Intracranial pressure in patients with dementia and communicating hydrocephalus

Chawla, J C; Hulme, A.; Cooper, R.

doi:10.3171/jns.1974.40.3.0376

Cited by 93 publications

(18 citation statements)

References 11 publications

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“…This finding accords with reports (Chawla et al, 1974;Symon and Dorsch, 1975;Lamas and Lobato, 1979;Borgesen and Gjerris, 1982;Kosteljanetz, 1986;Tans and Poortvliet, 1989;Malm et al, 1995) that groups of patients with 'normal pressure hydrocephalus' have a higher CSF pressure and a higher resistance to CSF absorption than either normal subjects or patients with degenerative neurologic disease. However, the mean difference between hydrocephalic and non-hydrocephalic patients is sufficiently small, relative to the range of variation of pressure and resistance among normals, that pressure and resistance measurements do not infallibly predict response to surgical shunting.…”

Section: 3supporting

confidence: 80%

The Pathogenesis of Normal Pressure Hydrocephalus: A Theoretical Analysis

Levine

1999

Bulletin of Mathematical Biology

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Hydrocephalus is an abnormal accumulation of cerebrospinal fluid (CSF) in the cerebral ventricles, usually caused by impaired absorption of the fluid into the bloodstream. Despite obstructed absorption and continued secretion of CSF into the ventricles at a near normal rate, the ventricular CSF pressure (VCSFP) is often normal. We attempt to understand how hydrocephalus can exist with normal VCSFP by exploring the role of the brain parenchyma in absorbing CSF in hydrocephalus. We test three theories: (1) the ventricular wall is impermeable to CSF; (2) ventricular CSF seeps into the parenchyma, from which it is efficiently absorbed; and (3) ventricular CSF seeps into the parenchyma but is absorbed inefficiently. We model the brain as a thick spherical shell consisting of a porous, elastic, solid matrix, containing interstitial fluid and blood. We modify the equations of poroelasticity, which describe flow of fluid through porous solids, to allow for parenchymal absorption. For each of the three theories we calculate the steady state changes in VCSFP and in parenchymal fluid pressure caused by an incremental defect in CSF absorption. We also calculate the-steady state changes in fluid content, tissue volume, tissue displacement, and stresses caused by a small increment of VCSFP. We conclude that only the second theory-seepage of CSF with efficient parenchymal absorption-accounts for the clinical features of normal pressure hydrocephalus. These features include sustained ventricular dilatation despite normal VCSFP, increased periventricular fluid content, and localized periventricular white matter damage.

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Section: 3supporting

confidence: 80%

The Pathogenesis of Normal Pressure Hydrocephalus: A Theoretical Analysis

Levine

1999

Bulletin of Mathematical Biology

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“…Air encephalography, isotope or metrizamide cisternography, measurement of cerebral blood flow (CBF), CSF-tap-test, long term intracranial pressure (ICP) monitoring and a different set of hydrodynamic studies and pressure/volume tests have been carried out with variable results 6' s, 9, H, 13, 15, 25,27,37,41,43,48,52,56,59,62 ICP monitoring and hydrodynamic studies have been widely reported in NPH syndrome. Normal or low ICP, with high or low amplitude beta waves and sometimes plateau waves especially during REM sleep have been reported as typical of NPH and clearly related with a good outcome 6-9' 13,16,17,27,35,37,42,49,59 Nevertheless, the value of long term ICP monitoring and/or CSF studies in order to select candidates to shunt is still controversial 7' 52 The sensitivity and specificity of ICP monitoring and CSF dynamics have not been defined yet. In general, a better knowledge of the different forms of' NPH is still necessary to get a better understanding of the natural evolution, clinical symptoms and signs and possible outcome in this important group of patients.…”

Section: Introductionmentioning

confidence: 99%

“…Later on, the syndrome of Normal Pressure Hydrocephalus (NPH) was completely outlined by Hakim and Adams in 1965 ~ ' 2, 29, 30. A Normal Pressure Hydrocephalus Syndrome (NPHS) can be idiopathic or secondary to subarachnoid haemorrhage, head injury, aqueductal stenosis, intracranial surgery and many other aetiologies 1, 2, 7, 13,29,30,34,36,59,63 From the clinical point of view, the diagnosis of NPHS is considered in those patients with gait disturbance, progressive dementia and urinary or faecal incontinence ~, 2, ~2, 34,52. Although the complete triad is perhaps the most frequent clinical presentation, incomplete and atypical forms of the syndrome have been reported13, 14,19,36,48,52,57,59 In spite of its apparent simplicity, NPH syndrome is a clinical complex entity, with incomplete physiopathological knowledge and too often contradictory opinions about its proper management.…”

Section: Introductionmentioning

confidence: 99%

Reappraisal of the intracranial pressure and cerebrospinal fluid dynamics in patients with the so-called ?Normal pressure hydrocephalus? syndrome

et al. 1991

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Fifty-four shunt-responsive patients were selected from a prospective protocol directed to study patients with suspected normal pressure hydrocephalus (NPH). Patients with gait disturbances, dementia, non-responsive L-Dopa Parkinsonism, urinary or faecal incontinence and an Evans ratio greater or equal to 0.30 on the CT scan were included in the study. As a part of their work-up all patients underwent intracranial pressure monitoring and hydrodynamic studies using Marmarou's bolus test. According to mean intracranial pressure (ICP) and the percentage of high amplitude B-waves, patients were subdivided in the following categories: 1) Active hydrocephalus (mean ICP above 15 mmHg), which is in fact no tone normal pressure hydrocephalus; 2) Compensated unstable hydrocephalus, when mean ICP was below 15 mmHg and B-waves were present in more than 25% of the total recording time and 3) Compensated stable hydrocephalus when ICP was lower or equal to 15 mmHg and beta waves were present in less than 25% of the total recording time. The majority of the patients in this study (70%) presented continuous high or intermittently raised ICP (active or unstable compensated hydrocephalus group). Mean resistance to outflow of CSF (Rout) was 38.8 mm Hg/ml/min in active hydrocephalus and 23.5 mm Hg/ml/min in the compensated group (Students t-test, p less than 0.05). Higher resistance to outflow was found in patients with obliterated cortical sulci and obliterated Sylvian cisterns in the CT scan. No statistically significant correlation was found when plotting the percentage of beta waves against pressure volume index (PVI), compliance or Rout. An exponential correlation was found when plotting beta waves against the sum of conductance to outflow and compliance calculated by PVI method (r = 0.79). Patients with the so-called normal pressure hydrocephalus syndrome have different ICP and CSF dynamic profiles. Additional studies taking into consideration these differences are necessary before defining the sensitivity, specificity and predictive value of ICP monitoring and CSF studies in selecting appropriate candidates for shunting.

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“…It has also been discovered that patients with fluctuat ing intracranial pressure show significantly better response to surgery than those with 'flat curves' [18,20]. Assuming that the fall ing spells are indeed caused by a hydroce phalic crisis as suggested by Adams et al [1], the good response to shunting in our 2 pa tients suffering from falling spells could be explained.…”

Section: Discussionmentioning

confidence: 62%

“…Sudden falls have also been described in association with colloid cysts of the third ventricle [15], obstructive hydrocephalus due to tumor in the floor of the fourth ven tricle [16], and aqueduct stenosis [17], Continuous intracranial pressure moni toring in NPH patients has demonstrated that there are often periods with elevated intraventricular pressure [18][19][20][21][22]. It has also been discovered that patients with fluctuat ing intracranial pressure show significantly better response to surgery than those with 'flat curves' [18,20].…”

Section: Discussionmentioning

confidence: 99%