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Study design A retrospective descriptive assessment of the clinical and radiologic outcomes of 11 patients who underwent transpedicular decompression for thoracic spine tuberculosis. Objectives To study the neurologic and radiologic outcomes in patients who underwent transpedicular decompression for thoracic spine tuberculosis. Summary of background data Several approaches have been used in the management of thoracic spine tuberculosis to achieve the goals of decompression of the cord followed by immobilization and antituberculous therapy. These range from conservative regimens of computed tomography-guided biopsy followed by bed rest and drug therapy to radical surgeries that involve extensive debridement of the vertebral body followed by instrumentation. The authors report their experience with a "middle path" regimen of transpedicular decompression followed by external immobilization and antituberculous therapy. Methods The charts of 11 patients were reviewed retrospectively for clinical outcome, and kyphotic angle was measured on the follow-up radiographs to ascertain progression of kyphosis. Results There was no worsening of the neurologic status in any patient, and 10 of the 11 patients returned to functional activity. There was no significant progression of kyphosis. Conclusions Our results show that the transpedicular approach is a viable and safe surgical option for ventral decompression in thoracic spine tuberculosis, followed by chemotherapy for 18 months and immobilization in an alkathene shell for 3 months.

We report the results of a prospective randomized controlled trial, which looked at the incidence of postoperative diabetes insipidus (DI) following the use of three different hydrocortisone protocols, and the results of a study, on the incidence of DI and cortisol response in patients not given hydrocortisone. In study 1, 114 patients with pituitary macroadenoma were randomized into three groups: conventional dose (inj. hydrocortisone 100 mg IV 6-hourly for 3 days); intermediate dose (inj. hydrocortisone 100 mg IV 6-hourly on day 1, 100 mg IV 8-hourly on day 2, and 100 mg IV 12-hourly on day 3); low dose protocol (inj. hydrocortisone 25 mg IV 6-hourly on day 1, 25 mg IV 8-hourly on day 2 and 25 mg IV 12-hourly on day 3). Radical excision was achieved in 92 patients. The incidence of DI with the conventional dose was 52%, intermediate dose, 36% and low dose, 24% (p = 0.025). Study 2 included 16 consecutive patients with Hardy's grade A & B pituitary adenoma. These patients were randomized to receive (Group I) or not receive (Group II) hydrocortisone. Patients in Group II demonstrated normal cortisol response intraoperatively and no patient developed features of hypocortisolism; the incidence of DI in this group was 14%. The low dose hydrocortisone protocol reduced the incidence of DI by 46% when compared with the conventional dose hydrocortisone protocol. In patients with grade A and B tumour with normal preoperative cortisol levels, the use of perioperative hydrocortisone can be avoided.

Although the clinical and imaging features and behaviour of brain stem gliomas in children are well documented, similar data are not available, for adults. We have carried out a retrospective study, on 101 consecutive patients (71 children and 30 adults) with a histologically verified brain stem glioma. Duration of symptoms, clinical features, imaging characteristics, histopathology and outcome were specifically compared in children and adults with brain stem glioma. Peak incidence was in the first decade in children and in the third and fourth decades in adults. Mean duration of symptoms before admission was 9.7 months in adults and 3.6 months in children (P

Thirty two poor grade patients (grade 3, 20 patients and grade 4, 12 patients) with tuberculous meningitis and hydrocephalus were prospectively studied to evaluate the response to external ventricular drainage in predicting outcome after shunt surgery. All grade 3 patients underwent a shunt procedure irrespective of their response to external ventricular drainage, and an attempt was made to correlate the immediate response to external ventricular drainage to their long term outcome. Patients in grade 4 underwent shunt surgery only if there was clinical improvement by at least one grade after external ventricular drainage. Follow up (mean 23.1 months) was available for 30 patients (93%). Of the 20 patients in grade 3, seven underwent shunt surgery directly, 13 after an external ventricular drainage. In the group which underwent drainage, the immediate clinical response was improvement in six, no change in six, and death in one. Long term improvement or death occurred almost equally in all the subgroups. The immediate response to external ventricular drainage was not predictive of the long term outcome in grade 3 patients. All 12 patients in grade 4 underwent an external ventricular drainage and only one improved. The rest continued to deteriorate and succumbed to the disease. Grade at admission was the single most important predictor of good outcome (p=0.002) and severity of hydrocephalus had an adverse impact on outcome (p= 0.04). The rest of the variables studied (age, duration of illness, duration of altered sensorium, CSF cell count, and CSF protein concentrations) had no effect on long term outcome. All patients in grade 3 should be given the benefit of shunt surgery without a trial of external ventricular drainage. However, patients in grade 4 should undergo an external ventricular drainage in view of the high mortality in this group.

Tumours of the pineal region are rare. Between 1983 and 1997, 128 patients with pineal masses were treated in our institution. Forty-eight (38%) of these were benign. There were 13 patients with meningiomas, 11 with epidermoid tumours, 10 with cystic lesions, five with vascular lesions, five with infective pathology and four with mature teratomas. All patients were managed surgically. Ventriculo-peritoneal shunts were inserted preoperatively to relieve hydrocephalus. Open surgery thereafter was mostly done through the supracerebellar infratentorial approach. The occipital transtentorial route was preferred for meningiomas. Stereotactic biopsy was used in two patients only. Radical excision of tumours was achieved in 55% of operated cases, partial excision in 25%. Radiation therapy, which was the mainstay of treatment earlier, was used only in two patients. Stereotactic radiosurgery was used in one patient. All patients followed up were found to be in good or excellent condition.

Two patients with posterior fossa arachnoid cysts associated with syringomyelia are discussed adding to the five cases already reported in the literature. The formation and progression of syringomyelia secondary to a posterior fossa cyst and its possible pathophysiology by dynamic CSF flow studies using magnetic resonance (MR) imaging are discussed and reviewed.

We hypothesized that when contrast-enhanced CT reveals a solitary cerebral cysticercus granuloma, MRI would not usually provide additional information that might assist in management. We retrospectively compared visualisation of solitary cysticercus granulomas on contrast-enhanced CT and MRI in 16 patients presenting with seizures; gadolinium (Gd) enhancement was used in 6 patients. The granuloma was delineated well on both CT and MRI in 15 patients; in one patient, in whom CT was performed with 10-mm slices, it was seen only on contrast-enhanced MRI, CT and unenhanced MRI revealing only the surrounding oedema. On CT the granuloma was seen best on thin (2-5 mm) contrast-enhanced sections (in 10 patients). On MRI, Gd-enhanced images showed the granuloma best, as a ring-enhancing lesion, in all 6 patients. In the other 10 patients, the granuloma was seen only on T2-weighted images in 8 and on both T1- and T2-weighted images in 2. On T2-weighted images a characteristic low-signal ring with a high-signal centre was seen in 12 patients. Sensitivity of the imaging techniques was: contrast-enhanced CT (5 and 10 mm slices) 93.8% (15/16); thin (2-5 mm) section contrast-enhanced CT 100% (6/6); unenhanced MRI 93.8% (15/16). MRI did not reveal additional granulomas or cysts in any patient. In patients strongly suspected to be harbouring this lesion, when 10-mm contrast-enhanced CT reveals only oedema, thin (2-5 mm) slice CT is a cost-effective alternative to MRI.

✓ Solitary cysticercus granulomas that produce seizures usually measure less than 20 mm in diameter and diminish in size spontaneously. Unlike live cysticercus cysts, they have not been known to increase in size. In a prospective follow-up study of 93 consecutive patients with epilepsy and small solitary lesions (< 20 mm in diameter) enhancing on computerized tomography (CT), 91 were found to have solitary cysticercus granuloma; of these, seven (7.7%) were diagnosed as having an enlarging cysticercus granuloma. Enlarging lesions were defined as those that, on follow-up CT, had increased by more than 50% of their original size but were still less than 20 mm in diameter (Group 1, three patients) or those that had increased to more than 20 mm (Group 2, four patients). Excision biopsy is recommended for Group 2 solitary lesions, regardless of the clinical progression, to eliminate the possibility of other pathologies. However, a trial of albendazole therapy with early CT re-evaluation (within 4 to 6 weeks) may be warranted in those with Group 1 lesions and in selected patients with Group 2 lesions. It is important to recognize the entity of enlarging solitary cysticercus granuloma to avoid mistaking it for a tuberculoma and treating the patient with empiric antituberculous therapy.

The main objective of our study was to evolve a practical management protocol for neurosurgical patients with hyponatremia and natriuresis, based on their blood volume status and hematocrit. Twenty-one patients with hyponatremia and natriuresis and 3 control patients were studied. Patients with hyponatremia were categorized on the basis of their hematocrit, central venous pressure, and total blood volume. Group A consisted of patients with hypovolemia and anemia (16 patients); Group B patients had hypovolemia but no anemia (5 patients); Group C included those with hypervolemia (0 patients). Patients in Groups A and B received isotonic saline (> 50 ml/kg/d) and oral salt (12 g/d). Additionally, those in Group A were transfused with 500 ml of whole blood. The end points in the study were 72 hours after entry or two consecutive serum sodium values of > 130 mEq/L, whichever was earlier. Hyponatremia was corrected in all the patients within 72 hours (1 patient, < 24 h; 13 patients, < 48 h; and 7 patients, < 72 h). We conclude that most neurosurgical patients with hyponatremia and natriuresis have hypovolemia, with or without anemia. Fluid and salt replacement and a blood transfusion rather than fluid restriction often results in the correction of the hyponatremia. Our findings offer indirect evidence to support the hypothesis that in most of these patients, hyponatremia is caused by cerebral salt wasting syndrome, rather than the syndrome of inappropriate secretion of antidiuretic hormone.

✓ It is commonly believed that differentiating solitary small cysticercus granulomas and small tuberculomas in patients with seizures is difficult without resorting to an excision biopsy. The aim of this study was to formulate clinical and computerized tomography (CT) criteria to distinguish these two entities in patients with epilepsy. Toward this end, clinical and CT data from six consecutive patients with histologically proven small solitary tuberculomas and 25 consecutive patients with histologically proven solitary cysticercus granulomas were compared. Evidence of raised intracranial tension and a progressive focal neurological deficit was seen only in patients with tuberculomas (two of six cases). All tuberculomas were greater than 20 mm in size and five of the six were irregular in outline. Only tuberculomas were associated with a midline shift on CT (four of six cases). All cysticercus granulomas were less than 20 mm in size and 24 (96%) of the 25 were regular in outline, conforming to one of two characteristic patterns. No cysticercus granuloma was associated with a midline shift. Based on the above clinical findings (evidence of raised intracranial tension and a progressive neurological deficit) and CT criteria (size, shape, and association with a midline shift), it is possible to separate these two entities in a majority of patients with seizures and with a single small lesion on CT.

Intracranial aspergillus granulomas over a 12-year period were studied retrospectively. Three distinctive types of presentations were seen, namely nine patients had the rhinocerebral form with primary involvement of the air sinuses and secondary involvement of the skull base, cranial nerves and brain, three patients with the apparently purely intracranial form presented like any other space occupying lesion and one patient who had a 'stroke-like' presentation had a parasellar lesion. None of these patients were immunocompromised. The clinical features, and the medical and surgical options are discussed together with outcome.

Five cases of incidentally detected pituitary macroadenomas are described. All five had suprasellar extensions, but none had visual field defects as tested by computed perimetry. One patient had sellar changes seen on an X-ray film taken following a head injury, while the others were detected by computed tomography performed for seizures, stroke and meningitis. Four patients underwent trans-sphenoidal surgery for suprasellar extensions with or without hypopituitarism, while one was managed conservatively as he had normal visual fields and pituitary function and there was a spontaneous decrease in size of the adenoma. The management of such incidental pituitary macroadenomas is discussed.

Intracerebral Schwannoma is a rare tumour which can mimic meningioma clinically, radiologically and morphologically. Immunohistochemical techniques are necessary to confirm the Schwann cell origin of the tumours. We report such a tumour in the posterior frontal parasagittal region. The origin of Schwann cells in the central nervous system is still speculative and various postulations are discussed.

The study describes the microsurgical neurovascular relationships of the root entry zone of lower cranial nerves in 23 cadavers. The vessel type, frequency of contact and site of contact on the root entry zone were analysed. Three types of vascular patterns (Types I-III) were found. Facial nerve: frequency of contact 31.8%; arterial contact 92.9%, Type I (lying across) 78.9%; anterior inferior cerebellar artery in 84.6%. Glossopharyngeal nerve: frequency of contact 23.9%; arteries 54.5%, veins 45.5%; posterior inferior cerebellar artery in 83.3% and Type II (loop) 50.1%. Vagus nerve: frequency of contact 26.1%, arteries 58.3%. Types II and III (passing through) formed 42.9% each. Hypoglossal nerve: frequency of contact 78.2%; vertebral artery 88.9%. No 'grooving' on any nerve was seen. Hence, 'contact' by a vessel at the root entry zone may not be significant in the etiology of lower cranial rhizopathies.

Arachnoid cysts of the posterior fossa are rather uncommon compared with their supratentorial counterparts. Spontaneous disappearance of middle cranial fossa arachnoid cysts has been reported but there are none in the English literature on the spontaneous fluctuation in size of a posterior fossa arachnoid cyst. We present a 41-year-old male, with a midline posterior fossa arachnoid cyst, which appeared to lessen in size spontaneously with complete disappearance of symptoms and then enlarged with a worsening in neurological status.

A rare case of an extradural brucellosis granuloma in the thoracic region is presented. Medical treatment delayed surgical intervention and led to total paraplegia with sphincteric disturbance despite improving serum antibody titres. However, delayed neurosurgical intervention resulted in near-total clinical recovery. Early surgical intervention in cases of significant spinal cord compression due to an extradural brucellosis granuloma with a progressive neurological deficit is recommended.

Sixty-eight patients with pituitary adenomas were classified into groups based on their invasiveness and functional status. Mean argyrophilic nucleolar organizer region proteins (AgNOR) counts obtained from 200 cells showed no correlation with the invasive status of pituitary adenomas. However, the functional tumours showed significantly higher AgNOR counts than non-functional tumours.

A study of the clinical, radiological, and pathological correlations in 43 patients with solitary cysticercus granuloma and epilepsy focused on factors that might help in predicting the presence of the parasite in the granuloma and those that might influence the formation of oedema around the granuloma. The duration of symptoms (< six months and > or = six months) and CT morphology of the granuloma (ring and disc, type A; nodular lesion, type B) were studied as factors that could possibly predict the presence of the parasite in the granuloma. The influence of sex of the patient and the presence of a neutrophilic response in the granuloma on the intensity of oedema around the lesion as seen on CT was also studied. The pathological features were studied in the excised granulomas. The intact or degenerated form of the cysticercus was evident in 22 of 43 specimens. Neither the duration of seizures (P = 0.17) nor the type of lesion on CT (P = 0.16) was predictive of the presence of the parasite in the granuloma. The sex of the patient (P = 0.51) and the neutrophilic response in the specimen (P = 0.73) did not correlate with the degree of oedema on CT indicating that neither of these host factors was a major determinant of oedema production. The findings point to the varied and unpredictable natural history of solitary cysticercus granulomas and the complex nature of host-parasite interactions in individual patients. The inability to predict the presence of the parasite in the granuloma on the basis of the clinical or radiological features precludes a selection of patients with such lesions for cysticidal drug treatment.

BACKGROUND While calcification of orbital hemangiomas has been reported previously, no reports exist of heterotopic ossifications occurring within the orbit. CASE DESCRIPTION A 30-year-old male presented with spontaneous onset of painless progressive proptosis of the left eye, with diplopia. The preoperative radiologic findings are presented. The lesion was excised completely. The pathologic features and probable causes are discussed. CONCLUSIONS Heterotopic ossification of the orbit should be considered in the differential diagnosis of an orbital lesion showing radiologic features of calcification or ossification.

Fifty four cases of single small (

Although infection is the commonest central nervous system complication following renal transplantation, brain abscess is uncommon. Over the last 11 years, five renal transplant recipients who had brain abscesses were treated by computed tomography (CT)-guided stereotactic aspiration. Three patients had a fungal abscess, one a tuberculous abscess and the other had a methicillin-resistant Staphylococcus aureus abscess. One patient required a craniotomy for the excision of a fungal abscess which was persistent after two CT-guided stereotactic aspirations. The survivors in this group are the patient with a tuberculous abscess who is alive and well 5 years after diagnosis, and another with a dematiaceous fungal abscess (phaeohyphomycosis). CT-guided stereotactic surgery is minimally invasive, and can safely be performed in these patients. It often leads to an aetiological diagnosis in renal transplant recipients with brain abscesses. Specific antibiotic management directed towards the causative organism rather than empirical treatment can be instituted following the procedure. Although the ultimate prognosis in these patients is bleak even with specific antibiotic therapy, an occasional patient might have a good outcome with prompt and appropriate therapy. Keywords: brain abscess; computed tomography guided stereotaxy; renal transplant recipients

A small posterior fossa volume has been thought to lead to hind brain herniation. The resultant obstruction to the CSF pathways at the level of the foraman magnum has been implicated in the development and subsequent progression of syringomyelia. This report highlights the gradual development of a small posterior fossa due to fibrous dysplasia of the occipital bone with consequent tonsillar herniation resulting in syringomyelia.

Objectives To evaluate (1) the clinical profile, treatment, and outcome of adult and pediatric patients presenting with intracranial abscess of otogenic origin and (2) the advantages of concurrent craniotomy and mastoidectomy. Design A prospective case series. Setting An academic tertiary referral center in India. Patients Thirty-six patients clinically diagnosed as having intracranial abscess that was secondary to suppurative otitis media and confirmed by computed tomographic scanning. Intervention Concurrent craniotomy and mastoidectomy. Results Children were more commonly affected than adults, and there was a male preponderance. All patients had cholesteatoma at surgery, although one third of the children had only granulation tissue on otoscopy. More than two thirds of the patients in both the groups presented with more than one intracranial complication and definitive surgical intervention was done later than 24 hours. Meningitis was the most frequent intracranial complication, followed by cerebellar abscess. There was no significant intraoperative or postoperative morbidity, mortality, recurrence of intracranial complications, or residual neurological deficits. Three children (14%) showed evidence of recidivism cholesteatoma requiring revision surgery. Conclusions In suppurative otitis media with intracranial complications, it is accepted practice to treat the neurosurgical complication first, followed by mastoidectomy at a later date after the patient has been stabilized. Craniotomy with concurrent mastoidectomy is not only safe, but it also removes the source of infection at the same time the complications are being treated, thus avoiding reinfection while the patient is awaiting the ear surgery. In addition, the treatment is completed with a single, shorter hospital stay, which is more economical for the patient.

Patients with parenchymatous mass lesions in the perirolandic area as seen by CT or MRI are unique in that identification of the central sulcus (CS) intraoperatively is crucial in determining the surgical strategy. Somatosensory-evoked potential (SEP) responses were used under general anaesthesia for the intraoperative identification of the central sulcus (CS). Sixty-five patients with parenchymatous mass lesions were included in the study and a phase reversal in the hand area across the central sulcus was used to identify this sulcus. Based on the clinical findings the patients were classified into three groups: Group A were patients with predominant motor deficits, Group B, patients with predominant sensory deficits; and Group C were patients with gross sensory and motor deficits. This study shows that in patients with predominant motor deficits a phase reversal with good amplitude was obtained in all cases. In patients with predominant sensory deficits a phase reversal could be obtained, but their amplitudes were markedly decreased. In patients with predominant sensorimotor deficits no phase reversal could be obtained. The central sulcus could not be located accurately by somatosensory evoked potentials in these cases (group C).

We document the clinical presentation, management and outcome of histologically verified, solitary, intrinsic brain stem tuberculomas in six patients. The neurological symptoms and signs in these patients did not distinguish their lesions from other intrinsic masses of the brain stem. On contrast-enhanced computed tomography (CT), the tuberculomas appeared as ring enhancing lesions in three patients and nodular contrast enhancing lesions in the other three. Diagnosis was established on the basis of CT-guided stereotactic biopsy in all patients. All patients were treated with antituberculous drugs for 18 months. Steroid therapy of 2-8 weeks duration was also used in four patients. At a median follow-up period of 20 months (range 9-51 months), three patients were asymptomatic and the other three were functioning independently with mild disability. Although isolated, intrinsic brain stem tuberculoma is an uncommon entity, it should be suspected in patients presenting with features of an intrinsic brain stem mass and a contrast-enhancing lesion on CT. CT-guided stereotactic biopsy usually provides evidence of the inflammatory nature of the mass although an aetiological diagnosis is often elusive. Early diagnosis and appropriate therapy with antituberculous drugs and steroids usually results in an excellent or good outcome in most instances.

We had previously suggested a protocol for the management of neurosurgical patients with hyponatremia and natriuresis that was based on their volume status as determined by actual blood volume measurements. All patients in that study were found to be hypovolemic or normovolemic and responded, within 72 hours, to salt and fluid replacement. In the present study, the validity of that protocol was tested using central venous pressure as the sole measure of volume status of patients with hyponatremia and natriuresis.Twenty-five consecutive patients (26 cases) who fulfilled the inclusion criteria typically used to diagnose the syndrome of inappropriate secretion of antidiuretic hormone were included in the study. Central venous pressure was used to classify patients as hypovolemic (5 cm of water), normovolemic (6-10 cm of water), or hypervolemic (11 cm of water). Hypovolemic patients were given fluids (50 ml/kg/d) and salt (12 g/d). Normovolemic patients were given normal fluid with 12 g of salt per day. In addition, patients with anemia (hematocrit,27%) were administered whole blood. The end point was a serum sodium of more than or equal to 130 mEq/L measured in two consecutive samples 12 hours apart or 72 hours after entry into the study. If the serum sodium was less than 130 mEq/L at the end of 72 hours, the clinical condition of the patient determined further management.Nineteen of 25 patients (26 cases) were hypovolemic, the rest were normovolemic. No patient was hypervolemic. Nineteen of 25 patients (26 cases) attained normal serum sodium values within 72 hours, and an additional 3 responded within the next 36 hours (108 h after entry into the study). One patient who was discharged on request had normalized her serum sodium a week later. Among the three nonresponders, who were severely hypovolemic, as revealed by blood volume measurement, and responded to increased fluid and salt administration. One was normovolemic and responded to increased salt administration. There were no complications related to the therapy.Hyponatremia with natriuresis in the neurosurgical setting responds to salt and fluid replacement guided by the patients' volume status as determined by the central venous pressure. This study also offers further indirect evidence to suggest that the syndrome of hyponatremia with natriuresis is most often caused by "cerebral salt wasting" rather than by the syndrome of inappropriate secretion of antidiuretic hormone.

BACKGROUND Parenteral administration of narcotics has been the mainstay for postoperative pain relief in patients undergoing lumbar laminectomy. However, this may lead to respiratory depression and nausea, which may be hazardous in these patients. METHODS We evaluated the efficacy of wound infiltration with bupivacaine in 45 consecutive patients undergoing elective single-level lumbar laminectomy for intervertebral disc prolapse in a prospective, double-blind, randomized controlled trial. Prior to wound closure, the muscle and subcutaneous tissues were infiltrated with bupivacaine 0.375% or sterile physiologic saline. Postoperatively, the patients were assessed hourly for pain and an analgesic administered if the patient had moderate or severe pain. RESULTS All the 21 placebo recipients required analgesics in the first 9 hours postoperatively, compared to only 11 of 24 patients who received bupivacaine (p < 0.001). The mean (standard deviation) time before administration of the first dose of analgesic postoperatively in the bupivacaine and placebo recipients was 807.7 (567.6) minutes and 181.4 (110.1) minutes, respectively (p < 0.001). No adverse effects of local wound infiltration were noted. CONCLUSIONS Local wound infiltration with bupivacaine is a safe and effective method for providing postoperative pain relief and reducing narcotic use in patients undergoing lumbar laminectomy.

✓ The benefits of the use of computerized tomography (CT)-guided stereotactic surgical techniques for the management of intrinsic brainstem masses diagnosed from clinical evaluation and imaging studies were evaluated vis-à-vis the risks involved in 71 consecutive patients. Seventy-two procedures were performed. The masses were diffuse, involving two or three contiguous brainstem segments, in 60 patients and focal in 11 patients. On the CT scans, 25 patients had hypodense nonenhancing masses, two had isodense nonenhancing masses, 19 had ring-enhancing masses, and 25 had heterogeneously enhancing masses. A positive biopsy was obtained in 68 of 69 patients (98.5%) undergoing a biopsy procedure. In nine patients (12.6%) with suspected malignant masses a benign pathology was diagnosed (four tuberculomas, two epidermoid cysts, one pyogenic abscess, one epidermal cyst, and one case of encephalitis). Additionally, fluid from cystic masses could be aspirated in eight cases, providing benefit in six (four patients had benign lesions and two had neoplastic lesions). Thereby, a total of 13 patients (18.3%) were deemed to have benefited from the surgery (two patients were included in both categories). Patients with focal masses and ring-enhancing masses had the highest proportion of benign lesions (60% and 36.8%, respectively) and therefore derived the most benefit from histological verification. There was no procedurerelated mortality. One patient (1.4%) suffered permanent morbidity and four others (5.6%) had transient worsening attributable to the procedure. The authors conclude that CT-guided stereotactic surgery of the brainstem is safe and reliable. Histological verification of all enhancing (especially ring-enhancing) and focal brainstem masses should be undertaken to identify patients with benign nonneoplastic lesions. Selected patients with diffuse hypodense nonenhancing masses with atypical clinical or imaging features may also benefit from stereotactic biopsy. Even in these patients the lack of enhancement on a contrast-enhanced magnetic resonance image, rather than the diffuse location of the tumor alone, should form the basis for diagnosing a malignant glioma. The main value of stereotactic surgery lies in the identification of benign masses in a significant proportion of patients with intrinsic brainstem masses and in providing a rapid and safe method for evacuation of the contents of cystic masses.

The neurosurgical manifestations in three patients with sphenoid sinus mucoceles and two others with fronto-eth-moidal mucoceles are presented. In two patients, sphenoid sinus mucoceles produced visual loss while in the other severe headache was the only symptom. Both patients with fronto-ethmoidal mucoceles presented with proptosis. All patients had surgical treatment. While other symptoms were relieved following treatment, visual loss remained unchanged in both patients in whom it was present. We recommend a high level of suspicion for mucoceles as a cause of sudden or progressive visual loss. Prompt surgical therapy is needed to achieve good visual outcome.

✓ A rare case is described of marked segmental stenosis of the axis secondary to developmental hypertrophy of the posterior neural arch causing cervical myelopathy. The patient made a remarkable recovery following decompressive laminectomy.

Tuberculous atlanto-axial dislocation is an uncommon disease. Five of six patients with tuberculous atlanto-axial dislocation were successfully managed using different strategies. The advantages and disadvantages of these different protocols and their appropriateness in a particular clinical situation are discussed.

In the National Neurosurgical Centre in the Sultanate of Oman, four patients with cranio-facial actinomycosis were seen over a 5-year period. All patients had osteomyelitis and intracranial granulomata and the diagnosis was confirmed with histopathology. In two cases the organisms were cultured. In three patients the cranial spread was by contiguity from the scalp and face while one case had the extradural granuloma following a dental extraction. With medication there was gross reduction of proptosis and intracranial lesion in one patient and in two there was marked reduction in the size of the intracranial lesion as seen on serial computerized tomographic scanning of the head (CT head). Three patients are now asymptomatic and are being followed up while one expired with subarachnoid haemorrhage. Although eradication of the disease is difficult, with adequate medication and appropriate surgical intervention, three of these patients continue to remain relatively symptom-free for long periods of time.

Retained surgical sponge is an uncommon complication in neurosurgical practice. We report two patients with retained surgical gauze and describe the clinical presentation and the characteristics of the foreign body on MRI.