Characterization of 3D bifurcations in micro-scan and MRA-TOF images of cerebral vasculature for prediction of intra-cranial aneurysms.

An aneurysm is a vascular disorder where ballooning may form in a weakened section of the wall in the blood vessel. The swelling of the aneurysm may lead to its rupture. Intra-cranial aneurysms are the ones presenting the higher risks. If ruptured, the aneurysm may induce a subarachnoid haemorrhage which could lead to premature death or permanent disability. In this study, we are interested in locating and characterizing the bifurcations of the cerebral vascular tree. We use a 3D skeletonization combined with a graph-based approach to detect the bifurcations. In this work, we thus propose a full geometric characterisation of the bifurcations and related arteries. Aside from any genetic predisposition and environmental risk factors, the geometry of the brain vasculature may influence the chance of aneurysm formation. Among the main achievements, in this paper, we propose accurate, predictive 3D measurements of the bifurcations and we furthermore estimate the risk of occurrence of an aneurysm on a given bifurcation.

[Record linkage of hospital discharge data and first health certificates: a test in the Val d'Oise]. / Chaînage d'enregistrements de séjours PMSI aux premiers certificats de santé: un test dans le Val d'Oise.

BACKGROUND: Our objective was to test the feasibility of an indirect linkage of data on births from health certificates (HC) with hospital discharge (HD) data. METHODS: The linkage was carried out for live births between April 1st and June 30th, 2011 in six of the nine maternity units in the district of Val d'Oise. The HC and HD had 3284 and 3550 births registered during this period, respectively. Linkage was conducted using variables available in both sources: number of fetuses, baby's birth date, gender, maternity unit of birth, maternal age, municipality of residence, gestational age and birth-weight. Two linkage methods were tested: a deterministic and a semi-deterministic method and a probabilistic approach. The latter method calculates a probability estimate for the strength of the relationship between two linked observations related to the discriminatory power and the error rate of the matched variables. For cases that were linked despite discordance on some of the matching variables, random samples of observations were checked against both HC and HD records to compute rates of false matches. RESULTS: The deterministic and semi-deterministic method linked 92.5% and 85.6% of observations in the HC and HD, respectively. The probabilistic method achieved a linkage rate of 99.6% for HC and 92.7% for HD. Cases only linked by the probabilistic method were more often preterm and had low birth-weight. Cases matched using the probabilistic method only had an error rate of 0.4% with 95% CI [0.2-0.6%]. CONCLUSION: Common items in the HC and HD make it possible to achieve a high rate of linkage. The probabilistic method links more births and, in particular, those at higher risk, and error rates were low.

[Surgical pathology costs more in emergencies: a bias in the clinical scoring index]. / La pathologie chirurgicale coûte plus cher en urgence: un biais des points ISA.

A retrospective study of all records of patients operated on for biliary lithiasis during the years 1995, 1996 and 1997 was performed in a general hospital setting to compare the costs of management according to presentation. This study shows that acute and chronic cholecystitis have statistically significantly different costs. The reimbursement plans, base on diagnostic related groups do not take this into account. This system disadvantages those centers which preferentially treat acute pathologies.

[Medical informatics (hospital information systems) in neonatology: reality and insufficiencies]. / Information médicale (programme de médicalisation des systèmes d'information) en nèonatologie: actualités et insuffisances.

The generalized implementation in France of hospital information systems (HIS) is often considered by the medical practitioners as a useless constraint. Nevertheless, they are now largely used by the administrative authorities for their economical evaluation of medical care. In neonatology HIS is applied to the hospitalized sick neonates as well as to the healthy newborn infants during their maternity hospital stay with their mother following birth. This paper focuses on the practical aspects and difficulties of the current French HIS in neonatology.

Topographical characterization of normal visual evoked responses.

A study of visual evoked responses in a normal population was carried out using a high-precision programmable stimulator and an innovative brain mapping system which presents the overall activity on a three dimensional surface representing the human head. The interpolation method used gives a more precise computation of the potential value between electrodes. Two normal distributions of visual responses are presented which were identified while trying to topographically characterize visual evoked responses in order to construct a comparative data base. The proposed classification of two normal groups was verified by means of a statistical topographic analysis with the significance probability mapping technique.

Exploration of cochlear function by otoacoustic emissions: relationship to pure-tone audiometry.

The amplitudes, growth functions and detection thresholds of evoked otoacoustic emissions (EOE) were measured in 44 normally hearing subjects and 138 patients with two categories of cochlear dysfunctions: (a) acoustic trauma; and (b) presbycusis. Separate sets of experiments were also performed: (a) detection of stimulus frequency emissions; and (b) click EOE. EOE properties were studied around 2 kHz, 1 kHz and 0.75 kHz (+/- 0.1 kHz). A partial correlation and multivariate analysis was carried out to investigate the relationships between EOE properties and puretone auditory thresholds (from 0.25 to 8 kHz, half-octave steps). For each experiment and each frequency, only one highly significant correlation was found, linearly relating the n kHz EOE threshold with the hearing threshold at 2n kHz: there was a shift of about one octave between EOE amplitudes and audiometric data. This means that EOE thresholds give no direct information about the local cochlear state. A simplified model has been implemented, which assumes that EOE thresholds and amplitudes are proportional to the total number of residual active sites along the organ of Corti, i.e., to the total length of active basilar membrane towards the base of the cochlea. It is shown that this model accounts for the results revealed by the statistical analysis and closely fits the experimental data.

[Secondary auditory risks from listening to portable digital compact disc players]. / Etude des risques auditifs secondaires à l'écoute des enregistrements numériques sur disque à l'aide d'appareils portables.

The recent availability of portable high-performance digital disc-players in addition to cassette players, and with an increased dynamical range, has enhanced the risk to hearing for their users. The present study aimed at attempting to evaluate this hazard. After selection of a digital player, 12 normally-hearing voluntary subjects were exposed to listening to two records (classical music and hard-rock) at an acoustic level complying with safety regulations. Their temporary threshold shifts (TTS) were determined at 4 and 6 kHz just after exposure. The 0.5 kHz auditory thresholds were also measured as a control. At 4 and 6 kHz, the average value of TTS was 5 dB (standard deviation 3.1 to 5.9 dB). There was no statistically significant difference neither between the TTS at 4 and 6 kHz (p > > 0.05), not between TTS for the two types of music. A voluntary subject, suffering from a mild high-frequency hearing loss, was also tested. His TTSs were higher than average and may have corresponded to slower recovery (may be non monotonous). Therefore special caution should be recommended in such cases. The measurements have pointed out that very high acoustic levels could be reached (125 to 127 dBA) with a Leq (1 hour) od 110 dBAi.e. much higher than tolerable levels. Thus there is a serious risk to hearing, possibly increased by high level transients. Moreover, better headphones are likely to provoke TTS also above 8 kHz, which might be evaluated by high-frequency audiometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypothetical roles of middle ear muscles in the guinea-pig.

The attenuation of incoming sounds induced by acoustic reflex triggering was evaluated from the cochlear microphonic response to test tones in 45 awake guinea-pigs. Although control electromyographic measurements proved that the stapedius muscle was contracting, neither impedance changes nor attenuation induced by contralateral reflex-eliciting sounds were detectable in 30 cases out of 45. For ipsi- and bilateral stimulations, an attenuation was detectable for 7 guinea-pigs out of 10. In the guinea-pigs for which a reflex-induced change was found on CM, the mean attenuation was weak i.e. of the order of 2 dB at 20 dB above reflex threshold. These results were quite different from those obtained during control experiments in the rabbit for which CM attenuation was much larger. However, large attenuations associated with middle ear muscle contractions were found in the guinea-pig in other circumstances, i.e. during self-vocalization or when spontaneous muscle contractions occurred during anaesthesia. It is concluded that middle ear muscles can have several different functions, and that even when it exists, attenuation of loud sounds might not be their primary role.

Intravenous immunoglobulin therapy for prevention of infection in high-risk premature infants: report of a multicenter, double-blind study.

The effectiveness of intravenously administered immunoglobulin (Ig) therapy for prophylaxis of infection was evaluated in high-risk preterm infants. Two hundred thirty-five premature newborns were randomly assigned, in a double-blind controlled trial, to treatment and placebo groups. Thirty-five infants (29%) of the Ig group and 29 (25%) of the placebo group had one or more episodes of certain infection. Thirty infants (25%) of the Ig group and 18 (16%) of the placebo group had one or more episodes of probable infection. No significant differences were observed in the incidence of certain or probable infection in treated and control infants. Nevertheless, among the infants who had one or more certain or probable episodes of infection, more of them belonged to the Ig group than to the placebo group. The possible deleterious effect of the administration of large amounts of polyspecific Ig is discussed.

[Early acroparesthesia in females: a sign disclosing heterozygote Fabry disease]. / Acroparesthésies féminines précoces: signe révélateur d'une maladie de Fabry à l'état hétérozygote.

Heterozygous Fabry's disease has an inconstant expression and very few complications. The theory of X-chromosome inactivation which, according to Lyon, occurs hazardly, is illustrated by the fact that the disease is expressed even in hemizygous women. Ophthalmic manifestations, as detected by the slit lamp method, are almost constant, 80 p. 100 of women with the disease having a verticillate cornea. Angiokeratoma is present in 20 p. 100 of the cases. Episodes of paraesthesia of the hands and feet are less common; in most cases they are attributed to the disease retrospectively, during family investigations. In two girls aged 10 and 11 years respectively and without history of Fabry's disease the only symptom suggestive of the diagnosis was paroxysmal acroparaesthesia. In one of the girls acroparaesthesia was associated with acrocyanosis, livedo and acro-osteolysis, but concordance was the only argument in favour of a link with Fabry's disease. Alterations of the extremities have been reported in this disease, including palmar erythema and a bluish discoloration of the palms due to dilatation of the superficial veins. Only two cases of livedo have been published. Acrosteolysis has never been documented in Fabry's disease, and its presence must be confirmed in further cases. The diagnosis of heterozygous Fabry's disease in these 2 girls was confirmed by the finding of ceramide trihexoside in urine and by leucocyte alpha-galactosidase levels that were 25 to 30 p. 100 of values obtained in controls. A study of the family of one of the girls showed that the father was involved; this hemizygous type of the disease with a 10 p. 100 alphagalactosidase level was totally asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Evoked otoacoustic emissions in guinea pig: basic characteristics.

Different types of evoked otoacoustic emissions (EOAEs) such as stimulus frequency emissions, tone burst and click EOAEs, were investigated in the guinea pig. Their correlates on cochlear microphonic potential were also recorded. Although it was confirmed that click EOAEs are difficult to detect in the guinea pig, partly because their delay (2 to 3 ms, measured on tone burst EOAEs) is much shorter than in man, other types of OAE were found in the interval (1.5-5 kHz) for almost every normal animal. Many of their properties were quite different from man, for instance their small number, low level, and the wide frequency range of some of them (up to 500 Hz), suggesting that they represent a sort of continuum. It is proposed that these particularities may not arise from different generating mechanisms but should be correlated with the well-known differences in hair cells patterns.

[Comparative results of data of brain stem auditory evoked potentials and imaging during an evaluation of the course of Recklinghausen's neurofibromatosis]. / Résultats comparés des données des potentiels évoqués auditifs du tronc cérébral et de l'imagerie lors d'un bilan de contrôle de l'évolution d'une neurofibromatose de Recklinghausen.

A comparative study of results of imagery and BERA, realized in a case of neurofibromatosis of Recklinghausen leads to the topographical diagnosis of a cerebral lesion without clinical symptomatology.

[Active cochlear mechanisms. Significance of a clinical study of acoustic emissions]. / Mécanismes actifs cochléaires, Intérêt de l'étude clinique des otoémissions.

Recent studies in inner ear physiology clearly show that active cochlear mechanisms play an important role in the normal auditory perception. One of the effects of these mechanisms is that the inner ear can emit acoustic energy towards the outer ear canal. Oto-emissions are currently recorded by various techniques adaptable to usual audiological devices. It is expected that more precise diagnoses to inner ear diseases might be deduced from their study.

[Diagnostic contribution of auditory and somesthetic evoked potentials in multiple sclerosis]. / Contribution diagnostique des potentiels évoqués auditifs et somesthésiques dans la sclérose en plaques.

Results of BERA measured on 52 patients with possible Multiple Sclerosis were compared with the diagnosis pronounced one year after the initial functional exploration. In 21 of these patients, somesthetic evoked potentials were recorded at the same time as the BERA. One year later, diagnosis was considered as likely in 23 cases, as eliminated in 15 cases, and still possible in 14 cases. 38 cases were kept after elimination of the group with "possible diagnosis"; in 68.5% of them, an agreement was found between the results of initially recorded BERA and the diagnosis pronounced one year later. A parallel study of the correlation carried out in 16 patients, for whom somesthetic evoked potentials were recorded, showed a diagnosis agreement in 69% of the cases.

[Meconium aspiration syndrome. Determination of a prognostic index]. / Syndrome d'inhalation méconiale. Détermination d'un indice pronostique.

A study was undertaken on 54 cases of meconial aspiration in order to establish a prognostic index allowing the early estimation of the risk of occurrence of refractory hypoxia. In order to do so, the factors statistically related to the occurrence of refractory hypoxia were taken into account. These factors consisted of the first arterial blood gas determination, first chest x-ray film and the initial Silverman index. A value was assigned to each parameter, with respect to the corresponding percentage of observed refractory hypoxias. The sum of the values determined the prognostic index, which varied from 6 to 25. For a high-risk threshold fixed at 15, sensibility was 78%, specificity 90% and the predictive value 84%. For an index between 16 and 20, 70% of patients developed refractory hypoxia. Occurrence was 100% for an index above 20 and refractory hypoxia occurred early. On the contrary with indexes between 6 and 14, occurrence was 15%. The calculation of this index might help clinicians in their therapeutic decisions.