Fluid Flow In Patients Research Articles

Early Improvement in Interstitial Fluid Flow in Patients With Severe Carotid Stenosis After Angioplasty and Stenting.

This study aimed to investigate early changes in interstitial fluid (ISF) flow in patients with severe carotid stenosis after carotid angioplasty and stenting (CAS). We prospectively recruited participants with carotid stenosis ≥80% undergoing CAS at our institute between October 2019 and March 2023. Magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI), and the Mini-Mental State Examination (MMSE) were performed 3 days before CAS. MRI with DTI and MMSE were conducted within 24 hours and 2 months after CAS, respectively. The diffusion tensor image analysis along the perivascular space (DTI-ALPS) index was calculated from the DTI data to determine the ISF status. Increments were defined as the ratio of the difference between post- and preprocedural values to preprocedural values. In total, 102 participants (age: 67.1±8.9 years; stenosis: 89.5%±5.7%) with longitudinal data were evaluated. The DTI-ALPS index increased after CAS (0.85±0.15; 0.85 [0.22] vs. 0.86±0.14; 0.86 [0.21]; P=0.022), as did the MMSE score (25.9±3.7; 24.0 [4.0] vs. 26.9±3.4; 26.0 [3.0]; P<0.001). Positive correlations between increments in the DTI-ALPS index and MMSE score were found in all patients (rs=0.468; P<0.001). An increased 24-hour post-CAS DTI-ALPS index suggests early improvement in ISF flow efficiency. The positive correlation between the 24-hour DTI-ALPS index and 2-month MMSE score increments suggests that early ISF flow improvement may contribute to long-term cognitive improvement after CAS.

Cerebrospinal Fluid Flow in Patients with Huntington's Disease.

Investigations of cerebrospinal fluid (CSF) flow aberrations in Huntington's disease (HD) are of growing interest, as impaired CSF flow may contribute to mutant Huntington retention and observed heterogeneous responsiveness to intrathecally administered therapies. We assessed net cerebral aqueduct CSF flow and velocity in 29 HD participants (17 premanifest and 12 manifest) and 51 age- and sex matched non-HD control participants using 3-Tesla magnetic resonance imaging methods. Regression models were applied to test hypotheses regarding: (i) net CSF flow and cohort, (ii) net CSF flow and disease severity (CAP-score), and (iii) CSF volume after correcting for age and sex. Group-wise analyses support a decrease in net CSF flow in HD (mean 0.14 ± 0.27 mL/min) relative to control (mean 0.32 ± 0.20 mL/min) participants (p = 0.02), with lowest flow in the manifest HD cohort (mean 0.04 ± 0.25 mL/min). This finding was explained by hyperdynamic CSF movement, manifesting as higher caudal systolic CSF flow velocity and higher diastolic cranial CSF flow velocity across the cardiac cycle, in HD (caudal flow: 0.17 ± 0.07 mL/s, cranial flow: 0.14 ± 0.08 mL/s) compared to control (caudal flow: 0.13 ± 0.06 mL/s, cranial flow: 0.11 ± 0.04 mL/s) participants. A positive correlation between cranial diastolic flow and disease severity was observed (p = 0.02). Findings support aqueductal CSF flow dynamics changing with disease severity in HD. These accelerated changes are consistent with changes observed over the typical adult lifespan, and may have relevance to mutant Huntington retention and intrathecally administered therapeutics responsiveness. ANN NEUROL 2023;94:885-894.

Comparison of Spectroscopic Properties of Intraocular Fluid in Patients with Cataract and Primary Open-Angle Glaucoma

The paper presents a comparison of spectroscopic properties of the intraocular fluid in patients with cataract (60 patients, 60 eyes) and the combination of cataract and primary open angle glaucoma (POAG, 36 patients, 36 eyes). The samples of intraocular fluid were collected during the surgery. Both groups of patients were treated with different types of local drug antihypertensive therapy with different multiplicity and duration of instillation during the preoperative period. The absorption spectra of the intraocular fluid were measured in the wavelength range of 190 – 1100 nm. Two absorption bands were observed with maxima at 202 and 267 nm in the absorption spectrum (the 2nd peak in the spectrum of some samples was shifted to larger wavelengths). The average absorbance of the intraocular fluid at the wavelength of 202 nm in patients without POAG was significantly lower than that in patients with POAG. This difference could be explained with accumulation of metabolites in intraocular fluid of patients with POAG, which in turn may be caused by slowing down the intraocular fluid flow in patients with POAG. Meanwhile, there were no statistically significant differences in average absorbance of the intraocular fluid at the wavelength of 267 nm between the patients of both groups.

Assessment of Cerebrospinal Fluid Flow in Patients with Foramen Magnum Meningiomas

Assessment of Cerebrospinal Fluid Flow in Patients with Foramen Magnum Meningiomas

Evaluation of the flow of cerebrospinal fluid as well as gender and age characteristics in patients with communicating hydrocephalus, using phase-contrast magnetic resonance imaging.

To determine the difference in the velocity parameters of cerebrospinal fluid flow in patients with varying severity of communicating hydrocephalus compared to a group of healthy volunteers without hydrodynamic disorders. The study involved 35 subjects with communicating hydrocephalus (25 subjects with Evans index of 0.31; 10 subject with Evans index of 0.46) and 62 healthy volunteers. The mean, volume, and peak flow velocities were determined at the different intracranial levels. Also were made an assessment of gender and age differences. Analysis of the differences between the mean values showed the progressive inhibition of cerebrospinal fluid outflow from the cranial cavity [in moderate communicating hydrocephalus-at 1.5 times (p<0.05), in severe communicating hydrocephalus at 2-2.5 times (p<0.01)], depending on the severity of enlargement of the ventricular system and, most likely, related to inhibition of its reabsorption. These changes may explain the clinical symptoms of subjects and serve as diagnostic criteria. Also it was revealed a significant influence of the factor of age on speed characteristics of the cerebrospinal fluid flow (F=5.3303, p=0.0003, for mean velocity).

Diagnostic accuracy of secretin-stimulated ultrasonography of the pancreas assessing exocrine pancreatic failure in cystic fibrosis and chronic pancreatitis

Objective. Volume output failure is a feature of decreasing exocrine pancreatic function. This parameter is assessed by secretin-stimulated MRI in several studies. Our purpose was to evaluate ultrasonography of the fluid in the descending duodenum and Wirsung duct (WD) after secretin stimulation as a measure of pancreatic fluid flow in patients expected to have severe output failure. Material and methods. We included subjects with chronic pancreatitis (CP), cystic fibrosis (CF) and a group of healthy controls in a prospective observation study. Transabdominal ultrasonography was performed before and during 15 min after secretin i.v. duodenal juice was collected by endoscopic short test (EST), and bicarbonate concentration measured. Patient groups were classified according to exocrine pancreatic function. Results. Pancreatic insufficient CF (CFI) patients and CP insufficient (CPI) patients showed less duodenal fluid filling compared to other groups (p < 0.001). Measures of the WD diameter could only identify the most severe failure in the CFI group (p < 0.001). Conclusion. Secretin-stimulated ultrasonography can be used to assess pancreatic fluid flow and may be combined with EST in the evaluation of exocrine pancreatic function. Fluid filling in the descending part of duodenum was the most accurate predictor of pancreatic insufficiency in both patient groups. The test demonstrated better diagnostic accuracy diagnosing exocrine pancreatic failure in the CF patients than in CP patients.

Pulsatile cerebrospinal fluid flow measurement using phase-contrast magnetic resonance imaging in patients with cervical myelopathy.

A technical report is presented. To investigate the relation between the severity of myelopathy and the degree of cerebrospinal fluid flow disturbance by using magnetic resonance imaging to measure the velocity of the cerebrospinal fluid flow in patients with cervical spondylotic myelopathy. Analyses of pulsatile cerebrospinal fluid flow measured by phase-contrast magnetic resonance imaging in healthy subjects and patients with Arnold-Chiari syndrome have been reported. Few studies have evaluated the change of pulsatile cerebrospinal fluid flow velocity and the waveform of the plotted velocity in patients with cervical spondylotic myelopathy. Study 1: Pulsatile cerebrospinal fluid flow was measured at C7, positioned with cervical spine flexion and extension, to investigate the influence of cervical alignment on the pulsatile cerebrospinal fluid flow in five patients with cervical spondylotic myelopathy. Study 2: In 31 patients with cervical spondylotic myelopathy, pulsatile cerebrospinal fluid flow was measured at C3 and C7, with the neck set centrally. The relevance of cerebrospinal fluid flow disturbance and the severity of myelopathy evaluated by the Japanese Orthopedic Association scoring system also were studied. Study 1: The waveform of plotted pulsatile cerebrospinal fluid flow velocity showed no change resulting from the position of the cervical spine. Study 2: A high correlation between the Japanese Orthopedic Association score and the cerebrospinal fluid pulsatile flow amplitude at C7 was demonstrated (r = 0.75; P < 0.0001). The average Japanese Orthopedic Association score of 14 patients whose cerebrospinal fluid flow velocity waveforms were absent was significantly lower (P < 0.0001) than that of 17 patients whose waveforms were present. The disturbance of pulsatile cerebrospinal fluid flow demonstrated high correlation with the severity of myelopathy. Measurement of cerebrospinal fluid flow disturbance can quantify the degree of dural sac and spinal cord compression.

Cerebrospinal fluid flow in patients with dilated ventricles studied with MR imaging.

The purpose of this study was to measure the cerebrospinal fluid (CSF) velocity and flow in the aqueduct in patients with wide ventricles with or without signs of normal pressure hydrocephalus (NPH) before and after shunt surgery. We studied 18 patients with wide ventricles with MRI and measured the CSF velocity values in the aqueducts. Twelve patients with the clinical triad of NPH were examined. Six patients were studied only before shunt surgery and 6 patients were studied both before and after shunt surgery. Three patients with wide ventricles without clinical triad of NPH, and 3 patients with hydrocephalus following subarachnoid hemorrhage were also examined. Seven NPH patients with hyperdynamic CSF flow and three NPH patients with normal CSF velocity and flow values showed a positive clinical response to shunt surgery. Two of the three patients with hydrocephalus and hyperdynamic CSF flow values in the aqueduct secondary to subarachnoid bleeding responded to shunt surgery. One patient with same disease and low CSF velocity and flow values did not respond. No change was detected in the CSF flow values of the aqueduct when measurements before and after shunt surgery were compared. Ventriculoperitoneal shunting does not change the CSF dynamics in the aqueduct.

Quantitative analysis of cerebrospinal fluid flow in patients with cervical spondylosis using cine phase-contrast magnetic resonance imaging.

To investigate changes in the cerebrospinal fluid flow in patients with cervical spondylosis using cine phase-contrast magnetic resonance (MR) imaging. The participants included 44 healthy volunteers, 11 asymptomatic patients with evidence of degenerative changes of the cervical spine revealed by MR imaging but no neurological symptoms referable to those abnormalities, and 23 symptomatic patients with myelopathy who underwent surgery. Cervical spondylotic myelopathy was evaluated using the Japanese Orthopedic Association scores, and the percentage reduction of the transverse cord area at the level of maximum cord compression was measured on T1-weighted magnetic resonance images. A cine phase-contrast MR pulse sequence with peripheral gating was used to measure the cerebrospinal fluid flow direction and velocity in the ventral subarachnoid spaces at the C1 and T1 levels. The velocity waveforms produced by plotting flow velocity at 16 intervals during one cardiac cycle significantly differed among the healthy volunteers, asymptomatic patients, and preoperative symptomatic patients. However, velocity waveforms did not differ between the healthy volunteers and the postoperative patients at the C1 level. Decreases of flow velocity were significantly correlated with the severity of myelopathy and the percentage reduction of cord area. Patients with severe myelopathy (Japanese Orthopedic Association score of 0-9 points) or greater than 30% reduction of cord area showed significantly decreased flow velocity compared with those with mild myelopathy (Japanese Orthopedic Association score of 10-17 points) or less than 30% reduction of cord area. Changes in flow velocity were not correlated with multiplicity of the lesion or the level of maximum cord compression. Postoperative improvement of flow velocity was not correlated with neurological recovery. Cine phase-contrast MR imaging allows quantitative and noninvasive assessment of changes in cerebrospinal fluid flow in patients with cervical spondylosis.

Quantitative Analysis of Cerebrospinal Fluid Flow in Patients with Cervical Spondylosis Using Cine Phase-Contrast Magnetic Resonance Imaging

Quantitative Analysis of Cerebrospinal Fluid Flow in Patients with Cervical Spondylosis Using Cine Phase-Contrast Magnetic Resonance Imaging

Quantitative Analysis of Cerebrospinal Fluid Flow in Patients with Cervical Spondylosis Using Cine Phase-Contrast Magnetic Resonance Imaging

Quantitative Analysis of Cerebrospinal Fluid Flow in Patients with Cervical Spondylosis Using Cine Phase-Contrast Magnetic Resonance Imaging

Quantitative Analysis of Cerebrospinal Fluid Flow in Patients with Cervical Spondylosis Using Cine Phase-Contrast Magnetic Resonance Imaging

Quantitative Analysis of Cerebrospinal Fluid Flow in Patients with Cervical Spondylosis Using Cine Phase-Contrast Magnetic Resonance Imaging

Interposition saphenous vein grafts for advanced occlusive disease and large aneurysms in the posterior circulation.

The authors report their initial experience with the use of interposition saphenous vein grafts between the external carotid artery and the proximal posterior cerebral artery. The indications, results, and technical aspects of the operation are reviewed. All patients accepted for surgery were at high risk for a posterior circulation infarct, and all patients with ischemic symptomatology had continued to progress while on anticoagulant drugs or anti-platelet agents. Thus, all patients were at high risk, and 11 of the 14 patients operated on were confined to bed before surgery. Intraoperative graft flows varied from 35 to 170 ml/min, and postoperative graft flows ranged from 75 to 311 ml/min in the patent grafts. There were three early graft occlusions and two late graft occlusions; these all occurred in patients with relatively low flows at the time of surgery (40 ml/min or lower). Subdural hygroma was the next most frequent complication to graft occlusion. It was thought to be caused by the pulsating graft anastomosed to a major vessel through a small opening in the basal arachnoid, which provided a new path for cerebrospinal fluid flow in patients with a degree of preexisting atrophy. One patient with a large aneurysm in the posterior circulation underwent proximal intracranial clipping of the vertebral artery and bypass grafting simultaneously. There were seven excellent results and two good results in nine patients in whom the graft remained patent. In the five patients with graft occlusion, there were two minor strokes, two major strokes, and one death.