Biomedical subjects

M Tadié

Publications and source records attributed to M Tadié.

At least 37 records · Page 2Linked to original sources

PubMed1999

Cervical anatomy of phrenic nerve roots in the rabbit. European Group for Research on the Larynx.

The cervical anatomy of the different nerve contributions that constitute the phrenic nerve (phrenic nerve roots and accessory phrenic nerve) were studied in rabbits. In 55 dissections, 6 main root arrangement types were observed. The roots that issued from the fourth and fifth cervical nerves (C4 and C5 roots) were constant. The C4 root was either short or long. The C6 root was at times absent, or sometimes double. An accessory phrenic nerve was present in 43% of the right and 28% of the left dissections. The distribution of the phrenic nerve roots often displayed left-right asymmetry. We conclude that a better knowledge of the cervical anatomy of the phrenic nerve is useful both in physiological studies involving diaphragm denervation and in experimental laryngeal reinnervation.

Animals↗

PubMed1999

[The place of MRI in the study of cerebrospinal fluid fistulas].

Results of CT and MRI explorations in 8 patients with cerebrospinal fluid (CSF) fistulae are reported and compared with surgical findings in 7. Sensitivity of MRI (CISS and fast T2 spin-echo sequences) was excellent giving perfect correlations with surgical findings in 7/7 cases. CT and MRI were found to provide complementary information suggesting they should be used in combination as first intention explorations of suspected CSF fistulae. Computerized cisternography should be used if MRI is contraindicated or if a clinically and biologically proven CSF fistulae is not visualized by CT or MRI.

Adolescent↗

PubMed1999

[Syringomyelia and Chiari abnormality in the adult. Analysis of the results of a cooperative series of 285 cases].

This chapter discusses the retrospective data found in 285 patients with syringomyelia associated with Chiari abnormality and collected from 18 neurosurgical departments. A pre and postoperative MRI study and a minimum follow up of at least 2 years were required. A scale of severity was fixed and tested before and after treatment. The size of the cyst, the degree of the foraminal obstruction were analyzed. The mean age at diagnosis was about 39 years and the duration of symptoms about 6.7 years. Sensory disorders were present in 91% of cases, pain in 66% and motor deficit in about 60%. According to our functional classification, the majority of our patients were moderately disabled and only 10.8% showed a severe impotence. Results of the two major surgical procedures, foramen magnum decompression (FMD) (88% of cases) and cyst shunting procedures (SP) (32% of cases) were evaluated with a mean follow-up period of 6.7 years (ranged from 2 to 14 years). Better clinical and morphological results (87% of stabilization or improvement for FMD versus 71% for SP) were obtained by FMD procedure comparing to SP, with the same rate of complications.

Adult↗

PubMed1999

[Post-traumatic syringomyelia].

Clinical and neuroradiological data were recorded in a series of 73 spinal cord injured patients (33 in Nantes, 40 in Paris-Bicêtre) in whom a post traumatic syringomyelia (PTS) developed. These findings and a review of the literature allow to point out some of the main characteristics in such a pathology. Clinical symptoms are frequent, the commonest of them are pain and sensory loss but any alteration of the neurological status after spinal cord injury has to be considered. Magnetic resonance imaging (MRI), sagittal and axial T1 and T2 weighted images, confirms the diagnosis of syrinx (area with the same signal intensity as CSF extending beyond the site of the initial lesion at least on 2 vertebral segments). MRI allows the diagnosis when it is performed in the follow up of asymptomatic patients. So PTS is not infrequent in spinal cord injured patients, for some of them in the first year after the trauma. The highest incidence is found in patients with complete thoracic lesions. Pathophysiology and surgical management have to take into account post traumatic residual stenosis of the vertebral canal.

Adult↗

PubMed1999

[Non-traumatic arachnoiditis and syringomyelia. A series of 32 cases].

We conducted a retrospective study of 32 patients treated for syringomyelia associated with non-traumatic arachnoid scarring. We selected the cases with documented history of arachnoiditis with pre and post-operative clinical evaluation of the neurological status and anatomical study on MRI with a minimal follow-up of one year. Extensive arachnoid scarring (Group I) was noted in 18 cases, after spinal meningitis in 15 cases (tuberculosis in 9 cases, listeria in 3 cases, pyogenic meningitis in 3 cases), subarachnoid hemorrhage in 3 cases. Focal arachnoid scarring (Group II) occurred in 10 cases, related to spinal surgery in 5 cases (meningiomas: 2, neurinomas: 2, thoracic discectomy: 1), to peridural anesthesia in 1 case, thoracic disc herniation in 1 case, Pott's disease in 1 case, no obvious cause in 2 cases. Basal arachnoid scarring without hindbrain herniation (Group III) was associated with birth injuries in 4 cases. Shunting of the syrinx to the subarachnoid or peritoneal cavity was associated with a recurrence rate of 60% whereas microsurgical dissection of the arachnoid scar and decompression of the subarachnoid space with a recurrence rate of 33%, with a mean follow-up period of 28 months. Successful long-term management of the syrinx was associated with basal or focal spinal arachnoid scarring, no history of spinal meningitis, microsurgical dissection of the arachnoid scar and decompression of the subarachnoid space.

Adult↗

PubMed1999

[Characterization of sensation disorders and neuropathic pain related to syringomyelia. A prospective study].

The present prospective study aimed to perform quantitative sensory testing (QST) in patients with painful or painless syringomyelia before and after surgical treatment of their syrinx (at 3 and 9 months). Eighteen consecutive patients with cervical or dorso-lumbar syringomyelia completed the study and 9 underwent surgery. Twelve patients had central neuropathic pain (of whom 6 were followed up). Spontaneous pain and brush-evoked allodynia were assessed. Von Frey hairs, vibrameter and a thermotest device were used to determine the mechanical-, vibratory-, thermal-detection thresholds, and the mechanical and thermal pain thresholds. Results showed evidence of deficits in temperature and pain sensibility in 17 cases, often associated with deficits in vibration and touch sensitivity (11 cases). Magnetic resonance scan, including axial images, demonstrated good correlation between paramedian extension of the syrinx and the laterality of thermal deficits. Somatosensory evoked potentials (11 patients) were abnormal in 9 cases at level, and showed good correlation with deficits in vibration. The magnitude of the thermal and tactile deficit was similar between areas of spontaneous pain and adjacent non painful areas. Surgery induced a significant decrease of tactile deficits, and to a lesser extent, of thermal deficits. Effects on neuropathic pain were positive in 3 patients (total disappearance of pain) and negligible or negative in 3 patients, despite collapse of the syrinx (in 2 cases). These results confirm that QST are useful in clinical practice to quantify the clinical results of surgery in patients with syringomyelia, and allow some hypotheses about the mechanisms of neuropathic pain in these patients.

Adult↗

PubMed1999

[Imaging of syringomyelia].

MRI is the best imaging method to evaluate syringomyelia. It is important to study from the posterior cranial fossa to the sacro-lumbar region and also the supra-tentorial structures. This complete analysis is essential to classify the syringomyelia and to investigate other associated malformations. Radiographs and CT scan are useful to analyze bone structures. For MRI, the new sequences with phased-array coils are also very important to study the entire spinal cord and the posterior fossa. It is essential to study the spinal cord with sagittal and axial spin echo T1 and fast spin echo T2 weighted images with sometimes coronal view, particularly when the patient presents a scoliosis, to have a correct morphological and functional evaluation. MRI gives an excellent study of the spinal cord with an excellent analysis of a primitive or foraminal syringomyelia, but also traumatic, infectious or post arachnoiditis syringomyelia. Spin echo T1 weighted images with injection of gadolinium can be used if an intra-medullary tumor is suspected. MRI is also useful for the post-operative follow up to evaluate the persistence of the medullary cyst and the enlargement of the foramen magnum.

Brain↗

PubMed1999

[Treatment of syringomyelia].

Treatment of syringomyelia utilizes two operative approaches: posterior fossa decompression and syrinx shunting (including subarachnoid, pleural and peritoneal shunting). MRI study is nowadays the indispensable tool for the evaluation of patients with syringomyelia and allows to choose the best therapeutic option. Posterior fossa decompression is regarded as the procedure of choice for syringomyelia with Chiari. After intradural exploration, additional steps may be necessary as excision of the cerebellar tonsils. Other therapeutic alternatives are associated with higher complication rates. Patients with persistent focal syrinxes after PFD respond best to syringoperitoneal shunts. For the management of post-traumatic syringomyelia, a large decompressive laminectomy at the fracture site is recommended; the use of a drain does not offer any long-term therapeutic advantage. Syringoperitoneal shunting is the treatment of post-infection syringomyelia but good long-term result is rare in this type of syrinx.

Budd-Chiari Syndrome↗

PubMed1998

Axonal regrowth through a collagen guidance channel bridging spinal cord to the avulsed C6 roots: functional recovery in primates with brachial plexus injury.

Intraspinal implantation of a collagen guidance channel (CGC) to promote axon regeneration was investigated in marmosets with brachial plexus injury. After avulsion of the right C5, C6 and C7 spinal roots, a CGC containing (group B) or not (group A) a nerve segment, or a nerve graft (group C), was ventro-laterally implanted into the cord to bridge the ventral horn and the avulsed C6 roots. No spinal cord dysfunction was observed following surgery. Two months later, the postoperative flaccid paralysis of the lesioned arm improved. In five months, a normal electromyogram of the affected biceps muscle was recorded in all repaired animals. Motor evoked potentials were obtained with a mean amplitude of 13.37 +/- 13.66 microV in group A, 13.21 +/- 5.16 microV in group B and 37.14 +/- 35.16 microV in group C. The force of biceps muscle contraction was 27.33 +/- 20.03 g (group A), 24.33 +/- 17.03 g (group B) and 37.38 +/- 21.70 g (group C). Retrograde tracing by horseradish peroxidase showed labelled motoneurons ipsilaterally located in the C5 and C6 ventral horn, nearby the implantation site. The mean labelled neurons was 32.33 +/- 21.13, 219.33 +/- 176.29 and 64.33 +/- 23.54 in group A, B and C respectively. Histological analysis presented numerous myelinated and unmyelinated regenerating axons in the implant of these animals. Statistical analysis did not show significant difference among the three repaired groups. Our results indicate that spinal neurons can regenerate through a CGC to avulsed nerve roots and induce motor recovery in primates.

Animals↗

PubMed1998

[Isolated intramedullary cysticercosis. Case report].

BACKGROUND AND PURPOSE: Cysticercosis is the most common parasitic disease affecting the central nervous system. Although it is still very rare in Europe, the frequency will increase due to the influx of immigrants from the endemic areas and increasing trips in these countries. Spinal intramedullary cysticercosis is an uncommon manifestation of neurocysticercosis. CLINICAL PRESENTATION: We report a case of pure intramedullary cysticercosis in a young white French girl, presenting as a progressive paraplegia with a cystic lesion in T4 on MRI. The diagnosis was made only after surgery by pathological examination. CONCLUSIONS: A preoperative diagnosis of spinal intramedullary cysticercosis must be suspected not only in an endemic area in the presence of multiple soft tissue calcifications and segmental lesions revealed by myelography or MRI studies, but also for all cystic lesion of central nervous system even in no endemic area. Surgery is the unique treatment which can be used for spinal intramedullary cysticercosis and with the use of the microsurgical techniques for medullar surgery the outcome is not as dismal as reported earlier.

Adult↗

PubMed1997

Strong expression of GFAP mRNA in rat hippocampus after a closed-head injury.

We investigated the spatiotemporal GFAP mRNA expression over a period of 11 days following brain injury in rats caused by impact acceleration, which is known to produce diffuse axonal injury (DAI). We observed widespread GFAP mRNA expression throughout the brain, which was more rapid and intense in the hippocampus. This expression was obvious in most animals 2 days after injury and appeared maximal at day 6. Although it decreased by day 11, the level of expression remained high compared with control levels. We noted slight differences in time of onset and the magnitude of the response between hippocampus and white matter structures or cortical areas. The different mechanisms able to trigger this response are discussed in regard to histopathological changes observed in DAI models.

Analysis of Variance↗

PubMed1997

Selective resection of the phrenic nerve roots in rabbits. Part II: Respiratory effects.

This study evaluates the delayed respiratory consequences of selective resection of one or several roots of the right phrenic nerve in rabbits. A total of 50 animals were operated on according to five modalities of root resection. A total of 11 animals served as control. The breathing pattern was analysed 8 weeks after surgery. Transdiaphragmatic pressure was measured during transjugular supramaximal stimulation of the phrenic nerve, unilaterally or bilaterally and during prolonged tracheal occlusion (PImax). No difference was observed between the esophageal pressure observed during bilateral phrenic nerve stimulation (BilPeso) in control animals when compared to animals with resection of the highest root of the right phrenic nerve (16.2 +/- 1.0 versus 14.5 +/- 1.0 cmH2O (mean +/- SE). Resection of the two highest or of the two lowest roots of the right phrenic nerve resulted in a similar BilPeso (11.3 +/- 0.8 versus 11.1 +/- 1.2 cmH2O). Preservation of only the accessory phrenic nerve (PN) resulted in a low value of BilPeso (9.8 +/- 1.0 cmH2O) similar to that obtained with complete denervation of the right hemidiaphragm. Ventilation and PImax were not different between the denervated or intact rabbits during quiet breathing. We conclude that in rabbits: (1) Diaphragmatic function is preserved after resection of the highest root of the phrenic nerve. (2) Diaphragmatic function is altered if only the APN is preserved.

Animals↗

PubMed1997

[Post-traumatic reconnection of the cervical spinal cord with skeletal striated muscles. Study in adult rats and marmosets].

In an attempt at repairing the injured spinal cord of adult mammals (rat, dog and marmoset) and its damaged muscular connections, we are currently using: 1) peripheral nerve autografts (PNG), containing Schwann cells, to trigger and direct axonal regrowth from host and/or transplanted motoneurons towards denervated muscular targets; 2) foetal spinal cord transplants to replace lost neurons. In adult rats and marmosets, a PNG bridge was used to joint the injured cervical spinal cord to a denervated skeletal muscle (longissimus atlantis [rat] or biceps brachii [rat and marmoset]). The spinal lesion was obtained by the implantation procedure of the PNG. After a post-operative delay ranging from 2 to 22 months, the animals were checked electrophysiologically for functional muscular reconnection and processed for a morphological study including retrograde axonal tracing (HRP, Fast Blue, True Blue), histochemistry (AChE, ATPase), immunocytochemistry (ChAT) and EM. It was thus demonstrated that host motoneurons of the cervical enlargement could extend axons all the way through the PNG bridge as: a) in anaesthetized animals, contraction of the reconnected muscle could be obtained by electrical stimulation of the grafted nerve; b) the retrograde axonal tracing studies indicated that a great number of host cervical neurons extended axons into the PNG bridge up to the muscle; c) many of them were assumed to be motoneurons (double labelling with True Blue and an antibody against ChAT); and even alpha-motoneurons (type C axosomatic synapses in HRP labelled neurons seen in EM in the rat); d) numerous ectopic endplates were seen around the intramuscular tip of the PNG. In larger (cavitation) spinal lesions (rat), foetal motoneurons contained in E14 spinal cord transplants could similarly grow axons through PNG bridges up to the reconnected muscle. Taking all these data into account, it can be concluded that neural transplants are interesting tools for evaluating both the plasticity and the repair capacities of the mammalian spinal cord and of its muscular connections.

Animals↗

PubMed1995

[A study of the influence of sutures and tension on skin cicatrization in loss of substance in 18 minipigs].

This study concerned the evaluation of wound healing after extensive skin resections in 18 minipigs, sutured with: continuous intradermal Polyglactin 910 suture or Polyamide, an interrupted intradermal sutures using the same resorbable suture material. Three equivalent groups were studied: 0, 3 and 6 cm skin resections were studied after using a dynamometer to record the tension necessary to join the wound margins. Results were evaluated 1 month later by light and electron microscopy, and were statistically correlated by Pearson's test. The wound tension was correlated with skin resection (r = 0.97, p < 10-4). The scar width was exponentially correlated with tension (r = 0.70, p < 10-3); the fibrous and cellular appearances increased with the skin resection. The absence of any significant statistical results prevents any conclusion concerning the superiority of one suture material or suture technique, but the group with no resection led to homogenous results, regardless of the suture technique, or suture material used. 3 and 6 cm resection the groups led to unpredictable and various results. Granulous reactions were observed in 7 out of 12 cases with resorbable suture, and only 1 of the 8 cases with non resorbable suture, but these results are not significant.

Animals↗

PubMed1995

[Stress-induced pituitary apoplexy in 2 phases].

A case of pituitary apoplexy occurring in the context of physical effort is reported. A 47-year-old man presented headache after a foot-race. Secondary visual deficit developed. On admission, bilateral cavernous sinus syndrome with bitemporal hemianopia was observed. The CT scan showed an enlarged sella eroded by an intrasellar soft tissue mass. Magnetic resonance imaging (MRI) confirmed the presence of the mass with peripheral enhancement following gadolinium injection. Decompression was carried out by transsphenoidal surgery. The microscopic study demonstrated infarction of the anterior hypophysis with peripheral tissular scarring. The post-operative outcome was characterized by visual recovery and anterior hypophyseal insufficiency. The possible pathophysiological mechanisms are discussed.

Endoscopy↗

PubMed1994

[Multiple cerebral aneurysms disclosed by subarachnoid hemorrhage. Apropos of 60 cases].

In a series of 60 consecutive patients, 137 multiple aneurysms (An) were discovered after subarachnoid hemorrhage. Multiple An were mostly double (83 % of the patients). The incidence of middle cerebral artery An was 42 %, internal carotid artery An 25.5 %, anterior communicating artery An 15 %. Both angiography (A degree) and CT scan could identify the ruptured An in 56 cases or at least the side of the ruptured An in the remaining 4 cases. Among the routine A degree criteria used to determine which one of the An had bled the most reliable ones appears to be: the existence of vasospasm of the parent artery, the bigger size of the sac, the irregular wall of the sac. The incidence of rupture is the highest in anterior communicating artery An (16/21). When an An located on the polygon of Willis is associated to a distal An, the former ruptures in 17 cases/18. All ruptured An were treated during the first operative session. In 47 patients (78.3%) all the An, ruptured and asymptomatic, were treated during the first procedure or in one or two additional surgical sessions. In 13 patients (22.7%) for several reasons only ruptured An and asymptomatic An that could be reached via the same craniotomy were treated. There was no morbidity or mortality related to the surgical treatment of asymptomatic An.

Aneurysm, Ruptured↗

PubMed1994

[Multicenter coordination and future strategy in spinal cord injuries].

Recovery of neurologic function after traumatic injury to the spinal cord can be significantly improved provided prompt medico-surgical decision is being taken, aiming at limiting post traumatic tissue damages extension. In an effort to optimize the triage of these patients, we set a multicentric emergency network program, involving cooperating staff from first care, surgical and rehabilitation departments. This program has allowed us to reduce substantially the time between trauma and medico-surgical treatment. Our first objective was to obtain spinal cord decompression and spinal stabilization as quickly as possible, the set-time limit being 8 hours at most after trauma. This emergency network being operational, we started a multicentric study to test whether the neurologic recovery following a spinal cord injury could be further improved by adding.

Emergency Medical Services↗

PubMed1988

[Vasospasm and ischemia in a series of 60 aneurysms treated quickly surgically].

Sixty patients with ruptured cerebral aneurysms were operated during the first 3 days after the onset of bleeding. In all cases the following investigations were performed: before surgery and 10 days after surgery angiography and CTScan, two months later a control CTScan. The first CTScans have been classified according to the staging defined by Fisher. Vasospasms (VS) were assessed comparing the arteriographies before and after surgery and classified as narrow or moderate; ischemia were assessed on post surgical CTScans. VS were found in any of the Fisher grades but were more frequent in grade 4; they occurred in 50% of cases (30 cases). Narrow VS were found 17 times in any Fisher grade. Ischemia occurred in 7 cases (1 death); following narrow VS in 6 cases. The high incidence of VS demonstration is emphasized: it is probably due to the lag time between bleeding and angiography and to the fact that angiographic controls were systematically performed. On the other hand ischemia occurred in 7 patients: the respective role of normalized intracranial pressure, hypervolemia, drug use and surgical procedure are discussed as candidate factors of this low incidence.

Brain Ischemia↗