Cerebrovascular disease (CVD) or stroke is one of the foremost causes of high morbidity and mortality for many nations of the world, posing a major socio-economic challenge in the occupational and neuro-rehabilitational programmes of the 'stroke-survivors'. For example, in USA alone it has been estimated that a sum of 3261 million dollars is spent as direct cost for treatment, in addition to 4104 million dollars as indirect costs, consequent on economic losses of 'stroke victims'. Thus, the new concept in stroke pathophysiology and strategies for stroke prevention have assumed global importance. Among all risk factors for strokes, hypertension is one of the most important and treatable factor. Community screening surveys, by well defined WHO protocol, have shown that nearly 15% of urban population is hypertensive (160/95 mm Hg or more). Though high blood pressure has the highest attributable risk for stroke, there are many other reasons such as patient's compliance in taking medicine and poor followup in clinical practice that may lead to failure in reducing stroke mortality. In subjects, who have transient ischaemic attacks (TIAs), regular use of antiplatelet agents like aspirin is well established in prevention of stroke. It is also mandatory to prohibit tobacco use and adjust dietary habits to control body weight. Associated conditions like diabetes mellitus etc. should also be treated. It is advisable to initiate community screening surveys on well defined populations for early detection of hypertension and TIAs. Primary health care centres should be the base stations for these surveys, because data gathered from urban hospitals will not truly reflect the crude prevalence rates for the community to design practical prevention programmes.

The authors present their surgical experience with fifty seven cases of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine, operated between January 1992 and January 1999. Continuous OPLL was seen in the majority of patients (40/57). Posterior decompressive surgery was performed in 18 patients, a median corpectomy and excision of the OPLL in 28 and anterior segmental decompression in 11 patients. One patient had a transient weakness of muscles supplied by the C5 myotome following a C4-C5 corpectomy. 84.2% of the patients showed improvement by at least one grade at the time of discharge. 92.8% of patients who underwent a corpectomy improved in the immediate post-operative period as compared to 90.9% of those who underwent an anterior segmental decompression and 83.3% of those who underwent a posterior decompressive procedure. 97.7% of the 44 patients followed-up between one and five years showed neurological improvement. Thirty-two patients (72.7 %) had regained normal or near normal neurological function and returned to their jobs. Good results were obtained when the surgical approach and the procedure adopted were individualised.

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.

There had been considerable debate regarding the surgical outcome of neuro-orthopaedic syndromes (NOS) and neurological syndromes in cases of split cord malformation (SCM). On retrospective analysis of 19 cases of SCM, thirteen were grouped under (Pang) type I and 6 in type II. Their age ranged from 1 month to 9 years (mean 3.5 years). 14 of these were male children. The NOS without neurological signs was detected in 6 cases where as pure neurological signs without NOS were seen in 8 patients. However, the rest 5 had mixed picture of NOS and neurological dysfunction. Nine of 19 cases presented with cutaneous stigmata, mainly in the form of hairy patch. 18 cases had other associated craniospinal anomalies i.e. hydrocephalus, meningomyelocoele, syrinx, dermoid, teratoma etc. Detethering of cord was done in all cases by removal of fibrous/bony septum. Associated anomalies were also treated accordingly. Follow up of these cases ranged from 6 months to 6 years. Six cases of NOS group neither showed deterioration nor improvement, and remained static on follow up. However, four of 8 children with neurological signs showed improvement in their motor weakness, and 1 in saddle hypoaesthesia as well as bladder/bowel function. In 5 cases of mixed group, two had improvement in their weakness and one in hypoaesthesia, but no change was noticed in NOS of this group as well. Hence surgery seemed to be effective, particularly in patients with neurological dysfunction.

Invasive infections caused by Acinetobacter baumannii in a post-operative neurosurgery ICU were studied. Sixty one patients admitted during a span of 11 months were culture positive for acinetobacter species from blood and/or CSF samples. They were followed up prospectively for evidence of infection and clinical outcome. 40 cases had clinical evidence of infection due to acinetobacter species while in 21 patients, the isolation of the organism was considered a contaminant. Acinetobacter baumannii was the most common organism associated with invasive infections. Respiratory tract was found to be the most common primary source of infection in patients with bacteraemia or meningitis. The age, sex and pre-operative hospital stay were not significantly different in the two groups (p>0.05), while post-operative hospital stay and mortality was significantly higher in patients with invasive infection (p<0.05). Acinetobacter baumannii was isolated from multiple sites (p<0.05) and repeatedly from the same site (p<0.001) in a significantly higher number of patients with invasive infections. Mortality was high in the patients infected with Acinetobacter baumannii. Even amongst the infected group, the patient shaving meningitis showed a higher mortality as compared to the patients having bacteraemia.

Twenty five consecutive patients with CT proven pure traumatic subarachnoid haemorrhage (tSAH) were studied, prospectively over a 6 month period. They constituted 2% of all head injuries. Most of the patients (88%) had a mild or moderate head injury at the time of admission, with a mean glasgow comma scale (GCS) of 10.68. The CT scan findings were divided into 3 grades. Grade 1 - blood in hemispheric region only (n=4), grade 2 - blood in basal region only (n=11), grade 3 - blood in both hemispheric as well as basal region (n=10). Transcranial doppler ultrasound (TCD) velocities were recorded in all patients by insonating the middle cerebral artery, internal carotid artery and anterior cerebral artery on both sides. All patients were also subjected to digital substraction angiography (DSA). All patients with mild head injury had normal TCD velocity (<100 cm/sec), while TCD velocities of more than 150 cm/sec were seen only in one patient with severe head injury. Patients with severe head injury were found to have grade 3 tSAH on CT. No statistically significant correlation was found between the CT grade and TCD velocities. Angiographic vasospasm was found in 2 patients with severe head injury only. 90.2% of patients had good outcome at discharge.

Proliferative activity of 94 pituitary adenomas was assessed by the determination of the growth fraction, using MIB-1 monoclonal antibody in formalin fixed, paraffin embedded sections. This index was correlated with clinical and radiological evidence of invasiveness. The mean Ki-67 labeling index for all pituitary adenomas was 0.84% (range 0-17.45%). Hardy stage E tumours (1.44%) had a higher Ki-67 labeling index (LI) as compared with Hardy stage 0 tumours (0.36%). The difference in the Ki-67 labeling indices between invasive and non-invasive adenomas was not statistically significant. Hence, the Ki-67 labeling index is not a reliable indicator of invasiveness in pituitary adenomas.

Diffuse idiopathic skeletal hyperostosis (DISH) has long been regarded as a benign asymptomatic clinical entity with an innocuous clinical course. Precise information is lacking in the world literature. Authors report the results of a retrospective analysis of 74 cases of DISH. Eleven patients presented with progressive spinal cord or cauda equina compression. In nine cases ossified posterior longitudinal ligament (OPLL) and in two cases ossified ligamentum flavum (OLF) were primarily responsible. Surgically treated patients (eight) had far better outcome as compared to the patients managed conservatively, as they had refused surgery. 'DISH' is neither a benign condition, nor it always runs a innocuous clinical course. In fact, in about 15% of the cases, serious neurological manifestations occur, which may require a major neurosurgical intervention.

The safety and efficacy of selective intraarterial administration of urokinase in five male patients, (age range 30 to 65 years, mean 41.2 years), with occlusive stroke involving the carotid territory and a normal cranial computed tomography scan was evaluated. The time elapsed before treatment ranged from one to 10 hours. Digital subtraction angiography disclosed distal internal carotid artery occlusion in one patient and occlusion of the middle cerebral artery or its branches in the others. The urokinase dose ranged from 120,000 to 500,000 units. In two patients who received thrombolytic treatment within three hours of the onset of symptoms, there was a 100% recanalisation associated with excellent neurological recovery. In the remaining three patients, recanalisation rate varied from 0 to 50% with partial recovery in two and no recovery in one patient. None had a haemorrhagic transformation of the infarct. Although no firm conclusions can be drawn because of the small number of patients studied, selective intraarterial urokinase therapy appears to be safe and useful in patients with carotid territory stroke if undertaken early. Only through a multicenter, randomized, controlled trial, enough number of patients can be recruited to verify these observations.

Traumatic occlusion of the middle cerebral artery (MCA) is a rare cause of cerebral infarct. We describe a case of MCA occlusion following blunt head trauma. The literature reports some 65 cases of MCA occlusion following non-penetrating blunt trauma to the head. Arterial dissection, cerebral vasospasm and thrombosis have been some of the theories discussed in the pathogenesis of this condition. We review the pathogenesis based on anatomy of the M1 segment.

A 46 year old man with trigeminal schwannoma displayed symptoms of ataxia with pathological laughter and crying. The tumour developed in the cerebellopontine angle, compressing the pontomesencephalic structures backward, extending in the posterior parasellar region and Meckel's cave. No recurrence of laughter and crying attacks were noted after total removal of the tumour. Theories of mechanism of pathological laughter and crying reported in the literature are reviewed.

Five cases of giant cavernous sinus neurofibroma arising from the ocular cranial nerves are reported. These patients collected over a period of 5 years consisted of 3 males and 2 females with an age range of 9 to 40 years and a mean of 20.6 years. Clinically, all patients presented with ocular palsies over a long period (mean 3.4 years). All of them underwent a frontotemporal craniotomy along with an orbito-zygomatic osteotomy and excision of the tumour. In patients with extension of the tumour into the orbit, the superior orbital fissure was drilled, the tenon's capsule was cut and the intraorbital portion was excised. The management of these tumours is discussed and the literature reviewed.

A case of lateral ventricular teratoma in neonate, where near total excision of tumour was done, is being reported with the review of literature.

A rare case of a young man with a diffusely calcified oligo astrocytoma in right parieto occipital region, which spread along the axonal fibres into right temporal lobe and to the left parietal lobe is presented. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated the extent of the lesion. The mass was partially resected.

We report a child with hydrocephalus due to tuberculous meningitis who developed a subcutaneous fluid collection around the ventriculoperitoneal shunt tube entry point, after one month of shunting. On investigation, he had decompressed ventricles with bilateral fronto parietal subdural hygroma. Bifrontal burr hole drainage helped resolution of both subdural effusion and subcutaneous scalp swelling. This complication is unique and its pathogenesis has been postulated.

The association of a solitary cerebral cysticercus granuloma with a subdural effusion is being reported. The granuloma and the effusion resolved following albendazole therapy. We speculate that the spread of the inflammatory changes around the granuloma to the subdural space could have led to the development of the subdural effusion.

Paraneoplastic limbic encephalitis is a rare clinical entity, associated most often with the oat cell carcinoma of the lung. Clinically, it presents with affective changes in personality, memory loss, confusional state, hallucinations, and seizures; with dementia being the common feature as the disorder progresses. Response to treatment is disappointingly poor.

Malignant peripheral nerve sheath tumour (MPNST) is a rare malignant neoplasm arising from the supportive non-neural component of the peripheral nerves. An unusual case of pain and weakness of the foot and calf muscles due to a giant MPNST of the sciatic nerve in the posterior compartment of the thigh is presented. The patient was already investigated as a case of sciatica due to a lumbar disc disease with a negative magnetic resonance imaging and then unsuccessfully operated elsewhere twice, with a misdiagnosis of tarsal tunnel syndrome. Neurosurgical referral prompted a diagnostic magnetic resonance study of the thigh, revealing the lesion, which was completely excised microsurgically with total relief in the pain and partial improvement in the weakness and sensations in the sole of the foot.

A patient with pituitary apoplexy is reported who, in addition to the clinical features of apoplexy, developed a cerebral infarct secondary to compression of the internal carotid artery. The mechanisms of a cerebral infarct associated with pituitary apoplexy are discussed.

Metastatic parotid tumours in the skull are very rare. An interesting case of a mucoepidermoid parotid tumour metastasizing to the skull vault is described in a patient who had previously been operated for a pituitary adenoma 20 years back with no post operative radiotherapy; however, she required hormonal supplementation therapy. She underwent an operation for a parotid tumour 7 years ago and received postoperative radiotherapy for the parotid tumour away from the site of the skull metastases. No local recurrence of the parotid tumour was noted. The initial diagnosis was that of a solitary intradiploic meningioma. Interesting clinico-radiological findings are presented.

Two females, in their sixth decade, presented with recurrent episodes of headache, vertigo, vomiting and altered sensorium. Both patients had persistent hyponatraemia as the only clue. Detailed investigations revealed a pituitary aetiology in both. One patient had a pituitary microadenoma while the other had an empty sella syndrome. The diagnosis and management is discussed and the relevant literature reviewed.

A rare case of primary malignant melanoma in the cerebello-pontine angle, in a 17 year old girl is presented. The patient presented with one month history of headache, diplopia, facial asymmetry and ataxia. The computerised tomography (CT) scan and magnetic resonance imaging (MRI) revealed a large cerebello-pontine angle mass with features suggestive of a melanoma. The typical black coloured, solid and vascular melanoma was excised completely. Cerebello-pontine angle melanoma are extremely rare tumours with dismal long term outcome in majority of these cases.

Primary spinal hydatid cysts are uncommon. Among these, intradural presentation is very rare. A case of primary spinal intradural hydatid cyst presenting as incomplete dorsal cord compression is reported here for its rarity.

Two unusual cases of meningiomas associated with opposite chronic subdural haematoma are presented.

We describe a patient in whom a hypodense nonenhancing mass on CT scan in the regions of quadrigeminal cistern, and causing obstructive hydrocephalus, was initially diagnosed as an epidermoid but subsequent MR evaluation and surgery resulted in the diagnosis of a racemose cysticercus cyst.

Xanthogranuloma are known to arise in the paranasal sinus or orbit. They may also arise primarily in the brain. Those arising from the sinuses or orbit might involve the intracranial cavity to some extent. But an extensive involvement of the cranial compartment is very rare. This report describes one such case.

A posterior fossa dermoid cyst in association with the Klippel-Feil syndrome, in a 4 year old child is reported. Early diagnosis to prevent complications like neural compression, cyst rupture and staphylococcal meningitis justifies investigation for posterior fossa dermoids in cases of Klippel-Feil syndrome. Their embryological basis is discussed.