Personalized mapping of the deep brain with a white matter attenuated inversion recovery (WAIR) sequence at 1.5-tesla: Experience based on a series of 156 patients.

OBJECTIVE: Deep brain mapping has been proposed for direct targeting in stereotactic functional surgery, aiming to personalize electrode implantation according to individual MRI anatomy without atlas or statistical template. We report our clinical experience of direct targeting in a series of 156 patients operated on using a dedicated Inversion Recovery Turbo Spin Echo sequence at 1.5-tesla, called White Matter Attenuated Inversion Recovery (WAIR). METHODS: After manual contouring of all pertinent structures and 3D planning of trajectories, 312 DBS electrodes were implanted. Detailed anatomy of close neighbouring structures, whether gray nuclei or white matter regions, was identified during each planning procedure. We gathered the experience of these 312 deep brain mappings and elaborated consistent procedures of anatomical MRI mapping for pallidal, subthalamic and ventral thalamic regions. We studied the number of times the central track anatomically optimized was selected for implantation of definitive electrodes. RESULTS: WAIR sequence provided high-quality images of most common functional targets, successfully used for pure direct stereotactic targeting: the central track corresponding to the optimized primary anatomical trajectory was chosen for implantation of definitive electrodes in 90.38%. CONCLUSION: WAIR sequence is anatomically reliable, enabling precise deep brain mapping and direct stereotactic targeting under routine clinical conditions.

[Medico-economic analysis of a neurosurgery department at a university hospital]. / Analyse médico-économique d'un service de neurochirurgie en centre hospitalier et universitaire.

OBJECTIVE: Economic and societal constraints require to take into account the economic dimension and medical performance of hospital departments. We carried out a self-assessment study, which we thought could be useful to share with the neurosurgical community. MATERIAL AND METHODS: Care and research activities were assessed from 2009 to 2013. We used institutional and assessment-body parameters in order to describe activities and perform a financial evaluation. It was a retrospective descriptive study based on the guidelines of the DHOS/O4 circular No. 2007/390 of October 29, 2007. RESULTS: The average annual, analytic income statement was +1.39 millions euros, for 63 beds with a 92% occupancy rate, including 6.7 full-time equivalent neurosurgeons (and assistants), for 2553 patients and 1975 surgeries. The average mortality rate was 2.74%. The annual mean length of stay was 6.82 days. Per year, on average 15.6% of patients were admitted in emergency and 76.9% returned home. The annual, act-related-pricing and publication-related incomes represented 77% and 0.6%, respectively of the total funding. Difficulties to find downstream beds for the most severe patients induced 1401 "waiting days" in 2012. CONCLUSION: Medico-economic analysis of a neurosurgery department at a university hospital was useful in order to take into account the care, teaching and research activities, as well as its related financial value.

Contribution of CT scan and CT-guided aspiration in the management of retropharyngeal abscess in children based on a series of 18 cases.

OBJECTIVE: This study was designed to analyse the contribution of CT scan to the management of retropharyngeal abscess in children and the place of CT-guided percutaneous aspiration as an alternative to surgical drainage. MATERIALS AND METHODS: Retrospective study including 18 children with a mean age of 38 months [range: 5-67 months] presenting with retropharyngeal infection between 2006 and 2011. All cases were initially assessed by contrast-enhanced CT scan of the neck. Clinical, radiological treatment and bacteriological data were collected. Radiological results were correlated with surgical and percutaneous aspiration findings (presence or absence of an abscess). RESULTS: The initial CT scan detected 14 abscesses, 3 cases of non-suppurative lymphadenitis and one case of retropharyngeal oedema. One case of non-suppurative lymphadenitis progressed to abscess after failure of antibiotic therapy and was treated surgically. Surgical drainage revealed a purulent collection in 11 cases and no collection in 3 cases. Four CT-guided percutaneous aspirations were successfully performed. Three cases were treated by antibiotics alone (2 cases of lymphadenitis and 1 case of retropharyngeal oedema). Bacteriological examinations revealed the presence of Streptococcus pyogenes in 78.5% of cases. The positive predictive value of the initial CT scan was 78.8% in our series. CONCLUSION: Contrast-enhanced neck CT scan confirmed the diagnosis of retropharyngeal abscess and the indication for surgical drainage. It must be performed urgently, on admission. When it is decided to treat the patient with antibiotics alone, follow-up imaging should be performed in the absence of improvement 24 to 48 hours after starting antibiotics. CT-guided percutaneous aspiration is both a diagnostic modality confirming abscess formation of an inflammatory lesion of the retropharyngeal space as well as a therapeutic tool, sometimes avoiding the need for surgical drainage.

Contribution of magnetic resonance imaging to the diagnosis of middle ear cholesteatoma: analysis of a series of 97 cases.

OBJECTIVES: To evaluate the reliability of magnetic resonance imaging (MRI) for the diagnosis of middle ear cholesteatoma and to determine the contribution of each MRI sequence. PATIENTS AND METHODS: A series of 97 cases was reviewed, corresponding to 89 patients (43 women, 46 men). Each patient was assessed by the following MRI protocol: T1-weighted, T2-weighted, early contrast-enhanced T1-weighted, delayed contrast-enhanced T1-weighted, and diffusion-weighted sequences. All patients were operated, for the first time in 16 cases and for second-look surgery in 81 cases. Radiological findings were compared to surgical and histological findings. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for each sequence. RESULTS: Seventy-four cholesteatomas were diagnosed at surgery. These lesions had a mean diameter of 8.29±5.46mm. The smallest cholesteatoma in this series was 2mm in diameter. Diffusion-weighted and delayed contrast-enhanced T1-weighted sequences had a sensitivity of 84.9% and 90.4%, a specificity of 87.5% and 75%, a positive predictive value of 95.4% and 91.7%, and a negative predictive value of 65.6% and 72%, respectively. T1-weighted, T2-weighted, and early contrast-enhanced T1-weighted sequences had a low specificity. CONCLUSIONS: MRI is a reliable imaging modality for the diagnosis of middle ear cholesteatoma. Diffusion-weighted and delayed contrast-enhanced T1-weighted sequences were discriminant. In the context of postoperative follow-up of cholesteatoma, these sequences allow better selection of cases requiring second-look surgery.

Electrical modulation of neuronal networks in brain-injured patients with disorders of consciousness: a systematic review.

Six clinical studies of chronic electrical modulation of deep brain circuits published between 1968 and 2010 have reported effects in 55 vegetative or minimally conscious patients. The rationale stimulation was to activate the cortex through the reticular-thalamic complex, comprising the tegmental ascending reticular activating system and its thalamic targets. The most frequent intended target was the central intralaminar zone and adjacent nuclei. Hassler et al. also proposed to modulate the pallidum as part of the arousal and wakefulness system. Stimulation frequency varied from 8Hz to 250Hz. Most patients improved, although in a limited way. Schiff et al. found correlations between central thalamus stimulation and arousal and conscious behaviours. Other treatments that have offered some clinical benefit include drugs, repetitive magnetic transcranial stimulation, median nerve stimulation, stimulation of dorsal column of the upper cervical spinal cord, and stimulation of the fronto-parietal cortex. No one treatment has emerged as a gold standard for practice, which is why clinical trials are still on-going. Further clinical studies are needed to decipher the altered dynamics of neuronal network circuits in patients suffering from severe disorders of consciousness as a step towards novel therapeutic strategies.

[Carotid-cavernous fistula: comparison of clinical and neuroradiologic features pre- and post-embolization]. / Fistule carotido-caverneuse : confrontation des aspects cliniques et neuroradiologiques pré- et post-embolisation.

We report the case of an 85-year-old patient, referred by her ophthalmologist for neuro-ophthalmologic consultation at the Clermont-Ferrand University Medical Center, for conjunctival hyperemia and ocular hypertension in the left eye for 12 months. The patient's only past medical history was treated, controlled arterial hypertension and there was no mention of falling or head trauma. MRI (magnetic resonance imaging) and angiography identified a type D carotid-cavernous fistula. Intravenous embolization was performed under general anesthesia by retrograde selective catheterization facial vein and ophthalmic vein and placement of coils into the cavernous sinus, resulting in regression of physical and functional signs immediately after the procedure. This case illustrates the symptoms of spontaneous carotid-cavernous fistula and immediate efficacy of embolization. We report the epidemiology, characteristics and various presentations of the condition.

[Surgical complications of deep brain stimulation: clinical experience of 184 cases]. / Complications chirurgicales de la stimulation cérébrale profonde : expérience clinique à propos de 184 cas.

BACKGROUND AND PURPOSE: Deep brain stimulation (DBS) is an effective treatment of movement disorders and psychiatric diseases. However, this surgery is still time consuming and associated with complications, among which we aimed to identify non-stimulo-induced adverse effects. Hence, we retrospectively systematically analyzed patients operated on, at our institution, using magnetic resonance imaging (MRI) direct anatomic mapping. METHODS: One hundred and seventy-five patients (184 surgeries) were performed between 1994 and 2008, for Parkinson's disease, essential tremor, dystonia and obsessive compulsive disorder. Primary anatomic targets were the subthalamic region, the intern pallidum and the thalamus. Final electrode positioning was adjusted according to intraoperative neuron recordings and acute stimulation tests. All surgically related adverse effects were collected. Life threatening or new non-planed surgery was considered as severe adverse effects. RESULTS: Adverse effects occurred 10 times (5.4%) during MRI acquisition, 24 times (13%) with five serious (2.7%) including one1 death (0.5%) during electrodes implantation and 17 times (9.2%) with four serious (2.2%) during neuropacemaker implantation. Electrodes were repositioned in six cases (five patients, n=3.4%). CONCLUSION: DBS efficiency is recognized however the significant incidence of adverse effects should prompt us to improve the procedures.

Flow-diverter silk stent for the treatment of intracranial aneurysms: 1-year follow-up in a multicenter study.

BACKGROUND AND PURPOSE: FD stent placement is a promising therapy for challenging intracranial aneurysms. Long-term evaluations about angiographic and morphologic results are still missing. This is the aim of this multicenter series. MATERIALS AND METHODS: We report our experience and 1-year FU in a retrospective chart review of 65 consecutive subjects with 77 unruptured or recanalized aneurysms that were treated with Silk FD stents at 6 centers in France. Both angiographic and clinical results were recorded before treatment and at 6 and 12 months after treatment. At the 12-month FU, relationships between angiographic aneurysm occlusion and shrinkage of the thrombosed aneurysm sac were evaluated. RESULTS: Stent deployment was achieved in 64 cases (98.5%) and failed in 1 case (1.5%). Seven misdeployments of the Silk stent caused the occlusion of 6 parent arteries. Overall acute/subacute procedural morbidity was 7.7%, and mortality was zero. Delayed complications were observed in 10.9% of subjects. At the 6-month FU, permanent morbidity was 7.8% and mortality was 3%. Complete occlusion occurred within 6 months in 68% of aneurysms and within 12 months after treatment in 84.5% of aneurysms. At the 12-month FU, in angiographically complete occluded aneurysms, MR imaging/CT analysis showed the complete disappearance of the thrombosed aneurysm in 30% of cases and partial shrinkage in 52%; furthermore, thrombosed aneurysms were stable in 11% of cases and enlarged in 7%. CONCLUSIONS: The Silk stent is an effective tool for the treatment of challenging aneurysms because it allows complete occlusion in most cases 1 year after treatment. Permanent morbidity was 7.8%, and mortality was 3%.

Osteoma of the internal auditory canal.

OBJECTIVE: Osteoma occurs almost exclusively in the head and neck region, only rarely developing into the internal auditory canal. We report an incidental finding of a case in the radiological evaluation of a patient with left hemifacial spasm. PATIENTS AND METHODS: A 79-year-old woman consulted for left hemifacial spasm associated with left anacusis. Symptoms occurred up to 30 years prior to the first radiological investigations. Computed tomographic (CT) and magnetic resonance (MRI) images were taken. RESULTS: MRI demonstrated a left internal auditory canal lesion with spontaneous hypointense signal on T1- and T2-weighted images. CT showed the lesion as a typically dense and opaque osteoma. It measured 0.6 cm in maximum size. No surgery was performed because of the slow-growing features of the lesion. Clinical monitoring was recommended. CONCLUSION: Osteomas are diagnosed incidentally in asymptomatic patients. Our case was symptomatic and raised the question of surgical management. This article discusses the presentation and management associated with this exceptional osteoma location.

[Case report of a 2-year-old child with palpebral rhabdomyosarcoma]. / Rhabdomyosarcome palpébral chez un enfant âgé de deux ans.

Rhabdomyosarcoma is an extremely virulent rare tumor whose early diagnosis considerably improves survival and visual prognosis. We report the case of a 2-year-old child with levator palpebrae superioris muscle rhabdomyosarcoma revealed by a sudden and isolated blepharoptosis. Initially, clinical and imaging investigations did not show any abnormality but a painful tumor with some hematoma quickly developed, so the investigations were repeated. The CT-scan showed an extra-conal tumor that had developed at the superior part of the orbit. Histology confirmed the diagnosis of embryonic rhabdomyosarcoma. Because of its results, treatment consisting of chemotherapy associating ifosfamide, vincristine, actinomycin and orbital radiotherapy of 40 Gy with a local addition of 10 Gy were administrated with successful results after a 3-year-follow-up.

Surgical pitfalls encountered with the semi-implantable middle ear transducer ossicular stimulator (MET-Otologics).

OBJECTIVE: To determine whether surgical pitfalls can be anticipated through a preoperative CT-Scan in case of middle ear implantation with a semi-implantable middle ear ossicular stimulator from Otologics (SIMOS). A second outcome measure was to assess the auditory gain obtained in the series. MATERIALS AND METHODS: A retrospective analysis of 19 consecutive surgical procedure for a SIMOS implantations was achieved. Preoperative Ct-Scans were analyzed and several measurements of the mastoid were taken out from axial transverse views, ie. the distance between the incus and the cortical mastoid bone [d(i-c)], the distance between the sigmoid sinus and the incus [d(i-ss)], the distance between the sigmoid sinus and the cortical bone of the mastoid [d(c'-ss)]. On coronal images, the dura of the middle fossa was described as procident if it was lower than the head of malleus and/or body incus. Auditory gain was calculated on pure tone and speech audiometry with bisyllabic words. RESULTS: All cases were successfully implanted. d(i-c) was on average at 33.1 +/- 2.6 mm in cases easy to implant. One case of contracted mastoid was difficult and led to the impaction of the sigmoid sinus. In this case the distance d(i-c) was shorter at 25 mm than the average minus 2 standard deviations of the others (27.9 mm). Also d(ss-c') was lower at 7 mm than the average minus 2 standard deviations of the others (7.6 mm). Two other cases led to difficult surgical procedures because of a low middle fossa dura. This too low middle fossa dura could be identified on preoperative coronal CT-scans in these two cases. Audiometric gains were remarkable, with an average of 39 +/- 16 dB. In case of severe sensorineural hearing loss the average gain was higher at 46 +/- 9 dB. Two revision-procedures were required, one for a device failure, the second because of skin alteration due to systemic inflammatory disease requiring corticosteroids. Mean follow-up was 50 +/- 22 months. CONCLUSION: The SIMOS is a powerful middle ear implant that can undoubtedly give a huge audiometric gain. The implantation procedure requires a precise microsurgical operation that can be hampered by anatomical conditions of the petrous bone. A thorough examination of preoperative CT-scan is highly recommended in order to obtain measurements of the mastoid in axial views, and the analysis of the position of the middle fossa dura in coronal views.

Long-term follow-up of 1036 cerebral aneurysms treated by bare coils: a multicentric cohort treated between 1998 and 2003.

BACKGROUND AND PURPOSE: The endovascular treatment (EVT) of cerebral aneurysms has experienced a revolution since 1991 with the introduction of platinum coil technology. During the past 10 years, there has been significant study of the feasibility of this technique, and clinical results of EVT have been published. The long-term durability of Guglielmi detachable coil (GDC) embolization of cerebral aneurysms still remains unknown. The purpose of this study was to evaluate the stability of anatomic occlusion of aneurysms and to assess the rate of recanalization and retreatment of these aneurysms. MATERIALS AND METHODS: Between January 1998 and December 2003, 1036 aneurysms (804 ruptured and 232 nonruptured) were treated consecutively with GDC coils in 5 neuroradiology centers. Procedural feasibility, acute angiographic occlusion results, morbidity, and mortality associated with this technique were assessed. All patients were regularly followed by digital subtraction angiography and MR imaging each year after treatment. RESULTS: Initial acute angiographic results in 1036 aneurysms demonstrated total occlusion in 731 patients (70.5%), subtotal occlusion in 252 (24.3%), incomplete occlusion in 20 (1.9%), and failures in 33% (3.3%) aneurysms. A remodeling technique was used in 10%. A second procedure was performed for 72 aneurysms (7%). The total aneurysm follow-up time was 49,923 months (4160.25 aneurysm-years). The retreatment period was either in the months following initial treatment in aneurysms incompletely occluded or in years due to recanalization or de novo aneurysms. Fewer than 5 patients rebled during 10 years of follow-up. Long-term follow-up angiograms were obtained in 899 aneurysms, with 646 total, 230 subtotal, and 23 incomplete results. CONCLUSIONS: Long-term follow-up of cerebral aneurysms is necessary to depict recanalization. Only 7% of the aneurysms were retreated. Use of bare coils gives a good long-term level of occlusion.

[Local intra-arterial fibrinolysis in a single-eyed patient with acute occlusion of the central retinal artery]. / Fibrinolyse intra-artérielle in situ chez une patiente monophtalme atteinte d'occlusion d'artère centrale de rétine.

We report the case of a single-eyed patient with acute occlusion of the central retinal artery on her functional eye. The patient was a 72-year-old women with high cardiovascular risk, bilateral severe myopia, and amblyopia in her right eye. The occlusion affected the left eye so treatment consisting of local intra-arterial fibrinolysis was initiated by administration of alteplase and sodic heparin in the left ophthalmic artery. The result was successful restoration of initial visual acuity after 1 month, which was stable at the 9-month-follow-up.

New electrophysiological mapping combined with MRI in parkinsonian's subthalamic region.

The subthalamic nucleus (STN) is the main target for deep brain stimulation in Parkinson's disease. We analysed the relationships between magnetic resonance imaging (MRI) anatomy and spontaneous neuronal activity to confirm the potential of microelectrode recordings to assist in determining the optimal surgical target. Ten bilateral surgeries were performed after 1.5-T (T2-weighted) anatomical MRI identification of the STN, zona incerta (ZI), Forel's field H2 (H2) and substantia nigra (SN). Spontaneous neuronal activity was recorded simultaneously along the distal 10 mm on a central track (optimally covering the STN) and a 2-mm anterior track. We calculated off-line mean firing rate and burst frequency on 248 neurons clustered according to anatomical structure. Subjective visual analysis of signal was also realized on-line, during surgery, to classify patterns of activity. Mean firing rate and burst frequency increased from H2-ZI to SN. The mean firing rate was higher in SN only using paired comparison (SN vs. its neighbours). The burst frequency was lower in H2 than in SN; using comparison with neighbours, it was lower in H2 and ZI. An irregular high activity (type 2C) was more often detected in STN and SN than in H2 and ZI. Anatomical boundaries and unitary recordings appear to be linked, supporting the ability of MRI to provide a detailed anatomy. Electrophysiological mapping combined with MRI is a useful tool for precise targeting in the subthalamic region.

[Interventional radiology: transoral approach to C2]. / Abord transbuccal de l'axis en radiologie interventionnelle.

PURPOSE: To assess the value of a direct transoral approach to C2 for interventional procedures. MATERIALS AND METHODS: A transoral approach to C2 was used in 4 patients (9-64 year old) with lytic lesion of the C2 vertebra and/or base of the odontoid over a 10 year period. Three patients underwent biopsy and 1 patient underwent vertebroplasty using biplane fluoroscopy. All procedures were performed under general anesthesia using a 13G needle directly introduced in the C2 vertebra through the posterior pharyngeal wall. RESULTS: None of the patients reported ill-effects from the procedure. Needle placement was satisfactory in all patients, without technical difficulty. No technical complication was noted. Specifically, no infectious complication occurred. CONCLUSION: Our results indicate that a direct transoral approach to C2 is safe for biopsy or vertebroplasty.

Feasibility, procedural morbidity and mortality, and long-term follow-up of endovascular treatment of 321 unruptured aneurysms.

BACKGROUND AND PURPOSE: The purpose of our study was to evaluate the technical feasibility, morbidity and mortality, and durability of occlusion of unruptured aneurysms treated with Guglielmi detachable coils (GDCs) with a long-term follow-up. MATERIALS AND METHODS: Between January 1998 and January 2005, we treated 321 unruptured aneurysms with GDCs in 5 neuroradiologic institutions. During this period, 63% of unruptured aneurysms were treated by endovascular technique. Procedural feasibility, technical complications, morbidity and mortality, and acute and long-term angiographic occlusion were assessed. RESULTS: Overall technical feasibility of coiling treatment was 94%; 302 aneurysms were treated by endovascular technique. At the end of the initial procedure, acute occlusion was classified as complete in 207 cases (70%), subtotal in 84 cases (26.1%), and incomplete in 11 cases (3.9%). Ischemic complications were observed in 28 patients (9%); 8 patients (2.6%) had perforation of their aneurysms. Treatment-related morbidity was 14.4%, and morbidity with clinical complications was evaluated at 7.7% (n = 23 patients). Five patients (1.7%) died as a result of aneurysm perforation. Final follow-up angiograms, after 9 secondary treatments, demonstrated complete occlusion in 193 patients (69.5%), subtotal in 80 aneurysms (28.5%), and incomplete occlusion in 5 (1.8%). Nineteen patients were lost to follow-up (6.3%). CONCLUSION: Endovascular coiling with detachable coils is an attractive option for treatment of unruptured aneurysms. This method of treatment is safe with a low rate of complications. Prospective studies with longer follow-up periods are needed to assess the long-term durability of occlusion in unruptured aneurysms.

[Adenoid cystic carcinoma of the external auditory canal]. / Carcinome adénoïde kystique du méat acoustique externe.

OBJECTIVES: To report a case of adenoid cystic carcinoma of the external auditory canal with petrous involvement. MATERIAL AND METHODS: A 50-year-old woman was referred to our department for the management of a necrotizing external otitis. Computed tomography and biopsy revealed an adenoid cystic carcinoma of the external auditory canal. RESULTS: The patient was treated by complete surgical excision. A radiation therapy completed the treatment. Follow-up time was 19 months without evidence of recurrence. Adenoid cystic carcinoma of the external auditory canal is a rare tumor. It's a special type of carcinoma developing from the ceruminous glands. Histogenesis is difficult and unsettled. The most important survival factor is removal of the tumor with histologically free margins. CONCLUSIONS: Lack of specific clinical and radiological signs makes the diagnostic challenging. The adenoid cystic carcinoma is a rare neoplasm of the external auditory canal. An initial aggressive wide "en bloc" surgical resection is mandatory.

[Radiology of central nervous system cavernomas]. / Imagerie des cavernomes du système nerveux central.

MRI is the best radiological technique to explore cavernomas, vascular malformations affecting the entire central nervous system. The presence of blood degradation products produces a specific aspect which enables excellent contrast resolution. Certain diagnosis can be established with MRI which can also be used to follow growth and modifications, particularly in familial forms. In the emergency setting, the first exam is often a CT-scan for patients presenting acute neurological sign(s) and/or with a clinical suspicion of hemorrhagic stroke. Angiography is generally not contributive because cavernomas are occult vascular malformations. Nevertheless, this exam is often necessary when an associated vascular abnormality is suspected, particularly a developmental venous abnormality.