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PubMed1996

Investigation of the efficacy of oxerutins compared to placebo in patients with chronic venous insufficiency treated with compression stockings.

The aim of this study was to investigate, if the the combined treatment of compression stockings and drug treatment with oxerutins (O-(beta-hydroxyethyl)-rutosides, Venoruton) provides additional benefit for patients with chronic venous insufficiency (CVI) compared to compression treatment alone. Oxerutins belong to the group of oedema protective agents and possess anti-exudative and membrane protective activity. A total of 133 female patients with CVI grade II participated in this double-blind, randomised, multi-centre, parallel-group study with two treatment groups. The whole study lasted for 19 weeks, and consisted of a one week placebo run-in phase, 12 weeks treatment phase, followed by a 6 weeks treatment-free follow-up period. All patients received a basis compression therapy that consisted of standard compression stockings. In order to standardise initial fitting of stockings in this multi-centre setting, stockings were fitted after one week of standard diuretics starting at baseline and then stockings were worn for the following 11 weeks. Patients were randomised to receive oxerutins (2 x 500 mg daily) or matching placebo. Leg volumes (water displacement) and associated subjective symptoms (visula analogue scale) were measured during a placebo run-in period at enrolment (week - 1) and half a week later (week - 1/2), at baseline week 0), at 4, 8, 12 weeks on treatment, and again after a 3- and 6-weeks treatment-free follow-up. The primary efficacy criterion, the area under the baseline from week 0 to week 18 (AUB0-18) of leg volume changes, as measurement of the global change of leg oedema during the study, resulted in a superior reduction of -5589 ml.d for the combined treatment with oxerutins compared to -2101 ml.d for placebo (p = 0.012). The mean change of leg volume compared to baseline after 12 weeks of treatment was -63.9 ml for stockings and oxerutins, and -32.9 ml for the patients who received stockings and placebo (p < 0.05). Oxerutins showed a prolonged effect in the follow-up phase compared to placebo, with mean AUB values for week 12 to week 18 of -1769 ml.d versus -133 ml.d (p < 0.01). The study demonstrated that the combined therapy of compression stockings and drug treatment with oxerutins is significantly superior in reducing leg oedema resulting from chronic venous insufficiency compared to compression treatment alone.

Aged↗

PubMed1996

Comprehension of time-compressed speech: effects of age and speech complexity.

The periodic sampling method of time compression is characterized by periodic removal of segments of speech according to predetermined compression rate (CR) and discard interval length (DIL). Fifteen middle-aged (42-54 years old) and 15 older (60-69 years old) adults participated in the study that assessed the combined effects of CR and DIL on the comprehension of time-compressed speech by aging adults. Three CRs (30, 45, and 60%), seven DILs (35 through 155 msec), and two types of speech materials were used. The subject's task was to report associations among the items mentioned in a time-compressed passage. In all cases, performance of the subjects deteriorated with increasing CR and DIL. The older adults were affected more by CR and DIL values than middle-aged adults. The difference in sentence complexity between the two speech materials affected both groups equally. In general, the results of the study indicated that (a) time-compressed speech differentiates between speech comprehension by middle-aged and older adults and (b) the effects of CR and DIL became more independent with increasing age of the listener and increasing complexity of the speech material. Reported results support the concept that time-compressed speech may be an effective signal in clinical assessment of adults whose auditory complaints are not explained by their peripheral hearing losses.

Adult↗

PubMed1997

A comparison of intermittent pneumatic compression of the calf and whole leg in preventing deep venous thrombosis in urological surgery.

PURPOSE: Intermittent pneumatic compression of the calf and/or thigh effectively decreases the incidence of deep venous thrombosis and other thrombotic sequelae but clinical data comparing these modalities are currently lacking. MATERIALS AND METHODS: A total of 90 patients undergoing major urological surgery was randomly assigned to receive calf length or thigh length pneumatic compression for antithrombotic prophylaxis. Duplex ultrasound of the lower extremities was performed preoperatively and twice postoperatively to evaluate for deep venous thrombosis. Health care providers in the operating room, recovery room and ward were asked to compare the compression systems, and a cost analysis was performed. RESULTS: A total of 47 patients wore the thigh length sequential pneumatic sleeves and 43 wore calf length uniform compression systems. A pulmonary embolus without evidence of deep venous thrombosis was detected in 1 patient (2%) using the thigh length system. A thrombus was detected in the common femoral vein by duplex ultrasonography in 1 patient (2%) with the calf length system. Nursing personnel found the calf length sleeves easier to apply and more comfortable by patient account but they were satisfied with both systems. There was a significant cost savings with the calf length pneumatic compression system. CONCLUSIONS: Calf and thigh length pneumatic compression systems similarly decrease the risk of deep venous thrombosis in patients undergoing urological surgery. The calf length system has the added advantage of being less expensive and easier to use.

Aged↗

PubMed1997

A comparison of compression ultrasound with color Doppler ultrasound for the diagnosis of symptomless postoperative deep vein thrombosis.

BACKGROUND: Despite advances in primary prophylaxis, venous thromboembolism still occurs in a considerable number of high-risk surgical patients. Screening with conventional ultrasound imaging to detect asymptomatic deep vein thrombosis (DVT) has been suggested as a strategy to improve management of such patients, but it is insufficiently sensitive. We evaluated the ability of color Doppler ultrasound to improve the sensitivity of compression ultrasound in the detection of asymptomatic DVT in high-risk orthopedic patients. METHODS: We prospectively evaluated bilateral compression and color Doppler ultrasound measurements of the entire leg in 204 consecutive patients who underwent elective hip or knee replacement surgery, using contrast venography as the reference test. The sensitivity, specificity, and positive predictive value of the ultrasonography tests were determined. RESULTS: The sensitivity, specificity, and positive predictive value (with 95% confidence intervals [CIs]) of compression ultrasound for the detection of proximal DVT were 60% (39%-81%), 96% (92%-99%), and 71% (48%-89%) respectively. The sensitivity, specificity, and positive predictive value (with 95% CIs) of compression ultrasound for the detection of calf vein thrombosis were 33% (18%-52%), 91% (83%-96%), and 58% (34%-80%), respectively. Color Doppler ultrasonography did not identify any additional proximal or calf vein thrombi to those detected by compression ultrasound alone. The sensitivity for all thrombi was 47% (95% CI, 34%-61%) with a positive predictive value of 65% (95% CI, 48%-79%). CONCLUSIONS: Color Doppler ultrasonography has a moderate to low accuracy for the detection of DVT in patients who have had hip and knee replacement surgery. Color Doppler ultrasonography does not increase the detection rate for asymptomatic DVT over compression ultrasound and thus cannot be recommended as a screening test in this setting.

Hip Prosthesis↗

PubMed1998

Measurement of soft tissue strain in response to consecutively increased compressive and distractive loads on a friction-based test bed.

PURPOSE: To abstract the essential elements of chiropractic prone leg checking and subject them to controlled, experimental parametric testing. DESIGN: Controlled, objective, repeated-measure analysis of the dynamic response of leg positions to distractive and compressive loading conditions. SETTING: Research laboratory in a chiropractic college. PARTICIPANTS: Twenty-five compression and 30 distraction subjects, most of whom were male, asymptomatic chiropractic students. INTERVENTION: The subjects were lowered to the prone position on a table optimized to detect dynamic leg positions, with separate sliding segments supporting each leg. A trial consisted of a 2-min control run, followed by two 2-min experimental runs in which compressive or distractive loads were applied incrementally to the table-leg segments. MAIN OUTCOME MEASURE: An optoelectric system measured real-time absolute and relative leg positions. RESULTS: Right legs showed a greater average response than left legs under both distractive and compressive loads, and tended to respond more proportionately to incremental load increases. The average response to compression exceeded the response to distraction. Both legs showed a greater average response in the second half of the trials. Correlation of weights with responses was about four times greater in traction than compression. CONCLUSION: The functional short leg is confirmed as a stable clinical reality, a multitrial mean of unloaded leg positional differences. The prone leg check may be a loading procedure, albeit unmeasured, that detects non-weight-bearing, functional asymmetry in loading responses. These probably reflect differences in left-right muscle tone, joint flexibility and tissue stiffness. The relatively nonmonotonic, nonlinear quality of left leg responses is consistent with asymmetric neurological responses.

Adult↗

PubMed1998

Elimination of microorganisms from dental operatory compressed air.

Compressed air is used to power high-speed handpieces, as well as to dry and clean surfaces in the oral cavity during patient treatment, in all dental operatories. The compressed air used in the dental operatories located in large institutions such as universities or hospitals is generally obtained from a central source, and is produced by continually running compressors. In operatories located in private practice settings, compressed air is obtained from small on-site air compressors, which may be run less frequently. A survey was made of operatories in the Montreal area to determine the microbial load of the compressed air produced by air compressors. An air sampler was used to collect compressed air and impinge it on a rotating agar medium surface. Compared to the air produced from compressors in constant use, the air collected from compressors that ran intermittently had a very high microbial load. The efficacy of an apparatus designed to sterilize the contaminated air produced by small, on-site compressors was tested. Called a Purilair, this device heats every particle of inflowing compressed air to 250 degrees C and then forces it through a fine-pore ceramic filter. In three private practice operatories, an in-line Purilair effectively sterilized the air being delivered by small compressors. The same result was obtained in the laboratory when lyophilized spores and cells of Bacillus stearothermophilus and conidia of Penicillium notatum and Aspergillus niger were sprayed into the intake line of the apparatus.

Academic Medical Centers↗

PubMed1998

Accuracy of screening compression ultrasonography and clinical examination for the diagnosis of deep vein thrombosis after total hip or knee arthroplasty.

OBJECTIVE: To determine whether compression ultrasonography or clinical examination should be considered as screening tests for the diagnosis of deep vein thrombosis (DVT) after total hip or knee arthroplasty in patients receiving warfarin prophylaxis postoperatively. DESIGN: A prospective cohort study. SETTING: A single tertiary care orthopedic centre. PATIENTS: One hundred and eleven patients who underwent elective total hip or knee arthroplasty were enrolled. Postoperatively the warfarin dose was adjusted daily to maintain the international normalized ratio between 1.8 and 2.5. Eighty-six patients successfully completed the study protocol. INTERVENTION: Before they were discharged from hospital, patients were assessed for DVT by clinical examination, bilateral compression ultrasonography of the proximal venous system and bilateral contrast venography. RESULTS: DVT was found in 29 patients (34%; 95% confidence interval [CI] 24% to 45%), and 6 patients (7%; 95% CI 3% to 15%) had proximal DVT. DVT developed in 18 (40%) of 45 patients who underwent total knee arthroplasty and in 11 (27%) of 41 patients who underwent total hip arthroplasty. The sensitivity of compression ultrasonography for the diagnosis of proximal DVT was 83% (95% CI 36% to 99%) and the specificity was 98% (95% CI 91% to 99%). The positive predictive value of compression ultrasonography was 71%. In contrast, clinical examination for DVT had a sensitivity of 11% (95% CI 2% to 28%) and a positive predictive value of 25%. CONCLUSIONS: DVT is a common complication after total hip or knee arthroplasty. Compression ultrasonography appears to be a relatively accurate noninvasive test for diagnosing postoperative proximal DVT. In contrast, clinical examination is a very insensitive test. Whether routine use of screening compression ultrasonography will reduce the morbidity of venous thromboembolism after joint arthroplasty requires confirmation in a prospective trial involving long-term follow-up of patients.

Aged↗

PubMed2004

Nerves in a pinch: imaging of nerve compression syndromes.

Nerve compression is a common entity that can result in considerable disability. Early diagnosis is important to institute prompt treatment and to minimize potential injury. Although the appropriate diagnosis is often determined by clinical examination, the diagnosis may be more difficult when the presentation is atypical, or when anatomic and technical limitations intervene. In these instances, imaging can have an important role in helping to define the site and etiology of nerve compression or in establishing an alternative diagnosis. MR imaging and ultrasound provide direct visualization of the nerve and surrounding abnormalities. For both modalities, the use of high-resolution techniques is important. Bony abnormalities contributing to nerve compression are best assessed by radiographs or CT. For the radiologist, knowledge of the anatomy of the fibro-osseous tunnels, familiarity with the causes of nerve compression, and an understanding of specialized imaging techniques are important for successful diagnosis of nerve compression.

Carpal Tunnel Syndrome↗

PubMed1993

Effects of local compression on peroneal nerve function in humans.

A new apparatus was developed to compress the anterior compartment selectively and reproducibly in humans. Thirty-five normal volunteers were studied to determine short-term thresholds of local tissue pressure that produce significant neuromuscular dysfunction. Local tissue fluid pressure adjacent to the deep peroneal nerve was elevated by the compression apparatus and continuously monitored for 2-3 h by the slit catheter technique. Elevation of tissue fluid pressure to within 35-40 mm Hg of diastolic blood pressure (approximately 40 mm Hg of in situ pressure in our subjects) elicited a consistent progression of neuromuscular deterioration including, in order, (a) gradual loss of sensation, as assessed by Semmes-Weinstein monofilaments, (b) subjective complaints, (c) reduced nerve conduction velocity, (d) decreased action potential amplitude of the extensor digitorum brevis muscle, and (e) motor weakness of muscles within the anterior compartment. Generally, higher intracompartmental pressures caused more rapid deterioration of neuromuscular function. In two subjects, when in situ compression levels were 0 and 30 mm Hg, normal neuromuscular function was maintained for 3 h. Threshold pressures for significant dysfunction were not always the same for each functional parameter studied, and the magnitudes of each functional deficit did not always correlate with compression level. This variable tolerance to elevated pressure emphasizes the need to monitor clinical signs and symptoms carefully in the diagnosis of compartment syndromes. The nature of the present studies was short term; longer term compression of myoneural tissues may result in dysfunction at lower pressure thresholds.

Adult↗

PubMed1983

Treatment of spinal cord compression: a retrospective analysis.

Epidural spinal cord compression from metastatic disease is a common neurological complication of cancer. The incidence is probably increasing owing to continual advancements in the treatment of cancer that have led to prolongation of life and a greater probability of secondary involvement of the spinal cord. A problem often encountered by the oncologist treating patients with epidural spinal cord compression is the recurrence of compression by metastatic tumor both in and out of the original treatment field. Radiotherapists are often presented with the difficult task of trying to determine the optimal dose/time fractionation with the hope of improving the therapeutic ratio. We have examined the charts of 80 patients treated at the Rhode Island Hospital during the last five years (1975-1980) with myelographic evidence of cord compression in order to determine 1) the recurrence rate of cord compression by metastatic tumor after radiotherapy treatment both in and out of the original treatment field; 2) the influence of various dose/fractionation schedules on the disease-free interval; 3) the percentage of recurrence out of the treatment field that might represent "skipped lesions" at the original time of diagnosis. Our results show 1) that 9 patients (11.3%) experienced recurrence within the original treatment field; 2) that 21 (26.3%) experienced recurrence within the spinal canal, but out of the original treatment field; 3) that 9 of the 21 (42%) cases of recurrence out of the original treatment field occurred within 1 week and thus were determined to be "skipped lesions" at the time of diagnosis; and 4) that there appears to be a dose-response relationship for those patients treated successfully without recurrences who did not have presenting symptoms of complete paraplegia.

Combined Modality Therapy↗

PubMed2005

Schwann cells upregulate vascular endothelial growth factor secondary to chronic nerve compression injury.

To better understand the pathogenesis of chronic nerve compression injuries, we investigated the possibility that Schwann cell production of vascular endothelial growth factor (VEGF) is responsible for the increased vascularity and Schwann cell proliferation associated with chronic nerve injury. In situ hybridization was used to evaluate VEGF mRNA production with immunohistochemistry to further localize the production of VEGF and its receptor proteins in an animal model of chronic nerve compression injury. VEGF mRNA and protein expression increased within Schwann cells as early as 2 weeks after compression and peaked by 1 month with a subsequent marked increase in the number of blood vessels. Thus, chronic nerve compression injury induces Schwann cells to increase VEGF production, which may be responsible for changes in neural vasculature secondary to chronic nerve compression injury. With a better understanding of these nerve injuries, more effective treatments may be developed to help patients with these impairments.

Animals↗

PubMed2000

Static compression is associated with decreased diffusivity of dextrans in cartilage explants.

The chondrocytes of adult articular cartilage rely upon transport phenomena within their avascular extracellular matrix for many biological activities. Therefore, changes in matrix structure which influence cytokine transport parameters may be an important mechanism involved in the chondrocyte response to tissue compression. With this hypothesis in mind, partitioning and diffusion of 3-, 10-, and 40-kDa dextrans conjugated to tetramethylrhodamine, and 430-Da tetramethylrhodamine itself, were measured within statically compressed bovine articular cartilage explants using a novel experimental apparatus and desorption fluorescence method. Partitioning and diffusion were examined as functions of solute molecular weight and matrix proteoglycan density, and diffusion was measured versus static compression up to 35% volumetric strain. In general, partition coefficients and diffusivities were found to decrease with increasing solute molecular weight. In addition, for a given solute, diffusivities decreased significantly with increasing static compression. Results therefore suggest a possible role for transport limitations of relatively large molecular weight solutes within the extracellular matrix in mediating the biological response of chondrocytes to cartilage compression.

Animals↗

PubMed1993

Spinal cord compression in metastatic cervical cancer.

Spinal cord compression secondary to metastatic cervical cancer may not be considered as a possible cause of neurologic symptoms by primary care physicians who do not often treat these patients. Delays in diagnosis and treatment may result in irreversible but potentially preventable neurologic changes. This report describes 5 cases of spinal cord compression in patients with metastatic cervical carcinoma, 2 of whom were previously undiagnosed with cervical cancer. These 2 patients represent 1.6% (2 of 121) of all new cervical cancer cases diagnosed during this time period. Two of 5 patients (40%) with spinal cord compression showed improvement following therapy by regaining the ability to walk, while none of the remaining patients had further acute deterioration of neurologic function. The mean survival of patients presenting with spinal cord compression from cervical cancer in this series was 4 months (maximum 6 months). This series illustrates the relative frequency with which spinal cord compression is seen in patients with a new diagnosis of invasive cancer. This diagnosis should be considered when evaluating neurologic complaints in known cervical cancer patients or any woman with apparent pelvic pathology. Rapid diagnosis and treatment of these lesions, while not likely to improve overall survival significantly, can improve function and alleviate symptoms.

Adult↗

PubMed1996

A study of motor and sensory evoked potentials in chronic cauda equina compression of the dog.

Previous experimental studies have shown the effects of acute compression of the spinal cord and peripheral nerve roots. Recently, however, a few studies of chronic compression of the cauda equina in animal models have been reported. The purpose of this study was to determine the long-term electrophysiologic changes resulting from chronic compression of the cauda equina in dogs. An animal model of lumbar spinal stenosis was prepared according to Delamarter's method. Four experimental groups, each containing six dogs, were studied. One group underwent only laminectomy of the sixth and seventh lumbar vertebrae; these animals served as controls. In the three other groups, a laminectomy was performed and the cauda equina was constricted by 25%, 50%, and 75%, respectively, to produce chronic compression. Weekly neurologic examinations were carried out, and the neurologic deficits were graded using a modified Tarlov system. Sensory, and motor evoked potentials were recorded preoperatively, immediately after constriction, and at 2 weeks and 1, 2, and 3 months postoperatively. The animals in the control group showed no changes in sensory or motor evoked potentials. The dogs in which the cauda equina had been constricted by 25% showed no neurologic deficits and only mild changes in sensory and motor evoked potentials. The dogs in which the cauda equina had been constricted by 50% showed mild initial motor weakness, and major changes in the evoked potentials. The dogs in which the cauda equina had been constricted by 75% showed significant weakness, paralysis of the tail, and urinary incontinence; all dogs were partially recovered by the 3rd month, but all still showed neurogenic changes in the evoked potentials. Sensory and motor evoked potentials revealed neurologic abnormalities before the appearance of neurologic signs and symptoms. Constriction of more than 50% was the critical point that resulted in complete loss or reduction of the evoked potentials and in neurologic deficits. Dogs in which motor and sensory evoked potentials recovered also showed gradual disappearance of neurologic symptoms and signs. Recovery of motor evoked potentials in particular was associated with complete disappearance of neurologic symptoms and signs. For accurate prognosis in cases of chronic cauda equina compression, a combined diagnostic study of sensory and motor evoked potentials is recommended.

Analysis of Variance↗

PubMedDate not supplied

Percutaneous vertebroplasty--initial clinical experience in osteoporotic and myelomatous compression fractures.

BACKGROUND: To review the clinical impact of vertebroplasty in osteoporotic and myelomatous compression fractures METHODS: Eleven compression fractures in eight patients were treated by percutaneous cement vertebroplasty over a three-year period, May 2000 to May 2003. RESULTS: Successful percutaneous stabilisation and cement injection was performed in all compression fractures. In five of eight patients (eight of eleven compression fractures) injection of cement yielded dramatic reduction in pain within 24 hours of the procedure. CONCLUSION: Preliminary experience suggests that percutaneous cement vertebroplasty is an effective well tolerated method of stabilisation of spinal wedge compression fractures resulting in dramatic reduction in associated pain in most cases.

Administration, Cutaneous↗

PubMed2001

[Metastatic epidural spinal compression: prognostic factors and results of radiotherapy].

BACKGROUND: The metastatic epidural spinal cord compression is an oncologic emergency. Presently, there is no agreement on a standard diagnostic or therapeutic algorithm. In spite of improvement in diagnostic imaging, a great proportion of patients are plegic at the time of the first presentation. PATIENTS AND METHODS: Therapy charts of 53 consecutive patients--31 male and 22 female--with metastatic epidural spinal cord compression treated with radiation therapy only have been analyzed. Median age was 60 years. The most frequent primary tumors were bronchogenic carcinoma (13 patients), breast cancer (ten patients) and prostate cancer (ten patients). RESULTS: MRI was the most sensitive diagnostic tool in detecting spinal cord compression. Plain X-ray films were not useful. Pain symptoms were improved in 66% of the patients. The most important prognostic factor was the pretreatment mobility status. 94% of the ambulatory patients kept their walking ability, but only one plegic patient could walk again after radiation therapy (p < 0.001). Patients whose back pain was presented to an oncologist were more likely to keep their walking ability by the end of the therapy. Patients with bronchogenic cancer and plegic patients had a significantly worse survival. CONCLUSION: Patients with a known malignant tumor and progressive or axial back pain should undergo MRI scan to rule out spinal cord compression. For patients without severe neurologic deficit and MRI proven epidural compression, radiation therapy is able to preserve walking ability and reduce pain. For patients with neurologic symptoms radiation therapy should start within 24 hours.

Adenocarcinoma↗

PubMed2000

[Biomechanics of interlocked nailing in humeral shaft fractures. Comparison of 2 nail systems and the effect of interfragmentary compression with the unreamed humeral nail].

In this biomechanical study the implanted Unreamed Humeral Nail (UHN) has been tested concerning bending and torsional stiffnesses. In literature other intramedullary implants have been criticized for insufficient rotatory stability especially in transverse and short oblique fractures of the humeral shaft. This study examined, whether the implanted UHN, as well as the UHN implanted with interfragmentary compression through a specific compression device, is able to augment torsional stiffness significantly. To evaluate bending and torsional stiffnesses, the UHN has been compared biomechanically to the Russell-Taylor humeral nail (RT) in paired mid-shaft osteotomized cadaveric humeri. Identic paired comparison has been performed with the UHN without and UHN with interfragmentary compression. In anterior-posterior, as well as medio-lateral direction stiffness under four-point-bending is significantly higher in stabilizing with the RT. Under torsional loading with moments of 4 Nm, 6 Nm and 8 Nm the UHN reached more than the double torsional stiffness. The RT, which is only dynamically interlocked, owns a high initial "play" between bolts and nail itself. Through additional interfragmentary compression stiffness of the UHN under four-point-bending in anterior-posterior, as well as medio-lateral direction augments significantly. Also under torsional loading with moments of 4 Nm, 6 Nm und 8 Nm torsional stiffness increases with interfragmentary compression significantly. In comparison to other biomechanical studies of different authorship it is clear, that this statically interlocked intramedullary nailing of the humeral shaft is superior to non-statically interlocked types of nailing concerning their stabilizing potency in torsion and serves especially for fracture types, which are critically under rotation, as transverse or short oblique humeral shaft fractures.

Biomechanical Phenomena↗

PubMed2005

The spectrum of magnetic resonance imaging findings in hypertension-related neurovascular compression.

Hypertension (HTN) has been controversially related to neurovascular compression (NVC) at the rostral ventrolateral (RVL) medulla in anatomical, surgical, and radiological reports. Our objective was to investigate the association between primary HTN and signs of NVC at the medulla oblongata on magnetic resonance imaging (MRI) and to explore a new classification based on image criteria. Subjects with (n=64) and without (n=29) HTN were studied. Three-millimeter slices, with 1-mm intervals in between, were performed on T2-weighted images in axial and coronal views. Attention was focused on the relationship between the upper medulla and the surrounding arteries. The findings were divided into three categories: 1) non-NVC: absence of signs of NVC, 2) NVC type I: an artery in contact with the RVL medulla but not compressing it, and 3) NVC type II: evident compression of the RVL medulla by an artery. Signs of NVC were observed in 65.7% (42/64) of the HTN group (type I: 39.1%, 25/42 patients; type II: 26.6%, 17/42 patients). Among the normotensive subjects, 27.6% (8/29) had signs of NVC; only one (3.3%) of these had NVC type II (evident compression), and the rest were NVC type I. We conclude that the presence of NVC at the RVL medulla on MRI is related to HTN. More importantly, the finding of frank compression (NVC type II) is present almost exclusively in hypertensive subjects; only one individual (3.3% of our normotensive population) had NVC type II.

Adult↗