CSF spaces in idiopathic normal pressure hydrocephalus: morphology and volumetry

PURPOSE: Idiopathic normal pressure hydrocephalus (NPH) is an important cause of dementia in the elderly; however, idiopathic NPH is often difficult to differentiate from normal aging and vascular dementias in which brain atrophy with ventricular dilatation (hydrocephalus ex vacuo or central atrophy) is present. To elucidate the distinctive features of the distribution of CSF in idiopathic NPH, we used MR imaging to investigate the morphologic features and volume of the CSF space in patients with idiopathic NPH compared with those with other dementias. METHODS: We assessed the size of four CSF compartments (the ventricle, basal cistern, sylvian space, and suprasylvian subarachnoid space) in 11 shunt-responsive patients with idiopathic NPH by semiquantitative and volumetric analyses of coronal T1-weighted MR images. The results were compared with those in 11 age- and sex-matched patients with Alzheimer disease and in 11 patients with vascular dementia. RESULTS: In patients with idiopathic NPH, the CSF volume was significantly increased in the ventricles and decreased in the superior convexity and medial subarachnoid spaces as compared with patients with other dementias. The sylvian CSF volume in patients with idiopathic NPH was significantly greater than in patients with Alzheimer disease. The volume of the basal cistern was comparable among the three groups. In several patients with idiopathic NPH, focally dilated sulci were observed over the convexity or medial surface of the hemisphere. CONCLUSION: Our results indicate that findings of enlarged basal cisterns and sylvian fissures and of focally dilated sulci support, rather than exclude, the diagnosis of shunt-responsive idiopathic NPH and suggest that this condition is caused by a suprasylvian subarachnoid block.     

Cortical variability and asymmetry in normal aging and Alzheimer's disease

The onset of Alzheimer's disease (AD) is accompanied by a complex and distributed pattern of neuroanatomic change, difficult to distinguish clinically from dynamic alterations in normal aging. Extreme variations in the sulcal patterns of the human cortex have made it difficult to identify diffuse and focal variations in cortical structure in neurodegenerative disease. We report the first comprehensive 3D statistical analysis of deep sulcal structure in vivo, in both normal aging and dementia. High-resolution 3D T1-weighted fast SPGR (spoiled GRASS) MRI volumes were acquired from 10 patients diagnosed with AD (NINCDS-ARDRA criteria; age: 71.9 +/- 10.7 years) and 10 normal subjects matched for age (72.9 +/- 5.6 years), gender, educational level and handedness. Scans were digitally transformed into Talairach stereotaxic space. To determine specific patterns of cortical variation in dementia patients, 3D average and probabilistic maps of primary deep sulci were developed for both normal and AD groups. Major sulci (including supracallosal, cingulate, marginal, parieto-occipital, anterior and posterior calcarine sulci, and Sylvian fissures) were modeled as complex systems of 3D surfaces using a multi-resolution parametric mesh approach. Variations and asymmetries in their extents, curvature, area and surface complexity were evaluated. Three-dimensional maps of anatomic variability, structural asymmetry and local atrophy indicated severe regionally selective fiber loss in AD. A midsagittal area loss of 24.5% at the corpus callosum's posterior midbody (P < 0.025) matched increases in structural variability in corresponding temporo-parietal projection areas. Confidence limits on 3D cortical variation, visualized in 3D, exhibited severe increases in AD from 2 to 4 mm at the callosum to a peak SD of 19.6 mm at the posterior left Sylvian fissure. Normal Sylvian fissure asymmetries (right higher than left; P < 0.0005), mapped for the first time in three dimensions, were accentuated in AD (P < 0.0002), and were greater in AD than in controls (P < 0.05). Severe AD-related increases in 3D variability and asymmetry may reflect disease-related disruption of the commissural system connecting bilateral temporal and parietal cortical zones, regions known to be at risk of early metabolic dysfunction, perfusion deficits and selective neuronal loss in AD.     

Structural cerebral pathology in schizophrenia: regional or diffuse?

Is brain pathology in schizophrenia topographically distinct? If so, are the putative regional changes unique to the disorder? To address these questions, 56 chronic schizophrenic Ss were compared with 16 psychiatric control Ss with mood disorders and with 31 healthy volunteers on multiple-volume measures of regional cerebral atrophy obtained with computed tomography. Generalized cortical and subcortical enlargement of spaces filled with cerebrospinal fluid sparing only the occipitoparietal cortex was found in the schizophrenic Ss compared with normal control Ss. Statistically significant differences in the extent of perisylvian atrophy were noted between schizophrenic Ss and patients with mood disorders: Schizophrenic Ss evidenced greater dilation of perisylvian fissures and sulci. The implications of the results for future research and for recent theories on the etiology of schizophrenia are discussed.     

Normal pressure hydrocephalus and hypertensive cerebrovascular disease

This report compares the clinical and post mortem findings in a case of normal pressure hydrocephalus (NPH) syndrome occurring in association with hypertensive cerebrovascular disease, with the only two such previously reported autopsied cases. The presence of hypertension and focal neurological findings in a patient with otherwise classic clinical and radiologic features of NPH syndrome should alert one to the possibility of hypertensive cerebrovascular disease as the cause of the syndrome. Transient improvement occurred following shunting in two, and none in the third case. All died within three years of illness. It appears shunting is not of significant benefit in these patients.     

Computerized tomography in the diagnosis of cerebral atrophy

Computerized tomograms were studied of 67 adults whose lumbar pneumoencephalograms were normal or showed ventricular dilatation with or without widening of the sulci. The maximum ventricular area, measured from 80 x 80 matrix printouts, correlates well with measures of ventricular size on the pneumoencephalogram. An area of 10 cm2 is suggested as the upper limit of normal. The correlation between measures of sulcal width on computerized tomography and pneumoencephalography is less precise, but normal sulci and gross degrees of cortical atrophy can be identified.     

Non-invasive detection of ongoing neuronal population activity in normal human hippocampus

In a prospective series of symptomatic adult hydrocephalus characterized by gait disturbance, cognitive impairment, and/or urinary incontinence, 88 of 118 patients (75%) had additional akinetic, tremulous, hypertonic, or hyperkinetic movement disorders. Their prevalence was highest in patients with idiopathic normal pressure hydrocephalus (NPH) of the elderly (56/65 patients, 86%), and they were less frequent in patients with secondary NPH (10/15, 66%), with nonhydrodynamic atrophic/other hydrocephalus (20/33, 61%), and with obstructive hydrocephalus/aqueductal stenosis (2/5, 40%). Akinetic symptoms were found in 73 of 118 patients (62%), and the most frequent movement disorder was upper extremity bradykinesia (55%). Akinetic, tremulous, hypertonic, and hyperkinetic movement disorders were exclusively secondary to causes not related to hydrocephalus in 24 of 118 patients (20%). The proportion of patients with movement disorders not attributable to only such causes was highest in the idiopathic NPH group (44/65, 68%). Thirteen of 118 patients (11%) presented with a parkinsonian syndrome. There was evidence for coexistent Parkinson's disease in four of these patients. Parkinsonism was found to be secondary to NPH in five patients and was found improved after shunting. Akinetic symptoms in patients with NPH generally responded favorably to CSF diversion, which was evident in 80% of a subset of this group. Various other movement disorders did not show definite improvement. The high prevalence of bradykinesia and other akinetic symptoms in NPH and the beneficial effect of shunting on such symptoms suggest that NPH may cause a more generalized disorder of motor function.     

Psychophysiology, signs and symptoms of disease the course of normal pressure hydrocephalus

Between May 1982 until January 1997 we investigated 200 patients suspected for normal pressure hydrocephalus (NPH) by performing an intrathecal infusion test. According to our experiences gait ataxia is the leading symptom of NPH. Regarding dementia we could not find a significant difference compared to cerebral atrophy. Bladder incontinence can be characterised as a symptom of late-stage NPH. The complete Hakim trias should not be overestimated in differential diagnostic considerations. Graduation of NPH and cerebral atrophy after the results of the infusion test in an early and late stage enables prognostic evaluation of the course of disease. Patients with NPH in an early stage report in the follow-up on an improvement of their symptoms after shunt operation (65 percent of patients), whereas 50 percent of the patients with late stage NPH were improved. The computer-aided infusion test allows secure differentiation between patients with NPH and those with cerebral atrophy.     

The radiodensity of medications seen on x-ray films

A 44-year-old Japanese man was diagnosed as having late adult-onset dentatorubral-pallidoluysian atrophy (DRPLA), whose CAG repeats in the DRPLA gene were 60 and 15. He developed gait disturbance, limb ataxia, pyramidal tract signs, dementia, and psychiatric symptoms including character changes within a few years of the above diagnosis. His T 2-weighted brain MRI showed symmetric high-signal lesions in the cerebral white matter and brain stem, in addition to cerebellar, brain stem, and cerebral cortical atrophy. Since the results of RI cisternography indicated that he manifested the clinical features of normal pressure hydrocephalus (NPH), V-P shunt operation was done. In a week after the operation, his gait disturbance, pyramidal tract signs, dementia and psychiatric symptoms were remarkably improved. White matter lesions have been thought to be concomitant with late adult-onset DRPLA patients, but some of these patients may have characteristics of NPH pathophysiology.     

Epilepsy in shunt-treated hydrocephalus

Although epilepsy is commonly associated with shunt-treated hydrocephalus, its relation to the shunting procedure and the criteria identifying postoperative epilepsy remain controversial. Of 283 patients shunted at Würzburg University Hospital over a 24-year period (1970 to 1994), 182 were followed up for a minimum of 1 year after shunt insertion and entered the study. The data were analyzed retrospectively in 1995 and 1996. Epilepsy was analyzed in relation to the etiology of hydrocephalus, functional status, time and site of shunt insertion, onset of seizures and seizure type, EEG changes, sex, shunt systems, and shunt revisions. Of the 182 patients studied, 37 (20%) developed epilepsy. The incidence of epilepsy varied according to the etiology of hydrocephalus: posthemorrhagic (5%), postinfectious (4%), connatal/miscellaneous/unknown (3%), myelomeningocele (2%), tumor/arachnoidal cyst/aqueduct stenosis (0%). Early shunting and poor functional status was associated with a higher risk for epilepsy. Epilepsy was not influenced by sex, shunt systems, or number of shunt revisions. Twenty-two (12%) of 182 patients developed epilepsy (generalized N=13, focal N=9) after intracranial shunting. Focal EEG abnormalities (N=16) were located mainly at the anatomical site of the shunt (N=14), but only three patients (2%) presented with focal seizures contralateral and focal EEG abnormalities ipsilateral to the site of the shunt. The presence of epilepsy was determined by the etiology of hydrocephalus rather than by surgical intervention. The incidence of postoperative epilepsy (12%) was low. Onset of epilepsy, clinical presentation of seizures, and EEG changes did not appear to be valid criteria for identifying shunt-related epilepsy. Thus, epilepsy as a complication of intracranial shunting might be overestimated in the literature.     

Siliconized glass versus polypropylene to reduce in vitro platelet activation

BACKGROUND: CSF shunting procedures are generally considered the fundamental therapy of syphilitic hydrocephalus. METHODS: We followed up with CSF analysis and MR imaging a patient with progressive mental and gait disturbances and tetraventricular hydrocephalus due to tertiary syphilis who was treated for 14 days with high dose intravenous penicillin alone. RESULTS: Clinical and CSF abnormalities resolved within a few months, whereas the hydrocephalus disappeared only 30 months after therapy. CONCLUSIONS: Before consideration of a CSF shunting procedure, a trial of high dose intravenous penicillin is warranted for patients with syphilitic hydrocephalus.     

White matter lesions in patients with idiopathic normal pressure hydrocephalus and in an age-matched control group: a comparative study

OBJECTIVE: To compare the occurrence of periventricular lesions (PVLs) and deep white matter lesions (DWMLs) in elderly patients with idiopathic normal pressure hydrocephalus (NPH) and in an age-matched control group. METHODS: PVLs and DWMLs were evaluated using T2-weighted magnetic resonance scans of 37 patients with idiopathic NPH and 35 participants from an age-matched control group. All patients with idiopathic NPH included in this study improved after shunting. The control group consisted of 16 healthy elderly persons and 19 patients with depression. To allow quantitative assessment and comparison, scores for PVLs and DWMLs were calculated. Furthermore, possible correlations between white matter lesion scores, ventricular width, and age were investigated. RESULTS: There was a significantly higher incidence of PVLs and DWMLs in patients with idiopathic NPH. The mean total PVL was 12.1 (range, 2-24) in the NPH group and 3.9 (range, 0-10) in the control group (P < 0.001). The mean total DWML score was 12.9 (range, 3-24) in the NPH group and 4.5 (range, 0-16) in the control group (P < 0.001). There were significant correlations between the severity of PVL and DWML scores in both groups. Only a weak positive correlation between the severity of DWMLs and age was found in the NPH group, whereas this correlation was significant in the control group. There was a significant negative correlation between the width of the anterior horns and the severity of both PVLs and DWMLs in patients with NPH; however, positive correlations were found in the control group. CONCLUSION: Elderly patients with idiopathic NPH have more frequent and more severe PVLs and DWMLs than people in age-matched control groups. Our data suggest a frequent co-occurrence of idiopathic NPH and vascular subcortical encephalopathy; however, they do not support a direct causal relationship.     

The role of neuroendoscopy in the treatment of pineal region tumors

The authors describe a technique for the initial management of patients with pineal region neoplams and symptomatic hydrocephalus. Endoscopic third ventriculostomy and, if possible, tumor biopsy are performed through a single precoronal burr hole. When indicated, formal tumor resection can be performed nonemergently, without the need for ventricular drainage or shunting.     

High-resolution magnetic resonance imaging of the intraorbital optic nerve and subarachnoid space in patients with papilledema and optic atrophy

OBJECTIVE: To evaluate the orbital portion of the optic nerve and the subarachnoid space using fast spin-echo magnetic resonance imaging in normal subjects and in patients with papilledema or optic atrophy. DESIGN: Measurements of the optic nerve complex on coronal images were made using high-resolution magnetic resonance imaging with fast spin-echo sequences. PATIENTS: Twenty-one patients, including 5 patients with papilledema due to congenital hydrocephalus, intracranial tumors, or meningitis, as well as 16 patients with optic atrophy, were studied. Sixteen healthy volunteers served as controls. MAIN OUTCOME MEASURES: The longitudinal diameter of the optic nerve, the longitudinal outer diameter of the subarachnoid space, the diameter ratio, and the area of the subarachnoid space were determined. RESULTS: In normal subjects, the ring-shaped area of high signal intensity that represented the subarachnoid space was widest behind the globe, then narrowed toward the orbital apex. In patients with papilledema, the area of the subarachnoid space was markedly dilated, the optic nerve was compressed, and the nerve sheath was widened, resulting in a small diameter ratio compared with that of controls. Patients with pallor of the temporal aspect of the optic disc appeared to exhibit dilation of the subarachnoid space; the size of the optic nerve was decreased more than that of the nerve sheath, resulting in a small diameter ratio compared with controls. Patients with complete pallor of the disc, however, exhibited hyperintense optic nerve complexes without a ring-shaped appearance toward the orbital apex. CONCLUSION: Fast spin-echo magnetic resonance imaging appears useful for objectively evaluating the optic nerve and surrounding subarachnoid space in patients with papilledema and optic atrophy.     

Clinical and experimental study on the long-term effect of dietary gamma-linolenic acid on plasma lipids, platelet aggregation, thromboxane formation, and prostacyclin production

A follow-up study was performed in nine patients with idiopathic normal pressure hydrocephalus (NPH) 37 months (mean) after shunting and 10 non-operated controls with comparable degrees of ventricular enlargement, gait disorder, and dementia. Five operated patients vs. no controls reported sustained general improvement (p < 0.02). Objectively improved gait at follow-up (compared with preoperative status) was found in five of the six tested NPH-patients vs. none of the controls (p < 0.005). Improved gait and/or psychometric function was found in four of six NPH vs. none of eight control patients (p < 0.02) after drainage of 40 ml cerebrospinal fluid (CSF tap-test). Improved gait during the CSF tap-test predicted continued improvement at follow-up. Temporal horn size was the only radiological variable which showed a (moderate) positive correlation with resistance to CSF absorption and rate of pressure increase. The size of the third ventricle diminished in parallel with clinical improvement.     

Police and mental health professionals. Collaborative responses to the impact of violence on children and families

Most pediatric patients with hydrocephalus are treated with ventriculoperitoneal (VP) shunt placement. However, shunt malfunction is common and is usually caused by mechanical failure. Shunt obstructions may be confirmed with radioisotope examination or with fluoroscopically guided injection of iodinated contrast material into the shunt reservoir. Disconnections or breaks are more readily detected at radiography in cases in which barium-impregnated shunt tubing was used. Migration and leakage may also occur. Cerebrospinal pseudocysts may be demonstrated with plain radiography and further evaluated with computed tomography (CT) and sonography. In increasing hydrocephalus, plain radiography may reveal sutural diastasis and increased cranial cavity size, and CT can be used to evaluate ventricle size. In cases of enlarging intracranial cysts, injection of iodinated contrast material followed by CT can help document a connection between the cyst and the ventricles. Ventriculitis and meningitis can be visualized at CT and magnetic resonance imaging as enhancement of the ventricular ependymal lining or cerebral cortical sulci. Other complications associated with VP shunts include surgery-related complications, shunt overdrainage and slit-ventricle syndrome, neoplastic metastasis, pleural effusion, and complications related to shunt variants. Imaging analysis is an essential adjunct to the clinical evaluation of patients with suspected VP shunt malfunctions or complications. Radiologists should be familiar with these potential problems and the diagnostic utility of various imaging modalities.     

Lymphocytic choriomeningitis virus-induced alterations of T helper-mediated responses in mice developing autoimmune hemolytic anemia during the course of infection

A slit-like ventricle is one of the serious complications which can occur after a shunting operation. Low pressure valve systems are usually applied for hydrocephalus during infancy. As a result the shape of the ventricle often becomes slit-like after the operation. Many shunt dependent children with slit-like ventricles have to undergo shunt revisions repeatedly. From April 1995 to February 1997 the authors used the Medos programmable Hakim valve system for 20 hydrocephalic children with slit-like ventricles who had been suffering from multiple shunt problems. The patients ages at the operation were between 3-16 Male:Female was 12:8. Follow up periods were 10-20 months. In 12 of 20 patients the shunt revisions were performed at the time of shunt dysfunction and the valve pressure levels were able to be set at the highest levels without the appearance of any symptoms. In this group the size of all the ventricles had become slightly enlarged. In the other 8 patients the operations were performed for fear of other troubles arising if shunt revisions were neglected. In this group the valve pressure levels were set with reference to the intraoperative ICP. It took a relatively long period to elevate the valve levels. Shunt dysfunction due to obstruction of the ventricular catheter was seen in one case but the symptom was not so severe and the catheter which had firmly adhered to the choroid plexus was removed endoscopically. In 2 cases of this series the shunt systems were successfully eliminated. The authors report the method and efficacy of their series using the Medos programmable Hakim valve system and a newly developed ventriculofiberscope for the slit-like ventricle of children.     

Factors affecting the outcome of foetal hydrocephaly

In this study, the authors attempt to provide an account of the factors that affect the outcome of hydrocephaly in 26 foetuses. The hydrocephalus was related to a myelomeningocele in 35% of patients. Sixty-two percent of foetuses showed intra-uterine progression of their hydrocephalus and 50% were shunted postnatally. At a mean follow up of 2 years, the outcome was considered "fair" in 54% of patients. Our findings demonstrate that in foetal hydrocephaly a more favourable outcome is expected in patients with hydrocephalus which does not progress in utero, in whom the labour is not induced before 36 weeks of gestation, who are delivered vaginally weighing more than 2.5 kg and have a head circumference below the 95th centile and a CT cortical mantle thickness of 2 cm and more and who are treated by CSF shunting. The diagnosis of the foetal hydrocephaly at or before 28 weeks of gestation and the presence of a myelomeningocele did not affect the outcome significantly. Neurosurgeons are reminded to keep an open mind for infants with foetal hydrocephaly and to offer active treatment to patients with a potentially favourable outcome.     

Electroencephalography and computerized transaxial tomography in patients with temporal lobe epilepsy

Computerized transaxial tomography was carried out on 112 patients with partial seizures with complex symptomatology. Structural abnormalities were defined in 33% of their studies: tumors in 8 patients, diffuse cerebral atrophy in 2, focal cortical atrophy in 27 and vascular abnormality in 1 case.     

Ultrasound of extracerebral spaces in infants: standardized examination technique

High resolution ultrasound (5/7.5 MHz, linear array) allows imaging of the extracerebral space in infants. A standardised state-of-the-art imaging technique is described that can be performed during routine cranial sonography. Diagnosing dilated subarachnoid space is possible by comparison to normal values. Pathological findings of the subarachnoid and subdural space can be differentiated. Evaluation of the following conditions is possible: external hydrocephalus, cortical atrophy, pyogenic meningitis, subdural hematoma and hygroma. High resolution ultrasound can add helpful information in situations in which magnetic resonance imaging or computed tomography were previously needed. Since it is a noninvasive method, ultrasound is ideal for follow-up studies and hence the method of choice.