configuration of the arterial pattern at the base of the brain in rhesus monkeys, dogs, sheep, goats and rabbits is described. The length and diameter of all vessels of the circulus arteriosus cerebri are measured. Variations are compared in relation to that of the typical pattern present in humans. In rhesus monkeys, dogs and rabbits, the circle of Willis is almost similar to that in human beings except that in these animals, (i) the anterior cerebral arteries join each other to form a single median vessel; (ii) in dogs, rabbits, goats and sheep the anterior cerebellar artery is a branch of posterior cerebral artery, and (iii) in goats and sheep, a considerable length of the internal carotid artery contributes to the formation of circulus arteriosus while the posterior cerebral artery arises from the posterior communicating artery.

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).

Calvarial tuberculosis.

BACKGROUND: Calvarial tuberculosis is rare, even in areas where tuberculosis is endemic. Primary calvarial tuberculosis, with no evidence of tuberculosis elsewhere in the body is a rarer entity. METHODS: Seven cases of calvarial tuberculosis are presented. The relevant clinicoradiological features and management are discussed. RESULTS: Two cases of primary calvarial tuberculosis could only be diagnosed after surgery. The other cases were diagnosed with the help of fine needle aspiration cytology (FNAC) and biopsy. CONCLUSION: A high index of suspicion and awareness of this condition may lead to more cases being diagnosed early. Surgery may be avoided in selected cases that can be treated primarily with antitubercular therapy.

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.

Histopathological and biochemical changes in the sutural region in craniosynostosis.

OBJECT: Histopathological observations and biochemical analysis of sutural bones in nine patients with craniosynostosis were compared with control subjects of the same age range. METHODS: Microscopic examination in craniosynostosis showed formation of an active osseous front, with higher osteoblastic activity than in controls. Biochemical analysis revealed higher calcium, phosphorus, alkaline phosphatase, phospholipids and chondroitin sulphate-A contents in sutural bones of the same patients. CONCLUSIONS: The present study systematically establishes a premature increase in osteogenesis in the sutures of craniosynostosis patients.

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.

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.

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.

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.

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.

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.

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.

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.

Spontaneous intracranial hematomas: role of dynamic CT and angiography.

Forty-five patients with spontaneous intracerebral hemorrhage (ICH) were studied prospectively by dynamic CT and cerebral angiography. The accuracy of dynamic CT in demonstrating the underlying vascular cause in ICH was evaluated. Dynamic CT correctly predicted 90% of aneurysms, 83% of AVMs and 100% of normal studies as compared to angiography. Cerebral angiography can be obviated in patients where dynamic CT does not show any obvious vascular anomaly.

Coagulation disorders and neo-membrane formation in the pathogenesis of chronic subdural haematoma.

Haematological investigations in the haematoma fluid and venous blood along with histological changes in the haematoma membrane were studied in twenty five patients of chronic subdural haematoma. Their median age was 60 years with a marked male predominance. Haemoglobin level in the haematoma fluid was unrelated to its age. Prolongation of prothrombin time and activated partial thromboplastin time was observed in all the haematoma fluid samples. Fibrinogen and antithrombin III levels were significantly decreased in haematoma fluid and fibrin degradation products were positive in 44 of these specimens. The neo-membrane showed 'giant' capillaries and abundant eosinophils with an inverse relationship between the presence of inflammatory cells andfibroblasts. These findings suggest a localized consumption coagulopathy and hyperfibrinolysis with reactive formation of a leaky neo-membrane resulting in recurrent haemorrhages and progressive enlargement of chronic subdural haematoma.

Brain abscess in renal transplant recipients: report of three cases.

BACKGROUND: Neurologic complications occur in about 30% of renal transplant patients, infections being the most common. We encountered three such patients and present our experience in the management of such cases. CLINICAL MATERIAL: Three cases of brain abscess in renal transplant recipients are reported. These patients presented from 9-60 months after the transplant. One patient had a pyogenic abscess; in the second the organism identified was Nocardia asteroides; in the third, a fungal infection was responsible. In two patients excision of the abscess was done, while in one repeated aspirations with intracavitary antibiotics were used. All received systemic antimicrobial therapy. CONCLUSIONS: Central nervous system (CNS) complications, specifically infections, are quite common in renal transplant recipients, but reports of brain abscesses in these patients are very rare. The treatment options for such patients are discussed.

Intracranial fungal granuloma.

BACKGROUND: Intracranial fungal granulomas are uncommon and their pathogenesis, clinical picture, and effectiveness of therapy remains unclear. METHODS: Thirty-two cases were studied retrospectively in two groups: (1) Rhinocerebral group (22 cases) had a chronic paranasal sinus (PNS) disease with secondary involvement of skull base, cranial nerves, and/or brain. The granulomas were adherent to dura, firm, avascular, and tough, requiring a knife to cut. (2) Primary intracranial group (10 cases) had no detectable PNS lesion at initial presentation. The granulomas were soft, suckable, and contained pus or necrotic material. RESULTS: Postoperative and overall mortality were 37.5% and 50%, respectively. Meningoencephalitis was the most common cause of death. Altered sensorium, pus in the granuloma, and/or severe brain edema were poor prognostic factors. All survivors except four have symptomatic residual or recurrent lesions. CONCLUSION: Early diagnosis with MRI or stereotactic biopsy, radical surgery, and high dose and chronic suppressive chemotherapy may improve overall results in these cases.

Growing skull fractures: a clinical study of 41 patients.

Growing skull fractures are rare complications of head injury, occurring almost exclusively in infants and children under the age of three. A retrospective review at our Institute yielded 41 patients with this entity over a period of 20 years (1975-1995). The age at presentation ranged from less than 1 year to 62 years, with 33 (80.5%) patients being less than 5 years of age. The cause of injury was either a fall from a height (93%) or a road traffic accident. The most common location of a growing skull fracture was either parietal or frontoparietal (56%). One patient had a posterior fossa growing skull fracture. CT scan was performed in 19 patients which demonstrated an underlying porencephalic cyst, hydrocephalus or a cyst communicating with the ventricle. In 5 children, a ventriculo-peritoneal shunt alone was performed. Twenty four patients underwent a duro- and cranioplasty while a duroplasty alone was performed in 8 patients. The material used for cranioplasty included acrylic, wire mesh, steel plates or autologous bone. Three patients died, one due to an anaesthetic complication and two as a result of postoperative meningitis. Post-operative CSF leaks occurred in 3 patients, which were managed by a lumbar drain. Six patients had local wound infection.