Long-standing overt ventriculomegaly in adulthood with primary presentation of psychiatric disturbance: A case report

RATIONALE

Hydrocephalus is a common disease in neurosurgery. The typical symptoms of hydrocephalus include urinary incontinence, gait instability, and cognitive decline. Irritability rarely occurs in patients with hydrocephalus. Irritability rarely occurs in patients with hydrocephalus, especially in long-standing overt ventriculomegaly of adulthood (LOVA).

PATIENT CONCERNS

A 30-year-old female was admitted to our hospital because of mental retardation and unstable gait for more than 15 years. She had undergone ventriculoperitoneal shunt 15 years prior due to ventriculomegaly and related symptoms. However, the shunt catheter was removed shortly after surgery because of blockage, with no further postoperative treatment.

DIAGNOSIS

The patient was diagnosed with long-standing overt ventriculomegaly according to her head circumference and clinical symptoms, including adult hydrocephalus development, overt triventriculomegaly and absence of a secondary cause for aqueductal stenosis in adulthood.

INTERVENTIONS

After considerable discussion, she underwent ventriculoperitoneal shunt placement and showed dramatic and sustained improvement.

OUTCOMES

The patient has been followed at 3-month intervals for over 2 years since discharge, and both the patient and family have reported a significant change in their daily life. She was able to live independently and control her emotions. Slight epilepsy was noted approximately 5 months after surgery but recovered 2 months later.

LESSONS

It is difficult to decide whether to treat LOVA when the in patients whose symptoms are not significant. We believe that early diagnosis and positive treatment can help improve outcomes and would recommend ventriculoperitoneal (VP) shunting in patients with LOVA.

Ventriculo-peritoneal shunt surgery in an infant with double aortic arch, patent ductus arteriosus and atrial septal defect

Double aortic arch with patent ductus arteriosus and atrial septal defect is an uncommon association. Such complex cardiac lesions may complicate an otherwise normal anesthetic course. We came across a case with aqueductal stenosis and hydrocephalus, scheduled for ventriculo-peritoneal shunt surgery, on an emergent basis. The child was managed successfully. The anesthetic implications of resultant left-to-right shunt with increased intracranial pressure have been described.

Diagnostik sylvischer und perisylvischer Epilepsien

The insula is a hidden part in the cerebral cortex about which relatively little neurological research has been done. The present manuscript describes architectural and evolutionary aspects of the insula reilii as well as its function, towards a better understanding of seizure semiology. As the literature of such casuistry is poor, some own cases are presented. Seizure semiology, imaging, magnetoencephalographic reports, resective epilepsy surgery, radiosurgical treatments, and thermolesions are described. Magnetic source imaging as noninvasive treatment can deliver important information for the involvement of sylvian and perisylvian regions in focal pharmacoresistant epilepsies.

Neuroendoscopic management of a solitary pineal region tumor. Case report of an adenocarcinoma metastasis

The present case describes a two-step endoscopic management of hydrocephalus and diagnosis of a single pineal region metastasis arising from a gastric adenocarcinoma. A 62-year-old man presenting with signs of subacute obstructive hydrocephalus from a pineal region mass had at first been treated with an endoscopic third ventriculostomy. As cerebrospinal fluid tumor markers (alpha-fetoprotein, beta-human chorionic gonadotropin) were negative, an endoscopic biopsy of the pineal region tumor was performed through a more anterior frontal burr hole. Pathology showed an adenocarcinoma and primary tumor work-up revealed an unsuspected gastric tumor, the pathology of which matched with the intracranial metastasis. The present report emphasizes the role of neuroendoscopy in pineal region tumors and reports a rare case of a solitary gastric adenocarcinoma metastasis in this location.

Abnormalities of CSF flow patterns in the cerebral aqueduct in treatment-resistant late-life depression: a potential biomarker of microvascular angiopathy

There is growing evidence that microvascular angiopathy (MVA) plays an important role in the development of dementia and affective disorders in older people. At currently available image resolutions it is not possible to image directly the vascular changes associated with MVA, but the effects on blood and cerebrospinal fluid (CSF) flow may be detectable. The aim of this study was to investigate a potential biomarker for MVA based on MRI of abnormalities in CSF flow. Since there is considerable indirect evidence that treatment resistance in late-onset depressive disorder is related to MVA, we assessed the method in a group of 22 normal volunteers and 29 patients with responsive (N=21) or treatment-resistant (N=8) late-onset depressive disorder. Single-slice quantified phase-contrast (PC) images of cerebral blood and CSF flow were collected at 15 points over a cardiac cycle, and the resulting flow curves were parameterized. Significant differences in the CSF flow (width of systolic flow peak and diastolic flow volume, both P<0.01) through the cerebral aqueduct were observed for the group of treatment-resistant patients when compared to age matched controls. No significant difference was observed for a group of 21 patients with treatment-responsive depression. The findings support the hypothesis that MR measurement of CSF flow abnormalities provides a biomarker of MVA, and thus could have application in a wide range of age-related diseases.

Effect of non-linear permeability in a spherically symmetric model of hydrocephalus

We examine a spherically symmetric model of the brain and apply non-linear permeability in a small strain poroelastic framework. Numerical solutions to the model show that non-linear effects tend to improve predictions of ventricle wall displacement and pressure increase in acute hydrocephalus in comparison with a constant permeability model. Our model is used to study different mechanisms for hydrocephalus: complete blockage of the aqueduct and normal pressure hydrocephalus (NPH), as well as offering observations on mechanical effects in idiopathic intracranial hypertension. In each situation it is possible to apply different parameter conditions to quantify mechanical effects that correspond to some observed symptoms. The results support and quantify ideas from Levine (2000, Ventricle size in pseudotumor cerebri and the theory of impaired CSF absorption. J. Neurol. Sci., 177, 85-94) on a poroelastic mechanism for some features of NPH and idiopathic intracranial hypertension.

An axisymmetric and fully 3D poroelastic model for the evolution of hydrocephalus

We formulate in general terms the equations for axisymmetric and fully 3D models of a hydrocephalic brain. The model is developed using small strain poroelasticity that includes non-linear permeability. The axisymmetric model is solved for four ventricle shapes, an ellipsoid, a 'peanut' shape, a 'cross' shape and a 'bone' shape. The distribution of fluid pressure, velocity and content in the deformed parenchyma for a blocked aqueduct provides new qualitative insight into hydrocepahlus. Some observations are offered for two forms of cerebrospinal fluid flow abnormality, normal pressure hydrocephalus and idiopathic intracranial hypertension. The model is extended to include a gravitational term in the governing equations and the effect of hydrostatic pressure variation is considered. Results of a fully 3D simulations are described for two horn-like lateral ventricles and one case with two lateral ventricles and a third ventricle.

Two-stage treatment of a tectal ganglioglioma: Endoscopic third ventriculostomy followed by surgical resection

Tumours of the quadrigeminal plate in adults are usually benign. Nevertheless, obstructive hydrocephalus due to compression of the Sylvian aqueduct is an almost invariable early finding. Whether or not direct excision is undertaken, temporary or permanent treatment of the hydrocephalus is warranted. Endoscopic third ventriculostomy is an alternative to insertion of a shunt and provides both acute and long-term relief of hydrocephalus-related symptoms. We chose a two-stage approach for treating a tectal ganglioglioma in an adult: endoscopic third ventriculostomy followed by surgical excision. The advantages and disadvantages of each therapeutic strategy are discussed.

Delayed pneumocephalus following shunting for hydrocephalus

Delayed pneumocephalus is a rare but well-reported complication of cerebrospinal fluid diversion procedures. In most cases the air enters the intracranial cavity via a skull base defect. We report a case of hydrocephalus secondary to aqueduct stenosis. The patient developed pneumocephalus 2 months after successful placement of a ventriculoperitoneal shunt. We describe an attempt at endoscopic diagnosis and repair of the fistula. This was unsuccessful, presumably because the defect was too small to localize even with the use of intrathecal fluorescein. We subsequently performed a conventional craniotomy and anterior fossa repair with placement of an antisiphon device. We suggest that in certain cases, when patients present with long-standing hydrocephalus, it may be advisable to insert either a high-pressure valve or antisiphon device as a primary measure.

Outcome Prediction of Third Ventriculostomy: A Proposed Hydrocephalus Grading System

An important factor in making a recommendation for different treatment modalities in hydrocephalus patients (VP shunt versus endoscopic third ventriculostomy) is the definition of the underlying pathology which determines the prognosis/outcome of the surgical procedure. Third ventriculostomies (3rd VS) are successful mainly in obstructive hydrocephalus but also in some subtypes of communicating hydrocephalus. A simple, easily applicable grading system that is designed to predict the outcome of 3rd VS is proposed. The hydrocephalus is graded on the basis of the extent of downward bulging of the floor of the third ventricle, which reflects the pressure gradient between the 3rd ventricle and the basal cisterns, presence of directly visualised CSF pathway obstruction in MRI, and the progression of the clinical symptoms resulting in five different grades. In this proposed grading system, grade 1 hydrocephalus subtype shows no downward bulged floor of the 3rd ventricle, no obstruction of the CSF pathway, and no progressive symptoms of hydrocephalus. There is no indication for 3rd VS. Grades 2 to 4 show different combinations of the described parameters. Grade 5 subtype shows a markedly downward bulged floor of the 3rd ventricle and direct detection of the CSF pathway obstruction (i.e., aqueductal stenosis) with progressive clinical deterioration. Retrospective application of this grading scheme to a series of 72 3rd VS has demonstrated a high correlation with the outcome: The success rate in grade 3 reached 40%, in grade 4: 58%, and in grade 5: 95%. This standardised grading system predicts the outcome of 3rd VS and helps in decision making for 3rd VS versus VP shunting.

Amplitude and phase of cerebrospinal fluid pulsations: experimental studies and review of the literature

OBJECT

A recently developed model of communicating hydrocephalus suggests that ventricular dilation may be related to the redistribution of pulsations in the cranium from the subarachnoid spaces (SASs) into the ventricles. Based on this model, the authors have developed a method for analyzing flow pulsatility in the brain by using the ratio of aqueductal to cervical subarachnoid stroke volume and the phase of cerebrospinal fluid (CSF) flow, which is obtained at multiple locations throughout the cranium, relative to the phase of arterial flow.

METHODS

Flow data were collected in a group of 15 healthy volunteers by using a series of images acquired with cardiac-gated, phase-contrast magnetic resonance imaging. The stroke volume ratio was 5.1 +/- 1.8% (mean +/- standard deviation). The phase lag in the aqueduct was -52.5 +/-16.5 degrees and the phase lag in the prepontine cistern was -22.1 +/- 8.2 degrees. The flow phase at the level of C-2 was -5.1 +/- 10.5 degrees, which was consistent with flow synchronous with the arterial pulse. The subarachnoid phase lag ventral to the pons was shown to decrease progressively to zero at the craniocervical junction. Flow in the posterior cervical SAS preceded the anterior space flow.

CONCLUSIONS

Under normal conditions, pulsatile ventricular CSF flow is a small fraction of the net pulsatile CSF flow in the cranium. A thorough review of the literature supports the view that modified intracranial compliance can lead to redistribution of pulsations and increased intraventricular pulsations. The phase of CSF flow may also reflect the local and global compliance of the brain.

A rare but life-threatening complication of ventriculo-atrial shunt

Insertion of ventriculoperitoneal and ventriculoatrial shunts is routinely performed. Infarction pneumonia and atrial thrombus formation are described as very rare complications of ventriculoatrial shunts. We present the case of a female patient with ventriculoatrial shunt insertion as long term treatment for aequeductal stenosis who presented with recurrent episodes of dyspnoea, chest pain, and unilateral pleural effusion. Diagnostic evaluation revealed a positive D-dimer test, bilateral basal infiltrates and pleural effusion. Transesophageal echocardiography established the diagnosis of a thrombus in the right atrium. Laboratory testing for thrombophilia revealed a homozygous factor V Leiden mutation. In the following, a shunt revision was performed.

Retrospective analysis of 400 neuroendoscopic interventions: the Hungarian experience

Object

The authors present the results of 400 consecutive neuroendoscopic interventions performed by a single surgeon in 373 patients during the last 8 years.

Methods

The study is based on a retrospective analysis of a continuously updated electronic database that includes patient history and radiological files. The success rate of the interventions is calculated.

Conclusions

The underlying pathological condition was hydrocephalus of various origins. The success rate within patient groups is given and the factors leading to successful surgery are emphasized. Recommendations on indications for neuroendoscopic operations are discussed.

Functional analysis of third ventriculostomy patency by quantification of CSF stroke volume by using cine phase-contrast MR imaging

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is increasingly used as alternative treatment for obstructive hydrocephalus. The aim of this study was to determine the utility of quantitative and qualitative examinations with cine phase-contrast MR imaging to determine the efficacy of ventriculostomy across time and whether CSF pulsation is restored after ETV.

METHODS

Thirty-eight patients treated with ETV were evaluated with cine phase-contrast MR within 1 month after surgery. Follow-up studies were performed after 1 year in 25 patients and after 2 years in 12. We evaluated flow void changes in the floor of the third ventricle and quantified the stroke volume at the site of the ventriculostomy. We also recorded changes in ventricular size and clinical outcome. To determine the restoration of CSF pulsation, we compared the CSF waveform at the ventriculostomy with the CSF waveform at the aqueduct in a healthy control group.

RESULTS

After ventriculostomy, restoration of pulsate motion characteristics of CSF circulation was observed. The stroke volume registered at ventriculostomy was maintained with time. There was a statistically significant relationship between clinical outcome and stroke volume. Overall flow magnitude was the most effective variable to determine which patients would improve after surgery. Values >75 mm3 showed a sensitivity of 76.7% and a specificity of 87.5% There was no relationship between ventricular size changes and clinical outcome. Patients with primary aqueduct stenosis had the best response to surgery, whereas patients with Arnold Chiari malformation or communicating hydrocephalus had the worst response.

CONCLUSION

Quantitative analysis with phase-contrast MR imaging indicates that ETV is an efficient technique for restoring CSF pulsation, with efficacy being maintained during the follow-up controls. Quantification of stroke volume at ventriculostomy is a good indicator of the functional status of ETV, and a high stroke volume in the ventriculostomy appears to be a positive predictor of favorable clinical outcome.

The use of an adjustable valve to treat over-drainage of a cyst-peritoneal shunt in a child with a large sylvian fissure arachnoid cyst

INTRODUCTION

The cyst-peritoneal shunt is a recognised surgical alternative in the management of sylvian fissure arachnoid cysts. Shunt overdrainage is well described in literature on ventriculo-peritoneal shunts, but not often appreciated as a complication of cysto-peritoneal shunts.

CASE REPORT

A 5-year-old boy presented with a symptomatic left sylvian fissure arachnoid cyst. This was initially treated by craniotomy and membrane fenestration in the carotid cistern. Recurrence led to insertion of a valveless cyst-peritoneal shunt 5 months later. Initial progress was followed by persistent headaches 18 months after shunt insertion. CT scan revealed a significant reduction in the cyst size, enlargement of the ipsilateral lateral ventricle, collapse of the contra-lateral ventricle and midline shift towards the side of the shunt. These findings were interpreted as over-drainage of the cyst-peritoneal shunt.

RESULT

A Codman Medos adjustable valve was inserted, with the intention of gradually increasing the pressure until the midline shift was restored and the contra-lateral ventricle was reconstituted. This was achieved with the valve set at 90 mm H(2)O, verified by CT scan. Radiological improvement was associated with dramatic symptomatic improvement.

CONCLUSION

Over-drainage of cyst-peritoneal shunts is often not appreciated, especially when the main manifestation is headaches. As it is difficult to predict the required valve pressure setting, it may be advisable to consider the use of an adjustable valve.

National and regional incidence of surgery for adult hydrocephalus in Sweden

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.

The pathophysiology of the aqueduct stroke volume in normal pressure hydrocephalus: can co-morbidity with other forms of dementia be excluded?

Variable results are obtained from the treatment of normal pressure hydrocephalus (NPH) by shunt insertion. There is a high correlation between NPH and the pathology of Alzheimer's disease (AD) on brain biopsy. There is an overlap between AD and vascular dementia (VaD), suggesting that a correlation exists between NPH and other forms of dementia. This study seeks to (1) understand the physiological factors behind, and (2) define the ability of, the aqueduct stroke volume to exclude dementia co-morbidity. Twenty-four patients from a dementia clinic were classified as having either early AD or VaD on the basis of clinical features, Hachinski score and neuropsychological testing. They were compared with 16 subjects with classical clinical findings of NPH and 12 aged-matched non-cognitively impaired subjects. MRI flow quantification was used to measure aqueduct stroke volume and arterial pulse volume. An arterio-cerebral compliance ratio was calculated from the two volumes in each patient. The aqueduct stroke volume was elevated in all three forms of dementia, with no significant difference noted between the groups. The arterial pulse volume was elevated by 24% in VaD and reduced by 35% in NPH, compared to normal (P = 0.05 and P = 0.002, respectively), and was normal in AD. There was a spectrum of relative compliance with normal compliance in VaD and reduced compliance in AD and NPH. The aqueduct stroke volume depends on the arterial pulse volume and the relative compliance between the arterial tree and brain. The aqueduct stroke volume cannot exclude significant co-morbidity in NPH.

CSF shunt removal in children with hydrocephalus

The possibility to remove a previously inserted CSF shunt device in hydrocephalic children is a well known though rare event for paediatric neurosurgeons. A retrospective analysis of our experience with a series of 850 children affected by non tumoral hydrocephalus shows that obvious shunt independence could be demonstrated in 3.2% of the patients (27 cases). The time interval between the CSF shunt insertion and removal ranged between 8 months and 12 years (mean: 8 years). Parameters analysed to search for any predictive elements were age at surgery, aetiology, type of prosthesis utilised, time interval between insertion and removal of the shunt, number of the possible revisions. The results of the study suggest that the highest incidence of shunt independence is reached in subjects operated on in early infancy, as 24 of 27 removed shunts were in patients operated on under 6 months of age, and the remaining in 2 children treated when less than 2 years old. Such a finding could be explained on the grounds of a delay in maturation of the CSF absorption mechanisms followed by a late normalisation in these patients. As regards to aetiology, 41% of the 27 patients considered in this series were affected by a post-haemorrhagic hydrocephalus, which was progressive, as demonstrated by serial neuroradiological examinations and echo-Doppler cerebral studies at the time of the surgical treatment. In six children the hydrocephalus was associated with myelomeningocele. Five patients had aqueduct stenosis and 2 communicating hydrocephalus. The types of CSF shunting system we utilised did not play any role in determining or facilitating shunt independence. No correlation was observed with the need and the number of shunt revisions. The role of the interval time between the insertion and the removal of the shunt was not analysable, because of the possible acquisition of the shunt independence prior to its demonstration at the moment of the surgical revision of the CSF shunt (elective lengthening because of the physiological body growth) or to the radiological demonstration of CSF shunt device disconnection. The same constraint prevents the evaluation of the actual overall incidence of shunt independence in shunted hydrocephalic children, as some of them could have harboured a non-functioning CSF shunt device, though unnoticed.

Endoscopic aqueductoplasty in the treatment of aqueductal stenosis

OBJECTIVE

Endoscopic aqueductoplasty is an option in the treatment of obstructive hydrocephalus caused by aqueductal stenoses. We report on our experience with this endoscopic technique, focussing on indications, operative technique, and results.

METHODS

A series of 39 endoscopic aqueductoplasties was performed in 33 patients harbouring a hydrocephalus caused by aqueductal stenosis. In 13 patients, a third ventriculostomy was simultaneously performed. There was no endoscopy-related mortality. One aqueductoplasty had to be abandoned. In 7 patients, reclosure of the restored aqueduct required an endoscopic revision. In 25 patients (76%), the hydrocephalus-related symptoms resolved or improved. The condition was unchanged in 8 patients. Four patients needed to be shunted. The ventricles decreased in size in 22 patients (67%), were larger in 2, and unchanged in the remaining 9 patients.

CONCLUSION

Endoscopic aqueductoplasty is a treatment option in patients with hydrocephalus caused by membranous aqueductal stenosis. Unfortunately, the reclosure rate is higher than initially expected. More experience and longer follow-up are necessary to determine the value of endoscopic aqueductoplasty in the treatment of hydrocephalus caused by aqueductal stenosis.

Attention to a painful cutaneous laser stimulus modulates electrocorticographic event-related desynchronization in humans

OBJECTIVE

To test the hypothesis that attention to painful cutaneous laser stimuli enhances event-related desynchronization (ERD) in cortical regions receiving nociceptive input.

METHODS

We used wavelet time-frequency analysis and bandpass filtering to measure ERD quantitatively in subdural electrocorticographic recordings while subjects either attended to, or were distracted from, a painful cutaneous laser stimulus.

RESULTS

ERD were observed over primary somatosensory and parasylvian (PS) cortices in all 4 subjects, and over medial frontal cortex in 1 subject. Laser-evoked potentials were also observed in all 3 regions. In all subjects, ERD was more widespread and intense, particularly over PS, during attention to laser stimuli (counting stimuli) than during distraction from the stimuli (reading for comprehension).

CONCLUSIONS

These findings suggest that pain-associated ERD is modulated by attention, particularly over PS.

SIGNIFICANCE

This study suggests that thalamocortical circuits are involved in attentional modulation of pain because of the proposed role of these circuits in the mechanisms of ERD.

Event-related functional MRI study on central representation of acute muscle pain induced by electrical stimulation

Although pathological muscle pain involves a significantly larger population than any other pain condition, the central mechanisms are less explored than those of cutaneous pain. The aims of the study were to establish the pain matrix for muscle pain in the full head volume and, further, to explore the possibility of a functional segregation to nonpainful and painful stimuli within the area of the parasylvian cortex corresponding to the secondary somatosensory area. Additionally, we speculate that a randomization of nonpainful and painful stimuli may target specific structures related to stimulus salience. We used event-related functional magnetic resonance imaging (MRI) and the high sensitivity of the 3-T MRI scanner to study the central processing of acute muscle pain induced by intramuscular electrostimulation. Brief nonpainful and painful stimuli (1-ms duration, interstimulus interval = 12 s) were randomly applied to the left abductor pollicis brevis of 10 subjects. The data disclose a pain matrix for muscle pain similar to that for cutaneous pain. Individual analysis suggests separate representations within the area bounded by the upper bank of the Sylvian fissure (SF) and the circular sulcus of insula (CSI). Nonpainful stimulation activated the superficial parietal operculum adjoining the SF, while the painful condition additionally targeted the deeper parietal operculum bordering the CSI. Randomization of stimuli of different intensities likely introduces cognitive components that engage neural substrates servicing the appreciation of stimulus salience in the context of affect-laden pain imposition.

Measurement of cerebrospinal fluid flow at the cerebral aqueduct by use of phase-contrast magnetic resonance imaging: technique validation and utility in diagnosing idiopathic normal pressure hydrocephalus

OBJECTIVE

We analyzed the reliability of a protocol for measuring quantitative cerebrospinal fluid (CSF) flow at the cerebral aqueduct and established the range of CSF flows in normal elderly patients, patients with Alzheimer's and other forms of dementia, and patients with idiopathic normal pressure hydrocephalus (NPH).

METHODS

A constant flow phantom was used to establish the accuracy of the CSF flow measurement. The clinical variability of the measurement was estimated by calculating the standard deviations and coefficients of variation of intra- and interobserver and intertrial data sets derived from three normal volunteers. A total of 236 patients were studied, including 47 normal elderly patients, 115 patients with cognitive impairment (9 with mild cognitive impairment, 46 with Alzheimer's disease, and 60 with other cognitive impairment), 31 patients in whom NPH was suspected but ultimately excluded, and 43 patients with a final clinical diagnosis of NPH.

RESULTS

The intraobserver, interobserver, and intertrial measurement variations of 6.4, 5.4, and 8.8%, respectively, were substantially smaller than the wide variation observed among subjects. There was no statistically significant difference in flow between normal elderly patients and patients with cognitive impairment (P = 0.91). When these populations were pooled, the average flow was 8.47 ml/min (standard deviation, 4.23; range, 0.9-18.5 ml/min). The average flow rate in patients with a final clinical diagnosis of NPH was 27.4 ml/min (standard deviation, 15.3; range, 3.13-62.2 ml/min). This was significantly higher than the flow rate in each of the other three groups (all, P < 0.001).

CONCLUSION

CSF flow measurements of less than 18 ml/min with a sinusoidal flow pattern are normal. CSF flow of greater than 18 ml/min suggests idiopathic NPH.

Elastance correlates with outcome after endoscopic third ventriculostomy in adults with hydrocephalus caused by primary aqueductal stenosis

OBJECTIVE

To study prospectively the correlation between clinical outcome after endoscopic third ventriculostomy (ETV) and resistance to the outflow of cerebrospinal fluid (R(out)) and elastance in adults with hydrocephalus caused by primary aqueductal stenosis (AS).

METHODS

R(out) and elastance were measured in the subarachnoid space and intraventricularly before ETV in 15 consecutive patients. Three months after the ETV, the clinical effect was evaluated by standardized indices, and R(out) and elastance were measured. If symptoms persisted and the ETV was patent, shunt surgery was offered. The effect of the shunt operation and R(out) were measured after 3 months.

RESULTS

Four patients experienced excellent improvement, six improved slightly, and five had unchanged or deteriorated symptoms after ETV. R(out) before ETV did not correlate with outcome. R(out) decreased after ETV with correlation to the clinical effect; in the six patients who had shunt surgery, R(out) decreased further. High preoperative elastance correlated strongly with a good outcome and reduction of ventricle size. Elastance did not change after ETV.

CONCLUSION

R(out) intraventricularly and in the subarachnoid space could not predict the outcome of the ETV, but the reduction in R(out) correlated positively with clinical improvement. Preoperative elastance correlated positively with clinical improvement, and elastance was unchanged after ETV. Clinical improvement correlated positively with reduction in ventricle size.

[MRI with cerebrospinal fluid measurement before and after endoscopic ventriculostomy and aqueductal stenosis]

PURPOSE

Evaluation of MR imaging and CSF flow measurement for planning and follow-up of neuroendoscopic third ventriculostomy in occlusive triventricular hydrocephalus.

METHOD

17 patients with occlusive hydrocephalus due to idiopathic or neoplastic aqueductal stenosis were examined before and after surgery with cardiac-gated T2-weighted and cardiac-gated phase contrast cine sequences. The visibility of anatomic structures and the patency of the ventriculostomy were evaluated.

RESULTS

In all 17 patients, the relevant anatomic structures were visible. The cine sequence demonstrated occlusion of the aqueduct and patency of the ventriculostomy in all cases, even in patients with doubtful clinical patterns.

CONCLUSIONS

MR imaging with additional cardiac-gated cine sequences allows exact preoperative diagnosis of occlusive hydrocephalus as well as patient selection and planning for endoscopic third ventriculostomy. Non-invasive follow-up, especially in patients with a doubtful clinical pattern, is possible.

Spontaneous resolution of acute obstructive hydrocephalus in the neonate

Spontaneous resolution of acute hydrocephalus without aspiration of cerebral fluid is rare. In a neonate born at full term this has only been reported once before. We report on one further case that was caused by intraventricular haemorrhage (IVH). The probable mechanism is resolution of the acute haemorrhage in the region of the aqueduct, resulting in resolution of the hydrocephalus itself. The importance of considering conservative management of acute hydrocephalus in the clinically stable neonate is emphasised.

Endoscopic ventriculostomy versus shunt operation in normal pressure hydrocephalus: diagnostics and indication

In contrast to the shunt operation the indication for an endoscopic ventriculostomy in patients diagnosed for normal pressure hydrocephalus is not scientifically established. Between September 1997 and December 1999 we operated on 48 patients diagnosed for normal pressure hydrocephalus. The 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 postoperatively. In 37 patients (77%) we have implanted a ventriculo-peritoneal shunt, and in 11 patients (23%) 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 groups of patients. 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 endoscopic assisted ventriculostomy.

The caudal infrasylvian surface in dyslexia: novel magnetic resonance imaging-based findings

OBJECTIVE

To detect anatomic abnormalities of auditory association cortex in dyslexia by measuring the area of the perisylvian region known as the caudal infrasylvian surface(s) (cIS) in dyslexic and control subjects.

BACKGROUND

Several quantitative morphometric investigations of cortical areas in dyslexia have focused on the cIS, which encompasses the supratemporal plane and the inferior bank of the posterior ascending ramus of the sylvian fissure. Inconsistencies in the results of these studies may be attributable in part to the use of measurement methods that do not account fully for surface undulations of the cIS.

METHODS

The authors used an MRI-based surface reconstruction technique that models the curvature of the cerebral cortex in three dimensions to obtain whole-hemisphere and regional surface area estimates. Measurements were obtained in both hemispheres of eight right-handed male dyslexic subjects and eight right-handed male control subjects.

RESULTS

The cIS area of dyslexic subjects was significantly larger than that of control subjects, and this result was not attributable to a difference in whole-hemisphere surface area. Neither the dyslexic nor control subjects showed a left or right asymmetry in this region, although there was a trend toward less variance of the asymmetry scores in dyslexic subjects.

CONCLUSIONS

The gross anatomic organization of this region is different in dyslexic subjects, and elucidation of the precise nature of these differences may be aided by surface modeling techniques.

Perisylvian dysgenesis. Clinical, EEG, MRI and glucose metabolism features in 10 patients

We studied 10 patients who had neurological disorders with a MRI-based diagnosis of perisylvian dysgenesis based on the fact that the parasagittal and centrifugal extremity of the sylvian fissure was abnormally mesial. This abnormality was bilateral in seven cases; in the other three patients, the contralateral sylvian fissure appeared either normal (two cases) or enlarged (open operculum). The perisylvian cortex had a polymicrogyric appearance in most patients. Potential aetiopathogenic factors were determined in four patients. In two of them, ischaemia at mid-gestation was ascribed to death of a co-twin in a context of monozygotic twinning. In the other two patients, who were siblings, genetic factors were suspected. Pseudobulbar palsy was found in eight patients and epilepsy in five patients. We used PET with [18F]fluorodeoxyglucose to test the hypothesis that, despite this clinical and MRI heterogeneity, regional cerebral glucose distribution could have common features in these patients. The analysis of PET data was performed by visual inspection in two cases and by using statistical parametric mapping (SPM) in eight patients compared with a control group. Segmented grey matter MRIs of seven out these patients were also analysed using SPM. We found that the abnormal perisylvian cortex had normal grey matter activity in eight patients and in the other two there was a heterogeneous pattern with areas of preserved metabolism and of decreased metabolism. Metabolic changes were also detected outside the polymicrogyric-like cortex; three patients had hypometabolic areas in cortical regions where the MRI appeared normal and had a normal intensity. When polymicrogyria extended into the white matter, this ectopic dysgenetic cortex was associated with a grey matter pattern within the white matter territory, and was detected by SPM as areas of PET hypermetabolism and MRI hyperintensity. In order to detect possible metabolic changes undetected by the individual analyses, the group of patients was compared with the control group. This comparison revealed bilateral hypometabolism in the frontal opercular cortex. We propose that these PET data be considered in light of the presumed cyto-architectonic pattern of perisylvian dysgenesis, i.e. polymicrogyria. In this malformation, two dense cell layers are separated by a necrotic sparse cell layer. We speculate that the amount of synaptic activity preserved in these dense cell layers depends on the importance and timing of the necrotic process; this hypothesis accounts for the large range of metabolic patterns found, from profoundly decreased glucose metabolism to nearly normal activity.

The microglial response to progressive hydrocephalus in a model of inherited aqueductal stenosis

Although gliosis has been reported to be a common and persistent feature in the white matter of hydrocephalic brains, no studies have identified the cell types that characterize this response. Therefore, the present study has employed histochemical methods to evaluate microglial cells in the brains of infant rats with inherited hydrocephalus. This strain of rats acquires hydrocephalus during late fetal stages due to aqueductal stenosis. Tissue from the sensorimotor and auditory cortices of 12- and 21-day-old hydrocephalic and normal H-Tx rats was processed and stained for the lectin microglial marker Griffonia simplicifolia (GSA-IB4). During the progression of hydrocephalus, GSA-positive cells exhibited three changes: (1) Cytologically, the cell bodies were enlarged, and their processes were thicker, longer and more numerous. These changes were most notable in the gray matter. (2) The packing density of GSA-positive cells was either increased or decreased, depending on the age of the animal and the severity of hydrocephalus. (3) Localized clusters of GSA-positive cells were conspicuous in the white matter of 12-day animals with mild hydrocephalus, and in the gray matter of 21-day animals with severe hydrocephalus. These results indicate that the microglial response is initiated during intermediate stages of hydrocephalus, and is not restricted to the periventricular white matter. These changes may signal other pathophysiologic events in the hydrocephalic brain, and demonstrate that microglia constitute one important element in the gliosis that accompanies hydrocephalus.

Dynamic MRI of cerebrospinal fluid flow in endoscopic percutaneous ventriculostomy

Endoscopic percutaneous ventriculostomy (EPV) is a new technique to restore the flow of the cerebrospinal fluid (CSF) to the basal cistern in patients with non-communicating hydrocephalus (NCH). Cardiac gated MRI techniques have been applied to demonstrate normal and abnormal CSF flow in humans. The aim of this study was to evaluate the ability of a new multislice spin echo dynamic MRI technique and amplitude and phase reconstruction to demonstrate the impairment of CSF flow through the aqueduct preoperatively and to assess the patency of the ventriculostomy after surgery. Thirteen patients with NCH were studied with dynamic MRI before and after EPV using multiple sagittal multislice gated SE acquisitions to demonstrate the CSF flow. Nine patients were clinically improved by EPS, two remained unchanged and two deteriorated. The permeability of the ventriculostomy was confirmed in all patients. We think that MRI flow studies are useful to demonstrate the site of impairment of CSF flow and its aetiology preoperatively, and to assess the permeability of the ventriculostomy after surgery in a non invasive way.

A clinically recognizable neuronal migration disorder: congenital bilateral perisylvian syndrome. Case report with long-term clinical and EEG follow-up

Congenital bilateral perisylvian syndrome (CBPS) is a recently described, neuronal migration disorder, characterized by pseudobulbar palsy, epilepsy and mental retardation and bilateral perisylvian dysplasia. A 15-year-old boy was diagnosed with CBPS according to the typical clinical, and magnetic resonance imaging (MRI) features. The patient was suffering from atypical absence seizures, repeating daily in spite of antiepileptic drug therapy, since age 7 years. He had also experienced rare generalized tonic-clonic seizures and complex partial seizures. Neurological examination showed severe restriction of tongue movements, severe dysarthria, dysphagia, facial diplegia, mild pyramidal signs and moderate mental retardation. A computed tomographic (CT) scan demonstrated bilateral perisylvian enlargement. The diagnosis was corrected with MRI after six years. Frequent irregular generalized spike and wave abnormalities and focal sharp and slow waves over the posterior regions of both hemispheres were shown by electroencephalograms (EEG). The patient was treated with Na-Valproate, carbamazepine and lamotrigine but did now show any significant change in seizure frequency in the eight-year follow-up period. Intractable seizures, mental retardation and particularly congenital pseudobulbar palsy suggest this congenital entity. Those patients who exhibit these typically clinical features, must have MRI.

Aqueduct compression from venous angioma: MR findings

Vascular compression as the cause of aqueductal stenosis is rare. In a 16-year-old girl with hydrocephalus, MR imaging provided evidence of aqueductal stenosis caused by a venous angioma in the tectum and midbrain. This indicates the usefulness of MR imaging for the evaluation of obstructive hydrocephalus.

The temporal lobes, reversed asymmetry and the genetics of schizophrenia

Mechanisms determining temporal lobe structural asymmetries may be involved in the pathogenesis of schizophrenia. To investigate the temporal lobes in familial schizophrenia, computed tomographic scans were obtained from 51 subjects (seven families). Enlargement of sylvian fissures and temporal lobe sulcal spaces was observed in family members with schizophrenia. The posterior one-third of the sylvian fissure was larger on the left side in subjects with schizophrenia, and larger on the right side in unaffected individuals. This disturbed pattern of posterior sylvian fissure asymmetry suggests that adjacent language regions may be affected in schizophrenia. An intermediate degree of disturbance in subjects who had schizophrenia-related illnesses or were obligate carriers suggests that genetic factors may be important determinants of temporal lobe asymmetries in familial schizophrenia.

[Late clinical manifestations of hydrocephalus associated with aqueductal stenosis]

Hydrocephalus associated with aqueductal stenosis is not uncommon after the 2nd year of life. In some patients, stenosis is due to slow-growing periaqueductal tumors that can only be revealed by magnetic resonance examination. We reviewed 31 cases of children with aqueductal stenosis and hydrocephalus diagnosed after the second year of life, and operated on in the Section of Paediatric Neurosurgery of UCSC between 1982 and 1993. Eighteen cases (Group I) had nonneoplastic aqueductal stenosis, while in 13 cases (Group II) it was demonstrated a periaqueductal tumor by NMR. Intracranial hypertension was the most frequent symptom at diagnosis in both groups. In Group I mental and growth retardation were frequent, while cerebellar signs were quite common in Group II. The treatment of choice for hydrocephalus was a V-P shunt. Tumors in Group II were not directly treated, because of their benign behaviour. Subdural hematoma was a relatively common shunt complication in these patients. In 2 cases we observed an atypic complication: patients developed an altered level of consciousness, upsight paresis and distony, without any sign of increased intracranial pressure, or cerebro-spinal fluid infection. One of these patients died; we treated the second patient with L-Dopa (Sinemet 150 mg/die); he progressively improved and had a complete remission of symptoms. Surgical mortality was nil; long-term mortality was 12.5%. In 76.1% of Group II patients we have not observed any tumor growth; 50% of Group I patients has still a complete remission of preoperative symptoms (follow-up 2-12 years).

Cine magnetic resonance imaging of aqueductal stenosis

Cerebral aqueductal stenosis is one of the most common causes of congenital and acquired hydrocephalus, but the etiology, pathophysiology and cerebrospinal fluid (CSF) dynamics of aqueductal stenosis have yet to be clarified. Utilizing cardiac gated cine magnetic resonance (MR) imaging, we evaluated aqueductal configuration and pulsatile motion of brain and CSF flow stimulated by cardiac pulsation in five patients with non-tumoral aqueductal stenosis. Cine MR of four cases revealed obliteration of the aqueduct by thickening mesencephalic tectum, turbulent CSF flow in the III ventricle, and absence of flow-related signal void, which in all normal cases indicates CSF movement within the aqueduct. In the remaining fifth case, with proximal dilation of the aqueduct resulting from thinning of the tectum, distortion of caudal (distal) tectum related to pulsatile motion of the brain caused funnel-like narrowing of the aqueduct, leading to incomplete obstruction and the absence of upward CSF flow during diastole.

Optic gliomas in neurofibromatosis type 1 (NF-1). Presentation of 31 cases

We present a series of 31 cases of optic glioma associated with neurofibromatosis type 1 in patients under 11 years of age. They represent 64% of all the optic gliomas seen in our service between September 1965 and September 1993. The optic nerves were affected in 25 cases (83%); 9 children (30%) had a isolated, unilateral tumor; 16 (53%) had involvement of the optic chiasm as well as of one or both optic nerves. In 6 cases (19%) only the chiasm was affected, with or without involvement of other intracerebral structures. A coincidental orbital plexiform neurofibroma was associated with a poor prognosis. Other complications included 8 cases (26%) presenting with slowly developing aqueductal stenosis requiring treatment with a shunt. High-resolution computed-tomographic scans provided well-defined images for the diagnosis of optic nerve glioma, but magnetic resonance imaging was the preferred procedure for the diagnosis of gliomas involving the chiasm and the optic tracts and radiations, particularly if there was no mass effect. In our patients, tumor growth was hardly noticeable during follow-up even up to 20 years, with no difference between patients who were treated with radiation and those who were not treated. However, endocrine disturbances developed in all cases subjected to radiotherapy, and were less frequent in untreated patients. Aqueductal stenosis was observed with similar frequency among both treated or untreated patients. Three patients died, two due to complications of hydrocephalus secondary to aqueductal stenosis and one because of respiratory problems due to compression of the hypothalamus and brainstem by the chiasm tumor. Two of the 3 patients who died had orbital plexiform neurofibroma.

Consensus: nosographic identification

Since hydrocephalus cannot be regarded as a single entity but is a group of illnesses whose pathophysiology remains unexplained in many aspects, its classification is particularly important. Various types of hydrocephalus are discussed with special reference to their etiology. The need for more research work is stressed.

Fourth ventricular entrapment caused by rostrocaudal herniation following shunt malfunction

The subacute development of isolated fourth ventricle (IFV) is a recognized complication following shunting of the lateral ventricles for congenital and acquired hydrocephalus. We present an unusual case of acute IFV in a clinical setting which has not previously been described. Subsequent to rostrocaudal herniation caused by an obstructed frontally placed ventricular catheter, IFV developed in our patient 24 h following shunt revision, necessitating placement of an additional fourth ventricle shunt system. No signs of intraventricular hemorrhage or cerebrospinal fluid (CSF) infection were detected at the time of shunt revision and there was no documentation of similar events in the perinatal history. Dependent upon the actual underlying etiology of this child's hydrocephalus, we hypothesize that two mechanisms may have accounted for this unusual and precipitous development of IFV. Following rostrocaudal herniation and caudal shift of the brainstem, progressive edema in the pons developed. If communicating hydrocephalus was the primary etiology, then midbrain edema occluded the aqueduct of Sylvius, preventing retrograde flow of CSF to the shunt. A distinctly different mechanism for acute IFV must be invoked if aqueductal stenosis was the preexisting cause for congenital hydrocephalus. Following herniation, brainstem displacement and edema resulted in obliteration of the lateral pontine and ambient cisterns, preventing the normal rostral migration of CSF around and over the mesencephalon. Cerebellar tonsillar herniation with impaction of the tonsils into the foramen magnum may have also contributed to obstruction of fourth ventricular outflow in both settings. This unusual case of acute onset IFV is presented in detail. The underlying etiologies and clinical settings in which IFV may develop is reviewed as well.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of disturbance of ependymal ciliary movement in development of hydrocephalus in rats

We have developed a new in vitro method of quantitatively analyzing ciliary movement in the ependymal wall of the aqueduct in rats. An axial slice of the midbrain containing ependymal wall was placed in a culture dish filled with a culture medium containing latex beads 1 micron in diameter at a concentration of 10(7) beads/ml. The movement of the beads caused by flow of culture medium generated by the to-and-fro ciliary movement was recorded by a high speed video system attached to an inverted phase-contrast microscope. Ciliary movement was expressed by the speed of the latex beads (micron/s). Aqueductal ciliary movement in congenitally hydrocephalic HTX rats, congenitally hydrocephalic WIC-Hyd rats, and other normal rats was evaluated. The results suggest that in congenitally hydrocephalic WIC-Hyd rats the degree of hydrocephalus related strongly to the degree of ciliary dyskinesia, but in congenitally hydrocephalic HTX rats it did not. Considering this discrepancy, we attempted to see whether or not hydrocephalus was caused by artificial disturbance of ependymal ciliary movement in vivo. We found that continuous infusion of metavanadate, an inhibitor of ciliary movement, into the III ventricle of normal Sprague-Dawley rats for 7 days induced dilatation of the ventricular system. Although the question whether or not disturbance of aqueductal ependymal ciliary movement is related to the development of human congenital hydrocephalus is debatable, the results of the present in vitro and in vivo experimental investigations appear to suggest that the disturbance of ciliary movement in the aqueduct could at least be one of the factors contributing to the inducement of hydrocephalus in experimental conditions.

MRI in aqueduct compression and obstructive hydrocephalus due to an ecstatic basilar artery

We describe a patient with an ecstatic basilar artery in whom MRI showed marked indentation of the floor of the third ventricle and backward displacement of the midbrain, probably causing aqueduct stenosis. It appeared likely that the associated hydrocephalus was due not only to any "water-hammer" effect, but also to occlusion of the aqueduct.

Non tumoural aqueductal stenosis with intermittent course. Case report after a six year follow up

Images

[A case with a diagnosis of apparent functional sylvian aqueductal stenosis]

A case with a presumptive diagnosis of a functional sylvian aqueductal stenosis is presented. The patient was a 64-year-old female, who suffered from progressive gait disturbance and dementia. On admission, CT-scan showed lateral and third ventricular dilatations. The pattern of the ventricular dilatation suggested an aqueductal stenosis. But CT-scan showed no tumorous lesion. RI-cisternography, RI-ventriculography, aqueductgraphy, and continuous monitoring of the intraventricular pressure of the third ventricle were performed in order to make a diagnosis. The results of these examinations led to the following conclusion. "Although there was no apparent mechanical obstruction or stenosis, the presence of circulatory failure of CSF, demonstrated apparent functional stenosis of the aqueduct sylvii." A VP-shunt operation was performed a month after her admission. Her symptoms improved remarkably.

Determination of ventricular fluid outflow resistance in patients with ventriculomegaly

Resorption of the ventricular fluid was studied by measuring ventricular fluid outflow resistance during steady state 1.5 and 5.0 ml/min infusions in 26 patients with substantial enlargement of the supratentorial ventricular system. This test may avoid unnecessary use of shunts, but a shunt could be introduced during the same procedure.

Fast multiphase MR imaging of aqueductal CSF flow: 2. Study in patients with hydrocephalus

The signal intensity in the region corresponding to the cerebral aqueduct was evaluated in three patients with noncommunicating tension hydrocephalus (caused by aqueductal obstruction in two and type I Arnold-Chiari malformation in the other), seven patients with suspected normal-pressure hydrocephalus (three of whom subsequently underwent successful shunting), and 10 patients with ex vacuo (atrophic) hydrocephalus. A gradient-echo MR sequence, called fast multiphase imaging, was used. Serial images corresponding to different phases of the cardiac cycle were acquired. No flow-related enhancement was observed over the entire cardiac cycle in the patients with noncommunicating hydrocephalus. Patients with normal-pressure hydrocephalus showed a higher aqueductal CSF signal intensity, consistent with increased systolic flow rates, than patients with ex vacuo hydrocephalus. When comparing the above two groups of patients with a control group of healthy volunteers, significantly higher and lower values of the (mean) maximum aqueductal signal intensity were found in the normal-pressure hydrocephalus patients and the ex vacuo hydrocephalus patients, respectively. Fast multiphase MR evaluation of aqueductal CSF flow may help to differentiate patients with different types of hydrocephalus.

Aqueduct stenosis--presentation and prognosis

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.

Blepharoclonus and parkinsonism associated with aqueductal stenosis

A 28-year-old man with a history of congenital hydrocephalus due to aqueductal stenosis shunted at 45 days of age is presented. At age 4 years the valve had to be removed because of septicemia. Twenty-three years later he developed parkinsonian signs and abnormal, involuntary rhythmic contractions of the eyelids. The latter were elicited on gentle eye closure. Parkinsonism promptly improved after ventriculoperitoneal shunting, but blepharoclonus persisted unchanged.