Active regulation of CSF flow with the subarachnoid basal cisterns as one of the key regulators: a novel concept and review of the literature

✓ Eight patients with “normal pressure hydrocephalus” are presented who demonstrated radiographic and occasional clinical evidence of progressive dilatation of the ventricles following pneumoencephalography. The characteristic pneumographic signs of tentorial obstruction to the flow of cerebrospinal fluid (CSF) had been documented in the original air contrast study. The authors postulate that pneumoencephalography in patients with normal pressure hydrocephalus may result in a sudden displacement of CSF from the ventricles into the already compromised basal cisterns, leading to further obstruction of CSF outflow and progressive ventricular dilatation. Other mechanisms such as reduction in the potential resorptive capacity of the ventricular ependyma by air replacing ventricular fluid may play a part. The value of repeat radiological studies 24 and 48 hours after the original pneumogram is emphasized both as an aid in the radiological diagnosis of normal pressure hydrocephalus and as an additional parameter for studying problems in CSF flow and absorption.

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

Journal of Neurosurgery ◽

10.3171/jns.2006.104.5.810 ◽

2006 ◽

Vol 104 (5) ◽

pp. 810-819 ◽

Cited By ~ 102

Author(s):

Mark E. Wagshul ◽

John J. Chen ◽

Michael R. Egnor ◽

Erin J. McCormack ◽

Patricia E. Roche

Keyword(s):

Cerebrospinal Fluid ◽

Stroke Volume ◽

Experimental Studies ◽

Volume Ratio ◽

Communicating Hydrocephalus ◽

Phase Lag ◽

Review Of The Literature ◽

Csf Flow ◽

Prepontine Cistern ◽

The Brain

Object A recently developed model of communicating hydrocephalus suggests that ventricular dilation may be related to the redistribution of pulsations in the cranium from the subarachnoid spaces (SASs) into the ventricles. Based on this model, the authors have developed a method for analyzing flow pulsatility in the brain by using the ratio of aqueductal to cervical subarachnoid stroke volume and the phase of cerebrospinal fluid (CSF) flow, which is obtained at multiple locations throughout the cranium, relative to the phase of arterial flow. Methods Flow data were collected in a group of 15 healthy volunteers by using a series of images acquired with cardiac-gated, phase-contrast magnetic resonance imaging. The stroke volume ratio was 5.1 ± 1.8% (mean ± standard deviation). The phase lag in the aqueduct was −52.5 ± 16.5° and the phase lag in the prepontine cistern was −22.1 ± 8.2°. The flow phase at the level of C-2 was +5.1 ± 10.5°, which was consistent with flow synchronous with the arterial pulse. The subarachnoid phase lag ventral to the pons was shown to decrease progressively to zero at the craniocervical junction. Flow in the posterior cervical SAS preceded the anterior space flow. Conclusions Under normal conditions, pulsatile ventricular CSF flow is a small fraction of the net pulsatile CSF flow in the cranium. A thorough review of the literature supports the view that modified intracranial compliance can lead to redistribution of pulsations and increased intraventricular pulsations. The phase of CSF flow may also reflect the local and global compliance of the brain.

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Magnetic resonance cisternography for visualization of intracisternal fine structures

Journal of Neurosurgery ◽

10.3171/jns.1998.88.4.0670 ◽

1998 ◽

Vol 88 (4) ◽

pp. 670-678 ◽

Cited By ~ 27

Author(s):

Yoshiaki Mamata ◽

Isao Muro ◽

Mitsunori Matsumae ◽

Taizo Komiya ◽

Hiroyuki Toyama ◽

...

Keyword(s):

Magnetic Resonance ◽

Healthy Volunteers ◽

Cranial Nerve ◽

Csf Flow ◽

Content Type ◽

Peripheral Pulse ◽

Fine Structures ◽

Magnetic Resonance Cisternography ◽

Basal Cisterns ◽

Fine Print

Object. To assess its usefulness in demonstrating cisternal anatomy, the authors investigated magnetic resonance (MR) cisternography in which a heavily T2-weighted turbo spin—echo method was used to visualize normal anatomical fine structures and lesions in the basal cisterns in 20 healthy volunteers and 43 patients. The authors applied peripheral pulse gating, which had been optimized to reduce artifacts in the cisterns attributable to cerebrospinal fluid (CSF) flow. Methods. The detectability of each cranial nerve was determined in healthy volunteers. The first, second, and third nerves and the seventh—eighth nerve complex were clearly visualized in all participants; the fifth nerve was clearly seen in 80% and the sixth cranial nerve in 50%. The fourth nerve and the ninth through 12th nerves were difficult to identify individually, except in some volunteers. To reduce artifacts caused by fast CSF flow, we determined the delays as a function of the time elapsed between two consecutive peaks of pulse wave in a peripheral pulse gate (P—P interval) at which there was reversal of flow direction to minimize the CSF flow—related artifact. Using peripheral pulse gating and a time delay of 30% of the R—R interval, the authors succeeded in minimizing the CSF flow—related artifacts. Magnetic resonance cisternography appears to be very useful for demonstrating intracisternal fine anatomy and enhancing the contours of the juxtacisternal lesion. A minute amount of CSF interposed between lesions and normal structures such as nerves, vessels, or bone structures can be detected by means of this sequence. In patients with facial spasm, axial images and oblique coronal images obtained in a plane parallel to the seventh—eighth cranial nerve complex demonstrated vascular compression in all 13 patients. The MR cisternography finding of compression was confirmed in all nine patients who underwent microvascular decompression. Conclusions. Magnetic resonance cisternography appears to show great promise for evaluation of patients with neurovascular compression or tumors in and around the basal cisterns; the procedure adds only a small amount of imaging time.

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Hydrocephalus in cerebral cysticercosis

Journal of Neurosurgery ◽

10.3171/jns.1981.55.5.0786 ◽

1981 ◽

Vol 55 (5) ◽

pp. 786-793 ◽

Cited By ~ 80

Author(s):

Ramiro D. Lobato ◽

Eduardo Lamas ◽

Jaime M. Portillo ◽

Ricardo Roger ◽

Javier Esparza ◽

...

Keyword(s):

Communicating Hydrocephalus ◽

Csf Flow ◽

Content Type ◽

Inflammatory Reactions ◽

Csf Shunting ◽

Cerebral Cysticercosis ◽

Flow Through ◽

Basal Cisterns ◽

Fine Print ◽

Internal Hydrocephalus

✓ The cases of 11 patients with hydrocephalus secondary to cerebral cysticercosis are analyzed. Most of the patients had suffered from epilepsy before they developed hydrocephalic symptoms, and computerized tomography showed that infestation of the parenchyma coexisted with ventricular or cisternal colonization. In four cases, the parasitic vesicles compromised cerebrospinal fluid (CSF) flow in the ventricular system, resulting in internal hydrocephalus. Communicating hydrocephalus, caused by the presence of Cysticercus larvae in the basal cisterns (Cysticercus racemosus), or by the occurrence of a chronic basal meningitis, or both, developed in seven more patients. Changes in CSF pressure were related to the number and location of the cysts and to the leptomeningeal inflammatory reactions evoked by them. The majority of patients presented with a chronic and relatively normotensive hydrocephalus. All patients except one had identifiable ventricular or cisternal Cysticercus larvae; these patients were treated with open removal of the cysts, and did well. However, most of them had impairment of CSF flow through the basal cisterns and required permanent CSF shunting. Communicating hydrocephalus due to leptomeningeal scarring was also successfully managed with extracranial shunting. Epilepsy was controlled with anticonvulsant therapy. Although good lasting results may be obtained with aggressive treatment of neurocysticercosis, patients are liable to relapse because surgery is only palliative in most instances.

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Chiari malformation and spinal interdural cyst: A proposed association and review of the literature

Surgical Neurology International ◽

10.25259/sni_1034_2021 ◽

2021 ◽

Vol 12 ◽

pp. 626

Author(s):

Raj Thakrar ◽

Bruce Tranmer ◽

Paul Penar

Keyword(s):

Chiari Malformation ◽

Treatment Options ◽

Flow Dynamics ◽

Review Of The Literature ◽

Csf Flow ◽

Csf Diversion ◽

Unclear Etiology ◽

Lumbar Cerebrospinal Fluid ◽

Meningeal Cysts ◽

Mass Lesions

Background: Interdural cysts are rare meningeal cysts with an unclear etiology. They are often mistaken for other mass lesions, including arachnoid cysts and tumors. Correctly identifying and classifying these cysts, as well as how they have formed in individual patients, are crucial to providing effective treatment options for patients. Case Description: We report a case of a patient with shunted idiopathic intracranial hypertension who developed a symptomatic Chiari malformation and was subsequently discovered to have a spinal interdural cyst. The Chiari malformation was likely due to intracranial hypotension secondary to lumbar cerebrospinal fluid (CSF) diversion. Once the shunt was removed, a spinal interdural cyst became clinically and radiographically evident, and the Chiari resolved, suggesting that both entities were effects of shared CSF flow dynamics. Conclusion: This cyst likely originated due to the trauma from remote repeated lumbar punctures and lumboperitoneal shunt placement, allowing CSF to enter the interdural space after the catheter was removed.

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Faculty evaluation: review of the literature most pertinent to dental education

Journal of Dental Education ◽

10.1002/j.0022-0337.1977.41.6.tb01095.x ◽

1977 ◽

Vol 41 (6) ◽

pp. 290-300

Author(s):

DW Chambers

Keyword(s):

Dental Education ◽

Faculty Evaluation ◽

Review Of The Literature

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Telepractice for Adult Speech-Language Pathology Services: A Systematic Review

Perspectives of the ASHA Special Interest Groups ◽

10.1044/2019_persp-19-00146 ◽

2020 ◽

Vol 5 (1) ◽

pp. 326-338 ◽

Cited By ~ 9

Author(s):

Kristen Weidner ◽

Joneen Lowman

Keyword(s):

Systematic Review ◽

Primary Progressive Aphasia ◽

Future Research ◽

Service Delivery Model ◽

Speech Language Pathology ◽

Review Of The Literature ◽

Research Designs ◽

Assessment And Treatment ◽

Language Pathology ◽

Screening Assessment

Purpose We conducted a systematic review of the literature regarding adult telepractice services (screening, assessment, and treatment) from approximately 2014 to 2019. Method Thirty-one relevant studies were identified from a literature search, assessed for quality, and reported. Results Included studies illustrated feasibility, efficacy, diagnostic accuracy, and noninferiority of various speech-language pathology services across adult populations, including chronic aphasia, Parkinson's disease, dysphagia, and primary progressive aphasia. Technical aspects of the equipment and software used to deliver services were discussed. Some general themes were noted as areas for future research. Conclusion Overall, results of the review continue to support the use of telepractice as an appropriate service delivery model in speech-language pathology for adults. Strong research designs, including experimental control, across multiple well-described settings are still needed to definitively determine effectiveness of telepractice services.

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