Hydrocortisone dose and postoperative diabetes insipidus in patients undergoing transsphenoidal pituitary surgery: a prospective randomized controlled study.

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.

The 'capsule' of pituitary macroadenomas represents normal pituitary gland: a histopathological study.

The goal of trans-sphenoidal pituitary adenoma surgery is radical excision of the tumour with preservation of endocrine function. Our hypothesis was that, even in macroadenomas extending into the suprasellar cistern, the 'capsule' of the tumour is the compressed normal pituitary gland. The biopsy material from 126 patients with pituitary macroadenomas were retrospectively reviewed to look for the presence of normal adenohypophysis. Fourteen patients with macroadenomas operated trans-sphenoidally were studied prospectively, sampling tissue from the periphery of the tumour for histopathology. From the retrospective data, we found that normal adenohypophysis was more often found at histopathology in the extracapsular excisions, rather than in the intracapsular excisions. In the 14 patients studied prospectively, normal adenohypophysial tissue was found histologically at all sites sampled except in areas where the tumour was invasive. In conclusion, while an extracapsular excision would offer the best chance for a surgical cure, preserving parts of the capsule may preserve normal and possibly functioning gland.

Interhemispheric subdural hematoma: an uncommon sequel of trauma.

Interhemispheric subdural hematomas are relatively uncommon and usually seen in patients with bleeding disorders. They may present with signs of the falx syndrome or seizures. The management options range from craniotomy and evacuation to conservative management. We report such a case in a patient with normal bleeding parameters, which was managed with a twist drill craniostomy and drainage of the hematoma.

Management of symptomatic vertebral hemangiomas: review of 13 patients.

Thirteen consecutive cases with symptomatic vertebral hemangiomas, managed during a five year period from January 1995 at the Christian Medical College and Hospital, Vellore, were analysed. Twelve patients had lesions in the thoracic and 1 in the sacral region. Eight patients had multiple level involvement. Seven patients had laminectomy and soft tissue component excision, of which one had intraoperative injection of absolute alcohol and one had postoperative radiotherapy. One patient had vertebrectomy and stabilization with preoperative embolization. One patient underwent only endovascular embolization. However, the focus of this communication is on 4 patients who underwent a CT guided percutaneous transpedicular injection of absolute alcohol into the affected vertebral body. In the surgical group, 6 patients had cavernous type and 2 patients had mixed type of hemangiomas. Ten patients improved on the Ranawat grade by the time of discharge. On the MRC grade, 11 patients had improved, one was grade 5 pre and postoperative, while one did not improve. Several options are available for the management of symptomatic vertebral hemangiomas and multiple modalities may have to be used for a single patient. CT guided percutaneous transpedicular injection of absolute alcohol shows promising results. However, long term follow up is mandatory.

Transsphenoidal line of vision on MRI for pituitary tumor surgery.

This study was done to determine the usefulness of the sagittal magnetic resonance image (MRI) in predicting the ease of resectability of pituitary adenomas operated through the transsphenoidal route. Tumors were graded according to Hardy's method and a new system proposed by us. In this system the amount of tumor above the line of vision (V-line) as seen on the sagittal MRI was estimated and correlated with the extent of excision assessed on the postoperative computed tomogram (CT). There were 7 Hardy's grade A (8.8%), 32 grade B (41.3%), 31 grade C (37.5%), 6 grade D (8.8%) and 2 grade E tumors (3.8%) among the 78 tumors studied. It was seen that most of the tumor volume was below the V-line in Hardy's grade A and B tumors. In grade C tumors 5 were < 25% above, 14 were 25-50% above and 12 were 50-75% above the V-line. A radical excision was possible in 15 of l9 grade C tumors in which < 50% of the tumor was above the V-line. However, only 5 of 12 with Hardy's grade C were radically excised when >50% of the tumor was above the V-line. In conclusion, Hardy's grade C tumors are not a homogenous group radiologically and using the V-line on MRI helps in predicting the case of respectability in a single stage.

Midbrain venous angioma with obstructive hydrocephalus.

A rare case of a mid brain venous angioma with obstructive hydrocephalus is described. A dilated draining vein from the lesion in the aqueduct as the cause of the hydrocephalus is highlighted, and interesting features of the pathology of venous angiomas and associated cavernous hemangioma are described. The management of this interesting condition is discussed.

Hemorrhagic necrosis of pituitary adenomas.

A clinicopathological study of 41 cases of pituitary apoplexy in a series of 324 surgically treated pituitary adenomas is presented. In 23 patients, the predominant operative finding was hemorrhage with or without necrosis. However, there were 15 (37.7%) cases where pale, necrotic tissue with no evidence of hemorrhage was found at surgery. Pale, necrotic material was particularly found when there was a long interval between the acute clinical event and surgery. It is concluded that the pale, necrotic debris represents one stage in the resorption process of blood after hemorrhagic necrosis of pituitary adenomas. This entity needs to be kept in mind especially since the material closely resemble the pultaceous material seen in craniopharyngiomas and epidermoid cysts.

Motor and somatosensory evoked potentials in a primate model of experimental spinal cord injury.

Motor and somatosensory evoked potentials (MEP and SSEP) were compared after experimental spinal cord injury in Bonnet monkeys (macaca radiata). The MEP and SSEP changes following graded injuries were related to clinical outcome. Eight healthy mature monkeys with a mean weight of 4.2 + 0.9 Kg were chosen for the study. Graded spinal cord injury was caused using 50, 100, 200, 300 gm-cm force by modified Allens' weight drop device. MEP and SSEP recordings were done before injury and at 0, 2, 4 and 6 hours after injury and on the 7th postoperative day. Neurological assessment was done at 24 hours and on the 7th day following injury. 50, 100, 200 gm-cm force caused partial injuries and 300 gm-cm force caused severe spinal cord injury. The predictive value of MEP and SSEP following partial injuries was 80% and 66.67% respectively. Both MEP and SSEP were 100% predictive in severe injury. MEP and SSEP monitoring can therefore be complementary to each other in predicting the neurological outcome in partial injuries to the spinal cord.

Determination of Ki-67 labeling index in pituitary adenomas using MIB-1 monoclonal antibody.

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.

Quantitative study of muscle spindles in suboccipital muscles of human foetuses.

The proprioceptive inputs from the cervical musculature play an important role in head-eye co-ordination and postural processes. Deep cervical muscles in humans are shown to have high spindle content. The density, distribution and morphology of muscle spindles were studied in superior oblique capitis, inferior oblique capitis and rectus capitis posterior major and minor three small suboccipital muscles. The muscles were obtained, post-mortem from stillborn human foetus. The spindle density was calculated as the ratio of mean spindle content to the mean wet weight of that muscle in grams. The distribution and arrangement of spindles within the muscle and their arrangement was studied. The spindle density of superior oblique muscle was found to be 190, that of inferior oblique was 242 and the rectus capitis posterior contained 98 spindles per gram of muscle. No tendon organs were seen. The serial transverse sections of inferior oblique muscle revealed muscle spindles of varying sizes, length varying between 100-650 microns and, diameter 50-250 microns. A complex parallel arrangements of group of large spindles were seen in the belly of the inferior oblique muscle, while the polar regions contain few small isolated spindles. The relevance of such high spindle receptor content in these tiny muscles is discussed.

Hemispherotomy for paediatric hemispheric epilepsy.

We present here the results of our series of peri-insular hemispherotomy for intractable hemispheric epilepsy. There were 6 children in this series with a mean age of 10.2 years and mean duration of seizures of 7.2 years. The seizure results were excellent in all children and they also showed significant improvement in functional status. This procedure has significant advantages when compared to other forms of hemispherectomy. However, a larger experience with longer periods of follow-up is needed.

Effect of dichloracetate on infarct size in a primate model of focal cerebral ischaemia.

Acidosis is a major contributing factor towards spread of the ischaemic focus in the brain. Drugs that increase pyruvate dehydrogenase activity could decrease the formation of lactic acidosis. The sodium salt of dichloracetic acid (DCA) has been found to be effective in reducing lactate. This study was undertaken to study the efficacy of DCA in reducing infarct size in experimental focal ischaemia in monkeys. Macaca radiata monkeys in the treatment group were given 35 mg per kilogram of dichloracetate intravenously immediately before occluding and interrupting the middle cerebral artery, and the control group was given saline as placebo under similar conditions. Mean infarct size expressed as a percentage of the size of the hemisphere in all the three brain slices was 35.38 in the control group as against l2.06 in the treated group (p=0. 0008).

The calcified intracorporeal vacuole: an aid to the pathological diagnosis of solitary cerebral cysticercus granulomas.

Fifty four cases of single small (<20 mm) enhancing CT lesions (SSECTLs) of the brain that were excised between 1987 and 1995 were reviewed histologically. In 28 cases the entire cysticercus or its parts were found. In the remaining 26 cases, most had a histological picture suggestive of a parasitic granuloma. In six of these 26 cases, small ovoid masses corresponding in morphology to the intracorporeal vacuoles of a cysticercus were seen lying free in the cavitary space of the granuloma. This lends further strength to the contention that SSECTLs of the brain are caused by cysticercus, and that in the event of a surgical excision, absence of obvious parasitic parts should necessitate a closer search, as calcareous residues of the parasite might be the only evidence of the cysticercal aetiology in the granuloma.

Management and outcome of brain abscess in renal transplant recipients.

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.

Haematopoietic tissue presenting as a sphenoid sinus mass: case report.

We report an incidentally discovered mass in the sphenoid sinus in a patient with beta thalassaemia and sickle-cell disease which proved to be an isolated site of extramedullary haematopoiesis in the skull.

Favorable outcome after radical excision of a 'Holocord' astrocytoma.

We report a favorable outcome following a staged radical excision of an intramedullary low-grade astrocytoma involving the entire spinal cord in a pediatric patient. Although the preoperative neurological status was poor, the eventual outcome was good. This highlights the importance of a good tumor-cord interface that permitted a radical excision of an extensive tumor. Since partial excision followed by radiotherapy usually results in disease progression in patients with low-grade astrocytomas, radical excision and follow-up is probably the treatment of choice.

Spontaneous fluctuation in the size of a midline posterior fossa arachnoid cyst.

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.

Central nervous system toxoplasmosis in acquired immunodeficiency syndrome: An emerging disease in India.

With the incidence of patients infected with human immuno-deficiency virus (HIV) increasing in India, the central nervous system (CNS) manifestations of the disease will be seen more frequently. The CNS may be primarily afflicted by the virus or by opportunistic infections and neoplasms secondary to the immune suppression caused by the virus. In India, although mycobacterium tuberculosis has been reported to be the most common opportunistic infection, toxoplasmosis may become as common owing to the ubiquitous nature of the protozoan. Since an empirical trial of medical therapy without histopathological diagnosis is recommended, the true incidence of this condition may remain under estimated. The role of ancillary tests such as radiology and serology in the initial diagnosis of this condition remain crucial. This report highlights two patients who were diagnosed to have acquired immuno-deficiency syndrome (AIDS) only after the biopsy of the intracranial lesion was reported as toxoplasmosis. Presently all patients for elective neurosurgery are tested for HIV antigen. The management protocol to be followed in a known patient with AIDS presenting with CNS symptoms is discussed in detail. The value of ancillary tests is also reviewed.