Biomedical subjects

G Lot

Publications and source records attributed to G Lot.

At least 19 recordsLinked to original sources

PubMed2004

Atlantoaxial rotatory subluxation with ankylosis in an 11-year-old girl: a case report.

STUDY DESIGN: Report of an 11-year-old girl with a left atlantoaxial rotatory subluxation and ankylosis found 20 months after she sustained a cervical injury. OBJECTIVE: To describe the radiographic characteristics of this rare deformity assessed with a combination of spiral CT scan with multiplanar three-dimensional reformations and functional CT scan. SUMMARY OF BACKGROUND DATA: Atlantoaxial rotatory subluxation is a well-known condition, but its association with lateral C1-C2 ankylosis has not been reported to our knowledge. METHODS: For a complete assessment of the dislocation, a combined morphologic volumetric and functional CT study was performed. RESULTS: Spiral CT showed an atlantoaxial rotatory subluxation with lateral C1-C2 ankylosis. CT study also demonstrated a lateral C1-C2 subluxation and an ipsilateral occipitoatlantal subluxation. Cervical MRI showed no spinal cord compression despite the seriousness of the dislocation process. CONCLUSIONS: Whereas "classic" spiral study with multiplanar and three-dimensional reformations allows precise assessment of relationships between the upper cervical vertebrae, as well as bony changes, a functional CT study is essential for cervical biomechanic assessment of rotational instabilities of the craniovertebral junction and upper cervical spine.

Ankylosis↗

PubMed2003

[Vascular complications after acoustic neurinoma surgery].

OBJECTIVE: To report six cases of vascular complications occurring after acoustic neuroma surgery and to discuss the postoperative signs and symptoms that should alert the surgeon, in order to undertake the appropriate treatment as soon as possible. METHODS: Four hundred thirty-two cases of acoustic tumors operated by the same surgeons between January 1991 and December 2000 were reviewed. RESULTS: Six cases of vascular complications were identified: one case of cerebral vasospasm secondary to persistence of subarachnoid blood after injury to Dandy's vein; three cases of arterial infarction giving rise to a partial anterior inferior cerebellar artery (AICA) syndrome with an unusual nystagmus in two cases (ipsilateral in one patient and strong controlateral in one patient presenting preoperative vestibular areflexia); one case of hematoma of the cerebello-pontine angle (CPA) causing strong ipsilateral nystagmus; and one case of venous infarction of the cerebellar vermis secondary to accidental sinus thrombosis. CONCLUSIONS: Vascular complications after acoustic neuroma surgery are potentially devastating and should be identified as early as possible. Rapid extubation is recommended for systematic neurologic assessment. Among abnormal signs and symptoms that should alert the surgeon, marked nystagmus ipsilateral to the operated side or contralateral in patient presenting preoperative vestibular areflexia appears to be of great value.

Adult↗

PubMed2002

Reversible leukoencephalopathy in cerebral amyloid angiopathy presenting as subacute dementia.

This report concerns a 71-year-old woman who had rapid progressive dementia along with myocloni and increased blood pressure. Cranial computed tomography and magnetic resonance imaging scans showed bilateral widespread white matter changes with mass effect. A brain biopsy revealed an amyloid angiopathy in leptomeningeal as well as cerebral cortex arteries. After 2 months of antihypertensive treatment, a dramatic improvement of cognitive functions and a spectacular regression of leukoencephalopathy were observed. We suggest that hypertensive encephalopathy may worsen or reveal cerebral amyloid angiopathy.

Aged↗

PubMed2002

[Contribution and Cost-Effectiveness of ABR and MRI in Acoustic Neuroma screening. Retrospective Study of 151 Cases].

The aim of this study was to retrospectively assess during two periods (1991-1995 and 1996-2000) if MRI spreading had changed: (1) private ENT physicians screening habits; (2) the average tumor size at the time of diagnosis and the diagnostic delay of acoustic neuroma; and (3) the cost of acoustic neuroma diagnosis. In addition, the sensibility of each diagnostic test was calculated on 151 tumors. Our results show no significant change neither in the screening strategy (except a mild decrease in CT-scan utilization) nor in the tumor size, diagnostic delay or diagnostic cost between the two periods. Even if MRI is the gold standard for acoustic neuroma diagnosis, our 86%-sensibility of ABR, increased to 99% if combined with stapedial reflex and caloric test may still incline to use ABR in selected cases.

Adolescent↗

PubMed2000

[Interest of free flaps for cranial base reconstruction].

We describe our experience in treating 7 patients who underwent skull base reconstruction with free flap (6 latissimus dorsi, 1 rectus abdominis) between October 1996 and November 1998. Four patients underwent temporal bone resection with auricular resection, 2 patients underwent anterior and middle cranial fossa resection, 1 patient underwent frontotemporal resection. There have been no failures of the free flaps and one cerebrospinal fluid leak. We advocate free flap reconstruction after temporal bone resection with auricular resection, and after anterior or middle cranial fossa resection when local flap options are not available or with complex dead space.

Adult↗

PubMed2000

[Residual left orbital phlebolith. An anatomic-clinical observation].

A 29-year-old female patient displayed a dense and hard left orbital mass, inferiorly, 3 years after she was treated through a neurosurgical approach for a left orbital varix. The lesion was hyperdense on CT-scan and was removed through a trans-conjunctival approach, with an excellent result. The histological diagnosis was a phlebolith.

Adult↗

PubMed2000

[Unusual preseptal location of an orbital cavernous hemangioma in African patient].

Cavernous hemangioma is the most common primary vascular orbital tumor in adults. Generally the benign tumor arises within the muscle cone, revealed by proptosis with choroidal folds, and more rarely develops in other orbital localizations. We report the case of a 42-year-old female African patient who had a cavernous hemangioma in an unusual anterior localization. Clinically, a small superficial tumor was palpated in the right superior nasal orbital angle. After complete surgical excision, the histopathological study established the diagnosis of cavernous hemangioma

Adult↗

PubMed2000

[Hearing preservation in vestibular schwannoma surgery: indications, techniques and results in the literature since 1990].

Many authors have recently reported hearing preservation for approximately two-thirds of acoustic neuroma patients. The results have driven them to recommend early surgery for all patients whose hearing might be saved. Inversely, other authors advocate that MRI-screening may be beneficial in some patients and suggest surgery only in case of tumor growth or progressive hearing loss. In order to facilitate therapeutic decision making, we reviewed the techniques and results in the main papers dealing with hearing preservation in the course of acoustic neuroma surgery published since 1990. This analysis showed that the average percentage of useful hearing preservation is about 31%. It is however difficult to compare the different series due to the different methodologies used. This emphasizes the need for standardization of hearing selection and reporting criteria to a) identify factors predictive of success (tumor characteristics, preoperative hearing, monitoring, surgical pathways), and b) elaborate well accepted decisional guidelines (early surgery or MRI screening), notably for small and non-symptomatic tumors which show increasing prevalence.

Audiometry↗

PubMed1999

Surgical treatment of dumbbell neurinomas of the cervical spine.

Cervical neurinomas ex-tending through the intervertebral foramen are uncommon. They raise difficult problems of surgical management. The few papers dealing with surgical technique for removal of these tumors are reviewed. The surgical approach has to be chosen from posterior, anterior, and anterolateral routes. Analysis is essentially devoted to the radicality of tumor resection, nerve root preservation, relation to the vertebral artery, and compromise of spinal stability.

Journal Article↗

PubMed1999

The extent of drilling in lateral approaches to the cranio-cervical junction area from a series of 125 cases.

The trans-condylar approach to the craniocervical junction area (CCJA) requires a more or less extensive drilling of the two first cervical joints (C0-C1 and C1-C2). The extent of drilling necessary to resect a lesion at the CCJA was analyzed from a series of 125 cases including 114 tumours and 11 non-tumoural processes treated using a lateral approach (postero-lateral or antero-lateral) over a 15-year period (1980-1995). The extent of drilling was estimated on CT scanner axial views from the reduction of the joints surface and three groups were determined: A/less than one third B/between one third and one half, and C/more than one half. The extent of drilling was compared with the lesion location in relation to the bone limits of the CCJA: within these limits, outside them and into the bony structures. It was also analyzed with regard to pathology when separated into three groups non-osseous tumours, osseous tumours and chordomas, and non tumoural processes. Only 26 cases had a significant drilling, i.e., more than one third of the joint surfaces and of these, 14 were more than one half. In all these 14 cases, the bone structures were already invaded and 13 of them were, to some extent, beyond the bone limits of the CCJA. Of the 12 cases with drilling between one third and one half, 11 involved the bone structures and 1 was located inside the CCJA bone limits. Drilling of more than one third was required only in the case of bone lesions: 10 out of 23 bone tumours, all the 14 cases of chordomas, one case of rheumatoid arthritis and one case of C1-C2 joint spondylosis. In the other cases including mostly non-osseous tumours, drilling was limited to less than one third, though a high rate of complete removal was achieved (98%). Stabilization by arthrodesis with posterior grafting (N = 10) or by lateral bone grafting (N = 5) was achieved in all cases involving more than one half drilling, and in one case of tuberculosis. By adequately choosing the surgical approach, the extent of drilling can always be minimal. Extensive bone resection is only necessary when the tumour has already destroyed the joints. In that case, lateral or posterior fusion is an efficient technique.

Axis, Cervical Vertebra↗

PubMed1999

Combined management of intracranial aneurysms by surgical and endovascular treatment. Modalities and results from a series of 395 cases.

The selective occlusion of saccular intracranial aneurysms may be achieved by two techniques: microsurgical clipping and endovascular coiling. Each of them have particular indications which need to be defined. We report on a series in which both techniques were applied. From September 1992 to June 1996, 395 consecutive patients with small or large aneurysm were treated either by surgery (N = 102) or by endovascular coiling (N = 293). Coiling was chosen each time the shape of the aneurysm seemed to be appropriate for this treatment: narrow neck and ratio neck diameter by sac diameter less than one third. Satisfactory results with complete or subtotal obliteration and no recanalization on the following controls at 1, 6, 12 and 36 months, were obtained in 92% before retreatment and in 98.8% after retreatment. Unsatisfactory results were observed after surgery in 7 cases and in 25 cases after embolization. After retreatment, it remains 3 post-surgical and 2 post-endovascular cases. In the overall series, good and excellent clinical outcome was noted in 90% for small aneurysms and in 86.5% for large ones; mortality was of 4.8%. In a series in which were applied both types of treatment, surgery in 25% and endovascular technique in 75%, good results in terms of aneurysm occlusion and clinical results were achieved. These results are as good as the best series in which surgery was the only choice. Therefore with appropriate selection, endovascular treatment is a good alternative for treatment of the majority of saccular aneurysms.

Adult↗

PubMed1999

Intramedullary cavernous angioma. Resection by oblique corpectomy.

BACKGROUND: Intramedullary cavernomas are rare lesions usually operated on via a posterior approach and myelotomy. CASE REPORT: A 42-year-old woman progressively developed a tetraplegia with sphincter disturbances over a period of 26 years. Magnetic resonance imaging showed a cervical intramedullary cavernoma with an extramedullary anterolateral exophytic portion. To avoid myelotomy, this lesion was approached directly via its anterior exophytic portion. Through a cervical anterolateral approach, the vertebral body of C4 and the intervertebral discs were obliquely drilled out. The posterior longitudinal ligament and the dura mater were opened. The exophytic portion was coagulated and the intramedullary portion was completely excised. The dura mater was closed and a bone graft was inserted between C3 and C5 and secured with a plate. RESULTS: After transient worsening, upper limb weakness improved from its preoperative status but paraparesis persisted after a follow-up of 12 months. The sphincter disturbances disappeared. CONCLUSIONS: The anterolateral approach combined with oblique corpectomy may be an appropriate technique in case of anterior intramedullary cavernomas. It provides direct access to the lesion, avoiding additional myelotomy.

Adult↗

PubMed1999

Spinal melanotic schwannoma: a tumour with poor prognosis.

AIM: To clarify the prognosis of melanotic schwannoma. This is a rare tumour which is generally considered as a benign lesion, reported in many cases with a short follow-up only. METHODS AND RESULTS: Five cases of spinal melanotic schwannoma were retrospectively studied. The tumours were examined using standard histological, immunohistochemical and ultrastructural methods. No features of malignancy (high mitotic count, atypia or necrosis) were found in the primary tumours. The follow-up period ranged from 3 to 7 years. Malignant clinical behaviour was clear-cut in four cases: three patients died from metastases to various sites and one presented several discrete spinal tumours of the same type seven years after the first operation. Only one patient presented no recurrence and was free of disease 6 years after initial diagnosis. The review of 57 cases of the literature (including our cases), showed that 15% of the cases had recurrences and 26.3% were complicated by metastasis. Only 53% of the cases followed for more than 5 years, were free of disease vs. 67.5% of the cases with shorter follow-up. Twenty additional cases had no follow-up. CONCLUSION: Appropriate long-term follow-up is required for all melanotic schwannomas, as it may recur or metastasize after more than 5 years, even in the absence of overt malignant histological features.

Adult↗

PubMed1999

Long-term follow-up of juvenile nasopharyngeal angiofibromas: analysis of recurrences.

OBJECTIVES: Juvenile nasopharyngeal angiofibroma often recurs if the tumor is large. This report is a long-term follow-up of these cases. It establishes the prognostic values of tumor extensions, analyzes the anatomic factors involved in recurrences, describes the spontaneous evolution of remnants based on a radiographic follow-up, and evaluates the pertinence of complex combined surgical approaches for invasive tumors and the value of complementary endoscopy. STUDY DESIGN: Retrospective review of 44 cases treated between 1985 and 1996. METHODS: Statistical analysis of the correlation between recurrence and tumor extension as evaluated by systematic analysis of 18 putative tumor extensions on preoperative computed tomography scans. RESULTS: Invasion of the skull base affected two-thirds of the patients, and the rate of recurrence was 27.5%. Extensions to the infratemporal fossa, sphenoid sinus, base of pterygoids and clivus, the cavernous sinus (medial), foramen lacerum, and anterior fossa were correlated with more frequent recurrence. Long-term radiographic follow-up revealed putative residual disease in nine asymptomatic patients: these remnants gradually involuted. CONCLUSIONS: The data in the current study emphasize the prognostic value of skull base invasion and the difficulty of complete resection of extended lesions. Tumor remnants detected in symptom-free patients should be kept under surveillance by repeated computed tomography scan, since involution may occur. Recurrent symptoms may be treated by radiotherapy (30 Gy) rather than by extended combined procedures. Endoscopic surgery should be combined with surgery for better control of skull base extensions.

Adolescent↗

PubMed1999

Multisegmental cervical spondylotic myelopathy and radiculopathy treated by multilevel oblique corpectomies without fusion.

OBJECTIVE: The description of the technique of multilevel oblique corpectomy (MOC) without fusion in the treatment of spondylotic myelopathy and radiculopathy and the analysis of the results of this technique from a series of 101 cases are presented. METHODS: MOC is performed using an anterolateral approach with control of the vertebral artery. The vertebral bodies are drilled obliquely from the lateral side toward the opposite posterolateral corner. More than half of the vertebral bodies are preserved, and no fusion procedure is required. The series of patients from 1992 through 1997 included 54 men and 47 women, with an average age of 57.9 years, who presented with myelopathy (n = 66) or radiculopathy (n = 35). MOC was realized on one to five levels from C2-C3 to C7-T1. Follow-up data were obtained by performing dynamic roentgenography, computed tomography, and magnetic resonance imaging 2 months, 1 year, and 3 years after surgery. RESULTS: The results (Japanese Orthopedic Association score) were improvement in 82% of the patients, worsening in 8%, and stabilization in 10%. Better results were observed in younger patients (<50 yr). No relation between results and duration of symptoms or number of levels could be established. One death occurred as a result of multiorgan failure. No late deterioration was observed; however, three patients with particular features showed delayed instability requiring fusion. CONCLUSION: MOC is a safe and efficient technique. It must be applied for patients with anterior compression and straight or kyphotic axis of the spine. No fusion is required regardless of the number of levels, providing there are no soft discs and there is no preoperative instability.

Bone Transplantation↗

PubMed1999

Transnasal endoscopic removal of an orbital cavernoma.

The approach to posterior and medial orbital tumors is still a challenge, since poor functional results are frequent. We report a case of cavernoma successfully removed by a modified transnasal endoscopic procedure. The patient, a 56-year-old woman, complained of a decrease in vision of the left eye. Magnetic resonance imaging evidenced a lesion in the posterior part of the orbital cavity, inferior to the optic nerve, extending to the sphenoidal cleft. The lesion was isodense on T1-weighted images and showed contrast enhancement. Because of the medial location of the tumor, the patient was referred to the otolaryngology department by the neurosurgeons, and a transnasal endoscopic approach was chosen. A large exposure of the operative field was obtained, and a cavernoma was removed. Rapid relief of the symptoms was obtained. In view of this good result, we advocate the transnasal endoscopic approach in cases of inferomedial and posterior intraconal lesions as an alternative and addition to the standard techniques of orbital surgery.

Endoscopy↗

PubMed1999

Sylvian aqueduct syndrome and global rostral midbrain dysfunction associated with shunt malfunction.

OBJECT: This study is a retrospective analysis of clinical data obtained in 28 patients affected by obstructive hydrocephalus who presented with signs of midbrain dysfunction during episodes of shunt malfunction. METHODS: All patients presented with an upward gaze palsy, sometimes associated with other signs of oculomotor dysfunction. In seven cases the ocular signs remained isolated and resolved rapidly after shunt revision. In 21 cases the ocular signs were variably associated with other clinical manifestations such as pyramidal and extrapyramidal deficits, memory disturbances, mutism, or alterations in consciousness. Resolution of these symptoms after shunt revision was usually slow. In four cases a transient paradoxical aggravation was observed at the time of shunt revision. In 11 cases ventriculocistemostomy allowed resolution of the symptoms and withdrawal of the shunt. Simultaneous supratentorial and infratentorial intracranial pressure recordings performed in seven of the patients showed a pressure gradient between the supratentorial and infratentorial compartments, with a higher supratentorial pressure before shunt revision. Inversion of this pressure gradient was observed after shunt revision and resolution of the gradient was observed in one case after third ventriculostomy. In six recent cases, a focal midbrain hyperintensity was evidenced on T2-weighted magnetic resonance imaging sequences at the time of shunt malfunction. This rapidly resolved after the patient underwent third ventriculostomy. CONCLUSIONS: It is probable that in obstructive hydrocephalus, at the time of shunt malfunction, the development of a transtentorial pressure gradient could initially induce a functional impairment of the upper midbrain, inducing upward gaze palsy. The persistence of the gradient could lead to a global dysfunction of the upper midbrain. Third ventriculostomy contributes to equalization of cerebrospinal fluid pressure across the tentorium by restoring free communication between the infratentorial and supratentorial compartments, resulting in resolution of the patient's clinical symptoms.

Adolescent↗

PubMed1999

Failure of third ventriculostomy in the treatment of aqueductal stenosis in children.

OBJECT: The goal of this study was to analyze the types of failure and long-term efficacy of third ventriculostomy in children. METHODS: The authors retrospectively analyzed clinical data obtained in 213 children affected by obstructive triventricular hydrocephalus who were treated by third ventriculostomy between 1973 and 1997. There were 120 boys and 93 girls. The causes of the hydrocephalus included: aqueductal stenosis in 126 cases; toxoplasmosis in 23 cases, pineal, mesencephalic, or tectal tumor in 42 cases; and other causes in 22 cases. In 94 cases, the procedure was performed using ventriculographic guidance (Group I) and in 119 cases by using endoscopic guidance (Group II). In 19 cases (12 in Group I and seven in Group II) failure was related to the surgical technique. Three deaths related to the technique were observed in Group I. For the remaining patients, Kaplan-Meier survival analysis showed a functioning third ventriculostomy rate of 72% at 6 years with a mean follow-up period of 45.5 months (range 4 days-17 years). No significant differences were found during long-term follow up between the two groups. In Group I, a significantly higher failure rate was seen in children younger than 6 months of age, but this difference was not observed in Group II. Thirty-eight patients required reoperation (21 in Group I and 17 in Group II) because of persistent or recurrent intracranial hypertension. In 29 patients shunt placement was necessary. In nine patients in whom there was radiologically confirmed obstruction of the stoma, the third ventriculostomy was repeated; this was successful in seven cases. Cine phase-contrast (PC) magnetic resonance (MR) imaging studies were performed in 15 patients in Group I at least 10 years after they had undergone third ventriculostomy (range 10-17 years, median 14.3 years); this confirmed long-term patency of the stoma in all cases. CONCLUSIONS: Third ventriculostomy effectively controls obstructive triventricular hydrocephalus in more than 70% of children and should be preferred to placement of extracranial cerebrospinal shunts in this group of patients. When performed using ventriculographic guidance, the technique has a higher mortality rate and a higher failure rate in children younger than 6 months of age and is, therefore, no longer preferred. When third ventriculostomy is performed using endoscopic guidance, the same long-term results are achieved in children younger than 6 months of age as in older children and, thus, patient age should no longer be considered as a contraindication to using the technique. Delayed failures are usually secondary to obstruction of the stoma and often can be managed by repeating the procedure. Midline sagittal T2-weighted MR imaging sequences combined with cine PC MR imaging flow measurements provide a reliable tool for diagnosis of aqueductal stenosis and for ascertaining the patency of the stoma during follow-up evaluation.

Adolescent↗