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Biomedical subjects

P Mercier

Publications and source records attributed to P Mercier.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Spontaneous spinal cord herniation: a little-known cause of Brown-Sequard syndrome. Report of two cases and review of the literature].

We report two cases of spinal cord herniation. The first one concerns a 28 year-old female who presented with an eighteen-month past history of spasticity of the right lower limb associated with somesthetic sensorial disturbances of the left side with a T4 level, related to a T3-T4 spinal cord herniation. The second case concerned a 58 year-old female with a past history of a left lower limb pyramidal syndrome associated with somesthetic and proprioceptive sensibilities disturbances of the right side with a T5 level related to a T4-T5 spinal cord herniation. Spinal cord herniation is an uncommon and underestimated cause of a progressive Brown-Sequard syndrome. The diagnosis is now easy on the MRI, showing a ventral attraction of the cord. The outcome is usually good, following the surgical reduction of the herniation.

Adult↗
PubMed1999

[Post-traumatic intracranial arterial aneurysm. Two cases with review of the literature].

Post-traumatic intracranial aneurysms are rare entity, which can appear following even benign head injuries. Their clinical manifestations are various, from a typical SAH to an uncommon intracerebral hematoma. Medical history runs usually from a couple of days to several years. Two cases of intracranial aneurysm have been observed from 1995 to 1998. The first case presented as a cortical aneurysm in a cerebral contusion following a week of evolution. The second case presented as a cortical hematoma with a head trauma 10 years before. All patients were operated on with uneventful follow-up. Post-traumatic intracranial aneurysms can exhibit an increase in size or a spontaneous thrombosis. Diagnosis is made by angiography, which has to be repeated if treatment has to be delayed. Best results are obtained by exclusion of the lesion, if allowed by the patient's condition.

Adult↗
PubMed1999

[Intracranial meningiomas revealed by hemorrhage. Report of three cases and literature review].

Three cases of meningioma revealed by hemorrage are reported. The first patient, 65 presented with a temporal hematoma associated with intraventricular contamination. The diagnosis of a tumoral origin of the hemorrhage was made only few weeks later when the total hematoma resorption was ended. The second patient, 49 presented with a sudden right hemiplegia. CTscan and MRI revealed a left frontal tumor surrounded by hematoma. The third patient, 46, presented with a transient aphasia and superior limb dysesthesia. CT scan showed a temporal hematoma; a carotid angiography revealed a typical meningioma blush. A review of the literature collected 54 additional cases of meningioma associated with hemorrage. Clinical findings and mechanisms are discussed.

Aged↗
PubMed1998

Anatomic study of the deep plantar artery: potential by-pass receptor site.

The deep plantar artery is the main anastomosis between the dorsal and plantar arterial systems of the foot; with no change of calibre it unites the dorsalis pedis artery to the deep plantar arch, the second segment of the lateral plantar artery, passing into the first intermetatarsal space. Our anatomic study of 20 dissections of the deep plantar artery allowed us to verify the near-constancy of its descriptive anatomy and relationships. The deep plantar artery, when present, only found in 16 of our 20 cases, is totally linked to the dorsalis pedis artery. Its easy accessibility via the dorsal route, its medium calibre and the absence of collateral branches make this artery a possible anatomic site for the performance of a distal bypass, the last option before an amputation of the foot becomes necessary, although such a case remains exceptional.

Arteries↗
PubMed1998

Anatomy of the arterial vascularization of the lips.

The findings from 12 dissections of previously injected facial masks, 8 dissections of the face following intraarterial injection of a red solution of Latex Neoprene, and a corrosion cast specimen allowed us to study the arterial supply of the lips. The arterial supply of the upper lip arises mainly from the superior labial arteries, but also from the subseptal arteries and from the subalar arteries. There is a figure of 8 shaped anastomotic system between these arteries lying on the upper lip. The arterial supply of the lower lip arises from the inferior labial arteries and from branches of the mental artery. A constant inferior labial arterial network was shown at the level of the lower lip arising in a fifth of cases from a T-shaped inferior labial artery. All these recent anatomic findings help us to improve our understanding of plastic surgery of the lips.

Arteries↗
PubMed1998

Adult age differences in on-line contingency judgements.

This research was designed to further our understanding of age differences in contingency judgements and to consider the role of working memory in such judgements. Experiment 1 examined age differences in contingency judgement accuracy when information processing requirements were manipulated. Young and older adults estimated the degree of contingency between two categorical variables. Contingencies, amount of information, and speed of execution were varied. Participants discriminated the contingencies well. Judgement accuracy declined with smaller numbers of trials and shorter intertrial intervals. The judgement deterioration was more severe for older adults. In Experiment 2, speed interfered again more with the judgements made by older adults. Modulations of this effect occurred as a function of stimulus duration and distribution of event frequencies. Overall, the judgement deterioration is consistent with Wagner's (1981) model of automatic memory processing.

Adolescent↗
PubMed1998

[The retro-auricular, transmastoid, infralabyrinth approach. A simple route for excision of tumors of the jugular foramen].

BACKGROUND: The jugular foramen is a complex area of the skull base. Its contents, the anatomical relationships in the region, and its location at the skull base, are responsible for problematic surgical approaches. The classical infratemporal surgical routes remain complex and difficult to perform. The lateral approach through a mastoidectomy is almost always associated with an anterior transposition of the facial nerve although that transposition is usually unnecessary. METHODS: Progressive drilling along the sinusojugular axis, inferior to the labyrinth and medial to the third portion of the facial nerve, combined with a simple neck dissection, allows the surgeon to nicely expose the jugular foramen. The surgical procedure is described, following a brief anatomical reminder of the essential relationships in the area. A clinical observation is used to illustrate the purpose. RESULTS: Most schwannomas of lower cranial nerves and small glomus jugulare tumors should be resected using this approach, which is a simplified lateral approach, without post operative facial palsy or cophosis. CONCLUSIONS: The infralabyrinthine approach is a simple way to expose the jugular foramen region compared with infratemporal complex and time-consuming approaches.

Adult↗
PubMed1997

HPA-10w(b) (La(a)): genetic determination of a new platelet-specific alloantigen on glycoprotein IIIa and its expression in COS-7 cells.

The heterodimeric complex glycoprotein (GP)IIb-IIIa, the fibrinogen receptor of platelets, carries numerous alloantigen systems. These polymorphisms are responsible for the immune response after transfusion or during pregnancy. In the latter case, the mother develops an antibody against an epitope present on fetal platelets, and this results in platelet destruction in the fetus. In this report, we describe the molecular characterization of a new alloantigen (La(a)) on GPIIIa responsible for neonatal alloimmune thrombocytopenia (NAIT). Using polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) and DNA sequencing, we found a point mutation (G to A) in a heterozygous state on the GPIIIa gene leading to amino acid substitution Arg to Gln at position 62 of the mature protein. Transient expression of GPIIb-IIIa complexes in Cos-7 cells using wild-type or mutated GPIIIa cDNA allowed us to demonstrate that this mutation was responsible for expression of the La(a) epitope.

Adult↗
PubMed1997

An anatomical study of the motor distribution of the mandibular nerve for a masseteric-facial anastomosis to restore facial function.

On account of the complex anatomy at the base of skull, surgery here may result in post operative cranial n. deficits. Facial palsy is often feared and its effects upon the patient's psychological and emotional well-being can be catastrophic. The modest results and the side effects of the facio-hypoglossal anastomosis used for facial rehabilitation have led us to consider an anastomosis between a motor branch of the trigeminal n. and the facial n. Dissection has allowed us to demonstrate that the masseteric n. offers the characteristics and the relationships which should make such an anastomosis feasible.

Cadaver↗
PubMed1997

[Sensitivity and specificity of thyreostimuline (TSH) determination on filter paper for the diagnosis of hypothyroidism in the elderly].

The aim of this study was to measure the prevalence of hypothyroidism in 239 elderly patients and to determine the validity of TSH assay on blood dried on filter paper (spot-test) for the diagnosis of hypothyroidism. The sensitivity and specificity of the spot-test were evaluated in a subgroup of 177 subjects. The prevalence of hypothyroidism was 14.2% (34/239). The spot-test did not give satisfactory results for the diagnosis of hypothyroidism in elderly subjects. Due to the lack of specificity, most of the positive results were false positives and the clinician had to rely on laboratory determination of plasma TSH level to confirm hypothyroidism in half of the patients. We do not recommend the spot-test for the diagnosis of hypothyroidism in the elderly. Laboratory assay of plasma TSH is required for confirming hypothyroidism in the elderly.

Aged↗
PubMed1997

[Prevention of hemorrhagic complications in the lateral retinacular section of the patella. A study of the lateral arteries of the knee applied to the prevention of knee hemarthrosis].

PURPOSE OF THE STUDY: Arthroscopic lateral retinacular release is one of the most employed procedures for patellar chondromalacia. A literature review show a complication rate of 10 to 18 p. 100 of postoperative hemarthrosis. This work aims to study the vessels anatomy of the lateral side of the knee in order to find anatomical landmarks allowing to avoid or coagulate them. MATERIAL AND METHODS: Thirty-three cadaver knees were dissected. Measures were made related to the lateral superior genicular artery and the lateral inferior genicular artery. A study using tracing-paper was also carried out. The main part of the work was more descriptive, studying anastomosis between the different arteries and veins location. RESULTS: Concerning the lateral superior genicular artery, measure analysis showed that this artery was always cut in lateral patellar retinaculum. This artery never runs more than one centimeter proximally to the base of patella, which is too insufficient to escape from lateral retinacular release. We noted the possibility of locating 90 p. 100 of lateral superior genicular arteries in a minimal distance of 15 mm, in front of the lateral proximal angle of the patella. Concerning the lateral inferior genicular artery, only a few arteries, protected in the meniscal wall in its early course, can remain intact. Two thirds of these arteries are very vulnerable running across the lateral side of the knee. The study of the tracing-papers confirmed topographic study measurements. The descriptive study emphasized the number and the importance of anastomoses between these different arteries. Each artery is flanked by two large satellite veins, which also attribute a veinous origin to a possible bleeding. DISCUSSION: The topographic study of the lateral inferior genicular vessels shows that their course varies. It seems necessary to avoid their division by performing the standard anterior lateral inferior arthroscopic portal proximally to these vessels. This can be realized at the beginning of the procedure through cutaneous transillumination. The lateral superior genicular vessels are always cut. They are nevertheless reachable through a small lateral incision of about 10 mm, distally to the lateral superior angle of the patella. 90 p. 100 at least of these arteries could be coagulated in such a way. We also emphasize the use of classical methods for the prevention of excessive venous bleeding, such as a compression dressing. CONCLUSION: Following this anatomical study, we suggest, as a supplementary precaution, a selective hemostasis of the lateral superior genicular vessels through a small incision associated with the location of the lateral inferior genicular vessels by cutaneous transillumination.

Arthroscopy↗
PubMed1997

[Intradural lumbar disk hernias. Apropos of 6 cases and review of the literature].

Transdural discal hernia is a rare complication of lumbar discal pathology. In this paper, we report five cases of transdural herniated disc and one intraradicular discal hernia. In the literature review, we found 97 cases since the first case described by Walter Dandy in 1942. The main risk in this exceptional location of discal hernia is to miss an intradural discal piece leading to a poor result. MRI or CT scan with intrathecal contrast can show an intradural lesion but they usually fail to indicate its precise nature.

Adult↗
PubMed1996

Cerebral venous thrombosis after myelography with iopamidol.

A young man developed intracranial hypertension immediately after myelography with non-ionic water-soluble contrast medium (iopamidol). Cerebral angiography showed extensive cerebral venous thrombosis. The common causes of thrombophlebitis were excluded. A relationship to the contrast medium was strongly suspected, since a similar case has been reported. The rheological properties and haemo-concentration induced by iopamidol could explain this complication.

Adult↗
PubMed1996

Microsurgical anatomy of the anterior choroidal artery.

In this study, the authors present the results of 50 dissections of the anterior choroidal a. in man. Fifty cerebral hemispheres were prepared with the classic techniques of preservation and vascular injection. An ectopic origin was observed in 4% of cases. The intracisternal segment of the anterior choroidal a. forms a neurovascular bundle with the optic tract and basal v. Most of its intraparenchymatous branches arise from the cisternal segment, while branches supplying the optic tract, lateral geniculate body and thalamus arise from the intraplexual segment. Constant anastomoses exist with the vertebrobasilar system, specially the postero-lateral choroidal and posterior cerebral aa. We discuss the importance of an adequate knowledge of the anatomy of the anterior choroidal a. and its relations in the surgical approach to arterial aneurysms and arteriovenous malformations of the region.

Arteriovenous Anastomosis↗
PubMed1996

Long-term stability of atrophic ridges reconstructed with hydroxylapatite: a prospective study.

PURPOSE: This article reports the results of an investigation of the long-term efficacy and stability of reconstructive surgery of atrophic ridges using dense hydroxylapatite (HA). PATIENTS AND METHODS: Subperiosteal HA was used as a first stage of reconstruction in 678 ridges, 645 mandibular and 35 maxillary, followed after 4 to 5 weeks by a total lowering of the floor of the mouth, vestibuloplasty, and skin graft in the mandible: a same-stage submucous vestibuloplasty was done in the maxilla. Patients were followed for an average of 5.3 +/- 2.7 years by the same surgical and prosthodontic team. The presence of severe or moderate radiographic change was analyzed in relation to gender, age, severity of atrophy, postoperative complications, clinical changes, patient satisfaction, and type of HA particles used alone or with a binder. RESULTS: Seventy-seven percent of cases had no observable radiographic changes, 13% had moderate changes, and 10% had severe changes, of which fewer than half also had severe clinical changes. Relationships were established between the presence of radiographic change and certain parameters, especially postoperative delay in healing, severe or moderate clinical changes, and type of HA particles used. CONCLUSION: Hydroxylapatite, when used alone or with binding agents, and in association with basic techniques of reconstructive surgery and soft tissue handling, is a predictable and stable biomaterial for ridge reconstruction.

Age Factors↗