Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Reference atlas”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 469 records · Page 26Linked to original sources
PubMed1995

The neural basis of the central executive system of working memory.

Working memory refers to a system for temporary storage and manipulation of information in the brain, a function critical for a wide range of cognitive operations. It has been proposed that working memory includes a central executive system (CES) to control attention and information flow to and from verbal and spatial short-term memory buffers. Although the prefrontal cortex is activated during both verbal and spatial passive working memory tasks, the brain regions involved in the CES component of working memory have not been identified. We have used functional magnetic resonance imaging (fMRI) to examine brain activation during the concurrent performance of two tasks, which is expected to engage the CES. Activation of the prefrontal cortex was observed when both tasks are performed together, but not when they are performed separately. These results support the view that the prefrontal cortex is involved in human working memory.

Adult↗
PubMed2005

Brain-derived neurotrophic factor induces a rapid dephosphorylation of tau protein through a PI-3 Kinase signalling mechanism.

The microtubule-associated protein tau is essential for microtubule stabilization in neuronal axons. Hyperphosphorylation and intracellular fibrillar formation of tau protein is a pathology found in Alzheimer's disease (AD) brains, and in a variety of neurodegenerative disorders referred to as 'taupathies'. In the present study, we investigated how brain-derived neurotrophic factor (BDNF), an extracellular factor that is down-regulated in AD brains, affects tau phosphorylation. BDNF stimulation of neuronally differentiated P19 mouse embryonic carcinoma cells resulted in a rapid decrease in tau phosphorylation, at phosphorylation sites recognized by Tau 1, AT 8, AT 180 and p 262-Tau antibodies. K 252 a, a tyrosine receptor kinase (Trk) inhibitor, attenuated this dephosphorylation event, suggesting that BNDF activation of TrkB is responsible for the tau dephosphorylation. In addition, BDNF had no affect on tau phosphorylation in the presence of wortmannin, a PI-3 Kinase inhibitor, or lithium, a GSK 3 beta inhibitor, suggesting that these two kinases are part of the signaling transduction cascade leading from TrkB receptor activation to tau dephosphorylation. These results suggest a link between a correlate of AD, decrease in BDNF levels and an AD pathology, tau hyperphosphorylation.

Animals↗
PubMed2004

Legal aspects of work-related mental illness and disorder.

Workers' compensation laws exist to compensate workers for injuries sustained on the job. In Israel, this includes mental as well as physical injuries, both generally described by the law as "work accidents." Courts readily accept mental injuries as work-related when they are caused by physical work events. In cases where a physical event precipitates mental injury, courts allow presumptions of work-relatedness as proof of part of the case. However, when a psychological event causes a psychological illness (referred to as "purely psychological" cases), courts must grapple with ascertaining whether these non-visible, internal events, often accompanied by multiple causes, have the requisite work connection to justify compensation. Ultimately, a court requires proof of each aspect of a purely psychological case to assure itself of the legitimacy of the claim. To provide courts with requisite proof of work-relatedness, a claimant in a purely psychological case must show that the event was sudden, unexpected, severe, and that it was caused in significant part by work, as viewed objectively, rather than on the basis of a claimant's subjective perception of reality. Gradual events, such as repetitive work stress, are generally not compensated. Presumptions of work-relatedness will not apply. The workers' compensation system cannot bear the burden for psychological events that occur as a usual part of the work environment or that are the result of multiple non-work-related causes.

Accidents, Occupational↗
PubMed1996

Regional glucose metabolic rates in the human brain: a PET study.

With the purpose of determining the regional cerebral glucose metabolic rates (rCMRglu) in the normal human brain in resting state, we measured with PET and FOG, as the tracer, the distribution of regional radioactivity levels in the brains of seven young healthy volunteers. The individual brain images were stereotactically standardised with the help of a computerised brain atlas. In the next steps, the global cerebral glucose metabolic rate (gCMRglu) in the individual subjects was normalised to 34 mumol/ 100 g/min, followed by the averaging of the stereotactically standardised and metabolically normalised brain images across the subject population. In the final step, on the basis of high precision anatomical information, three-dimensional (3-D) volumes-of-interest (VOI's), covering over thirty anatomical structures in the brain, were created and the rCMRglu values inside the VOI's were determined in the averaged image. The present measurements of the rCMRglu values are in outstanding agreement with those determined in earlier quantitative PET-FDG studies, demonstrating that stereotactically standardised and metabolically normalised images of regional radioactivity distributions in the brain can be used for quantitative determination of rCMRglu values.

Adult↗
PubMed1996

Localized cerebellar reductions in benzodiazepine receptor density in human partial epilepsy.

BACKGROUND: Previous studies suggest that the morphological substrate for cerebellar dysfunction is destruction of Purkinje cells, but disagree on whether this is caused by seizure- or drug-related toxicity. The benzodiazepine (BZ) receptor antagonist flumazenil tagged with carbon 11 is a sensitive marker of Purkinje cells. OBJECTIVE: To investigate whether cerebellar dysfunction in partial epilepsy is related to seizures through cerebrocerebellar connections. DESIGN: Positron emission tomography with [11C] flumazenil was conducted in 5 patients with frontal lobe seizures, 12 patients with mesial temporal lobe seizures, and 7 healthy men. Eight patients also had [18F]-fluorodeoxyglucose positron emission tomography. Cerebellar regions of interest were delineated using magnetic resonance imaging and a computerized anatomical brain atlas, and the epileptogenic regions were determined with a multimethod assessment. RESULTS: Patients with frontal lobe seizures had a significantly reduced BZ receptor density in the anterior cerebellum contralateral to the seizure onset region (P < or = .001), 2-way repeated-measure analysis of variance). Patients with mesial temporal lobe seizures had reductions in the ipsilateral (posterior and anterior) cerebellum (P < or = .001 for both). No significant asymmetries were found in regional glucose metabolism. CONCLUSIONS: The observed distribution of BZ receptor reductions is congruent with animal experiments showing tht frontal lobe projections to the cerebellum are crossed, whereas projections from mesial temporal loe are predominantly ipsilateral. The results thus indicate a functional relation with seizures and may reflect excitotoxic lesions or specific changes in the gamma-aminobutyric BZ system.

Adult↗
PubMed2002

Sexual dimorphism in the corpus callosum: a characterization of local size variations and a classification driven approach to morphometry.

We present two complementary quantitative approaches to the problem of characterizing morphometric variations between two distinct populations. The case presented focuses solely on local size variations, but the general method can easily be applied to other scalar morphometric quantities. The first method uses a statistical parametric map (SPM) to ascertain a P value, which indicates whether any statistically significant differences exist between the populations. The second method focuses on finding the best single measurement which can be used for classifying the two populations. For our case study midsagittal cross sections of the corpora callosa from a population of normal males and females are nonrigidly registered (spatially normalized) to an atlas. The resulting deformations are then used to ascertain (i) whether there are any statistically significant differences between the populations and (ii) whether these differences allow one to perform classification. We make use of the Jacobian of the deformation field and normalize it to account for overall volume changes allowing us to focus on differences which are more related to morphometry than scale. From the (SPM) approach to the problem we find evidence of statistically significant differences in the morphology between the populations. Using a linear discriminant function we find that these differences do not appear to be useful for classification. Thus, this dataset provides an example of how statistically significant effects may not be of much diagnostic value. They may be of interest to the research community, but of little value to the clinician.

Adult↗
PubMed2006

Is this "my" patient? Development and validation of a predictive model to link patients to primary care providers.

BACKGROUND: Evaluating the quality of care provided by individual primary care physicians (PCPs) may be limited by failing to know which patients the PCP feels personally responsible for. OBJECTIVE: To develop and validate a model for linking patients to specific PCPs. DESIGN: Retrospective convenience sample. PARTICIPANTS: Eighteen PCPs from 10 practice sites within an academic adult primary care network. MEASUREMENTS: Each PCP reviewed the records for all outpatients seen over the preceding 3 years (16,435 patients reviewed) and designated each patient as "My Patient" or "Not My Patient." Using this reference standard, we developed an algorithm with logistic regression modeling to predict "My Patient" using development and validation subsets drawn from the same patient set. Quality of care was then assessed by "My Patient" or "Not My Patient" designation by analyzing cancer screening test rates. RESULTS: Overall, PCPs designated 11,226 patients (68.3%, range per provider 15% to 93%) to be "My Patient." The model accurately categorized patients in development and validation subsets (combined sensitivity 80.4%, specificity 93.7%, and positive predictive value 96.5%). To achieve positive predictive values of > 90% for individual PCPs, the model excluded 19.6% of PCP "My Patients" (range 5.5% to 75.3%). Cancer screening rates were higher among model-predicted "My Patients." CONCLUSIONS: Nearly one-third of patients seen were considered "Not My Patient" by the PCP, although this proportion varied widely. We developed and validated a simple model to link specific patients and PCPs. Such efforts may help effectively target interventions to improve primary care quality.

Adult↗
PubMed2004

Detection of diffuse abnormal perfusion in SPECT using a normal brain atlas.

Visual assessment, with significant inter- or intraobserver variability, is still the norm for the evaluation of Single Photon Emission Computerized Tomography (SPECT) cerebral perfusion studies. We present in this paper an automated method for screening SPECT studies to detect diffuse disseminated abnormalities based on a computerized atlas of normal regional cerebral blood flow (rCBF). To generate the atlas, a set of normal brain SPECT studies are registered together. The atlas contains the intensity mean, the nonlinear displacement mean, and the variance of the activity pattern. A patient is then evaluated by registering his or her SPECT volume to the atlas and computing the nonlinear 3-D displacement of each voxel needed for the best shape fit to it. A voxel is counted as "abnormal" if the intensity difference between the atlas and the registered patient (or if the 3-D motion necessary to move the voxel to its registered position) is superior to 3 SD of normal mean. The number of abnormal voxels is used to classify studies. We validated this approach on 24 SPECT perfusion studies selected visually for having clear diffuse anomalies and 21 normal studies. A Markovian segmentation algorithm is also used to identify the white and gray matters for regional analysis. Based on the number of abnormal voxels, two supervised classifiers were tested: (1) minimum distance-to-mean and (2) Bayesian. The analysis of the intensity and displacement "abnormal" voxels allow one to achieve an 80% correct classification rate for the whole brain and a 93% rate if we consider only voxels in the segmented gray matter region.

Algorithms↗
PubMed2005

Normative estimates of cross-sectional and longitudinal brain volume decline in aging and AD.

OBJECTIVE: To test the hypotheses 1) that whole-brain volume decline begins in early adulthood, 2) that cross-sectional and longitudinal atrophy estimates agree in older, nondemented individuals, and 3) that longitudinal atrophy accelerates in the earliest stages of Alzheimer disease (AD). METHODS: High-resolution, high-contrast structural MRIs were obtained from 370 adults (age 18 to 97). Participants over 65 (n = 192) were characterized using the Clinical Dementia Rating (CDR) as either nondemented (CDR 0, n = 94) or with very mild to mild dementia of the Alzheimer type (DAT, CDR 0.5 and 1, n = 98). Of these older participants, 79 belonged to a longitudinal cohort and were imaged again a mean 1.8 years after baseline. Estimates of gray matter (nGM), white matter (nWM), and whole-brain volume (nWBV) normalized for head sizes were generated based on atlas registration and image segmentation. RESULTS: Hierarchical regression of nWBV estimates from nondemented individuals across the adult lifespan revealed a strong linear, moderate quadratic pattern of decline beginning in early adulthood, with later onset of nWM than nGM loss. Whole-brain volume differences were detected by age 30. The cross-sectional atrophy model overlapped with the rates measured longitudinally in older, nondemented individuals (mean decline of -0.45% per year). In those individuals with very mild DAT, atrophy rate more than doubled (-0.98% per year). CONCLUSIONS: Nondemented individuals exhibit a slow rate of whole-brain atrophy from early in adulthood with white-matter loss beginning in middle age; in older adults, the onset of dementia of the Alzheimer type is associated with a markedly accelerated atrophy rate.

Adolescent↗
PubMed1999

One atlas - three anatomies: relationships of the Schaltenbrand and Wahren microscopic data.

The stereotaxic atlas of Schaltenbrand and Wahren is widely used for orientation in functional neurosurgery of the human diencephalon. As the sagittal, frontal, and horizontal microscopic series were gathered from three different cerebral hemispheres, loci with the same ACPC (anterior commissure-posterior commissure) coordinates are not exactly anatomically corresponding. We compared the 3-D position of 21 anatomical structures in the three series based on their digitally interpolated solid volume representations. Regression analysis of the centres of gravity revealed strong linear correlations between series (0.944< or = Pearson's r< or = 0.976, alpha<0. 0001). Thus calculation of anatomically corresponding sites based on the regression equations seems justified. Volumetry revealed that the sagittally sectioned thalamus is approximately 10% larger than the frontally and 40% larger than the horizontally sectioned thalamus. So as to match it to the sagittal series, the frontal series has to be widened in lateral direction by 19%, in anteroposterior and dorsobasal (vertical) direction it has to be compressed by 5 and 9%, respectively. In contrast, the distance of structures from the midline in the horizontal and sagittal series is very similar. The horizontal series is, however, 25% smaller than the sagittal one in anteroposterior and 17% in vertical direction. On average, thalamic nuclei in the right hemisphere of brain LXXVIII (horizontal microscopic series) were located 2 mm more anterior as compared with the left side (sagittal series), which fact may be explained by difference in size and/or asymmetry. Spatial overlap between corresponding thalamic nuclei from the three series amounted to only 0-28% when superimposed in the ACPC reference space. Linear transformation towards an average led to significant increase (0-37%, p<0.001) of the overlap and ameliorated the quality of the fit of thalamic borders. Limited increase of the overlap is in part due to pronounced differences in the size of thalamic nuclei between the series.

Anatomy, Artistic↗
PubMed2005

Eliminating the limitations of manual crimping in stapes surgery? A preliminary trial with the shape memory Nitinol stapes piston.

OBJECTIVE: Manual piston malcrimping in stapedotomy may be the major cause of the occurrence of the significant, interindividual variations of postoperative air-bone gap (ABG), air-bone gap closures (ABGC), and postoperative recurrences of conductive hearing loss. To eliminate the effects of manual crimping on stapedotomy outcomes, the self-crimping, shape memory alloy Nitinol stapes piston was investigated and hearing evaluated. STUDY DESIGN: Prospective, preliminary case-control study in a tertiary care referral center. METHODS: Sixteen patients with otosclerosis undergoing reversed stapedotomy using the Nitinol stapes piston were matched to reference patients out of our conventional titanium piston database. The effects of the self-crimping Nitinol piston on the postoperative ABGC, the postoperative air-bone gap (ABG) variations, and the postoperative short-term hearing results were investigated 3, 6 and 9 months postoperatively. These data were statistically compared with the results of the control patients in our titanium stapes piston database. RESULTS: The mean postoperative ABG and the interindividual variations of the postoperative ABG were significantly smaller in the Nitinol group, the extent of ABGC greater in the Nitinol piston group, but not significant. The postoperative short-term stability of ABGC was similar in both groups. No infections or adverse reactions occurred during follow-up. CONCLUSION: Our preliminary results suggest that the self-crimping shape memory alloy Nitinol stapes piston eliminates the limitations of manual malcrimping in stapedotomy, thus optimising the surgical procedure. This allows reliable, safe, and consistent air-bone-gap closure in patients with otosclerosis up to 1 year after surgery.

Adult↗
PubMed1999

The sensory somatotopic map of the human hand demonstrated at 4 Tesla.

Recent attempts at high-resolution sensory-stimulated fMRI performed at 1.5 T have had very limited success at demonstrating a somatotopic organization for individual digits. Our purpose was to determine if functional MRI at 4 T can demonstrate the sensory somatotopic map of the human hand. Sensory functional MRI was performed at 4 T in five normal volunteers using a low-frequency vibratory stimulus on the pad of each finger of the left hand. A simple motor control task was also performed. The data were normalized to a standard atlas, and individual and group statistical parametric maps (SPMs) were computed for each task. Volume of activation and distribution of cluster maxima were compared for each task. For three of the subjects, the SPMs demonstrated a somatotopic organization of the sensory cortex. The group SPMs demonstrated a clear somatotopic organization of the sensory cortex. The thumb to fifth finger were organized, in general, with a lateral to medial, inferior to superior, and anterior to posterior relationship. There was overlap in the individual SPMs between fingers. The sensory activation spanned a space of 12-18 mm (thumb to fifth finger) on the primary sensory cortex. The motor activation occurred consistently at the superior-most extent of the sensory activation within and across subjects. The sensory somatotopic map of the human hand can be identified at 4 T. High-resolution imaging at 4 T can be useful for detailed functional imaging studies.

Adult↗
PubMed2006

Relevance of correction for rotational targeting error in functional neurosurgery.

OBJECTIVE: A prospective study is presented on the amount of targeting error that is due to rotational deviations between the atlas and the stereotactic coordinate system. MATERIALS AND METHODS: We investigated 14 volunteers with a stereotactic frame fixed to their heads by tight adhesive bands. Sagittal, coronal and axial T2-weighted MRI scans, as well as MPRage sequences, were performed. The anterior and posterior commissures and one additional point on the midline (the septum pellucidum) were determined on the axial T2-weighted images. Bilateral atlas coordinates for the subthalamic nucleus (STN), globus pallidus pars interna (GPi) and nucleus ventralis intermedius (Vim) were transformed to stereotactic frame coordinates, either without correction or by 2-point or 3-point correction. A total of 896 coordinates (x, y, z for the STN, GPi and Vim in both hemispheres) were calculated. RESULTS: Although the mean differences between the two algorithms (0.24 +/- standard deviation of 0.33 mm) were within the range of system-immanent inaccuracies in MRI-guided stereotaxy, deviations of up to 2.8 mm occurred. No significant correlation was found regarding the amount of rotational angle and the differences in x-, y-, or z-coordinates when 2-point and 3-point transformations were compared. CONCLUSIONS: The reliability of meticulous trajectory planning might be compromised significantly by using only 2-point-based correction or no calculations at all.

Adult↗
PubMed2003

Relationship between alignment of upper and lower cervical spine in asymptomatic individuals.

OBJECT: The aim of this study was to establish standard values for the normal alignment of the upper cervical spine and to clarify its relationship with the lower cervical spine in terms of alignment METHODS: Three hundred thirteen asymptomatic volunteers (155 men and 158 women) participated in this study. Lateral radiographs were obtained with the neck in neutral position, and the angles formed by the occiput (Oc) and the axis, the atlas and the axis, and C-2 to C-7 were measured. The mean Oc-C2 angle was 14.5 +/- 8 degrees in men and 16 +/- 8.5 degrees in women; the mean C1-2 angle was 26.5 +/- 7 degrees and 28.9 +/- 6.7 degrees, respectively; and the mean C2-7 angle was 16.2 +/- 12.9 degrees and 10.5 +/- 10.3 degrees, respectively. Although weak, statistically significant negative correlation was observed between Oc-C2 and C2-7 angles (r = -0.31 in men and -0.37 in women), and between C1-2 and C2-7 angles (r = -0.22 in men and -0.22 in women). The correlation coefficient between the Oc-C2 and C2-7 angles was greater than that between the C1-2 and C2-7angles. CONCLUSIONS: Such relationships between alignment of the upper and lower cervical spines should be taken into consideration when performing occipitocervical fusion.

Adolescent↗
PubMed2005

[The tobacco problem in French-speaking Africa and regional perspectives of the French-speaking African tobacco observatory].

The tobacco problem is one which is both global and political. The epidemic and the growing smoking crisis in Africa is a menace to the health of our continent, with significant socio-economic repercussions to follow in the coming years. Approximately 1.1 billion people around the world smoke, and between now and the year 2025, this number will most likely increase to 1.6 billion. By 2030, 10 million tobacco-related deaths will have occurred, and for the most part those deaths will be concentrated in developing countries. The tobacco industry clearly lies at the heart of the development of the tobacco pandemic in the 20th century. Specifically, cigarettes have made tobacco a massively consumed product, constantly expanding and opening up new markets; the day before yesterday it was men, yesterday it was women and youth, and today it is the developing world. The strategy is identical: increase sales, and do goat a price which puts a heavy burden on the population's health. The industries turn themselves towards developing countries, and namely Africa, in order to compensate for their losses in the markets of the Northern Hemisphere at a time when the demand in these countries is decreasing. The industry's cynical strategy targets Africa as its strongest potential market for development, counting on an estimated increase in consumption of 16% over the next decade, according to WHO's recent World Tobacco Atlas. The illegal importation of cigarettes is a practice which is growing more and more within African countries, with a well-structured African network for smuggling. Smuggled cigarettes are even more toxic with very elevated levels of nicotine and tar. Sponsorship as well as direct and indirect advertising are rapidly developing in all kinds of formats, with a proliferation of aggressive advertising messages targeting African populations with cynicism, manipulation, the complicity of smuggling in broad daylight, and disrespect for the law, while exploiting all of the themes which promote tobacco use to the target audiences (youth, women, the poorest groups). Everyday the tobacco industry recruits new African smokers to replace those who die. The future of the industry is represented by about 8 out of 10 people who began smoking before the age of 18 years old. It was imperative to establish a Tobacco Observatory in Francophone Africa (OTAF) in order to resituate the African tobacco situation, contribute to the development of the French-speaking nations in Africa, and to make known and increase awareness of its needs, its initiatives, and its actions across the world, and finally to effectively fight against tobacco and the industry's practices. One year after OTAF was established in Bamako thanks to the consolidated efforts of all its members and support of the French League against Cancer and the International Union against Cancer, OTAF OTAF is an independent entity whose mission is to gather, analyse and disseminate information on all aspects of tobacco with the objective of soliciting and supporting public health activities and interventions. It is a reference centre for Francophone Africa and a technical advisory group for the public authorities on tobacco issues. OTAF's work is counted upon to inform the public authorities on the most effective measures to use in the fight against tobacco. OTAF's duty is to promote activities which protect the health of young people and non-smokers, and communicate on the harmful effects of tobacco and the tobacco industry's practices. The goal is to organise a fight against tobacco based on solid, scientific data of the highest level of quality. OTAF is the only Francophone African surveillance organisation for monitoring the tobacco epidemic, and the practices, schemes and methods of the tobacco industry which are known to be dishonest Today, OTAF is a unique reference centre as far as the fight against tobacco is concerned in Francophone Africa. It is a partner in a number of projects with the French League against Cancer, the International Union against Cancer, and the International Union for Health Promotion and Education, among others. The success of OTAF has been crowned by a trophee having been awarded by WHO and an honorary degree signed by WHO's Director General.

Africa, Northern↗
PubMed2006

Inter-rater reliability of manual segmentation of the superior, inferior and middle frontal gyri.

Precise rules for locating the anatomical boundaries of the dorsolateral prefrontal cortex (DLPFC) or its subdivisions, i.e., superior, inferior and middle frontal gyri (SFG, IFG and MFG) on magnetic resonance images (MRI), have not been defined. The present study describes the inter-rater reliability of manual segmentation of the SFG, IFG and MFG using guidelines based on sulcal-gyral anatomical boundaries as well as the cytoarchitectonic features of the sub-regions of the prefrontal cortex (PFC). Variations in the application of these guidelines in different subjects to account for normal sulcal variability were developed using the atlas of Ono et al. (Ono, M., Kubik, S., Abernathey, C.D., 1990. Atlas of the Cerebral Sulci. Georg Thieme Verlag, New York). Based on previous cytoarchitectonic studies, the coronal plane of the anterior termination of olfactory sulcus (ATOS) was used as a landmark for delimiting the boundary between the frontal pole (FP) and the frontal gyri. The left hemisphere gray-matter volumes of the SFG, IFG and MFG were determined using a set of 10 MRIs (5 normal and 5 schizophrenia subjects) by two trained raters independently. The intra-class correlation coefficients (ICC) for the SFG, IFG and MFG volumes by the two raters were 0.97, 0.94 and 0.93, respectively. Thus, we describe a reliable method of parcellating the SFG, IFG and MFG, which constitute the DLPFC, a brain region involved in a variety of neuropsychiatric conditions.

Adolescent↗
PubMedDate not supplied

Gd-DTPA enhancement of the cisternal portion of the oculomotor nerve on MR imaging.

PURPOSE: To describe a radiographic finding--enhancement of the cisternal portion of the third cranial nerve on postcontrast MR--and to correlate it with patients' clinical symptoms and ultimate diagnosis. MATERIALS AND METHODS: Thirteen consecutive patients with enhancement of the cisternal portion of the third cranial nerve on postcontrast MR were retrospectively identified; 50 control patients referred for pituitary microadenomas were also retrospectively reviewed. FINDINGS: The enhancement was bilateral in six patients and unilateral in seven patients. Four of the six patients with bilateral enhancement had unilateral oculomotor nerve palsies; none had bilateral third cranial nerve palsy. Five of the seven patients with unilateral enhancement had ipsilateral third nerve palsies. Of the nine patients with third nerve palsies, the pupil was involved in four patients. Follow-up studies were available in six patients, four of whom had third nerve palsy. Resolution of the enhancement correlated with resolution of the symptoms in two patients. The patients' underlying diagnoses were lymphoma (four), leukemia (one), viral meningitis (one), neurofibromatosis (two), inflammatory polyneuropathy-HIV related (one), ophthalmoplegic migraine (one), Tolosa-Hunt syndrome (one), coccidioidomycosis (one), and diabetes (one). No enhancement was seen in any of the controls. CONCLUSION: Enhancement of the cisternal segment of the third cranial nerve is always abnormal, revealing an underlying inflammatory or neoplastic process. However, it is not always associated with clinically apparent oculomotor nerve dysfunction.

Adult↗
PubMed2002

Relationships between dental calcification stages and skeletal maturity indicators in Thai individuals.

The purpose of this study was to investigate the relationship between the stages of calcification of various teeth and skeletal maturity stages among Thai individuals. The study subjects consisted 139 male subjects and 222 female subjects ranging in age from 7 years to 19 years. A total of 361 hand-wrist and panoramic radiographs were obtained and analyzed. The tooth development of the mandibular canines, first and second premolars, and second and third molars were assessed according to the Demirjian's system. Skeletal age and skeletal maturity stages were determined from hand-wrist radiographs by using the method outlined in the atlas of Greulich and Pyle and the Fishman's system, respectively. The Spearman rank order correlation coefficient revealed significant relationships (r = 0.31-0.69, P < .01) between dental calcification stages and skeletal maturity stages. The second premolar was the tooth showing the highest correlation (r = 0.66 in male subjects, r = 0.69 female subjects). The third molar demonstrated the poorest correlation (r = 0.47 in male subjects, r = 0.31 in female subjects). The canine stage F for both sexes (63.2% for female subjects, 54.1% for male subjects) coincided with the MP3 stage. The second molar stage E for female subjects (51.4%) and stage G for male subjects (66.7%) were related to the S stage and the MP(3cap) stage, respectively. This suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period. However, further study is recommended in a larger sample size, and future studies should address development of the canines and second molars.

Adolescent↗