The arachnoid granulations of the superior sagittal sinus were examined for blockage by erythrocytes in 43 cases of subarachnoid haemorrhage. Ten cases had survived for more than two weeks after the haemorrhage. Among 33 cases with acute haemorrhage, 17 had evidence of blocking of the granulations. The severity of the block varied from complete clogging of nearly all granulations to slight filling of a few of them. Cases with some days' survival showed evidence of phagocytosis of the entrapped erythrocytes by macrophages. Several of the cases with old haemorrhage had groups of haemosiderin macrophages in the granulations but none showed fibrosis (except for one single villus). It is concluded that clogging of the arachnoid granulations may contribute to the raised intracranial pressure in some cases of acute subarachnoid haemorrhage. However, the observations do not support the hypothesis that the haemorrhage may lead to fibrosis or scarring of the granulations with chronic impairment of the cerebrospinal fluid resorption and subsequent hydrocephalus.

In order to study the cause of the great individual variations in kaolin-induced hydrocephalus, the lower brain stem and upper spinal cord were examined histologically in a series of young rabbits that had received injections of kaolin into the cisterna magna. Animals with complete occlusion of the outlets from the fourth ventricle into the subarachnoid space showed only a moderate ventricular dilatation, while cases with marked hydrocephalus also plugs of kaolin in the caudal part of the fourth ventricle. The intraventricular kaolin was adherent to the roof of the fourth ventricle by strands of connective tissue and it is suggested that the plugs served as valves that initially occluded the opening of the central canal and were then lifted away as the ventricle dilated and the roof moved posteriorly. The animals with marked hydrocephalus also had extensive dilatation of the central canal with cleft formation in the posterior columns. The observations support the concept that in hydrocephalus the central canal may serve as an alternative resorption route for the cerebrospinal fluid through communication with the spinal subarachnoid space.

Lumbar thecoperitoneal shunting was carried out in patients with communicating hydrocephalus due to long-standing tuberculous meningitis. At the time of this surgical procedure, the filum terminale was excised to achieve filum terminostomy. The central canal of the excised filum terminale in seven hydrocephalic children and an equal number from control cases was studied histologically. These observations indicate that the central canal of the filum terminale dilates in communicating hydrocephalus, and the dilatation is proportionate to the lateral ventricular enlargement.

BACKGROUNDFournier's gangrene (FG) is a rare but life-threatening disease. Although originally thought to be an idiopathic process, FG has been shown to have a predilection for patients with diabetes as well as longterm alcohol misuse; however, it can also affect patients with non-obvious immune compromise. The nidus is usually located in the genitourinary tract, lower gastrointestinal tract, or skin. FG is a mixed infection caused by both aerobic and anaerobic bacterial flora. The development and progression of the gangrene is often fulminating and can rapidly cause multiple organ failure and death. Because of potential complications, it is important to diagnose the disease process as early as possible. Although antibiotics and aggressive debridement have been broadly accepted as the standard treatment, the death rate remains high. Aim -The purpose of this study is to highlight the aetiopathogenesis, risk factors and outcomes of Fournier's gangrene. MATERIALS AND METHODSA retrospective descriptive study was conducted on 288 patients of Fournier's gangrene (ICD-9 CM 608.83) from January 2013 to December 2016 at King George Hospital, Visakhapatnam, Andhra Pradesh, India. All cases who were found to have Fournier's gangrene at the time of admission were included in the study. RESULTSAmong the total 288 patients, 280 were male (97.23%) and 8 were female (2.77%). These cases represented less than 0.02% of hospital admissions. The overall incidence was 1.6/100,000 males, which peaked in males who were 50 to 79 years old (3.3/100,000). The overall case fatality rate was 22.91% (66). Primary underlying cause leading to Fournier's gangrene is not identified in 46 (15.97%) patients, which is referred as idiopathic variety. In remaining 242 (84.03%) cases, anorectal disease is leading cause (133, 46.18%) followed by genitourinary diseases (89, 30.90%) and other identifiable aetiology in 20 (6.94%) cases. The risk factors frequently associated with Fournier's gangrene are diabetes mellitus which is observed in 171 (59.37%), chronic alcoholism in 135 (46.87%), immunosuppression due to advanced malignancy 9 (3.12) and AIDS 5 (1.73%) and other unidentifiable risk factors in 44 (15.27%). Some patients have more than one risk factor like chronic alcoholism and diabetes mellitus 77 (26.73%). CONCLUSIONPatients with Fournier's gangrene are rarely treated at most hospitals because of lack of ICU facilities and unawareness of aetiopathogenesis. It is a very aggressive disease which needs prompt early diagnosis and aggressive management with broad spectrum antibiotics and thorough early debridement. Despite of aggressive management the mortality is still high.