Development of cerebellar atrophy 15 years after basilar artery occlusion: hypoperfusion or coincidence?
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Arterial Occlusive Diseases↗
Biomedical subjects
A Lindner
Publications and source records attributed to A Lindner.
Identification of Doppler microembolic signals with a bigate probe in patients with prosthetic heart valves.
BACKGROUND AND PURPOSE: The applicability of a bigate probe, simultaneously harvesting two spatially separated vessel segments, in the identification of Doppler microembolic signals (MES) was evaluated. METHODS: One hundred and ninety-seven patients with artificial heart valves were bilaterally monitored over two segments of each middle cerebral artery, with a minimal distance of 5 mm between them, using 2 MHz probes. Time delay in the appearance of high intensity transients between the two segments was calculated off-line, using dedicated software, integrated in the Doppler device. RESULTS: Bigate monitoring was feasible in 96% of patients. MES prevalence and counts were 37% and 26 (18-44) respectively. All but 8.8% of the 2932 MES signals recorded appeared in both Doppler channels, with a time delay of 4.4 (4.2-4.7) msec (range between 0 and 34 msec). Time delay in 97% of artifact signals was under 1 msec. Application of 1 msec as low and 20 msec as high cut-off point between MES and artifacts resulted in the correct identification of 97% of artifacts and 89.6% of MES. CONCLUSIONS: The multigate approach is a reliable method for identification of Doppler microembolic signals in patients with prosthetic heart valves. The value of this technique in other patient groups remains to be evaluated.
Aortic Valve↗
Ophthalmoplegia plus: clinical relevance of magnetic resonance tomogaphy findings.
The diagnostic value of magnetic resonance imaging (MRI) in patients with ophthalmoplegia plus was evaluated. Twenty patients in whom the diagnosis of opthalmoplegia plus was clinically and histochemically established underwent magnetic resonance and electrophysiological studies. Three types of neuroradiological abnormalities were found in 14 patients: (1) cerebral and/or cerebellar atrophy (n = 11), (2) hyperintense lesions of the white matter or pyramidal tract (n = 2), or (3) both (n = 1). The diagnostic yield of MRI was low, since clinically or electrophysiologically manifest lesions were missed in 4 cases and the pathological findings were non-specific, since they are seen in several demyelinating diseases. Our results suggest that MRI provides no additional information in patients with manifest ophthalmoplegia plus. We conclude that clinical presentation and evidence of ragged red fibers are the cornerstones in diagnosis of ophthalmoplegia plus.
Adult↗
[Differential sciatica pain diagnosis from the neurologic viewpoint].
Low back pain and sciatica with or without neurological deficits represent frequent disorders in clinical practice. Both, history and neurological examination are essential for localizing underlying lesions and initiating appropriate investigations. Pain location, sensory symptoms, motor signs and reflexes are extremely reliable in indicating which motor root(s) or peripheral nerve(s) are affected. Sometimes, pain and/or paraesthesia are the only presenting symptoms. Therefore differential diagnosis of low back pain and sciatica is various. This article summarizes the differential diagnosis of low back pain and sciatica according to the site of the lesion as follows: 1. lesions of the spinal cord, 2. lesions of the nerve roots (L4, L5, S1-S3), 3. lesions of the lumbosacral plexus, 4. peripheral nerve lesions (sciatic nerve, peroneal nerve), 5. low back pain and sciatica due to neuropathies, and 6. low back pain and sciatica as a symptom of other neurological disorders. Additionally, the status of neuroradiological procedures in establishing diagnosis is discussed.
Diagnosis, Differential↗
Iatrogenic spinal epidural abscesses: early diagnosis essential for good outcome.
Spinal epidural abscess usually arises by hematogenous, lymphatic or venous spread. The frequent use of invasive procedures at the spinal cord such as epidural injections to produce analgesia has led to an increased incidence of iatrogenic abscesses. We describe 8 patients who developed iatrogenic spinal epidural abscesses after paravertebral or intragluteal punctures respectively intravenous catheters to produce analgesia. Deep paravertebral or intragluteal injections were the cause of abscess formation in five, a contaminated intravenous line in two and a peridural catheter in one case. Pain of the affected vertebral column and malaise were the leading symptoms and Staphylococcus aureus was isolated in all cases. Diagnosis was made by means of magnetic resonance (n = 7) or Computed tomography (n = 1). Outcome was excellent with early therapy consisting of laminectomy and/or antibiotic treatment in the six patients treated within two days of appearance of symptoms. Invasive procedures at the spinal cord can lead to iatrogenic spinal epidural abscesses. Physicians dealing with deep punctures and catheter procedures should be aware of early symptoms and signs of an epidural abscess, since early diagnosis and specific therapy are the most important factors for a good outcome.
Abscess↗
Comparison of transcranial sonography, magnetic resonance imaging, and single photon emission computed tomography findings in idiopathic spasmodic torticollis.
Various lines of evidence suggest that the basal ganglia and thalamus are involved in the pathogenesis of idiopathic dystonia, but unfortunately neuroradiological and pathological data are sparse and controversial. In this study, we have examined 10 patients with spasmodic torticollis by neuroimaging techniques, including transcranial sonography (TS; n = 10), conventional (n = 10) and diffusion-weighted (n = 5) magnetic resonance imaging (MRI), and single photon emission computed tomography (SPECT; n = 10), employing [123I]iodobenzamide (IBZM) as a ligand with a high affinity to the D2 receptor. In seven patients, TS showed small hyperechogenic lesions in the medial segments of the lentiform nucleus contralateral to the side of head deviation. In accordance with the site of TS abnormalities, diffusion-weighted MRI displayed a hyperintense lesion in only one patient, while standard MRI of this area was normal in all patients. SPECT revealed a slight but statistically nonsignificant reduction of IBZM tracer uptake in an area corresponding to the dorsal portions of the striatum in 9 of the 10 patients. TS findings support the hypothesis that structural alternations of the pallidothalamic circuit contralateral to the side of head deviation are involved in the pathogenesis of idiopathic spasmodic torticollis. TS may be more sensitive in detecting basal ganglia alterations than MRI.
Adult↗
[Multiple, disseminated hypodensities in cranial CT. Multiple disseminated ischemia in pneumococcus-induced cerebral vasculitis].
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Adult↗
Outcome in juvenile-onset myasthenia gravis: a retrospective study with long-term follow-up of 79 patients.
Randomised and controlled treatment studies of juvenile-onset myasthenia gravis have not been published. We therefore report our retrospective analysis of 79 patients with juvenile-onset myasthenia gravis observed for as long as 30 years. The mean age at onset was 13.7 years and median follow-up 7.7 years. The initial presentation was generalised disease in 90% and ocular disease in the remaining patients. Sixty-five patients (82%) were thymectomised. In 14 of these, treatment consisted of a combination of azathioprine (2-3 mg/kg), corticosteroids (prednisolone up to 60 mg for a maximum duration of 12 months with subsequent tapering) and acetylcholinesterase (AChE) inhibitors, and of azathioprine and AChE inhibitors in 27 patients. One patient received azathioprine and 22 AChE inhibitors only; in another no further medication was necessary. In the severely affected group (n = 16), plasmapheresis was performed additionally before thymectomy and continued for some time after the operation. Treatment was started between 1 and 14 months (mean 2.4 months) after the onset of myasthenic symptoms. No thymectomy was done in 14 patients, and immunosuppressive treatment and AChE inhibitors were given in 9 of these cases. One patient received azathioprine only; 4 patients received AChE inhibitors only. The histology of the thymus gland showed follicular hyperplasia in 89% of the 65 thymectomised patients and normal findings in the remainder. Remission occurred in 60% of patients who underwent thymectomy and in 29% of those who were not thymectomised. Hyperthyroidism (6 patients, 8%), diabetes mellitus (2 patients, 3%) and rheumatoid arthritis (2 patients, 3%) were the most frequent associated immune-mediated diseases. Epileptic seizures and neoplasia were coincident diseases in 2 (3%) and 3 (4%) patients, respectively. There were no deaths from thymectomy or from immunosupression. This open, retrospective analysis suggests that juvenile-onset myasthenia gravis can be treated satisfactorily in most patients by the use of thymectomy and/or immunosupressive medication.
Adolescent↗
Solitary plasmocytoma of the mandible--a combined approach for treatment and reconstruction.
A 44-year-old man presented with a solitary plasmocytoma in the left mandible. After neoadjuvant radiation therapy and chemotherapy, a bone marrow biopsy was taken for cryopreservation. In simulation surgery, tumour resection and primary reconstruction were planned on an individual stereolithographic 3-D skull model. Radical tumour resection and primary reconstruction using a microvascular iliac crest bone graft was performed. In case of extensive osteolysis and/or mandibular asymmetry due to tumourous bone enlargement, preoperative model planning has proved to be a useful tool for primary reconstruction. In the three-year follow up, the patient showed no recurrence of disease.
Adult↗
HPLC fractions of human uremic plasma inhibit the RBC membrane calcium pump.
We have reported that uremic plasma filtrates (UF) inhibit the red blood cell (RBC) membrane calcium pump. The inhibitor was dialyzable, smaller than 3,000 molecular weight, heat-stable, and protease-resistant. In the present study, we used reverse-phase preparative HPLC, analytical HPLC, and Sephadex G-25 elution to identify inhibitory fractions. Inhibition was confirmed in three different bioassays: (1) Sr2+ efflux in intact RBC, the primary bio-assay; (2) 45Ca efflux in intact RBC; and (3) calcium ATPase activity in isolated RBC membranes. Active fractions were analyzed by mass spectrometry, capillary electrophoresis, enzymatic analysis, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. These demonstrated a number of compounds, including: sugars, polyols, osmolytes like betaine and myoinositol, amino acids, and other metabolites, such as 3-D-hydroxybutyrate, dimethylglycine, trimethylamine-N-oxide, guanidinoacetic acid and glycine. Many individual compounds were then tested for an effect on the calcium pump. Thus, HPLC was able to separate a substantial number of compounds in inhibitory fractions. Efforts are under way for precise identification of the inhibitor, to advance our understanding of uremic toxicity and/or hypertension in CRF.
Adult↗
[Transcranial color-coded duplex ultrasound in interventional therapy of cerebral aneurysms. A pilot study].
PURPOSE: To assess the diagnostic potential of transcranial colour-coded duplex sonography in the recognition of residual perfusion of coiled cerebral aneurysms. METHOD: 10 patients (7 female, 3 male) with angiographically verified cerebral aneurysms (basilar artery n = 2, mean size 8.5 mm; supraclinoid internal cerebral artery n = 2, mean size 15.5 mm; posterior communicating artery n = 2, mean size 7 mm; anterior communicating artery n = 2, mean size 4.5 mm) were examined by TCCD using a 2.25 MHz probe immediately following embolisation and 12-24 hours prior to angiographic evaluation. RESULTS: 9 patients had a sufficient temporal bone window. Transtemporal localization of the embolised aneurysms was feasible in 7 of the 9 cases. One partially thrombosed aneurysm of the basilar artery (1 mm) and one completely thrombosed aneurysm of the anterior communicating artery could not be visualised. In 7 cases no discrepancies between TCCD and angiography were evident, since rest, perfusion (n = 6) and complete thrombosis were unanimously diagnosed as such. Mean size of the rest perfused lumina was 4.4 mm (minimum 1.5 mm; maximum 8 mm). Platinum coils appeared as hyperechogenic lesions with an echogenicity comparable to the skull. CONCLUSION: With TCCD residual perfusion of coiled aneurysms was feasible in most cases. The method seems to be specific but not sensitive in the detection of incompletely coiled aneurysms. Limitations are insufficient transtemporal bone windows and inaccessible aneurysm location, especially the anterior communicating artery.
Adult↗
Transcranial duplex sonography of hyperacute intracerebral hemorrhages.
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Acute Disease↗
Parkinson's disease and depression: evidence for an alteration of the basal limbic system detected by transcranial sonography.
OBJECTIVES: Depression is a frequent symptom in Parkinson's disease. Compelling evidence suggests a role of the brainstem in the control of mood and cognition. In patients with unipolar depression transcranial sonography (TS) studies have shown structural alteration of the mesencephalic brainstem raphe which could suggest an involvement of the basal limbic system in the pathogenesis of primary mood disorders. The objective of the present study was to evaluate whether a similar alteration could be found in depressed patients with Parkinson's disease using TS. METHODS: Thirty patients with Parkinson's disease and 30 age and sex adjusted controls were examined by TS. Raphe echogenicity was rated semiquantitatively. The severity of motor symptoms and depression was rated using standard research instruments. RESULTS: Raphe echogenicity was significantly reduced in depressed patients with Parkinson's disease compared with nondepressed patients with Parkinson's disease and control subjects. Raphe echogenicity correlated negatively with degree of motor impairment, and differences in raphe echo between depressed and non-depressed patients with Parkinson's disease were upheld when motor impairment was controlled for. CONCLUSION: These preliminary findings suggest that, as in unipolar depression, a morphological alteration of the brainstem raphe might be involved in the pathogenesis of depression in Parkinson's disease. This raphe alteration may reflect involvement in the basal limbic system in the pathogenesis of secondary depression. This concept is in line with current knowledge on the pathogenesis of both depression in Parkinson's disease and primary depressive disorders.
Aged↗
A genetic sequence change in the 3'-noncoding region of the androgen receptor gene in prostate carcinoma.
OBJECTIVE: We intended to identify structural changes in the hormone-binding domain and C-terminal region of the androgen receptor (AR) gene in carcinoma of prostate specimens. METHODS: Twelve prostate cancer specimens from prostate resections were analyzed for the presence of mutations in the E-H exons and part of the 3'-untranslated region of the AR cDNA, using RT-PCR and direct sequencing. RESULTS: A polymorphic sequence spanning 17 nucleotides was identified in the 3'-untranslated region of the AR cDNA from one prostate carcinoma tissue, suggesting the presence of a somatic mutation. No mutations were identified in the coding sequence of the hormone-binding domain of the AR cDNA. CONCLUSION: These results suggest that AR mutations are probably uncommon molecular events in the early stages of prostate cancer.
Adenocarcinoma↗
Influence of oxygen ventilation on Doppler microemboli signals in patients with artificial heart valves.
BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the influence of inhalation of 100% oxygen on microembolic signal (MES) counts in patients with artificial cardiac valves. METHODS: A total of 134 outpatients were examined. Transcranial Doppler baseline monitoring (45-minute duration) was performed in all patients under resting conditions. The first 30 patients subsequently underwent transcranial Doppler monitoring for at least 20 minutes under noninvasive positive pressure ventilation with 100% oxygen and for an additional 30 minutes under resting conditions. The same protocol was applied to all following patients with a baseline MES count > or = 10, while the examination was discontinued in the remaining patients. RESULTS: Baseline MES counts < 10, which remained unchanged during oxygen inhalation and the subsequent resting period, were observed in 26 of 30 initial patients. A total of 46 patients with MES counts > or = 10 were identified. Oxygen application was feasible in 43 patients. An exponential MES decrease was noted in 42 patients during oxygen inhalation (statistically significant in 38 patients), followed by a subsequent increase in 38 of 43 patients (statistically significant in 25 patients) under resting conditions. CONCLUSIONS: The exponential reduction of MES counts observed in this study corresponds to blood denitrogenation, thus strongly arguing for nitrogen bubbles as underlying embolic material in prosthetic valve carriers.
Adolescent↗
Intracranial microembolic signals in 500 patients with potential cardiac or carotid embolic source and in normal controls.
BACKGROUND AND PURPOSE: We undertook this study to evaluate the prevalence and clinical correlations of Doppler microembolic signals (MES) in stroke-prone patients. METHODS: Patients with potential cardiac (n = 300) or carotid (n = 100) embolic source and control subjects (n = 100) were monitored with transcranial Doppler sonography for MES. Transthoracic (n = 192) and/or transesophageal (n = 134) echocardiography and carotid studies (continuous-wave Doppler, n = 181; color-coded duplex, n = 47) were performed in all patients with potential native cardioembolic source. Carotid disease was evaluated by means of continuous-wave Doppler (n = 87), color-coded duplex (n = 70), or intra-arterial angiography (n = 24) in patients with potential carotid embolic source. RESULTS: Overall MES prevalence was 23% in patients with potential native cardioembolic source (infective endocarditis [n = 7] 43%, left ventricular aneurysm [n = 38] 34%, intracardiac thrombus [n = 23] 26%, dilative cardiomyopathy [n = 39] 26%, nonvalvular atrial fibrillation [n = 24] 21%, valvular disease [n = 80] 15%), 55% in patients with prosthetic cardiac valves (mechanical [n = 77] 58%, porcine [n = 7] 43%, homografts [n = 5] 20%), 28% in patients with carotid disease (symptomatic [n = 46] 52%, asymptomatic [n = 54] 7%; P < .01), and 5% in control subjects. No relationship between MES counts and patients' age, sex, or actual medication was noted. The sensitivity and specificity of MES detection in identifying patients with potential embolic sources were 31% and 95%, respectively. CONCLUSIONS: Our study confirmed the reported clinical significance of MES in patients with carotid disease and the high specificity of this technique. The demonstrated low sensitivity of MES detection could be due to short monitoring duration or application of antihemostatic treatment. Prospective large-scale studies are needed to determine the definitive value of MES detection as a diagnostic method in patients with potential cardioembolic source.
Adult↗
Doppler microembolic signals in children with prosthetic cardiac valves.
BACKGROUND AND PURPOSE: The aim of this study was the evaluation of the prevalence and counts of Doppler microembolic signals (MES) in children with prosthetic cardiac valves and their comparison to those obtained in corresponding adult patients. PATIENTS AND METHODS: Nine children and 43 adults with ATS valves implanted in the aortic position were monitored over both middle cerebral arteries with transcranial Doppler ultrasound. MES were identified on-line according to standard criteria. Heart rate and rhythm, valve type, size and duration, patients' height, International Normalized Ratio, and prevalence of neurological complications were obtained from all study participants. RESULTS: MES prevalence and counts were significantly higher in children compared with adult patients (100% versus 25.5% and 58 [18.5 to 115.5] versus 55 [2 to 10.5], median, 95% CI, respectively). No corresponding differences in valve duration of valve implant were evident, but children has heart rates and were significantly smaller compared with adults. A positive correlation between patients' size, heart rate, and MES counts was noted. CONCLUSIONS: MES counts in children with mechanical prosthetic valves are significantly higher compared with those in corresponding adults. We hypothesize that this is due to (1) the shorter distance between aortic valve and middle cerebral artery, since cavitation bubbles have a short life span and are bound to dissolve with time, and (2) the faster heart rate in children, resulting in a higher number of valve closures per minute.
Adolescent↗
Transrectal ultrasonographically assisted radical retropubic prostatectomy.
Radical prostatectomy is associated with difficulty in determining the division site of the urethra adjacent to the apical region of the prostate. We present the results of a feasibility clinical trial in three patients to determine whether intraoperative transrectal ultrasonography may assist during radical retropubic prostatectomy. Using this technique the apex is readily identified and a detailed view of the urethral stump could be obtained. In one case residual apical tissue was identified and excised. The creation of the vesicourethral anastomosis was documented and its water tightness was demonstrated. We conclude that transrectal ultrasonography can be performed during radical retropubic prostatectomy and may be helpful in selected cases.
Adenocarcinoma↗