Biomedical subjects

N Salamon

Publications and source records attributed to N Salamon.

12 recordsLinked to original sources

PubMed2006

Cholesterol level and symptomatic hemorrhagic transformation after ischemic stroke thrombolysis.

BACKGROUND: Prestroke statin use may improve ischemic stroke outcomes, yet there is also evidence that statins and extremely low cholesterol levels may increase the risk of intracranial hemorrhage. We evaluated the independent effect of statin use and admission cholesterol level on risk of symptomatic hemorrhagic transformation (sHT) after recanalization therapy for acute ischemic stroke. METHODS: We analyzed ischemic stroke patients recorded in a prospectively maintained registry that received recanalization therapies (IV or intra-arterial fibrinolysis or endovascular embolectomy) at a university medical center from September 2002 to May 2006. The independent effect of premorbid statin use on sHT post intervention was evaluated by logistic regression, adjusting for prognostic and treatment variables known to predict increased HT risk after ischemic stroke. RESULTS: Among 104 patients, mean age was 70 years, and 49% were men. Male sex, hypertension, statin use, low total cholesterol and low-density lipoprotein (LDL) cholesterol, current smoking, elevated glucose levels, and higher admission NIH Stroke Scale (NIHSS) score were all associated with a greater risk of sHT in univariate analysis. After adjusting for covariates, low LDL cholesterol (odds ratio [OR], 0.968 per 1-mg/dL increase; 95% CI, 0.941 to 0.995), current smoking (OR, 14.568; 95% CI, 1.590 to 133.493), and higher NIHSS score (OR, 1.265 per 1-point increase; 95% CI, 1.047 to 1.529) were independently associated with sHT risk. CONCLUSIONS: Lower admission low-density lipoprotein cholesterol level with or without statin use, current smoking, and greater stroke severity are associated with greater risk for symptomatic hemorrhagic transformation after recanalization therapy for ischemic stroke.

Aged↗

PubMed2006

Diffusion tensor MRI shows abnormal brainstem crossing fibers associated with ROBO3 mutations.

Horizontal gaze palsy with progressive scoliosis (HGPPS) is caused by mutations in the ROBO3 gene, critical for the crossing of long ascending medial lemniscal and descending corticospinal tracts in the medulla. Diffusion tensor imaging in a patient with HGGPS revealed the absence of major pontine crossing fiber tracts and no decussation of the superior cerebellar peduncles. Mutations in the ROBO3 gene lead to a widespread lack of crossing fibers throughout the brainstem.

Adult↗

PubMed2006

Electrical conductivities of the freshly excised cerebral cortex in epilepsy surgery patients; correlation with pathology, seizure duration, and diffusion tensor imaging.

The electrical conductivities (sigma) of freshly excised neocortex and subcortical white matter were studied in the frequency range of physiological relevance for EEG (5-1005 Hz) in 21 patients (ages 0.67 to 55 years) undergoing epilepsy neurosurgery. Surgical patients were classified as having cortical dysplasia (CD) or non-CD pathologies. Diffusion tensor imaging (DTI) for apparent diffusion coefficient (ADC) and fractional anisotropy (FA) was obtained in 9 patients. Results found that electrical conductivities in freshly excised neocortex vary significantly from patient to patient (sigma = 0.0660-0.156 S/m). Cerebral cortex from CD patients had increased conductivities compared with non-CD cases. In addition, longer seizure durations positively correlated with conductivities for CD tissue, while they negatively correlated for non-CD tissue. DTI ADC eigenvalues inversely correlated with electrical conductivity in CD and non-CD tissue. These results in a small initial cohort indicate that electrical conductivity of freshly excised neocortex from epilepsy surgery patients varies as a consequence of clinical variables, such as underlying pathology and seizure duration, and inversely correlates with DTI ADC values. Understanding how disease affects cortical electrical conductivity and ways to non-invasively measure it, perhaps through DTI, could enhance the ability to localize EEG dipoles and other relevant information in the treatment of epilepsy surgery patients.

Action Potentials↗

PubMed2006

Magnetic source imaging localizes epileptogenic zone in children with tuberous sclerosis complex.

The authors assessed whether magnetoencephalography/magnetic source imaging (MEG/MSI) identified epileptogenic zones in patients with tuberous sclerosis complex (TSC). In six TSC children with focal seizures, ictal video-EEG predicted the region of resection with 56% sensitivity, 80% specificity, and 77% accuracy (p = 0.02), whereas interictal MEG/MSI fared better (100%, 94%, and 95%, respectively; p < 0.0001). Interictal MEG/MSI seems to identify epileptogenic zones more accurately in children with TSC and focal intractable epilepsy.

Child↗

PubMed2005

The human cerebral cortex on MRI: value of the coronal plane.

The evaluation of different cortical areas of the cerebral cortex has been analyzed using MRI of 50 normal subjects without any neurological symptoms. This analysis has been made with different spin echo and gradient echo in T1 or T2 in three different planes: horizontal, sagittal and coronal. The most accurate plane to define important cortical areas such as Broca area, Wernicke area, temporal cortex at the level of the superior temporal sulcus, angular gyrus, supra marginal gyrus, hippocampal and parahippocampal cortices as well as that of the parieto or temporo-occipital areas is the coronal plane. Evidently it must be correlated with the other orthogonal planes. To be compared with the main Atlas of Neuroanatomy these sections must be perpendicular or parallel to the plane passing through the anterior and posterior commissures. MRI of patients with neurological disorders must have, as a routine, a series of MR sections performed in the coronal plane, as well as in horizontal and sagittal ones. The coronal plane is certainly the most precise to evaluate these areas involved in language, memory, visuo spatial or behavioral functions. It must be always compared with the rest of the neuroradiological examination and correlated with the clinical neurological signs.

Amygdala↗

PubMed2005

Three-dimensional preoperative maps of hippocampal atrophy predict surgical outcomes in temporal lobe epilepsy.

The authors used surface-based anatomic mapping to detect features of hippocampal anatomy that correlated with surgical outcomes in patients undergoing surgery for mesial temporal lobe epilepsy with hippocampal sclerosis. Compared with a seizure-free group, hippocampal profiles for the non-seizure-free group had greater diffuse ipsilateral atrophy and more region-specific contralateral atrophy in the anterior, lateral hippocampus. These atrophic regions may indicate areas of increased epileptogenicity, contributing to poorer surgical outcomes.

Adult↗

PubMed2005

Analysis of the brain-stem white-matter tracts with diffusion tensor imaging.

The authors have reviewed the diffusion tensor imaging (DTI) of the brain stem in 19 subjects, consisting of 15 normal volunteers and four multi-system atrophy patients. The study was performed with 1.5 T MRI scanners. DTI was correlated with an automated program allowing superposition of the structural anatomy. Axial, sagittal, and coronal images demonstrated major white-matter fibers within the brain stem, including cortico-spinal tracts, transverse pontine fibers, and medial lemniscus. Smaller fibers, such as medial longitudinal fascicles and central tegmental tracts are difficult to visualize. To identify the anatomical orientation of the brain stem, white-matter fibers will help us understand the different functional disease processes, and DTI will play an important role for the evaluation of the different white matter fibers in the brain stem.

Adult↗

PubMed2004

[Magnetic resonance studies in Alzheimer's dementia. What routine scanning shows].

Magnetic resonance images of the brain acquired in relationship to the commissural plane have been analyzed in twenty cases classified as Probable Alzheimer's disease (Pr. AD). These examinations have been compared to normal aged matched subjects. All examinations have been made in strict correlation with the planes defined by Talairach and Tournoux (1988). The analysis of brain cortical damage was made by evaluating the sulci of the brain mainly on coronal sections correlated with simultaneous image review of the same area on the two other orthogonal planes. In Pr. AD, an asymmetric atrophic pattern was found mainly on the following areas: amygdaloid nucleus, para hippocampal gyrus, hippocampus, areas 22 and 21, temporal pole, insula, dorso frontal cortex, angular gyrus, superior parietal lobule. The primary motor and visual areas were normal in all cases.

Aged↗

PubMed1998

Short-term assessment of periradicular corticosteroid injections in lumbar radiculopathy associated with disc pathology.

We evaluated periradicular injection of corticosteroids performed by neuroradiologists under fluoroscopic guidance in the treatment of lumbosacral nerve root pain in 40 patients (average age 48 years) presenting with lumbosciatica or radiculopathy not responding to conservative treatment. Patients with root pain due to infectious, neoplastic or inflammatory diseases were excluded, as were patients who needed immediate surgery. Pain was evaluated using a visual analogue scale (VAS) 10 and 90 days after the injection. After 10 days a substantial decrease in root pain was observed, with a statistically significant decrease in mean VAS. This decrease was observed in 90% of patients, and it persisted after 90 days in 85%. Side effects were rare, mild and disappeared spontaneously. They were related to the drug injected (corticosteroids).

Adrenal Cortex Hormones↗

PubMed1997

Contrast-enhanced magnetization transfer MR of the brain: importance of precontrast images.

PURPOSE: To determine the importance of obtaining precontrast T1-weighted magnetization transfer (MT) MR images for better interpretation contrast-enhanced T1-weighted MT images. METHODS: One hundred fifty-five patients referred for MR imaging of the brain were examined prospectively with noncontrast T1-weighted imaging, noncontrast T1-weighted imaging with MT, contrast-enhanced T1-weighted imaging, and contrast-enhanced T1-weighted imaging with MT. In the patients who had abnormally increased signal intensity on postcontrast images (with or without MT), the four imaging sequences were evaluated with regard to number of lesions and lesional signal intensity. For each of the sequences, two experienced neuroradiologists subjectively graded the lesions on a scale of 1 to 4 (4 being the most conspicuous) with regard to abnormally increased signal intensity. RESULTS: Twenty-two of the 155 patients had increased signal intensity on one or more of the postcontrast sequences. Eight of these 22 patients had increased signal intensity of one or more lesions on images without MT. All these lesions were seen better on images obtained with MT. An additional six of the 22 patients had increased signal intensity of one or more lesions on images obtained with MT that was not detected on images obtained without MT. Eight of the 22 patients had no high signal intensity on noncontrast images with or without MT. One of the eight had increased number and conspicuity of lesions on postcontrast MT images. CONCLUSIONS: A significant number of patients had increased signal intensity on noncontrast T1-weighted images with MT that was not seen on noncontrast T1-weighted images without MT. This high signal intensity was also visible on postcontrast MT images, and would have been mistaken for pathologic enhancement if noncontrast MT images had not been available for comparison.

Adult↗

PubMed1995

Generalization of the orienting response to significant stimuli: the roles of common and distinctive stimulus components.

This study focused on the effects of common and distinctive stimulus components on the generalization of the orienting response (OR) to significant stimuli. Compound pictorial stimuli were used as the relevant items memorized by the subjects. Skin conductance responses were measured during the subsequent presentation of a stimulus sequence that included a test stimulus that shared some common components with the relevant one. The two types of stimulus components (common and distinctive) were independently manipulated. As predicted by the feature-matching theory, both types of features affected OR generalization, but the distinctive components effect was due mainly to a large decline in OR with the introduction of the first distinctive component. As hypothesized, no interaction was observed between the effects of common and distinctive components. Contrary to expectations, similar OR generalization was obtained regardless of whether the test stimulus was constructed by deleting stimulus components from the relevant stimulus or by adding components to that stimulus.

Adult↗

PubMed1981

Acute maxillary sinusitis in children.

We sought to correlate the clinical, radiographic, and bacteriologic findings in maxillary sinusitis in 30 children who had both upper-respiratory-tract symptoms and abnormal maxillary radiographs. Cough, nasal discharge, and fetid breath were the most common signs, but fever was present inconsistently. Facial pain or swelling and headache were prominent symptoms in older children. Bacterial colony counts of greater than or equal to 10(4) colony-forming units per milliliter were found in 34 of 47 sinus aspirates obtained from 23 children. The most common species recovered were Streptococcus pneumoniae, Haemophilus influenzae, and Branhamella catarrhalis. No anaerobic bacteria were isolated. Viruses were isolated from only two sinus aspirates. There was a poor correlation between the predominant species of bacteria recovered from either the nasopharyngeal or throat culture and the bacteria isolated from the sinus aspirate. This study demonstrates that children with both upper-respiratory-tract symptoms and abnormal sinus radiographs are likely to harbor bacteria in their sinuses, suggesting that such children have bacterial sinusitis.

Acute Disease↗