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N Makris

Publications and source records attributed to N Makris.

At least 37 records · Page 2Linked to original sources
PubMed2000

Volume reduction in the caudate nucleus following stereotactic placement of lesions in the anterior cingulate cortex in humans: a morphometric magnetic resonance imaging study.

OBJECT: The goal of this study was to test hypotheses regarding changes in volume in subcortical structures following anterior cingulotomy. METHODS: Morphometric magnetic resonance (MR) imaging methods were used to assess volume reductions in subcortical regions following anterior cingulate lesioning in nine patients. Magnetic resonance imaging data obtained before and 9 +/- 6 months following anterior cingulotomy were subjected to segmentation and subcortical parcellation. Significant volume reductions were predicted and found bilaterally within the caudate nucleus, but not in the amygdala, thalamus, lenticular nuclei, or hippocampus. Subcortical parcellation revealed that the volume reduction in the caudate nucleus was principally referrable to the body, rather than the head. Furthermore, the magnitude of volume reduction in the caudate body was significantly correlated with total lesion volume. CONCLUSIONS: Taken together, these findings implicate significant connectivity between a region of anterior cingulate cortex (ACC) lesioned during cingulotomy and the caudate body. This unique data set complements published findings in nonhuman primates, and advances our knowledge regarding patterns of cortical-subcortical connectivity involving the ACC in humans. Moreover, these findings indicate changes distant from the site of anterior cingulotomy lesions that may play a role in the clinical response to this neurosurgical procedure.

Adolescent↗
PubMed2000

The role of antibiotics after dilatation and curettage in women with metrorrhagia in the prevention of pelvic inflammatory disease.

A follow-up study was carried out in 67 healthy women with negative vaginal-cervical cultures after an endometrial curettage for metrorrhagia. The women were separated into two treatment groups and clinically followed for one month after the operation. The first group included 33 women (aged 23-67, mean 43) who received doxycycline 200 mg daily for a period of one week after the procedure. The second group included 34 women (aged 28-70, mean 43.5) who did not receive any antibiotic regimen after the dilatation and curettage. Four and three women from the 1st and 2nd group, respectively, developed PID during follow-up; a difference not statistically significant.

Adult↗
PubMed1999

Structural and functional brain asymmetries in human situs inversus totalis.

OBJECTIVE: To determine whether individuals with situs inversus totalis (SI), a condition in which there is a mirror-image reversal of asymmetric visceral organs, have alterations in brain asymmetries. BACKGROUND: The human brain is asymmetric in structure and function. Although correlations between anatomic asymmetries and functional lateralization in human brain have been demonstrated, it has been difficult to further analyze them. Characterization of asymmetries of brain structure and function in SI might advance the understanding of these relationships. METHODS: Using anatomic and functional MRI techniques, we analyzed asymmetries in the brains of three individuals with SI. RESULTS: Two major anatomic asymmetries of the cerebral hemispheres, the frontal and occipital petalia, were reversed in individuals with SI. In contrast, SI subjects had left cerebral hemisphere language dominance on functional MRI analysis as well as strong right-handedness. CONCLUSION: These observations suggest that the developmental factors determining anatomic asymmetry of the cerebral petalia and viscera are distinct from those producing the functional lateralization of language.

Adult↗
PubMed1999

Thalamic and amygdala-hippocampal volume reductions in first-degree relatives of patients with schizophrenia: an MRI-based morphometric analysis.

BACKGROUND: Schizophrenia is characterized by subcortical and cortical brain abnormalities. Evidence indicates that some nonpsychotic relatives of schizophrenic patients manifest biobehavioral abnormalities, including brain abnormalities. The goal of this study was to determine whether amygdala-hippocampal and thalamic abnormalities are present in relatives of schizophrenic patients. METHODS: Subjects were 28 nonpsychotic, and nonschizotypal, first-degree adult relatives of schizophrenics and 26 normal control subjects. Sixty contiguous 3 mm coronal, T1-weighted 3D magnetic resonance images of the brain were acquired on a 1.5 Tesla magnet. Cortical and subcortical gray and white matter and cerebrospinal fluid (CSF) were segmented using a semi-automated intensity contour mapping algorithm. Analyses of covariance of the volumes of brain regions, controlling for expected intellectual (i.e., reading) ability and diagnosis, were used to compare groups. RESULTS: The main findings were that relatives had significant volume reductions bilaterally in the amygdala-hippocampal region and thalamus compared to control subjects. Marginal differences were noted in the pallidum, putamen, cerebellum, and third and fourth ventricles. CONCLUSIONS: Results support the hypothesis that core components of the vulnerability to schizophrenia include structural abnormalities in the thalamus and amygdala-hippocampus. These findings require further work to determine if the abnormalities are an expression of the genetic liability to schizophrenia.

Adult↗
PubMed1999

Cortical abnormalities in schizophrenia identified by structural magnetic resonance imaging.

BACKGROUND: Relatively few magnetic resonance imaging studies of schizophrenia have investigated the entire cerebral cortex. Most focus on only a few areas within a lobe or an entire lobe. To assess expected regional alterations in cortical volumes, we used a new method to segment the entire neocortex into 48 topographically defined brain regions. We hypothesized, based on previous empirical and theoretical work, that dorsolateral prefrontal and paralimbic cortices would be significantly volumetrically reduced in patients with schizophrenia compared with normal controls. METHODS: Twenty-nine patients with DSM-III-R schizophrenia were systematically sampled from 3 public outpatient service networks in the Boston, Mass, area. Healthy subjects, recruited from catchment areas from which the patients were drawn, were screened for psychopathologic disorders and proportionately matched to patients by age, sex, ethnicity, parental socioeconomic status, reading ability, and handedness. Analyses of covariance of the volumes of brain regions, adjusted for age- and sex-corrected head size, were used to compare patients and controls. RESULTS: The greatest volumetric reductions and largest effect sizes were in the middle frontal gyrus and paralimbic brain regions, such as the frontomedial and frontoorbital cortices, anterior cingulate and paracingulate gyri, and the insula. In addition, the supramarginal gyrus, which is densely connected to prefrontal and cingulate cortices, was also significantly reduced in patients. Patients also had subtle volumetric increases in other cortical areas with strong reciprocal connections to the paralimbic areas that were volumetrically reduced. CONCLUSION: Findings using our methods have implications for understanding brain abnormalities in schizophrenia and suggest the importance of the paralimbic areas and their connections with prefrontal brain regions.

Adult↗
PubMed1999

MRI-Based topographic parcellation of human cerebral white matter.

We describe a virtually automatic comprehensive parcellation of the human cerebral central white matter, which is based upon T1-weighted MRI scans. The system, which is "rule-based," is developed from prior anatomic studies of the human brain and experimental studies of connectivity in animals as elaborated in the companion manuscript. Boundaries which delineate anatomic subregions of the white matter are computed from the geometric features of anatomic landmarks visible in the imaging data. The fiber systems of the central white matter are ordered topographically into three compartments, reflecting the inferred arrangements of principal neural systems pathways. These include an outer radiate (fibers principally radially aligned), an intermediate sagittal (fibers principally sagittally aligned), and deep bridging (fibers bridging hemispheres or cortex and deep structures) compartments. Each of these compartments is secondarily parcellated into smaller units to increase the anatomic specificity and spatial resolution of the system. The principal intended uses for this system of anatomic subdivision are for the volumetric characterization of forebrain white matter in normal and abnormal brains and for precision and specificity of localization in focal lesion-deficit correlation studies.

Adult↗
PubMed1999

MRI-Based topographic parcellation of human cerebral white matter and nuclei II. Rationale and applications with systematics of cerebral connectivity.

We describe a system for parcellation of the human cerebral white matter and nuclei, based upon magnetic resonance images. An algorithm for subdivision of the cerebral central white matter according to topographic criteria is developed in the companion manuscript. In the present paper we provide a rationale for this system of parcellation of the central white matter and we extend the system of cerebral parcellation to include principal subcortical gray structures such as the thalamus and the basal ganglia. The volumetric measures of the subcortical gray and white matter parcellation units in 20 young adult brains are computed and reported here as well. In addition, with the comprehensive system for cerebral gray and white matter structure parcellation as reference, we formulate a systematics of forebrain connectivity. The degree to which functionally specific brain areas correspond to topographically specific areas is an open empirical issue. The resolution of this issue requires the development of topographically specific anatomic analyses, such as presented in the current system, and the application of such systems to a comprehensive set of functional-anatomic correlation studies in order to establish the degree of structural-functional correspondence. This system is expected to be applied in both cognitive and clinical neuroscience as an MRI-based topographic systematics of human forebrain anatomy with normative volumetric reference and also as a system of reference for the anatomic organization of specific neural systems as disrupted by focal lesions in lesion-deficit correlations.

Adult↗
PubMed1999

MRI-based brain volumetrics: emergence of a developmental brain science.

MRI-based brain volumetrics is an established methodology of great versatility and reliability with a broad range of potential applications in medicine and basic human brain science. We consider here, more theoretical implications of brain tissue volumes. Specifically, we suggest that volume is an evolutionarily and developmentally regulated fundamental property of tissue, in this instance the brain and its component structures. Within this framework (1), regularities in relative variation of volumes with respect to mean volume of a structure are viewed as systematic manifestations of the rules of histogenetic process (2), regularities in the relative strength of correlation of volumes of structures are suggested to reflect constraints which serve systematically the requirements of neural systems operation. These hypotheses, if supported by extensive observation, may guide the design of applications of MRI based volumetric analysis of the human brain.

Animals↗
PubMed1999

Day clinic diagnostic hysteroscopy in a state hospital.

Within 6 years (1991-97), a total of 680 diagnostic hysteroscopies were performed at the Day Clinic of the 1st Department of Obstetrics and Gynecology of the University of Athens ("Alexandra" Hospital). The procedure was done without general or other forms of anesthesia, using the Siegler method of approach. However in 12 cases with cervical stenosis (1.7%) and 21 patients with marked nervousness (3.1%) general anesthesia proved inevitable. The leading indication was repeated failure of IVF (54.7%), while other indications included abnormal bleeding, amenorrhea and oligomenorrhea, a history of abortions, and infertility. Abnormal hysteroscopic findings were observed in 276 cases (40.5%) among which intrauterine adhesions, endometrial hyperplasia and polyps were the most common. We had no major complications or fatalities in our series and hysteroscopy proved to be a very useful, accurate and safe method of assessing uterine and endometrial functional status.

Adult↗
PubMed1999

Anogenital intraepithelial lesions in HIV positive patients. Report of 3 cases with 3-year follow-up.

Three cases of HIV-positive immunocompromised women, complicated by anogenital intraepithelial lesions are presented in the present paper. Two patients, aged 42 and 33, had a combination of cervical intraepithelial neoplasia grade 3 (CIN 3) and anal intraepithelial neoplasia grade 2 (AIN 2). The other one, aged 26, presented an association of CIN 2 and AIN 1. All lesions were HPV-associated and proved by colposcopically-guided biopsies.

Adult↗
PubMed1999

How to avoid suboptimal management of cervical carcinoma by simple hysterectomy.

OBJECTIVE: To determine the reasons leading to an inappropriate simple hysterectomy in the presence of carcinoma of the cervix and to evaluate factors related to survival. METHODS: All preoperative information was abstracted from 63 cervical cancer patients cleared by simple hysterectomy from 1980-1993. Cervical cancer screening history as well as the indication for hysterectomy were analyzed. The 5-year survival was calculated and correlated with the tumour histological subtype and presumed stage of disease. RESULTS: The most common preoperative symptom was abnormal uterine bleeding (73%). The absence of preoperative cytology, an inadequately evaluated abnormal Pap smear and the failure to differentiate from endometrial carcinoma were the main causes leading to an inappropriate simple hysterectomy. The cumulative 5-year survival was 63.5% and was correlated with the presumed stage of disease and the histological subtype. CONCLUSION: Only with close adherence to the cervical cancer screening guidelines and appropriate evaluation of presenting symptoms can we avoid inappropriate management of cervical carcinoma with simple hysterectomy.

Adult↗
PubMed1999

The management of breech presentation in the last three decades.

In order to evaluate the changes in management of breech presentation during the last three decades, a retrospective analysis of the "Alexandra" Hospital records was undertaken. The years, 1965, 1975, 1985, 1995 and finally 1997 were used as pilot years for this purpose. The cesarean section, breech presentation and breech cesarean section rates were calculated for each year. Specific breech cesarean section rates in respect to birth weight and parity as well as perinatal mortality rates were also recorded for each pilot year. The overall cesarean section rate rose from 8.0% in 1965 to 25.2% in 1995 and 25.1% in 1997 while the breech cesarean rate climbed from 16.9% in 1965 to 74.1% in 1995 and 72.3% in 1997, irrespective of birth weight. A trend towards vaginal delivery of breeches in multiparous women till 1985 became less apparent in later years. During the same period, a marked decrease of the perinatal mortality rate was observed from 70.1/1000 in 1965 to 36.6/1000 in 1997. In conclusion, a more than four-fold increase of the breech cesarean section rate was apparently rewarded by a two-fold decrease in perinatal mortality.

Breech Presentation↗
PubMed1998

The effect of the duration of GnRH-agonist down regulation before ovarian stimulation on the biological and clinical outcome after intracytoplasmic sperm injection.

The object of this study was to compare the biological outcome (oocyte maturity, fertilization, cleavage) and the clinical outcome after a 'long' (15-24 days) and a 'long-long' (25-40 days) protocol of GnRH-agonist administration for intracytoplasmic sperm injection. Group A consisted of 51 patients with a 15-24-day down regulation period and Group B consisted of 35 patients with a 25-40-day down regulation period, all of which entered ICSI due to severe male factor infertility. Duration and amount of gonadotropin stimulation, serum E2 on the day of hCG administration, number of oocytes retrieved, oocyte maturity, fertilization rate, cleavage rate and pregnancy outcome were comparable for the two groups of patients. Therefore, a flexible period of pituitary desensitization can be employed, allowing us to simplify planning for patients and for the medical staff without affecting the outcome of the trial.

Adult↗
PubMed1998

Semiautomatic segmentation of brain exterior in magnetic resonance images driven by empirical procedures and anatomical knowledge.

This work demonstrates encouraging results for increasing the automation of a practical and precise magnetic resonance brain image segmentation method. The intensity threshold for segmenting the brain exterior is determined automatically by locating the choroid plexus. This is done by finding peaks in a series of histograms taken over regions specified using anatomical knowledge. Intensity inhomogeneities are accounted for by adjusting the global intensity to match the white matter peak intensity in local regions. Automated results are incorporated into the established manually guided segmentation method by providing a trained expert with the automated threshold. The results from 20 different brain scans (over 1000 images) obtained under different conditions are presented to validate the method which was able to determine the appropriate threshold in approximately 80% of the data.

Brain↗
PubMed1998

Gyri of the human neocortex: an MRI-based analysis of volume and variance.

This magnetic resonance imaging (MRI)-based morphometric analysis of cortical topography in the human brain is based upon the segmentation and parcellation of volumetric T1-weighted MRI data for a set of 20 young adult brains including 10 males and 10 females. For the most part, each parcellation unit (PU) of the neocortex corresponds to a single or a portion of a single gyrus. The volumes of each PU were computed for each brain. Subsets of PUs were also grouped so as to represent the neocortex for the frontal, temporal, parietal and occipital lobes. The coefficient of variation of the mean volume of total neocortex and that of the neocortex assigned to individual lobes cluster around 10%, whereas that of neocortex assigned to the individual gyri (PU) is more than twice that value. Approximately 80% of the total variance in gyral volume arises from determinants interactive for individual and specific gyri, while only approximately 10% of the total variance appears to be a reflection of uniform scaling to total neocortical volume. Sexual dimorphism contributes a pervasive though relatively small component of this variance. These results have implications for the study of structure-function correlation, and the proper statistical methods of handling volumetric data in morphometric studies. In addition, the nature of the covariance structure of the data will lead to future hypotheses regarding the relationships between the various potential genetic and epigenetic gyral influencing factors.

Adult↗
PubMed1998

Cocaine decreases cortical cerebral blood flow but does not obscure regional activation in functional magnetic resonance imaging in human subjects.

The authors used functional magnetic resonance imaging (fMRI) to determine whether acute intravenous (i.v.) cocaine use would change global cerebral blood flow (CBF) or visual stimulation-induced functional activation. They used flow-sensitive alternating inversion recovery (FAIR) scan sequences to measure CBF and blood oxygen level-dependent (BOLD) sensitive T2* scan sequences during visual stimulation to measure neuronal activation before and after cocaine and saline infusions. Cocaine (0.6 mg/kg i.v. over 30 seconds) increased heart rate and mean blood pressure and decreased end tidal carbon dioxide (CO2). All measures returned to baseline by 2 hours, the interinfusion interval, and were unchanged by saline. Flow-sensitive alternating inversion recovery imaging demonstrated that cortical gray matter CBF was unchanged after saline infusion (-2.4 +/- 6.5%) but decreased (-14.1 +/- 8.5%) after cocaine infusion (n = 8, P < 0.01). No decreases were detected in white matter, nor were changes found comparing BOLD signal intensity in cortical gray matter immediately before cocaine infusion with that measured 10 minutes after infusion. Visual stimulation resulted in comparable BOLD signal increases in visual cortex in all conditions (before and after cocaine and saline infusion). Despite a small (14%) but significant decrease in global cortical gray matter CBF after acute cocaine infusion, specific regional increases in BOLD imaging, mediated by neurons, can be measured reliably.

Adult↗