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Purpose Age and etiology play a crucial role in success of endoscopic third ventriculostomy (ETV) as a treatment of obstructive hydrocephalus. Outcome is worse in infants, and controversies still exist whether ETV is superior to shunt placement. We retrospectively analyzed 70 patients below 2 years from 4 different centers treated with ETV and assessed success. Methods Children Results We collected 70 patients. ETV success rate was 41.4%. The highest rate was in tumor-related hydrocephalus and fourth ventricle outlet obstruction (62.5%, 60%) and the lowest rate was in Chiari-type II and following infection (16.7%, 0%). The below 3 months age group showed relatively lower success rate (33.3%) in comparison to older groups which showed similar results (46.4%, 46.6%). Statistically, a previous VP shunt was a predictor for failure (p value Conclusion Factors suggesting a high possibility of failure were age

Background: The study carried out to assess long-term outcomes of endoscopic third ventriculostomy (ETV) on less than two years of hydrocephalous children and to determine prognostic factors of ETV success in this population. Methods: our study was a retrospective cohort study carried out on 40 hydrocephalus children who underwent ETV surgery. Clinical data retrieved from patient’s medical records, and we did an active follow-up. We used Kaplan-Meier and life-table approaches to assess 6 months success rate of ETV. We also used multiple cox regression to determine prognostic factors associated with success. Moreover, the ROC curve analysis was used to assess how ETV success score (ETVSS) can predict the possibility of ETV failure. Results: The mean age of patients at surgery time was 7.8 (±7.8) months, and 60% were male. The mean failure time of ETV was 4.5 months, and the most common etiology was aqueduct (27.0%). According to our finding age at surgery time (hazard ratio [HR]=2.2, 95% CI=1.1, 3.4) and birth age (HR=4.4, 95% CI 1.1, 17.2) were the main factors associated with ETV failure. We also observed, statistically lower HR for patients with aqueduct etiology (HR=0.1, 95% CI=0.01, 0.9). Moreover, the area under the ROC curve was estimated at 76.1, illustrating partial validity to predict ETV failure in the study population. Conclusion: According to our findings, ETV could suggest treating Hydrocephaly in young kids with particular attention on over 6-month patients and those who were mature at birth. However, more studies are required to confirm our findings.

Purpose To evaluate the incidence and clinical importance of brain gliomas – optic pathway gliomas (OPGs) and especially gliomas outside the optic pathway (GOOP) for children with neurofibromatosis type 1 (NF1), additionally, to assess the causes of obstructive hydrocephalus in NF1 children with an emphasis on cases caused by idiopathic aqueduct stenosis. Subjects and methods We analysed data from 285 NF1 children followed up on our department from 1990 to 2010 by the same examination battery. Results We have found OPGs in 77/285 (27%) children and GOOPs in 29/285 (10,2%) of NF1 children, of who 19 had OPG and GOOP together, so the total number of brain glioma was 87/285 (30,5%). GOOPs were significantly more often treated than OPGs (p > 0.01). OPGs contain clinically important subgroup of 14/285 (4.9%) spreading to hypothalamus. Spontaneous regression was documented in 4/285 (1.4%) gliomas and the same number of NF1 children died due to gliomas. Obstructive hydrocephalus was found in 22/285 (7.7%) patients and 14/22 cases were due to glioma. Idiopathic aqueduct stenosis caused hydrocephalus in 6/22 cases and was found in 2.1% of NF1 children. Two had other cause. Conclusions The total brain glioma number (OPGs and only GOOPs together) better reflected the overall brain tumour risk for NF1 children. However, GOOPs occur less frequently than OPGs, they are more clinically relevant. The obstructive hydrocephalus was severe and featuring frequent complication, especially those with GOOP. Idiopathic aqueduct stenosis shows an unpredictable cause of hydrocephalus in comparison with glioma and is another reason for careful neurologic follow up.

We present the case of a patient with severe obstructive sleep apnoea (OSA) and hypoventilation syndrome who had hydrocephalus and acquired aqueduct stenosis. A link between these conditions in our patient is postulated. We discuss the mechanisms through which this might have occurred and the potential problems which might arise in applying non-invasive ventilation to a patient with hydrocephalus. LEARNING POINTS: Patients with severe obstructive sleep apnoea (OSA) and hypoventilation require AVAPS-AE ventilation to deal with obstructive and central events which may occur. Arterial blood gas analysis and MRI of the brain are indicated in the assessment of patients with severe OSA. Hydrocephalus may develop in patients with severe OSA if there is a structural brain abnormality but may resolve with OSA treatment.

Background and purpose To examine prenatal MRI and postnatal imaging in fetuses with congenital aqueductal stenosis (CAS) to determine the frequency of association of rhombencephalosynapsis (RES) and how it may affect neonatal intensive care unit (NICU) course. Materials and methods A single center IRB-approved retrospective study of children with CAS was performed. Prenatal MRI, postnatal images, and clinical data were reviewed. Statistical analysis was performed with SAS statistical software package version 9.3. Results Aqueduct obstruction was confirmed for all 30 participants. Hydrocephalus required shunting in all but one (97%). Fifteen neonates had CAS with rhomboencephalosynapsis (RES) (50%). Although neonatal course between the two groups was comparable, 53% of CAS with RES neonates required feeding assistance versus 20% in CAS only (P = 0.128). Shunting in the CAS with RES group occurred at average of 6 days of life versus CAS group at 55 days (P = 0.196). Biometry measurements showed a statistically significant decrease in pons antero-posterior diameter in both groups (CAS only P = 0.0049 and CAS with RES P = 0.0003) when compared with norms for gestational age. Conclusion CAS has a high association with RES. Feeding assistance in the NICU and earlier neurosurgical intervention may be required in patients with CAS who also have RES.

Background: In a small percentage of children born with congenital hydrocephalus, enlargement of the head and the presence of ventriculomegaly may halt and ultimately stabilize the condition designated as arrested hydrocephalus. Arrested hydrocephalus in children is typically due to congenital aqueduct stenosis, which can be described appropriately as a stasis existing within the channel between the third and fourth ventricles. Os odontoideum (OO) is an uncommonly occurring pathology at the craniovertebral junction. Although the clinical and radiologic features of its existence and the therapeutic options for its pathology have been widely discussed within the medical literature, its true etiology has been a source of divisive debate, proposing both a traumatic as well as a congenital mechanism. The etiology of OO has been heartily debated in the literature for several years as well. Most authors have come to support a posttraumatic causality. However, strong evidence exists to support a congenital origin to this rarely observed malformation. Methods: Within this case study we present a 24-year-old woman with atlantoaxial subluxation that exists secondary to an orthotropic OO. The patient had a history of arrested hydrocephalus due to congenital aqueductal stenosis beginning in early childhood. She presented with normal intelligence and was neurologically without deficits before the occurrence of an atlantoaxial dislocation. Unfortunately, the pathology was initially misdiagnosed as a decompensation state of the arrested hydrocephalus, and after 8 months the patient became wheelchair bound. Following this unfortunate event the correct diagnosis was ultimately uncovered. Subsequently a C2-1 instrumentation procedure resulted in excellent alignment and fusion. Conclusions: To the best of our knowledge, this is the first example of an aqueduct stenosis in the setting of an existing OO, a combination that might be another clue in favor of a congenital etiology.

Summary ‘Benign’ aqueduct stenosis is a common cause of hydrocephalus in the paediatric population and is frequently treated by endoscopic third ventriculostomy. Occasionally, aqueduct stenosis can be a prelude to the development of other pathology, as is seen in these two cases of pineal tumours developing in patients whose hydrocephalus was successfully treated with endoscopic third ventriculostomy. The case histories are presented, along with the recommendation for increased radiological screening of patients with this usually ‘benign’ presentation.

Tumours of the pineal region are uncommon. We report on a 62-year-old male presenting with Parinaud's syndrome and aqueduct stenosis caused by a cystic tumour in the pineal region. During surgery, adjacent to the cystic tumour, a second smaller tumour was identified, which was clearly separate from the first tumour and from the pineal gland. Histological examination disclosed the cystic tumour as an epidermoid cyst, whereas the second tumour demonstrated histological and immunohistochemical features of a pineocytoma. The unique finding of two different types of tumours in the pineal region is evaluated with regard to the histogenesis of epidermoid cysts and pineocytomas.

This study was designed with an aim to detect the congenital anomalies appear to be linked to and in conjunction with hydrocephalus fetuses in Sudan, when ultrasound is used to exam fetuses in the second and third trimesters of pregnancy. This prospective cohort study was performed from December 2011 to December 2013, in a group consists of 5000 single gestation pregnant Sudanese women. In all cases, maternal ages were 35 years up to 48 years; mean age of 42.5 years. Pelvic; obstetric ultrasound scanning protocol used should meet the standards established by the American Institute of Ultrasound in Medicine (AIUM) for scanning in the second and third trimesters of pregnancy. Statistical Package for the Social Sciences (SPSS) was used to analyze the results. Diagnosed hydrocephalus cases (0.4%) were found to be associated with other fetal anomalies as aqueduct stenosis (45%), spina bifida (30%), Arnold-Chiari malformation (20%) and Dandy-Walker malformation (5%). The incidence of congenital anomalies and hydrocephalus in Sudanese fetuses showed considerable variation among different regions of Sudan. Hydrocephalus is associated with certain congenital anomalies. In agreement with previous studies, hydrocephalus is predominantly in male rather than female fetuses. The prevalence of fetal anomalies and hydrocephalus are within previously reported ranges.

Objects: The most important function of the programmable valve (PV) is to limit the shunt-dependent flow of the cerebrospinal fluid by upgrading valve pressure. This activates the regular circulation of cerebrospinal fluid, which may make successful removal of the shunt possible once sufficient cerebral development has been achieved. The purpose of this paper is to indicate the possibility of shunt removal using the programmable Medos and Sophy valves (one programmable Sophy valve was specially designed for this situation). Methods: Prior to regular use of the PV, removal of existing shunt systems was attempted in 57 children, since some systems malfunctioned and others had abdominal tubes that were meanwhile too short as the children had grown as they became older. Shunt removal was successfully achieved in only 18 patients (32%). However, in patients in whom PV valves were used, shunt removal was successful in 68 out of 114 patients (57%). This shows that the success rate of shunt removal becomes significantly higher when PV valves are used. The 68 cases in which PV valves were used and shunt removal was successful were divided into three groups: A, B, and C. In group A (36 cases, 53%), the Medos valve was used for the initial PV shunt implantation and the pressure was gradually increased up to 200 mmH2O. The shunt systems were then withdrawn. Group B (29 cases, 43%) includes patients who experienced both the minor symptoms and ventricular enlargement attributable to increased valve pressure. The pressure was gradually upgraded by pumping several times and was maintained at close to 200 mmH2O. After 6–24 months' observation shunt removal was performed, and in 21 out of 29 cases the outcome was good. However, the remaining 8 patients (12%) still had symptoms and required shunt reinsertion. The specially designed Sophy valves were then used, which allowed the pressure to be set at above 200 mmH2O. The pressure was increased by degrees up to 400 mmH2O and kept at the same level for 6–24 months. The shunt systems were then removed successfully. Although a high pressure setting was required over a sustained period, a total of 29 patients (43%) were able to have their shunts removed. In group C (3 cases, 4%), which included patients with aqueduct stenosis, the pressure was raised and thus allowed ventricle enlargement. Third ventriculostomy was performed under neuroendoscopy with the shunt pressure maintained at a high level. Shunt systems were removed successfully. Conclusions: This study showed that it is possible to remove the shunt systems in 50% or more of pediatric hydrocephalus cases in which PV valves are used. This is achieved through careful control of the valve pressure. Close observation is essential during the period when the PV pressure is maintained at a high level, as well as 6–12 months after shunt removal.

Chronic hydrocephalus, most commonly the result of aqueduct stenosis, is associated with both primary and secondary amenorrhea. Only six cases of secondary amenorrhea have been reported to date. We describe a women with cystic fibrosis who presented with secondary amenorrhea as a consequence of Chiari-I malformation and resultant hydrocephalus. The biochemical picture was characterized by hypogonadotropic hypogonadism. Resolution of the amenorrhea was observed to occur following 3rd ventriculostomy.

Thunderclap headache is well known to be a presenting feature of a variety of causal events. Indeed, a primary form is considered in the International Classification of Headache Disorders-II, but such diagnosis must be made only after exclusion of a possible secondary cause. We report a case of late-onset idiopathic aqueductal stenosis presenting with thunderclap headache, in the absence of abnormal neurological findings or indirect signs of raised intracranial pressure. The patient recovered completely after endoscopic third ventriculostomy. This case indicates primary aqueduct stenosis as a possible, never previously reported, cause of thunderclap headache.

We report on two abortuses with hydrocephalus due to congenital stenosis of the aqueduct of Silvius. The occurrence of this disorder in two siblings (a male and a female) with normal parents supports the autosomal recessive pattern of inheritance. Such a mechanism of inheritance should be taken into account when counselling families with congenital hydrocephaly due to aqueduct stenosis.

The purpose of this study is to evaluate the changing epidemiology of paediatric hydrocephalus over the past three decades in a single institution. All children treated for newly diagnosed hydrocephalus during the 1985–1990 (group A) and the 2000–2005 periods (group B) were enrolled and classified according to the associated cause of hydrocephalus. A significant 8.8% decrease of the incidence of hydrocephalus was noticed between the two time periods, resulting from the reduction of hydrocephalus associated to myelomeningocele, aqueduct stenosis (p = 0.04), CNS infection (p = 0.03), cranio-cerebral malformation and head injuries; post-haemorrhagic hydrocephalus remained stable, while the tumour-associated one increased (p

In the 14-year period from 1974-1987 during which CT scanning was available in Edinburgh, 36 patients with benign, non-tumour related aqueduct stenosis were identified from a group of 342 patients with hydrocephalus. In terms of age at presentation, the patients separate into two groups, 9 cases diagnosed during the first year of life and 27 patients aged from 7 to 72 years. The presentation in the early cases was fairly acute, the diagnosis was secure and the operative treatment by ventricular peritoneal shunt was relatively free of complications. In the older patients, the first presentation was more chronic, and further investigation required a change of diagnosis in 5 of the 27 patients. More than half of the patients had recurrent symptoms which were much more acute and operative treatment was attended by a significant number of complications including death from intraventricular haemorrhage in one case.

In Sweden, the annual incidence of surgery for hydrocephalus was 3.4 per 100,000 adults between the years 1996 and 1998. The most common indication for surgery was normal pressure hydrocephalus (NPH; 47%), followed by high-pressure hydrocephalus (27%). Seventy-three percent of the patients had communicating hydrocephalus, of which 63% had NPH. Twenty percent of the patients had non-communicating hydrocephalus, of which half resulted from aqueduct stenosis. The annual incidence of operations varied between regional clinics from 2.3 to 6.3 per 100,000 inhabitants.

A dog with hydrocephalus as a result of aqueduct stenosis and cerebellar herniation underwent ventriculoperitoneal shunting. Magnetic resonance images and computed tomography scans taken after the surgery revealed subdural accumulations of haemorrhagic fluid and cereberocortical collapse caused by overshunting and leakage of cerebrospinal fluid from the site of insertion of the shunt. However, the degree of cerebellar herniation was reduced after the shunt was inserted, and the dog did not develop any neurological signs and made good progress.

The beneficial effects of stereotactic third ventriculostomy versus ventriculoperitoneal shunt were evaluated in 62 paediatric patients and analysed in relation to age, sex, clinical history, presence of meningomyelocele, magnetic resonance imaging measurements of hydrocephalus and third ventricle floor size. The third ventriculostomy were done on 50 patients using the Richard-Wolf® Caemaert Endoscope and the Leksell Stereotactic Frame Model G. These patients were operated using the 4-French Fogarthy catheter to open the base of the third ventricle. During the same period of study 12 paediatric patients with aqueduct stenosis who were managed by ventriculoperitoneal shunt were included. Both surgical procedures were compared. Statistically univariate analysis revealed that those patient with an age group of more than six months undergoing ventriculostomy had good outcome. Multivariate analysis revealed that past history of haemorrhage and/or meningitis were predictors of poor outcome. Sex, size of lumbar meningocele at birth, abnormal ventricular anatomy or narrow third ventricular floor size were non predictors of bad outcome in these patients. There was no difference in outcome in both the shunt or ventriculostomy group.

In contrast to shunt operation the indication for an endoscopic ventriculostomy in patients diagnosed for normal pressure hydrocephalus is not scientifically established. From September 1997 to March 1999 we operated on 36 patients diagnosed for normal pressure hydrocephalus. Diagnosis was established by means of the intrathecal lumbar or ventricular infusion test, the cerebrospinal fluid tap test and MRI-CSF flow studies pre- and post-operatively. In 30 patients (83%) we implanted a ventriculo-peritoneal shunt, and in 6 patients (17%) we performed the endoscopic assisted third ventriculostomy. With our created NPH recovery rate and use of the clinical grading for normal pressure hydrocephalus created by Kiefer and Steudel we compared the operative results of both patient groups. In patients with a pathologically increased resistance to CSF outflow in the lumbar infusion test a shunt implantation is indicated. Patients whose outflow resistance is increased in the ventricular infusion test but with a physiological lumbar infusion test are suspected for a functional aqueduct stenosis and should be treated by means of an endoscopic assisted ventriculostomy.

Genetic counselling in families with congenital hydrocephalus internus (CHI) in combination with aqueduct stenosis (AS) is often difficult due to an uncertain aetiology. We present a series of 35 patients with CHI and AS focusing on the aetiology and presumed recurrence risk for siblings. In 13 patients (37.1%) a genetic aetiology was identified with an increased recurrence risk for siblings. The relative frequency of patients with X-linked hydrocephalus in our sample was in accordance with the literature (2/35), but was more frequent in other diseases with Mendelian inheritance. Conclusion In addition to the well-known X-linked and autosomal recessive forms of aqueduct stenosis with hydrocephalus, this malformation can occur in other diseases with Mendelian inheritance. This finding is of considerable importance for genetic counselling and prognosis.

A kindred is reported on with suspected autosomal dominant congenital hydrocephalus and aqueduct stenosis. In contrast to patients with X-linked congenital hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS) our patients were not mentally retarded and they did not show any pyramidal tract dysfunction or clasped thumbs; the pyramids were not affected either, as was confirmed by autopsy, CT or MRI. Molecular genetic studies in our patients have not revealed abnormalities of eight exons of the L1 neural adhesion molecule gene that is related to HSAS.

In two adults, both schizophrenia and hydrocephalus were associated with aqueduct stenosis. The prevalence is argued to be above chance, and may contribute to the neurodevelopmental hypothesis of the causality of schizophrenia.

Various ways in which blockage of cerebrospinal fluid pathways can lead to increasing intracranial pressure and enlargement of the ventricles are discussed. The necessity of understanding the valvular morphology involved is stressed as fundamental to the search for optimal treatment methods.

X-linked aqueductal stenosis is a recessive X-linked syndrome (HC-MR) characterized by hydrocephalus (HC), mental retardation (MR) and clasped thumbs (Mc Kusick 39700). The different symptoms are not always present and a large inter- and intrafamilial variability exists.

A 52-year-old woman who had been apprehended for shoplifting was found to have normal-pressure hydrocephalus due to aqueduct stenosis. We ascribe the shoplifting to impairment of social judgment, which was one of the observed fea tures of a dementia. Cerebrospinal fluid diversion by means of a ventriculo-peritoneal shunt resulted in resolution of her symptoms. ( J Geriatr Psychiatry Neurol 1990;3:229-230).

We report a case of tension pneumocephalus following the insertion of a ventriculoperitoneal shunt for hydrocephalus secondary to aqueduct stenosis and discuss the possible genesis of the complication, diagnosis and treatment.

Four cases are described in which visual field defects followed enlargement of the third ventricle. Three were due to aqueduct stenosis while in one case a left cerebellar hemisphere tumour was discovered. The visual field defects comprised a unilateral scotoma, bilateral scotomata and, in two patients, incongruous bitemporal hemianopia.

6 dogs were anesthetized and a silver clip attached to a cotton plug as surgically placed in the aqueduct of Sylvius. An immediate postoperative lateral skull film was obtained to demonstrate the position of the clip. The animals developed signs of hydrocephalus within hours after the procedure. 2 weeks after placement of the aqueduct plug, the animals received a permanent ventriculostomy. Immediate pre- and postoperative ventriculostomy lateral skull films were taken again to indicate position of the silver clip. Finally, a lateral skull film was taken 2 weeks after ventriculostomy and just prior to sacrifice. Radiological techniques were standardized. In this experimental setting downward brain stem herniation predominated and upward herniation of the brain stem was an infrequent occurrence.

Cerebrospinal fluid rhinorrhea and intraventricular pneumocephalus occurred in an adolescent with aqueduct stenosis whose ventriculoperitoneal shunt occluded repeatedly due to a faulty on-off control. The possible mechanisms are discussed, the urgency of treatment is stressed, and the risk of pneumocephalus when a shunt is used to treat cerebrospinal fluid rhinorrhea is pointed out.

Stenosis of the aqueduct of Sylvius accounts for about one third of cases of congenital hydrocephalus. At least 32 families have been reported in which the aqueduct stenosis is inherited in an X linked fashion. In half of these families, flexed adducted thumbs were noted in some affected family members. Occasionally other male members were mentally retarded, suggesting limited expression of the gene. The problem of giving genetic advice to an isolated, clinically unremarkable, case of aqueduct stenosis remains, so a family study was undertaken based on 24 such cases seen at The Hospital for Sick Children over a 19-year period. There were 15 male and nine female index patients. The diagnosis was confirmed in all cases by air encephalogram. One boy had a radial club hand and another developed clasped thumbs secondary to spasticity. No cases had hyaloidoretinal dysplasia. The 15 boys had 18 brothers and 19 sisters, of whom one sister was similarly affected. The nine girls had 12 sibs, none of whom was affected. This study, combined with a similar study in the USA, suggests that the empirical risk of recurrence of a sporadic case of aqueduct stenosis is about 4.5%.

Three patients with hydrocephalus and aqueduct stenosis are described, who also have schizophrenia defined according to strict diagnostic criteria. There are no previous reports of such an association.

Eighteen infants and children with typical congenital hydranencephaly were studied by pneumoencephalography, water-soluble contrast ventriculography, and cisternography (radioisotope or metrizamide). Pneumoencephalography and ventriculography suggested that the aqueduct was obstructed or markedly stenotic in all cases. Cisternography demonstrated blocks at the aqueduct and at the level of the basal-ambient cisterns in most cases. These findings support the concept that aqueduct stenosis is an important factor in the hydrocephalic process of hydranencephaly.

A 35-day-old hydrocephalic infant was found by autopsy to have a small nodular mass protruding into the aqueductal channel. The mass, approximately 2.5 mm in size along the neuroaxis and 1.9 mm in transverse plane, subependymally occupied the roof of the aqueduct. This was thought to be the cause of hydrocephalus in this infant. A review of literature on the subject has not shown any other comparable case.

Summary Nine cases of expansive infantile hydro-cephalus were investigated by injecting Small amounts of I131-Diodrast intra-ventricularly. Urinary excretion of the tracer was determined during the first 4-5 hours after injection. The cumulative excretion of Diodrast from the C.S.F. differs in cases with communicating hydrocephalus from those with stenosis of the aqueduct. The investigation is rapid and easily performed and has not produced any side effects.

Summary Three cases are reported of aqueduct stenosis associated with cystic dilatation of the suprapineal recess. The diagnosis and possible effects of this lesion are briefly discussed.

SUMMARY:Trigeminal neuralgia was the presenting symptom in two patients with aqueduct stenosis, hydrocephalus, and raised intracranial pressure. Treatment of the hydrocephalus resulted in the remission of pain in both patients.

The expansion of the suprapineal recess which occurs in aqueduct stenosis receives only passing mention in most radiological discussions of the subject (Davidoff and Epstein, 1950; Schechter and Zingesser, 1967; Taveras and Wood, 1964). Three cases have been reported at length (Lavender and DuBoulay, 1965), mainly for the ventriculographic interest. This report points up the local effect of the distended suprapineal recess, the resulting specific symptom of vertical ocular paresis, not hitherto associated with aqueduct stenosis, and the ventriculographic features. Clinical features. A nine-year-old girl was admitted because of headache, vomiting and clumsiness of movements. During severe measles at the age of five years, and again during mumps at the age of six, “encephalitic” manifestations had been noted. In the past year she had complained of headaches while, in recent months, clumsiness of movements, culminating in insecure gait in the last week had become evident. Two days before admission, she first...

The phenomenon of a congenital cystic dilatation of the fourth ventricle, recognised at the end of the 19th century, is a well-defined morphological and clinical entity known as the Dandy-Walker syndrome. The progress of neuroradiological diagnosis and neurosurgical treatment of hydrocephalus and tumours of the posterior fossa led to the recognition of a secondary, non-congenital dilatation of the fourth ventricle as a specific clinical syndrome, frequently associated with signs of a posterior fossa mass. This was first called the ‘Post-operative Dandy-Walker syndrome’ [13, 19], ‘double compartment hydrocephalus’ [3], ‘cystic transformation of the fourth ventricle’ or ‘trapped fourth ventricle’ [26]. The term ‘isolated fourth ventricle’, introduced by Hawkins [8] allows a precise definition, as it is used by Scotti et al. [20].

Ventriculo-cisternostomy, introduced by TORKILDSEN in 1939 (8) for the treatment of occlusive hydrocephalus, has been used as a final treatment in patients with nontumorous occlusive hydrocephalus and as a palliative operation in cases with surgically inaccessible deep-seated tumors producing occlusion of CSF pathways within the ventricular system. Since the introduction of ventriculo-atrial and ventriculo-peritoneal shunts, particularly since the beginning of the 1960’s, the number of Torkildsen operations performed in neurosurgical centers has diminished and some neurosurgeons have almost completely abandoned the procedure. Major reviews dealing with indications and results were reported by GERLACH, who analysed 931 patients operated on in the Departments of Neurosurgery in Germany till 1960 (1), GROSCHEL and MARGUTH, who reported on 155 patients operated on between 1951 and 1959 (2), and LANG and P1A (3). Complications of the procedure were reviewed by LORENZ in 1963 (4).

Seven litters and 17 near-term rats of mothers treated with teratogens during gestation were analyzed for concordance and discordance of congenital malformations of the central nervous system. In animals with spina bifida a firm association with Arnold-Chiari malformation was found but only in fetuses near term. Associations with aqueduct stenosis and hydrocephalus were poor. In general, the findings support the theory that the components of the spina bifida complex develop from a common teratogenic disturbance but independent from each other.

Hydrocephalus with aqueduct stenosis was a consistent feature in mice which received a single intraperitoneal injection of 6-aminonicotinamide (6-AN) on day 5 postnatal. Chronological investigation revealed that 6-AN-treated mice had aqueductal obstruction with edematously swollen ependymal cells and spongy changes in the periaqueductal gray matter in the early stage (on days 5 and 7 postinjection). However, these cytoplasmic edema of the ependymal and glial cells totally subsided by day 30 postinjection, leaving an obliterated aqueduct with a few remnants of ependymal cells without reactive gliosis. This abnormality of aqueductal lesions in the chronic stage was similar to those of human congenital hydrocephalus. These findings raise the possibility that some form of human congenital hydrocephalus may result from ependymal cell degeneration due to exposure to certain noxious substances in the perinatal period.

The case histories of five adult patients with hydrocephalus and aqueduct stenosis are presented. All the cases were associated with prominent psychotic symptoms (delusions, hallucinations or thought disorder). In the three cases where operative intervention was carried out the diagnosis was made in adult life. Using the Present State Examination all five cases were classified as having schizophrenic psychosis. The possible reasons for this association are discussed.

The contribution of plain X-rays to the management of 170 patients suspected or actually found to have posterior fossa disease has been retrospectively assessed. A useful contribution was made in 4%.