Cognitive changes after cerebrospinal fluid shunting in young adults with spina bifida and assumed arrested hydrocephalus

Utility of intracranial pressure monitoring as a diagnostic tool in pediatric ventriculomegaly

OBJECTIVE

Intracranial pressure (ICP) monitoring is commonly utilized for identifying pathologic ICP in cases of traumatic brain injury; however, its utility in hydrocephalic children has not been elucidated. Although patients with typical (pressure-active) hydrocephalus present with clear signs and/or symptoms and the need for cerebrospinal fluid (CSF) diversion is often clear, others may have arrested or pressure-compensated hydrocephalus with pathologic ICP elevation masked by ambiguous signs or are completely asymptomatic. Without treatment these pathologic ICP elevations may affect neurologic development or crescendo over time leading to neurological decline. The purpose of this study is to investigate the utility of ICP monitoring as a diagnostic tool in this relatively common patient population and identify ventriculomegaly patients with and without pathologic ICP, thus improving accuracy of identifying those with and without surgical needs.

METHODS

36 patients (≤ 17 years old) underwent 41 inpatient ICP recording sessions between 2016 and 2022 and were retrospectively reviewed. This included patients with a history of severe, nonprogressive ventriculomegaly and normal fundoscopic examinations lacking traditional signs and symptoms concerning for elevated ICP. Nighttime pathological plateau waves were defined as sustained elevations of ICP ≥ 2x baseline for a duration of ≥ 5 minutes.

RESULTS

The mean age of patients was 5.5 years old (range 0-17 years old). 46.3% of patients had prior endoscopic third ventriculostomy (ETV), 14.6% had prior ventriculoperitoneal shunt (VPS), and 39% were without prior surgical intervention. Roughly half (51.2%) of patients had congenital ventriculomegaly while other patients had ventriculomegaly due to other pathologies such as germinal matrix hemorrhage/intraventricular hemorrhage (GMH/IVH) (29.3%), stroke (4.9%), cerebral infections/meningitis (2.4%), or unknown etiology (12.2%). The average procedure time was 19.1 ± 10.5 minutes, and mean length of stay was 2.8 ± 0.7 days. Pathologic ICP was demonstrated in 12 cases (29.3%), 4 (33.3%) of which were asymptomatic. Pathologic ICP was found in 7 of 19 (36.8%) in the prior ETV group, 1 of 6 (16.7%) in prior shunt group, and 4 of 16 (25%) in the non-surgical group (p = 0.649). Among those with pathologic ICP, 6 (50%) cases received an ETV, 5 (41.7%) cases underwent VPS placement, and 1 (8.3%) case underwent a VPS revision. There were no infectious complications or cases of hemorrhage. 4 patients required repositioning of the ICP monitor due to dislodgement.

CONCLUSION

Inpatient ICP monitoring is a safe and effective diagnostic tool for evaluating the presence of pathologic ICP in severe, persistent non-progressive ventriculomegaly. The use of ICP monitoring may aid in identifying patients with pressure-compensated hydrocephalus who demonstrate pathologic ICP where surgical intervention may be warranted, while preventing unnecessary CSF diversion in those without pathology.

Establishing ranked priorities for future hydrocephalus research

OBJECTIVE

The aim of this initiative was to develop a ranked list of hydrocephalus research priorities as determined by the hydrocephalus patient community in conjunction with the healthcare and scientific community.

METHODS

Using the validated methodology published by the James Lind Alliance (JLA), the Hydrocephalus Association (HA) administered two surveys and hosted a final prioritization workshop. Survey One solicited open-ended responses from the community. From these responses, a long list of priority statements was developed. This list was then consolidated into a short list of research priority statements, which, after a nonsystematic literature review, were verified as being research uncertainties. Survey Two asked the community members to select their top 10 priorities from the short list. The final prioritization leading to a final ranked top 20 list of hydrocephalus research priorities took place at a virtual workshop led by a team of trained facilitators, by means of an iterative process of consensus building.

RESULTS

From Survey One, 3703 responses from 890 respondents were collected, leading to a long list of 146 priority statements. The consolidated short list contained 49 research priority statements, all of which were verified as uncertainties in hydrocephalus research. From an analysis of Survey Two responses, the top 21 research priority statements were determined. A consensus on these statements was reached at the virtual workshop, leading to a final ranked top 20 list of hydrocephalus research priorities, within which needs were apparent in several areas: development of noninvasive and/or one-time therapies, reduction of the burden of current treatments, improvement of the screening and diagnosis of hydrocephalus, improved quality of life, and improved access to care.

CONCLUSIONS

By gathering extensive input from the hydrocephalus community and using an iterative process of consensus building, a ranked list of the top 20 hydrocephalus research priorities was developed. The HA will use this ranked list to guide future research programs and encourages the healthcare and scientific community to do the same.

Comparison of intracranial pressure prediction in hydrocephalus patients among linear, non-linear, and machine learning regression models in Thailand

BACKGROUND

Hydrocephalus (HCP) is one of the most significant concerns in neurosurgical patients because it can cause increased intracranial pressure (ICP), resulting in mortality and morbidity. To date, machine learning (ML) has been helpful in predicting continuous outcomes. The primary objective of the present study was to identify the factors correlated with ICP, while the secondary objective was to compare the predictive performances among linear, non-linear, and ML regression models for ICP prediction.

METHODS

A total of 412 patients with various types of HCP who had undergone ventriculostomy was retrospectively included in the present study, and intraoperative ICP was recorded following ventricular catheter insertion. Several clinical factors and imaging parameters were analyzed for the relationship with ICP by linear correlation. The predictive performance of ICP was compared among linear, non-linear, and ML regression models.

RESULTS

Optic nerve sheath diameter (ONSD) had a moderately positive correlation with ICP (r=0.530, P<0.001), while several ventricular indexes were not statistically significant in correlation with ICP. For prediction of ICP, random forest (RF) and extreme gradient boosting (XGBoost) algorithms had low mean absolute error and root mean square error values and high R2 values compared to linear and non-linear regression when the predictive model included ONSD and ventricular indexes.

CONCLUSIONS

The XGBoost and RF algorithms are advantageous for predicting preoperative ICP and establishing prognoses for HCP patients. Furthermore, ML-based prediction could be used as a non-invasive method.

Non-invasive assessment of cerebrospinal fluid flow dynamics using phase-contrast magnetic resonance imaging in communicating hydrocephalus

This work aims to evaluate the changes in cerebrospinal fluid (CSF) hydrodynamics in patients diagnosed with communicating hydrocephalus. Besides, we establish the relationship between CSF flow dynamic parameters on the midbrain aqueduct and intracranial pressure (ICP). CSF hydrodynamics analysis was performed using Phase-Contrast Magnetic Resonance Imaging (PC-MRI) techniques on the midbrain aqueduct of 41 patients diagnosed with communicating hydrocephalus and 22 healthy volunteers. The correlation between CSF average flow in the midbrain aqueduct and intracranial pressure measured by Lumbar Puncture (LP) was assessed in patients with hydrocephalus. Pearson correlation coefficient was used to establish the correction between the average CSF flow of midbrain aqueduct and ICP. CSF dynamic parameters of the midbrain aqueduct in hydrocephalus patients, including peak positive velocity (7.348 cm/s), average velocity (0.623 cm/s), average flow (50.799 mm³/s), and regions of interest (ROI) area (9.978 mm²) were significantly higher than in the healthy controls (p < 0.05). This was after adjusting the age, gender, heart rate, systolic blood pressure, diastolic blood pressure, and body mass index. However, only the peak negative velocity of the midbrain aqueduct did not significantly differ between the groups (p = 0.209). A positive correlation was noted between the average flow (AF) of the midbrain aqueducts and ICP in hydrocephalus patients (y (AF) = 0.386× (ICP)-33.738, r = 0.787, p < 0.05). Reference data of CSF flow dynamic parameters was obtained through the PC-MRI in middle-aged healthy volunteers and communicating hydrocephalus patients. Although the sample size was constrained, this study has significant contributions. For instance, a significant correlation was noted between the average CSF flow of the aqueduct and ICP. This therefore provides a reference for clinicians to monitor ICP in patients with hydrocephalus.

Ventriculomegaly in children: nocturnal ICP dynamics identify pressure-compensated but active paediatric hydrocephalus

INTRODUCTION

Paediatric ventriculomegaly without obvious signs or symptoms of raised intracranial pressure (ICP) is often interpreted as resulting from either relative brain atrophy, arrested "benign" hydrocephalus, or "successful" endoscopic third ventriculostomy (ETV). We hypothesise that the typical ICP "signature" found in symptomatic hydrocephalus can be present in asymptomatic or oligosymptomatic children, indicating pressure-compensated, but active hydrocephalus.

METHODS

A total of 37 children fulfilling the mentioned criteria underwent computerised ICP overnight monitoring (ONM). Fifteen children had previous hydrocephalus treatment. ICP was analysed for nocturnal dynamics of ICP, ICP amplitudes (AMP), magnitude of slow waves (SLOW), and ICP/AMP correlation index RAP. Depending on the ONM results, children were either treated or observed. The ventricular width was determined at the time of ONM and at 1-year follow-up.

RESULTS

The recordings of 14 children (group A) were considered normal. In the 23 children with pathologic recordings (group B), all ICP values and dependent variables (AMP, SLOW) were significantly higher, except for RAP. In group B, 12 of 15 children had received a pre-treatment and 11 of 22 without previous treatment. All group B children received treatment for hydrocephalus and showed a significant reduction of frontal-occipital horn ratio at 1 year. During follow-up, a positive neurological development was seen in 74% of children of group A and 100% of group B.

CONCLUSION

Ventriculomegaly in the absence of signs and symptoms of raised ICP was associated in 62% of cases to pathological ICP dynamics. In 80% of pre-treated cases, ETV or shunt failure was found. Treating children with abnormal ICP dynamics resulted in an outcome at least as favourable as in the group with normal ICP dynamics. Thus, asymptomatic ventriculomegaly in children deserves further investigation and, if associated with abnormal ICP dynamics, should be treated in order to provide a normalised intracranial physiology as basis for best possible long-term outcome.

Reappraisal of Pediatric Normal-Pressure Hydrocephalus

While normal-pressure hydrocephalus (NPH) is most commonly diagnosed in older adulthood, a significant body of literature has accumulated over half a century documenting the clinical phenomenon of an NPH-like syndrome in pediatric patients. As in adult NPH, it is likely that pediatric NPH occurs due to a heterogeneous array of developmental, structural, and neurodegenerative pathologies, ultimately resulting in aberrant cerebrospinal fluid (CSF) flow and distribution within and around the brain. In this review, we aimed to systematically survey the existing clinical evidence supporting the existence of a pediatric form of NPH, dating back to the original recognition of NPH as a clinically significant subtype of communicating hydrocephalus. Leveraging emergent trends from the old and more recent published literature, we then present a modern characterization of pediatric NPH as a disorder firmly within the same disease spectrum as adult NPH, likely with overlapping etiology and pathophysiological mechanisms. Exemplary cases consistent with the diagnosis of pediatric NPH selected from the senior author’s neurosurgical practice are then presented alongside the systematic review to aid in discussion of the typical clinical and radiographic manifestations of pediatric NPH. Common co-morbidities and modern surgical treatment options are also described.

Survival and outcome in patients with aneurysmal subarachnoid hemorrhage in Glasgow coma score 3-5

BACKGROUND

Outcome of early, aggressive management of aneurysmal subarachnoid hemorrhage (aSAH) in patients with Hunt and Hess grade V is hitherto limited, and we therefore present our results.

METHODS

Retrospective study analyzing the medical data of 228 aSAH patients in Glasgow Coma Score 3-5 admitted to our hospital during the years 2002-2012. Background and treatment variables were registered. Outcome was evaluated after 3 and 12 months.

RESULTS

We intended to treat 176 (77.2%) patients, but only 146 went on to aneurysm repair. Of 52 patients managed conservatively, 27 had abolished cerebral circulation around arrival and 25 were deemed unsalvageable. One-year overall mortality was 65.8% and most (84.7%) of the fatalities occurred within 30 days. One-year mortality was higher in patients > 70 years. Without aneurysm repair, mortality was 100%. After 1 year, 21.9% of all patients lived independently and 4.8% lived permanently in an institution. Outcome in the 78 survivors (34.2%) was favorable in 64.1% in terms of modified Rankin Scale score 0-2, and 85.9% of survivors were able to live at home. Return to work was low for all 228 patients with 14.0% of those employed prior to the hemorrhage having returned to paid work, and respectively, 26.3% in the subgroup of survivors.

CONCLUSIONS

Even with aggressive, early treatment, 1-year mortality is high in comatose aSAH patients with 65.8%. A substantial portion of the survivors have a favorable outcome at 1 year (64.1%, corresponding to 21.9% of all patients admitted) and 85.9% of the survivors could live at home alone or aided.

[Decompensation of chronic internal hydrocephalus in an adult patient]

We report a rare case of decompensated chronic internal hydrocephalus in an adult patient. A 35-year-old woman experienced acute intracranial hypertension in 3 weeks after relief of postoperative inflammation in the oral cavity (tooth extraction). MRI revealed severe internal hydrocephalus. Third ventriculostomy was followed by significant clinical improvement. However, postoperative survey and subsequent neuroimaging confirmed no reduction of ventricular system. Thus, decompensation of chronic hydrocephalus following dental intervention and subsequent oral inflammation was assumed. Impaired venous outflow from the brain and destabilization of CSF circulation can be considered as a pathogenetic mechanism.

Incidence, diagnostic criteria and outcome following ventriculoperitoneal shunting of idiopathic normal pressure hydrocephalus in a memory clinic population: a prospective observational cross-sectional and cohort study

OBJECTIVE

To evaluate diagnostic criteria for idiopathic normal pressure hydrocephalus (INPH) among patients with memory impairment, and to estimate the incidence of INPH.

DESIGN

Prospective observational cross-section and cohort study of diagnostic accuracy.

SETTING

Memory Disorders Clinic following referral by the medical practitioners.

PARTICIPANTS

408 consecutive patients enrolled 2010-2014.

OUTCOME MEASURES

Reference diagnostic test was the clinical judgement of an experienced specialist based on the presence of cognitive impairment and/or balance and gait disorders in the presence of dilated ventricles. Mini-Mental State Examination (MMSE), Tinetti balance and gait tests were performed before and 12 months after ventriculoperitoneal shunt surgery. The association between reference diagnosis, clinical and brain CT scan measurements was estimated by multivariate Poisson regression. Triage index diagnostic test scores were calculated from the regression coefficients, with diagnostic thresholds selected using receiver operating characteristic analysis.

RESULTS

The presence of balance and/or gait disorders, especially fear of falling, difficulty standing on toes/heals, urinary disturbances, ventriculomegaly with Evans ratio greater than Combined Diagnostic Threshold (0.377-{Maximum width of posterior horns*0.0054}), strongly predict the diagnosis of INPH; while hallucinations and/or delusions and forgetfulness reduce the likelihood of the diagnosis. This triage index test had high sensitivity (95.2%) and specificity (91.7%). 62 of 408 (15%) participants with cognitive impairment had INPH, an incidence of 11.9/100 000/year and 120/100 000/year over 75 years. 96% of participants following shunting, compared with 45% of the non-shunted, improved by over 25% of available measurable improvement in either MMSE or balance/gait scores (51% difference; 95% CI 28% to 74%; p<0.001), and 56% vs 5% improved by over 50% of maximum in both (51% difference; 95% CI 30% to 73%; p<0.001).

CONCLUSION

The triage index test score is a simple tool that may be useful for physicians to identify INPH diagnoses and need for referral for shunt surgery, which may improve cognitive, balance and gait functioning.

Are Shunt Revisions Associated with IQ in Congenital Hydrocephalus? A Meta -Analysis

Although it is generally acknowledged that shunt revisions are associated with reductions in cognitive functions in individuals with congenital hydrocephalus, the literature yields mixed results and is inconclusive. The current study used meta-analytic methods to empirically synthesize studies addressing the association of shunt revisions and IQ in individuals with congenital hydrocephalus. Six studies and three in-house datasets yielded 11 independent samples for meta-analysis. Groups representing lower and higher numbers of shunt revisions were coded to generate effect sizes for differences in IQ scores. Mean effect size across studies was statistically significant, but small (Hedges' g = 0.25, p < 0.001, 95 % CI [0.08, 0.43]) with more shunt revisions associated with lower IQ scores. Results show an association of lower IQ and more shunt revisions of about 3 IQ points, a small effect, but within the error of measurement associated with IQ tests. Although clinical significance of this effect is not clear, results suggest that repeated shunt revisions because of shunt failure is associated with a reduction in cognitive functions.

Short- and long-term neurobehavioral effects of lumbar puncture and shunting in patients with malabsorptive hydrocephalus after subarachnoid haemorrhage: An explorative case study

BACKGROUND

The neuropsychological effects of lumbar puncture and shunting in terms of cognitive functioning and quality of life were analyzed prospectively in four patients with malabsorptive hydrocephalus who became symptomatic in the chronic state after aneurysmal subarachnoid haemorrhage (SAH).

METHODS

A comprehensive battery of neuropsychological tests was applied to four patients before and shortly after lumbar puncture and six months later. In three of them a shunt has been inserted, one patient was treated by repeated lumbar punctures. In addition, the patients completed a quality of life and a depression questionnaire before lumbar puncture and after shunting. The data were analyzed using single-case methodology.

RESULTS

Hydrocephalus was associated with pronounced cognitive deficits in terms of functions of attention, short- and long-term memory, concentration and motor fine-coordination but not with a general mental deterioration. Quality of life and affect were also substantially impaired. Neuropsychological tests of fronto-cortical cognitive capacity, motor fine coordination and reaction time proved to be sensitive for the short-term effects of lumbar puncture. Memory functions and the capacity of divided attention needed more time for regeneration and improved substantially after shunt implantation.

CONCLUSIONS

We found a complex pattern of cognitive improvement after lumbar puncture and shunting. Furthermore, our results also show a typical cluster of cognitive deficits associated with malabsorptive hydrocephalus including motor dysfunction. These preliminary findings should be confirmed in larger patient samples.

Surgical management of arrested hydrocephalus: Case report, literature review, and 18-month follow-up

OBJECTIVE

Arrested hydrocephalus is stable ventriculomegaly without evidence of neurologic deterioration or symptoms. Management of arrested hydrocephalus in asymptomatic adults is controversial, with little clinical data. This case highlights the potential for decompensation in adults with arrested hydrocephalus and reviews the literature regarding pathophysiology and management of this clinical entity.

PATIENTS AND METHODS

A 39 year-old gentleman with arrested hydrocephalus incidentally found during work-up for new-onset seizure and managed conservatively for ten years presented with increasing headache, memory loss, gait instability and urinary and fecal incontinence. Stable massive triventriculomegaly was documented on serial brain imaging, and ophthalmologic exam revealed no papilledema.

RESULTS

The patient underwent endoscopic third ventriculostomy with immediate post-operative improvement of headache, resolution of incontinence, and cessation of seizures. At 15 months after surgery, neuropsychiatric testing demonstrated improvement in visuomotor skills, problem solving, verbal fluency and cognitive flexibility compared to his pre-operative baseline. At 18 months after surgery he remained seizure free with full continence and significant improvement in headaches.

CONCLUSION

Early recognition of arrested hydrocephalus and its potential for decompensation may prompt surgical treatment and prevent neurologic deterioration.

Adult quality of life in congenital hydrocephalus operated cases. A twenty years retrospective study

Congenital hydrocephalus is a health problem in many countries and in Romania the pediatric neurosurgical department of the Emergency Hospital “Bagdasar-Arseni” has a large number of such patients. This is a retrospective study and it includes the patients with congenital hydrocephalus operated between 1992 and 2012 in the pediatric neurosurgical department of the Emergency Hospital “Bagdasar-Arseni”. The functional outcome was assessed using Karnofsky Performance Scale, Hydrocephalus Outcome Questionnaire and Glasgow outcome scale. The total number of the patients was 372, with a predominance of boys (212 boys versus 160 girls) and at the time of our study 168 patients were over 16 years old. Functional outcome of the children over 16 years old assessed using Karnofsky Performance Scale, showed that 73 patients were above 80 and leading independent lives, and 95 were less than 80 points. The results would be better if all these patients would benefit from schooling for children with special needs.

The lack of relationship between intracranial pressure and cerebral ventricle indices based on brain computed tomography in patients undergoing ventriculoperitoneal shunt

BACKGROUND

In this study we investigated whether cerebral ventricle indices based on brain computed tomography (CT) scans are reliable for predicting intracranial pressure (ICP) in hydrocephalic patients.

METHODS

Electronic medical records of 221 patients undergoing ventriculoperitoneal shunt due to hydrocephalus were retrospectively reviewed. Cerebral ventricle indices including Evans' index, third ventricle index, cella media index, and ventricular score were calculated from transverse diameters measured at various levels on preoperative brain CT scans. ICP was considered as CSF opening pressure. Patients were categorized into three groups: communicating hydrocephalus, non-communicating hydrocephalus, and normal pressure hydrocephalus (NPH). The non-communicating hydrocephalus group was further divided according to the obstruction site; aqueduct, fourth ventricle outlet, third ventricle, and the foramen of Monro. The primary endpoint was the extent of the correlation between cerebral ventricle indices and ICP in each hydrocephalus group.

RESULTS

No cerebral ventricle index correlated with ICP in patients with communicating hydrocephalus (n = 113) and NPH (n = 62). In the non-communicating hydrocephalus group (n = 46), only the third ventricle index revealed moderate negative correlation with ICP (r = -0.395, p < 0.01). In subgroup analyses, the third ventricle index showed a strong negative relationship with ICP only in patients with the third ventricle obstruction (r = -0.779, p < 0.05).

CONCLUSIONS

In this study we showed that although an inverse correlation existed between ICP and the third ventricle index only in patients with non-communicating hydrocephalus due to obstruction of the third ventricle, cerebral ventricle indices based on brain CT scan were non-reliable predictors of ICP in hydrocephalic patients.

Neuropsychological Outcome after Endoscopic Third Ventriculostomy

Background: Cognitive dysfunction is a common complaint associated with obstructive hydrocephalus. The purpose of this study was to determine the effect of endoscopic third ventriculostomy (ETV) on the neuropsychological outcome in patients presenting with cognitive decline and obstructive hydrocephalus. Methods: A retrospective review of patients who underwent ETV at the University of Calgary and had both pre and post operative neuropsychological testing, was completed. Presenting clinical features, etiology of hydrocephalus and ventricle size utilizing frontal occipital horn ratio was obtained. Outcomes and complications of the ETV were recorded. Detailed measures of intelligence, attention and concentration, executive function, visual and verbal memory, language functions and fine motor skills were completed. Post treatment change was determined utilizing Reliable Change Index. Results: A total of 13 patients were identified. Etiology of the hydrocephalus was aqueductal stenosis in 8 and tectal glioma in 4. The majority of patients (11 of 13, 85%) demonstrated cognitive dysfunction at the borderline (≤1 SD) or impairment level (≤1.5 SDs) in at least one domain. Nine patients (69%) showed reliable improvement in at least one cognitive domain. The greatest improvement was seen with visual memory (42%). One quarter to one third of patients demonstrated improvement on tests of intelligence quotient, verbal memory, attention and concentration, and executive function. Two patients declined in executive functioning. Ventricle size improved in eight patients. Conclusions: ETV is a safe effective procedure, capable of producing reliable improvements in cognitive dysfunction with hydrocephalus. Patients with cognitive complaints alone may benefit from ETV.

Unilateral cortical hyperexcitability in congenital hydrocephalus: a TMS study

INTRODUCTION

Changes in cortical excitability are considered to play an important role in promoting brain plasticity both in healthy people and in neurological diseases. Hydrocephalus is a brain development disorder related to an excessive accumulation of cerebrospinal fluid (CSF) in the ventricular system. The functional relevance of cortical structural changes described in this disease is largely unexplored in human. We investigated cortical excitability using multimodal transcranial magnetic stimulation (TMS) in a case of congenital hydrocephalus with almost no neurological signs.

METHODS

A caucasian 40 years old, ambidextrous and multilingual woman affected by occult spina bifida and congenital symmetrical hydrocephalous underwent a TMS study. The intracortical and interhemispheric paired pulse paradigms were used, together with the mapping technique.

RESULTS

No significant differences were found in the resting motor thresholds between the two hemispheres. Instead, the intracortical excitability curves were statistically different between the two hemispheres (with short intracortical inhibition (SICI) being strongly reduced and intracortical facilitation (ICF) enhanced in the right one), and the interhemispheric curves showed a general hyper-excitability on the right hemisphere (when conditioned by the left one) and a general hypo-excitability in the left hemisphere (when conditioned by the right one). It is noteworthy that an asymmetric right hemisphere (RH) change of excitability was observed by means of mapping technique.

CONCLUSION

We hypothesize that in this ambidextrous subject, the observed RH hyper-excitability could represent a mechanism of plasticity to preserve functionality of specific brain areas possibly devoted to some special skills, such as multilingualism.

Neuroimaging of ventriculoperitoneal shunt complications in children

The ventriculoperitoneal shunt is the mainstay of treatment for hydrocephalus. Despite its widespread use and safety record, it often malfunctions due to complications such as obstruction, breakage, migration and infection. This necessitates a systematic approach to diagnosing the etiology of shunt failure. Any evaluation should begin with an appraisal of the patient's symptoms. In acute malfunction, nausea, vomiting, irritability, seizures, headache, lethargy, coma and stupor are seen. In chronic malfunction, neuropsychological signs, feeding pattern changes, developmental delay, decline in school performance, headaches and increased head size are often seen. The next step in evaluation is a CT scan of the head to evaluate ventricular size. Prior imaging studies should be obtained for comparison; if the ventricles have enlarged over time, shunt malfunction is likely. If there is no such increase or dilation in the first place, other diagnoses are possible. However, "slit ventricle syndrome" should also be considered. When prior imaging is not available, pumping the reservoir, a radionuclide shuntogram, a shunt tap or even surgical exploration are options. The goals of this paper are to provide an algorithm for evaluating shunt malfunction and to illustrate the radiographic findings associated with shunt failure.

Hydrocephalus status in spina bifida: an evaluation of variations in neuropsychological outcomes

OBJECT

The effect of hydrocephalus status on neuropsychological outcomes in children with spina bifida (SB) has not been carefully evaluated. The authors hypothesized a stepwise progression of outcomes related to hydrocephalus status (shunt-treated, arrested, or no hydrocephalus) and that motor, spatial, and executive function tasks would be more sensitive to hydrocephalus status than vocabulary and reading tasks.

METHODS

Two hundred eight children (mean age 11.2 years) with SB were grouped according to hydrocephalus status: shunt-treated hydrocephalus (166 children), arrested hydrocephalus (18 children), and no hydrocephalus (24 children). Sixty-one typically developing children were included as a control group (mean age 12.05 years). All children were tested across neuropsychological content domains, including verbal and nonverbal IQ, reading and mathematical achievement, explicit memory, visuospatial function, executive function, and motor skills.

RESULTS

There was a stepwise progression of outcomes. Averaging across tasks, performance scores of children with SB and no hydrocephalus (mean standard score 92.60) were higher than those of children with SB and arrested hydrocephalus (mean standard score 86.86), and scores of children in the latter group were higher than those of children with SB and shunt-treated hydrocephalus (mean standard score 82.30). All 3 groups scored lower than the control group (mean standard score 105.94). Fine motor tasks best differentiated the arrested-hydrocephalus and shunt-treated groups. Verbal and executive function tasks, often associated with socioeconomic status, best differentiated the group of children with SB and no hydrocephalus from the control group.

CONCLUSIONS

With the exception of fine motor skills and small differences in memory and spatial domains, children with SB and arrested or shunt-treated hydrocephalus have similar neuropsychological profiles. Performance of all 3 groups of children with SB was below that of the control group, which also reflects the lower socioeconomic status of the children with SB.

Prospective memory in adults with spina bifida

INTRODUCTION

Individuals with neurodevelopmental disorders have been observed to show accelerated cognitive aging or even dementia as early as 30 and 40 years of age. Memory deficits are an important component of age-related cognitive loss.

METHODS

In this study, we investigated prospective memory, which is often impaired in aging, in a group of 32 adults with spina bifida meningomyelocele (SBM), including members of the oldest living cohort successfully treated with shunts to divert excess cerebrospinal fluid, ventriculomegaly, and hydrocephalus, who are now around 50 years of age. Seventeen typically developing adults provided a comparison group.

RESULTS

The SBM and comparison groups differed in the prospective memory total score as well as in both time-based and event-based subscores. Prospective memory was impaired in both older and younger individuals with SBM. However, the percentage of individuals with impaired or poor prospective memory was three times higher in the older SBM group than in the younger SBM group. The results are considered in relation to specific features of the complex brain reorganization in SBM.

Treatment of myelomeningocele: a review of outcomes and continuing neurosurgical considerations among adults

OBJECT

Myelomeningocele is the most severe congenital malformation of the CNS that is compatible with survival. From the time of the development of practical treatment for hydrocephalus in the late 1950s, affected individuals began to survive into adulthood in substantial numbers. Data on the neurological status of these individuals are sparse, as are descriptions of their continuing requirements for neurosurgical care.

METHODS

A review of the literature was undertaken using the PubMed database maintained by the National Library of Medicine. Formal grading of the quality of evidence was not attempted, but methodological issues affecting validity or generalizability were noted.

RESULTS

Observations from 2 major longitudinal studies of cohorts of patients treated without selection using contemporary neurosurgical techniques have been published at intervals beginning in the mid-1970s. Numerous cross-sectional, institutional reviews have focused on neurosurgical issues in adulthood: hydrocephalus, Chiari malformation Type II and syringomyelia, and secondary spinal cord tethering. The organization of medical services for adults with myelomeningocele has received limited study.

CONCLUSIONS

Surviving adults with myelomeningocele achieve a wide range of neurological and functional outcomes, the most critical and adverse determinant of which is symptomatic CSF shunt failure. From a neurosurgical standpoint, adults with myelomeningocele remain clinically active indefinitely, and they deserve periodic neurosurgical surveillance.

Neuropathology and structural changes in hydrocephalus

In the context of spina bifida, hydrocephalus is usually caused by crowding of the posterior fossa with obstruction to cerebrospinal fluid flow from the forth ventricle, and less often by malformation of the cerebral aqueduct. Enlargement of the cerebral ventricles causes gradual destruction of periventricular white matter axons. Motor, sensory, visual, and memory systems may be disturbed through involvement of the long projection axons, periventricular structures including the corpus callosum, and the fimbria-fornix pathway. Secondary changes occur in neuronal cell bodies and synapses, but there is minimal death of neurons. The clinical syndrome of hydrocephalic brain dysfunction is thus due to subcortical disconnection. Some of the brain dysfunction is reversible by shunting, probably through restoration of cerebral blood flow and normalization of the extracellular environment. However, destroyed axons cannot be restored.

Size of third and fourth ventricle in obstructive and communicating acute hydrocephalus after aneurysmal subarachnoid hemorrhage

In patients with acute hydrocephalus after aneurysmal subarachnoid haemorrhage (SAH), lumbar drainage is possible if the obstruction is in the subarachnoid space (communicating hydrocephalus). In case of intraventricular obstruction (obstructive hydrocephalus), ventricular drainage is the only option. A small fourth ventricle is often considered a sign of obstructive hydrocephalus. We investigated whether the absolute or relative size of the fourth ventricle can indeed distinguish between these two types of hydrocephalus. On CT-scans of 76 consecutive patients with acute headache but normal CT and CSF, we measured the cross-sectional surface of the third and fourth ventricle to obtain normal planimetric values. Subsequently we performed the same measurements on 117 consecutive SAH patients with acute hydrocephalus. These patients were divided according to the distribution of blood on CT-scan into three groups: mainly intraventricular blood (n = 15), mainly subarachnoid blood (n = 54) and both intraventricular and subarachnoid blood (n = 48). The size of the fourth ventricle exceeded the upper limit of normal in 2 of the 6 (33%) patients with intraventricular blood but without haematocephalus, and in 15 of the 54 (28%) patients with mainly subarachnoid blood. The mean ratio between the third and fourth ventricle was 1.45 (SD 0.66) in patients with intraventricular blood and 1.42 (SD 0.91) in those with mainly subarachnoid blood. Neither fourth ventricular size nor the ratio between the third and fourth ventricles discriminates between the two groups. A small fourth ventricle does not necessarily accompany obstructive hydrocephalus and is therefore not a contraindication for lumbar drainage.

Neuropsychological assessment of adult patients with shunted hydrocephalus

OBJECTIVE

This study is planned to determine the neurocognitive difficulties of hydrocephalic adults.

METHODS

THE RESEARCH GROUP CONTAINED HEALTHY ADULTS (CONTROL GROUP, N : 15), and hydrocephalic adults (n : 15). Hydrocephalic group consisted of patients with idiopathic aquaduct stenosis and post-meningitis hydrocephalus. All patients were followed with shunted hydrocephalus and not gone to shunt revision during last two years. They were chosen from either asymptomatic or had only minor symptoms without motor and sensorineural deficit. A neuropsychological test battery (Raven Standart Progressive Matrices, Bender-Gestalt Test, Cancellation Test, Clock Drawing Test, Facial Recognition Test, Line Orientation Test, Serial Digit Learning Test, Stroop Color Word Interference Test-TBAG Form, Verbal Fluency Test, Verbal Fluency Test, Visual-Aural Digit Span Test-B) was applied to all groups.

RESULTS

Neuropsychological assessment of hydrocephalic patients demonstrated that they had poor performance on visual, semantic and working memory, visuoconstructive and frontal functions, reading, attention, motor coordination and executive function of parietal lobe which related with complex and perseverative behaviour. Eventually, these patients had significant impairment on the neurocognitive functions of their frontal, parietal and temporal lobes. On the other hand, the statistical analyses performed on demographic data showed that the aetiology of the hydrocephalus, age, sex and localization of the shunt (frontal or posterior parietal) did not affect the test results.

CONCLUSION

This prospective study showed that adult patients with hydrocephalus have serious neuropsychological problems which might be directly caused by the hydrocephalus; and these problems may cause serious adaptive difficulties in their social, cultural, behavioral and academic life.

Cognitive Functioning and Health-Related Quality of Life 1 Year After Aneurysmal Subarachnoid Hemorrhage in Preoperative Comatose Patients (Hunt and Hess Grade V Patients)

OBJECTIVE

The objective of this study was to determine cognitive functioning and health-related quality of life 1 year after aneurysmal subarachnoid hemorrhage in preoperative comatose patients (Hunt and Hess Grade V patients).

METHODS

Patients who were comatose at hospital arrival and thereafter were investigated for 1 year using a comprehensive neuropsychological test battery and 2 HRQOL questionnaires.

RESULTS

Thirty-five of 70 patients survived the bleed, and 26 underwent neuropsychological testing. Two distinct patient groups emerged, one (n = 14) with good cognitive function, having mild deficits only, and the other (n = 12) with poor cognitive and poor motor function. Patients performing poorly were older (P = .04), had fewer years of education (P = .005) and larger preoperative ventricular scores, and were more often shunted (P = .02). There were also differences between the 2 groups in the Glasgow Outcome Scale (P = .001), the modified Rankin Scale (P = .001), and employment status. HRQOL was more reduced in patients with poor cognitive function.

CONCLUSION

A high fraction of survivors among preoperative comatose aneurysmal SAH patients (Hunt and Hess grade V) recover to good physical and cognitive function, enabling them to live a normal life.

The neuropsychology of normal pressure hydrocephalus (NPH)

Normal pressure hydrocephalus (NPH) accounts for one of the few known forms of reversible dementia. Varied aetiology and clinical presentation contribute to difficulties with early or differential diagnoses, and delayed surgical treatment may be less efficacious. Clinical neuropsychology provides a means of determining a cognitive profile for NPH, assisting in differential diagnosis, tracking the disorder's progression and assessing the efficacy of treatment. This article will review possible applications of clinical neuropsychology and propose a clinical assessment protocol for NPH.

Treatment of hydrocephalus in adults

The following patients with multiple complex diagnoses define the adult hydrocephalus population: (1) transition patients (previously treated for hydrocephalus as children), (2) adults with previously untreated congenital hydrocephalus, (3) adults with acquired hydrocephalus with an identifiable etiology, and (4) patients with suspected or proven idiopathic normal pressure hydrocephalus. Restricting the outpatient care or hydrocephalus clinic definition to a single hydrocephalus patient subpopulation limits our understanding of these patients and effectively abandons the remaining adult patients with hydrocephalus to a less focused and potentially less effective healthcare arrangement. A comprehensive adult hydrocephalus clinic model is described and recommended to advance our understanding of this diverse patient population, which will ultimately lead to the development and provision of a better standard of patient care.

Fetal spina bifida repair--current trends and prospects of intrauterine neurosurgery

Myelomeningocele is a common dysraphic defect leading to severe impairment throughout the patient's lifetime. Although surgical closure of this anomaly is usually performed in the early postnatal period, an estimated 330 cases of intrauterine repair have been performed in a few specialized centers worldwide. It was hoped prenatal intervention would improve the prognosis of affected patients, and preliminary findings suggest a reduced incidence of shunt-dependent hydrocephalus, as well as an improvement in hindbrain herniation. However, the expectations for improved neurological outcome have not been fulfilled and not all patients benefit from fetal surgery in the same way. Therefore, a multicenter randomized controlled trial was initiated in the USA to compare intrauterine with conventional postnatal care, in order to establish the procedure-related benefits and risks. The primary study endpoints include the need for shunt at 1 year of age, and fetal and infant mortality. No data from the trial will be published before the final analysis has been completed in 2008, and until then, the number of centers offering intrauterine MMC repair in the USA is limited to 3 in order to prevent the uncontrolled proliferation of new centers offering this procedure. In future, refined, risk-reduced surgical techniques and new treatment options for preterm labor and preterm rupture of the membranes are likely to reduce associated maternal and fetal risks and improve outcome, but further research will be needed.

Relationship between serum sodium level and brain ventricle size after aneurysmal subarachnoid hemorrhage

OBJECTIVE

To study the relationship of serum sodium levels and brain ventricle size after aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Serum sodium levels and brain computed tomography (CT) scans were obtained simultaneously and within 21 days from onset of SAH in 69 patients. Serum sodium levels were compared with brain ventricle size on CT. The index of third ventricle was calculated from brain CT, and we studied its relationship to GOS (Glasgow Outcome Scale) scores.

RESULTS

There was obvious correlation between serum sodium levels and index of third ventricle (r = -0.753). GOS scores correlated with serum sodium levels in patients with hypernatremia.

CONCLUSION

There was a negative correlation between serum sodium levels and cerebral ventricle size in SAH patients. Hypernatremia is one factor leading an unfavorable prognosis in SAH patients.

Prospective, declarative, and nondeclarative memory in young adults with spina bifida

The consequences of congenital brain disorders for adult cognitive function are poorly understood. We studied different forms of memory in 29 young adults with spina bifida meningomyelocele (SBM), a common and severely disabling neural tube defect. Nondeclarative and semantic memory functions were intact. Working memory was intact with low maintenance and manipulation requirements, but impaired on tasks demanding high information maintenance or manipulation load. Prospective memory for intentions to be executed in the future was impaired. Immediate and delayed episodic memory were poor. Memory deficits were exacerbated by an increased number of lifetime shunt revisions, a marker for unstable hydrocephalus. Memory status was positively correlated with functional independence, an important component of quality of life.

Short-term medical management of hydrocephalus

Hydrocephalus is an excess accumulation of cerebrospinal fluid in or around the brain that can be produced by a broad spectrum of disorders. It can develop at any age and its incidence is increasing, both in infants and adults. Although the standard treatment of hydrocephalus is cerebrospinal fluid shunting, there are certain circumstances in which medical treatment, alone or in combination with shunting, has been suggested as an alternative. This review aims to present and discuss the indications for pharmacological treatment in the medical management of hydrocephalus, and the drugs most frequently used. Carbonic anhydrase inhibitors, loop diuretic agents, osmotic agents and fibrinolytic therapy are discussed. The most suitable drug seems to be acetazolamide, alone or in combination with furosemide. At present, osmotic agents are no longer used in the treatment of hydrocephalus. Fibrinolytic therapy administered directly into the ventricular system may not avoid the need for shunt placement, but may help in the management of hydrocephalus by preventing or reducing the rate of catheter obstruction and accelerating clot resolution.

A multilevel analysis of cognitive dysfunction and psychopathology associated with chromosome 22q11.2 deletion syndrome in children

We present a multilevel approach to developing potential explanations of cognitive impairments and psychopathologies common to individuals with chromosome 22q11.2 deletion syndrome. Results presented support our hypothesis of posterior parietal dysfunction as a central determinant of characteristic visuospatial and numerical cognitive impairments. Converging data suggest that brain development anomalies, primarily tissue reductions in the posterior brain and changes to the corpus callosum, may affect parietal connectivity. Further findings indicate that dysfunction in "frontal" attention systems may explain some executive cognition impairments observed in affected children, and that there may be links between these domains of cognitive function and some of the serious psychiatric conditions, such as attention-deficit/hyperactivity disorder, autism, and schizophrenia, that have elevated incidence rates in the syndrome. Linking the neural structure and the cognitive processing levels in this way enabled us to develop an elaborate structure/function mapping hypothesis for the impairments that are observed. We show also, that in the case of the catechol-O-methyltransferase gene, a fairly direct relationship between gene expression, cognitive function, and psychopathology exists in the affected population. Beyond that, we introduce the idea that variation in other genes may further explain the phenotypic variation in cognitive function and possibly the anomalies in brain development.

Maternal-fetal surgery for myelomeningocele: neurodevelopmental outcomes at 2 years of age

OBJECTIVE

This study was undertaken to examine short-term neurodevelopmental outcomes in children with myelomeningocele (MMC) who underwent in utero neurosurgical closure.

STUDY DESIGN

Between 1998 and 2002, 51 fetuses underwent in utero MMC closure at our Center. Thirty (63%) of these children have returned for neurodevelopmental testing at 2 years of age using the Bayley Scales of Infant Development and Preschool Language Scales.

RESULTS

Overall shunt rate was 43% in this group. Neurodevelopmental testing found 67% with cognitive language and personal-social skills in the normal range, 20% with mild delays, and 13% with significant delays. Children with shunted hydrocephalus scored lower than those with unshunted ventriculomegaly.

CONCLUSION

Children who have undergone fetal MMC closure have characteristic neurodevelopmental deficits that do not appear worsened by fetal surgery, and developmental outcomes may be improved by decreasing the need for ventriculoperitoneal shunting.

Neuropsychophysiological findings in a case of long-standing overt ventriculomegaly (LOVA)

Long-standing overt ventriculomegaly in adults (LOVA) is a clinical entity characterized by chronic hydrocephalus with infant onset, slow evolution and clinical disturbances during adulthood. Few cases are reported in literature describing the evident contrast between the severity of hydrocephalus and the relatively spared neurological functioning and cognitive aspects. The authors describe a 59-year-old man with congenital hydrocephalus complaining of persistent gait impairment. Neurological examination showed a mild paraparesis, severe higher cortical function impairment but relatively sparing of daily living activity. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a very remarkable ventriculomegaly compressing the brain cortex but sparing the cerebellum and the brainstem. Brain Single Photon Emission Computer Tomography (SPECT) showed a prevalent cerebellar perfusion as well. Neuropsychological testing was consistent with severe cognitive deterioration and attention disorders. Language and praxis functions seemed to be preserved. Auditory oddball ERPs (P300) showed morphological abnormalities especially of late components. This case report demonstrates in vivo the level of adaptation to which human brain can reach under chronic mechanic stress conditions. The striking poor cerebral parenchyma representation and the relatively spared language and praxic abilities account for a functional reorganization of residual structures due to the neural plasticity.

Volumetric, connective, and morphologic changes in the brains of children with chromosome 22q11.2 deletion syndrome: an integrative study

Chromosome 22q11.2 deletion syndrome is a highly prevalent genetic disorder whose manifestations include developmental disability and sometimes mental retardation. The few studies that have examined brain morphology in different samples from this population have found similar general patterns, mostly using region of interest measures. We employed voxel-based techniques to concurrently examine specific morphologic changes in multiple brain tissue measures. Results were similar to previous findings of volumetric reductions in the posterior brain. They also extended them in two ways. First, our methods provided greater specificity in the localization of changes detected. Second, the combination of our measures of gray and white matter along with cerebrospinal fluid volume and fractional anisotropy, which indicates the structure of white matter, showed a posterior displacement of and morphologic changes to the corpus callosum in affected children.

Occult Hydrocephalus in Children with Cerebral Palsy

OBJECTIVE:

Many children with cerebral palsy have chronic ventriculomegaly as a consequence of perinatal intraventricular hemorrhage or periventricular leukomalacia, without symptoms of hydrocephalus. Children with cerebral palsy who are treated with intrathecal baclofen have a higher rate of cerebrospinal fluid (CSF) leaks along the baclofen catheter than do adults treated with intrathecal baclofen. We postulated that the cause of the increased frequency of CSF leaks was increased CSF pressure, that is, occult hydrocephalus.

METHODS:

Lumbar punctures were performed in 24 children with cerebral palsy and asymptomatic ventriculomegaly. Their median age was 4.7 years. Mild or moderate ventriculomegaly was present in 23 children and severe ventriculomegaly was present in 1 child.

RESULTS:

Opening pressures were abnormally high in 23 (96%) of 24 children and ranged from 22 to 41 cm H2O (mean, 27.3 cm H2O). Opening pressures did not correlate with the extent of ventriculomegaly.

CONCLUSION:

Children with cerebral palsy and ventriculomegaly seem to have a high incidence of increased CSF pressure, and thus, of occult hydrocephalus. The increased pressure is probably a significant cause of the increased frequency of CSF leaks for these children during intrathecal baclofen therapy. The long-term risks of untreated increased CSF pressures in this patient population are not known but are cause for concern. Treatment with CSF shunts offers the potential of improved development, which was reported anecdotally in some children who were treated with ventriculoperitoneal shunts after their pressure was found to be increased. Prospective multicenter studies of this problem are needed.

Chronic hydrocephalus in adults

Chronic hydrocephalus is a complex condition, the incidence of which increases with increasing age. It is characterised by the presence of ventricular enlargement in the absence of significant elevations of intracranial pressure. The clinical syndrome may develop either as a result of decompensation of a "compensated" congenital hydrocephalus, or it may arise de novo in adult life secondary to a known acquired disturbance of normal CSF dynamics. The latter may be due to late onset acqueductal stenosis or disruption of normal CSF absorptive pathways following subarachnoid hemorrhage or meningitis ("secondary" normal pressure hydrocephalus (NPH)). In some cases the cause of the hydrocephalus remains obscure ("idiopathic" NPH). In all forms of chronic hydrocephalus the clinical course of the disease is heavily influenced by changes in the brain associated with aging, in particular cerebrovascular disease. Recent research has challenged previously held tenets regarding the CSF circulatory system and this in turn has led to a radical rethinking of the pathophysiological basis of chronic hydrocephalus.

Ventriculostomia endoscópica: influencia de factores predisponentes al fallo y evolución del tamaño ventricular

INTRODUCTION

Endoscopic third ventriculostomy is the treatment of choice for non communicating hydrocephalus at our institution. Several factors have been associated with failure of endoscopic third ventriculostomy. The goals of the study have been to evaluate the outcome, the influence of factors theoretically prone to failure of ventriculostomy and the evolution of ventricular size.

MATERIAL AND METHODS

Fifty-six patients (mean age 48.5 yrs) treated with an endoscopic third ventriculostomy during the period 1997-2002 were analysed retrospectively. Hydrocephalus was classified as acute (68%) and chronic forms. Etiology was classified in space-occupying lesions (59%), primary aqueductal stenosis (34%) and Chiari malformation (7%). The presence of the following factors theoretically prone to failure was considered: age below one year, history of mielomeningocele, cerebrospinal fluid (CSF) infection, intracranial haemorrhage, radiotherapy, craniotomy and previous treatment of hydrocephalus with a shunt. Ventricular size was measured linearly with four ventricular index pre- and postoperatively.

RESULTS

The global success rate was 71.4% (mean follow-up 26 months). Endoscopic third ventriculostomy for hydrocephalus secondary to cerebral metastases obstructing CSF pathways was associated with a higher risk of failure (p=0.006). None of the risk factors considered was associated with a higher risk of failure. The evolution of the ventricular size measured with linear methods is associated with outcome. Evans ratio, third ventricle index, cella media index and ventricular score decreased in patients whose outcome is satisfactory and increased in those cases deemed clinical failures (p< 0.05).

CONCLUSION

The risk of failure increases in patients with cerebral metastases close to CSF pathways, likely due to the concurrence of mechanisms other than obstruction. Changes in ventricular size are associated with outcome.

Lack of relationship between resistance to cerebrospinal fluid outflow and intracranial pressure in normal pressure hydrocephalus

OBJECTIVE

To explore whether calculation of resistance to cerebrospinal fluid (CSF) outflow (Rout) by the lumbar constant rate infusion test in a reliable way predicts the intracranial pressure (ICP) profile in normal pressure hydrocephalus (NPH).

METHODS

A prospective study was undertaken including 16 cases with clinical signs of normal pressure hydrocephalus that were investigated with both continuous ICP monitoring and the lumbar constant rate infusion test. Intracranial pressure monitoring was performed for about 24 h, and supplied with a simultaneous lumbar constant rate infusion test at the end of the monitoring period. The pressure recordings were analysed using the Sensometrics Pressure Analyser. Various characteristics of the pressure curves were compared.

RESULTS

The continuous ICP recordings were considered as normal (mean ICP<11.5 mmHg) in all 16 cases. The lumbar infusion test showed an apparently abnormal resistance to CSF outflow (Rout) (> or =12.0 mmHg/ml/min) in 12 of 16 cases. There was no relationship between lumbar Rout and mean ICP during sleep. We could not find any relationship between lumbar Rout and number of nightly ICP elevations of 1525 mmHg lasting 0.5 or 1 min. Neither resistance to CSF outflow (Rout) nor mean ICP during sleep was related to the ventricular size.

CONCLUSIONS

The results of this prospective study revealed no significant relationship between resistance to CSF outflow (Rout) and the ICP profile in NPH cases. The results also suggest that caution should be made when predicting the ICP profile on the basis of measuring the lumbar CSF pressure for a few minutes duration.

Chronic hydrocephalus in rats and humans: white matter loss and behavior changes

Chronic hydrocephalus that begins in childhood and progresses only very gradually is sometimes called "arrested" hydrocephalus. Data suggest that this state eventually can become symptomatic and may be treatable by shunting. However, the pathological substrate of the disorder is not entirely understood. We studied chronic hydrocephalus in rats, 9 months after induction by kaolin injection into the cisterna magna, and in humans. In both circumstances, destruction of periventricular white matter structures was worst in those with the largest ventricles. Structures damaged include the corpus callosum, corticospinal tract, and fimbria/fornix projections from the hippocampus. Myelin turnover was increased. These changes were associated with deficits of motor and cognitive function. The cerebral cortex was largely spared. There appears to be a threshold of ventricle size beyond which functional changes manifest, but this undoubtedly is modified by factors such as age of onset and rate of enlargement. These data support the need for persistent follow-up of patients with chronic, apparently stable hydrocephalus. A slight increase in size of already enlarged ventricles might cause significant axonal damage.

Neuropsychological findings in congenital and acquired childhood hydrocephalus

Hydrocephalus is an increase in cerebrospinal fluid volume that can be caused by a variety of etiologies. The most common connatal and acquired causes of hydrocephalus are spina bifida, aqueduct stenosis, and preterm low birthweight infants with ventricular hemorrhage. In general, the literature suggests mild neuropsychological deficits associated with hydrocephalus, which are predominant in visuospatial and motor functions, and other nonlanguage skills. Although the precise nature of the neuropsychological deficits in hydrocephalus are not completely known, several factors such as etiology, raised intracranial pressure, ventricular size, and changes in gray and white matter tissue composition as well as shunt treatment complications have been shown to influence cognition. In fact, the presence of complications and other brain abnormalities in addition to hydrocephalus such as infections, trauma, intraventricular hemorrhage, low birthweight, and asphyxia are important determinants of the ultimate cognitive status, placing the child at a high risk of cognitive impairment.

Neuropsychological outcome in relation to the traumatic coma data bank classification of computed tomography imaging

The Traumatic Coma Data Bank (TCDB) classification of CT (computed tomography) scan has been related to the general outcome and intracranial pressure evolution. Our aim was to analyse the relationship of this classification with neuropsychological outcome and late indices of ventricular dilatation. Fifty-seven patients with a moderate or severe head injury (mean admission Glasgow Coma Scale Score, 7.7) were studied from 122 consecutive cases. There were 49 males and 8 females (mean age, 27.7 years). Subjects were classified into TCDB categories on the basis of their most serious acute CT scan finding. From the last control CT scan image, performed at a mean of 6.12 months postinjury, several measures of ventricular dilatation were calculated. Neuropsychological assessment at 6-month included tests of verbal and visual memory, visuoconstructive functions, fine motor speed, and frontal lobe functions. Patients with diffuse injury type I showed better neuropsychological outcome than patients with more severe diffuse injuries and those with mass lesions. Within the diffuse injury groups, the degree of diffuse damage was related to measures of verbal memory and attention and cognitive flexibility. Ventricular enlargement was more evident in patients with mass lesions and it decreased in the remaining groups as the severity of diffuse injury diminished. These results show that there is a relationship between acute intracranial lesion diagnosis according to TCDB classification and neuropsychological results and ventricular dilatation indices at 6 months postinjury.

Fetal surgery for myelomeningocele

Myelomeningocele is a devastating birth defect affecting a significant number of live births worldwide. Prenatal repair of myelomeningocele has been performed in the United States for 5 years with mixed results. The initial intent was to preserve distal neurological function by covering the exposed spinal cord. Although there has been relatively little effect on distal sensorimotor function, prenatal repair serendipitously led to an apparent reduction in hindbrain herniation and a possible decreased need for ventriculoperitoneal shunting. The long-term clinical consequences of these findings are not clear. What is clear, however, is that further study in the form of a prospective, randomized trial is mandatory.