Biomedical subjects

F Tankéré

Publications and source records attributed to F Tankéré.

11 recordsLinked to original sources

PubMed2004

[The hypolossal-facial anastomosis in man. A model for studying peripheral and central nervous system plasticity].

Hypoglossal-facial anastomosis (HFA) is a cross-over between the proximal stump of the hypoglossal nerve (XII) and the distal one of the facial nerve (VII). The hypoglossal axons regrow within the sheaths of facial fibres, allowing the progressive reinnervation of the facial muscles. This model is interesting to study some mechanisms of plasticity of the nervous system for several reasons: 1) It is a quite simple and reproducible model of pathophysiological state. It allows the study of 2) the modifications of the nervous system induced by the HFA, both upwards and downwards to the lesion and 3) the modifications of reflex activities involving intrapontine connections such as the blink reflex. The electrophysiological features of the trigemino-facial (TF) and trigemino-hypoglossal (TG) connections demonstrated that a central reorganisation of the blink reflex (BR) was induced by HFA: the afferent volleys of the TF and TH reflexes elicited by cutaneous and mucosal trigeminal afferents respectively have been shown to project onto common interneurones located within the trigeminal principal sensory nucleus. A long-term prospective study showed: 1) a reinnervation of the facial muscles by the hypoglossal axons is a necessary perequisite for the central reorganisation of BR, 2) a hyperinnervation of the facial muscles by the hypoglossal axons, 3) a transient and regressive cross-innervation of paralyzed face by the healthy contralateral facial nerve.

Central Nervous System↗

PubMed2003

Hypoglossal-facial nerve anastomosis: dynamic insight into the cross-innervation phenomenon.

The authors investigated the evolution of the dynamic features of the cross-innervation process in patients with complete facial palsy due to facial nerve transection during surgery for acoustic neuroma removal followed by a hypoglossal-facial nerve anastomosis (HFA). Clinical and electrophysiologic investigations were carried out before and over a 3-year period after HFA. Cross-innervation had started by the 10th day, progressed to the seventh to eighth month, then decreased and finally disappeared by the 12th month after HFA. Ipsilateral reinnervation was observed by the fourth month, progressed to the 12th to 18th month, and remained stable for the remainder of the follow-up period.

Adult↗

PubMed2002

Midbrain deafness with normal brainstem auditory evoked potentials.

The authors report two cases of patients with word deafness. The word deafness occurred after a head injury for the first patient and after an arterio venous malformation embolization for the second patient. MRI demonstrated bilateral lesions of the inferior colliculi but brainstem auditory-evoked potentials (BAEP) were within normal limits. These cases demonstrated that lesions involving the two inferior colliculi induced pure word deafness but do not affect BAEP.

Balloon Occlusion↗

PubMed2002

Prognostic value of mandibular involvement in oral cavity cancers.

OBJECTIVES: The aim of the study was to determine, in a homogeneous population, the prognostic impact of mandibular involvement in oral cancers. STUDY DESIGN: Retrospective study of 117 patients with T4 squamous cell carcinoma of the oral cavity treated by surgery and radiotherapy in the ENT Department of Bichat-Claude Bernard Hospital. All patients had histologically confirmed mandibular involvement. Patients with partial involvement of the mandible underwent rim mandibulectomy (RM) and those with extensive invasion underwent segmental mandibulectomy (SM). METHODS: The local failure rate and the overall survival curves were calculated with respect to type of mandibulectomy. The causes of death were analysed. RESULTS: The surgery was conservative in 55 cases (47%) and segmental in 62 patients (53%). The degree of mandibular involvement did not influence the local failure rate (29% and 25% in the RM and SM groups, respectively). On the other hand, it strongly influenced vital outcome, as five-year survival was only 25.4% after segmental mandibulectomy, compared to 40% after rim mandibulectomy. The metastases and the second primary tumors were more frequent in the SM group. CONCLUSION: The degree of mandibular invasion influenced the survival rate of patients with squamous cell carcinoma of the oral cavity but this difference is not due to local failure.

Adult↗

PubMed2002

[Treatment of Bell's palsy with acyclovir and methylprednisolone].

OBJECTIVE: An open therapeutic trial was conducted in patients with Bell's palsy. Results were compared with data in the literature. MATERIALS AND METHODS: Between 1997 and 2000, 76 patients with Bell's palsy were treated with intravenous methylprednisolone (2 mg/kg/day) and acyclovir (5-10 mg/kg/8 hours) for 7 days. Treatment was initiated in all patients before the 14th day of illness. Severity of the palsy was scored on the first day of treatment and again one year later using the House and Brackman scale. RESULTS: Grade II or III palsy were observed in 38% of the patients at initial presentation, grades IV to VI in 62%. After treatment, 92% of the patients had reverted to grades I and II (good outcome) and only 8% had sequelae at 1-year follow-up. All patients with initial grade I or II recovered completely. For patients with grade IV, V, or VI complete recovery at 1 year was observed in 94, 86 and 50% respectively. CONCLUSION: Data in the literature suggest that corticosteroids should improve recovery in Bell's plasy. In our study, adjunction of acyclovir did not demonstrate any clear improvement in the cure rate. Benefit could depend on early prescription.

Acyclovir↗

PubMed2002

[Parapharyngeal chondrosarcoma and Ollier's disease: a case report and review of the literature].

OBJECTIVES: Ollier's disease is a constitutional pathology of unknown etiology. It is characterized by bone dysplasia generating numerous enchondromas. The malignant degeneration of this dysplasia is well known. The aim of this article is to study the diagnostic, therapeutic and prognostic characteristics of these lesions. MATERIAL AND METHODS: We report a case of parapharyngeal chondrosarcoma extended to the base of the skull in a patient with Ollier's disease. The treatment was a surgical removal by a cervicotransoral incision combined with a preauricular incision and with a mastoidectomy. It was therefore possible to control the skull base, the parapharyngeal space, the infratemporal fossa and the major neurovascular structures. The removal of the lesion was completed at the level of the clivus and sphenoid with optics (30 and 70 degrees ). We discuss this treatment and the follow up on the bases of literature data. RESULTS: The neoplastic degeneration of enchondromas is estimated between 25 to 50% of cases. The most frequent location is the pelvic bones. Chondrosarcomas are slow growing tumors and their metastatic potential is less significant as we note it in our case report. Their diagnostic is essentially based on histological criteria's and their treatment is surgical. CONCLUSION: Chondrosarcomas of the ENT area occurring with Ollier's disease is rare. Their prognostic is good if the surgical treatment is well done.

Adult↗

PubMed2000

Further evidence for a central reorganisation of synaptic connectivity in patients with hypoglossal-facial anastomosis in man.

In normal subjects, electrical stimulation of trigeminal mucosal afferents (lingual nerve - V3) can elicit a short latency (12.5+/-0. 3 ms; mean+/-S.D.) reflex response in the ipsilateral genioglossus muscle (Maisonobe et al., Reflexes elicited from cutaneous and mucosal trigeminal afferents in normal human subjects. Brain Res. 1998;810:220-228). In the present study on patients with hypoglossal-facial (XII-VII) nerve anastomoses, we were able to record similar R1-type blink reflex responses in the orbicularis oculi muscles, following stimulation of either supraorbital nerve (V1) or lingual nerve (V3) afferents. However, these responses were not present in normal control subjects. Voluntary swallowing movements produced clear-cut facilitations of the R1 blink reflex response elicited by stimulation of V1 afferents. In a conditioning-test procedure with a variable inter-stimulus interval, the R1 blink reflex response elicited by supraorbital nerve stimulation was facilitated by an ipsilateral mucosal conditioning stimulus in the V3 region. This facilitatory effect was maximal when the two stimuli (conditioning and test) were applied simultaneously. This effect was not observed on the R1 component of the blink reflex in the normal control subjects. These data strongly suggest that in patients with XII-VII anastomoses, but not in normal subjects, both cutaneous (V1) and mucosal (V3) trigeminal afferents project onto the same interneurones in the trigeminal principal sensory nucleus. This clearly supports the idea that peripheral manipulation of the VIIth and the XIIth nerves induces a plastic change within this nucleus.

Adult↗

PubMed2000

Prognostic value of lymph node involvement in oral cancers: a study of 137 cases.

OBJECTIVE: The aim of this study was to assess the prognostic value of lymph node involvement in patients with squamous cell carcinoma of the oral cavity. STUDY DESIGN: Retrospective study of 137 patients with T4 squamous cell carcinoma of the oral cavity treated by surgery and radiotherapy (84 N0, 23 N1, 16 N2,14 N3). Twenty-three patients in the N0 group had a history of surgery or radiotherapy. One hundred fourteen patients underwent limited or radical neck dissection unilaterally or bilaterally. METHODS: The histological charts were reviewed and correlated with preoperative lymph node clinical stage. The local failure rate and the overall survival curves were calculated with respect to clinical and histological stages. The causes of death were analyzed. RESULTS: No evidence of lymph node metastasis was found in 47.4% of cases (54 of 114 patients). Among the node-positive (N+) patients, 39 had rupture of the lymph node capsule (R+). In the N0 group, 27.8% of patients were N+. Regional control rates after surgery and radiotherapy were 95% at 1 year and 85.4% at 5 years. The local failure rates were 6% in N0, 8.7% in N1, 31.2% in N2, 51.7% in N3, 9% in node-negative (N-), and 29% in N+R+ patients. The overall survival rates at 3 and 5 years were, respectively, 44.7% and 34.8% in the N0 group, 37.7% and 37.7% (same rate at 3 and 5 years) in the N1 group, and 31.2% and 15.8% in the N2 group. None of the patients in the N3 group survived beyond 2 years. The overall survival rates at 5 years were 42.8% and 17.5% in the N- and N+ groups, respectively. CONCLUSIONS: In patients with locally advanced tumors (T4), clinical nodal status and histological nodal invasion were key prognostic factors. The presence of occult metastases in the N0 group justifies routine neck dissection.

Adult↗

PubMed2000

[Prognostic influence of cutaneous involvement in malignant tumors of the oral cavity].

The aim of this study was to assess the prognostic influence of cutaneous involvement in T4 squamous cell carcinoma of the oral cavity. The population was a homogeneous group of 137 patients. Cutaneous tumor localizations were observed in 20 of them. Surgery and radiotherapy were given in 103 cases and salvage surgery was performed in 34. Local control at 5 years was achieved in 68.5 % of the patients. Carcinologic failure rate was 55 % and 27.3 % in patients with and without cutaneous involvement respectively (p =0. 013). 5-year survivor rate was also correlated with cutaneous involvement: 10 % versus 32.2 % (p <0.0001).

Adult↗

PubMed1998

Reflexes elicited from cutaneous and mucosal trigeminal afferents in normal human subjects.

It has been shown that in patients in whom the central stump of the hypoglossal nerve has been anastomosed to the peripheral stump of a lesioned facial nerve, supraorbital nerve stimulation can elicit a short-latency reflex (12.5+/-0.6 ms; mean+/-S.D.) in facial muscles similar to the R1 disynaptic blink reflex response, but not followed by an R2 blink reflex component46. Thus in addition to replacing the facial neurons at peripheral synapses, these hypoglossal nerves contribute to a trigemino-hypoglossal reflex. The aim of this work was to study the type of reflex activities which can be elicited in both facial and tongue muscles by electrical stimulation of cutaneous (supraorbital nerve) or mucosal (lingual nerve) trigeminal (V) afferents in normal subjects. The results show that although stimulation of cutaneous V1 afferents elicits the well-known double component (R1-R2) blink reflex response in the orbicularis oculi muscles, it does not produce any detectable reflex response in the genioglossus muscle, even during experimental paradigms designed to facilitate the reflex activity. Conversely, stimulation of mucosal V3 afferents can elicit a single reflex response of the R1 type in the genioglossus muscle but not in the orbicularis oculi muscles, even during experimental paradigms designed to facilitate the reflex activity. These data are discussed in terms of two similar but separate circuits for the R1 responses of cutaneous (blink reflex) and mucosal (tongue reflex) origins. They suggest that in patients with hypoglossal-facial (XII-VII) nerve anastomosis, the short-latency trigemino-'hypoglossal-facial' reflex of the R1 blink reflex type observed in facial muscles following supraorbital nerve stimulation could be due to changes in synaptic effectiveness of the central connectivity within the principal trigeminal nucleus where both cutaneous and mucosal trigeminal afferents project.

Adult↗

PubMed1998

Electrophysiological determination of the site involved in generating abnormal muscle responses in hemifacial spasm.

In patients with hemifacial spasm (HFS), abnormal muscle responses due to abnormal cross-transmission are observed in facial muscles. However, the site in the facial nerve responsible for the cross-transmission remains a matter of controversy. We have developed a model in which by considering the electrophysiological parameters involved in producing the abnormal muscle response, we can determine the site of the abnormal cross-transmission within the facial nerve. This model was applied to HFS patients with three different etiologies: idiopathic, post-Bell's palsy, and post-XII-VII anastomosis. Our data show that: in idiopathic HFS, the cross-transmission may occur in the facial nerve at the level of the pontocerebellar angle; in post-Bell's palsy, it is inside the petrous bone; and in XII-VII anastomosis, it must be in the extracranial part of the facial nerve. The possible mechanisms for this cross talk are discussed in terms of ephaptic transmission or of a central hyperexcitability in the facial motor nucleus.

Adult↗