Security and reliability of CUSTOMBONE cranioplasties: A prospective multicentric study.

BACKGROUND: Repairing bone defects generated by craniectomy is a major therapeutic challenge in terms of bone consolidation as well as functional and cognitive recovery. Furthermore, these surgical procedures are often grafted with complications such as infections, breaches, displacements and rejections leading to failure and thus explantation of the prosthesis. OBJECTIVE: To evaluate cumulative explantation and infection rates following the implantation of a tailored cranioplasty CUSTOMBONE prosthesis made of porous hydroxyapatite. One hundred and ten consecutive patients requiring cranial reconstruction for a bone defect were prospectively included in a multicenter study constituted of 21 centres between December 2012 and July 2014. Follow-up lasted 2 years. RESULTS: Mean age of patients included in the study was 42±15 years old (y.o), composed mainly by men (57.27%). Explantations of the CUSTOMBONE prosthesis were performed in 13/110 (11.8%) patients, significantly due to infections: 9/13 (69.2%) (p<0.0001), with 2 (15.4%) implant fracture, 1 (7.7%) skin defect and 1 (7.7%) following the mobilization of the implant. Cumulative explantation rates were successively 4.6% (SD 2.0), 7.4% (SD 2.5), 9.4% (SD 2.8) and 11.8% (SD 2.9%) at 2, 6, 12 and 24 months. Infections were identified in 16/110 (14.5%): 8/16 (50%) superficial and 8/16 (50%) deep. None of the following elements, whether demographic characteristics, indications, size, location of the implant, redo surgery, co-morbidities or medical history, were statistically identified as risk factors for prosthesis explantation or infection. CONCLUSION: Our study provides relevant clinical evidence on the performance and safety of CUSTOMBONE prosthesis in cranial procedures. Complications that are difficulty incompressible mainly occur during the first 6 months, but can appear at a later stage (>1 year). Thus assiduous, regular and long-term surveillances are necessary.

Surgical treatment of hypothalamic hamartomas.

Hypothalamic hamartomas are aberrant masses, composed of abnormally distributed neurons and glia. Along endocrine and cognitive symptoms, they may cause epileptic seizures, including the specific gelastic and dacrystic seizures. Surgery is the treatment of drug-resistant hamartoma epilepsy, with associated positive results on endocrine, psychiatric, and cognitive symptoms. Recently, alternatives to open microsurgical treatment have been proposed. We review these techniques and compare their efficacy and safety. Open resection or disconnection of the hamartoma, either through pterional, transcallosal, or transventricular approach, leads to good epileptological control, but its high complication rate, up to 30%, limits its indications. The purely cisternal peduncular forms remain the only indication of open, pterional approach, while other strategies have been developed to overcome the neurological, endocrine, behavioral, or cognitive complications. Laser and radiofrequency thermocoagulation-based disconnection through robot-guided stereo-endoscopy has been proposed as an alternative to open microsurgical resection and stereotactic destruction. The goal is to allow safe and complete disconnection of a possibly complex attachment zone, through a single intraparenchymal trajectory which allows multiple laser or radiofrequency probe trajectory inside the ventricle. The efficacy was high, with 78% of favorable outcome, and the overall complication rate was 8%. It was especially effective in patients with isolated gelastic seizures and pure intraventricular hamartomas. Stereotactic radiosurgery has proved as efficacious and safer than open microsurgery, with around 60% of seizure control and a very low complication rate. Multiple stereotactic thermocoagulation showed very interesting results with 71% of seizure freedom and 2% of permanent complications. Stereotactic laser interstitial thermotherapy (LiTT) seems as effective as open microsurgery (from 76 to 81% of seizure freedom) but causes up to 20% of permanent complications. This technique has however been highly improved by targeting only the epileptogenic onset zone in the hamartoma, as shown on preoperative functional MRI, leading to an improvement of epilepsy control by 45% (92% of seizure freedom) with no postoperative morbidity. All these results suggest that the impact of the surgical procedure does not depend on purely technical matters (laser vs radiofrequency thermocoagulation or stereotactic vs robot-guided stereo-endoscopy) but relies on the understanding of the epileptic network, including inside the hamartoma, the aim being to plan an effective disconnection or lesion of the epileptogenic part while sparing the adjacent functional structures.

Early successful reperfusion after endovascular therapy reduces malignant middle cerebral artery infarction occurrence in young patients with large diffusion-weighted imaging lesions.

BACKGROUND AND PURPOSE: Malignant middle cerebral artery infarction (MMI) is a severe complication of acute ischaemic stroke (AIS). The aim of our study was to assess whether successful reperfusion after endovascular therapy (EVT) in AIS with clinical and imaging predictors of MMI decreased its occurrence. METHODS: Data were collected between January 2014 and July 2018 in a monocentric prospective AIS registry of patients treated with EVT. Patients selected were <65 years old with severe anterior circulation AIS with a National Institutes of Health Stroke Scale score >15, baseline Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score ≤ 6 and baseline diffusion-weighted imaging lesion volume >82 mL within 6 h of symptom onset. Successful reperfusion was defined as a Thrombolysis in Cerebral Ischemia score ≥ 2b. Occurrence of MMI was the primary endpoint. RESULTS: A total of 66 EVT-treated patients were included in our study. MMI occurred in 27 patients (41%). In unadjusted analysis, successful reperfusion was associated with fewer MMIs (31.8% vs. 65.0%; P = 0.015) and with more favorable outcome at 3 months (50% vs. 20%; P = 0.023). In multivariate analysis, successful reperfusion was associated with an adjusted odds ratio (95% confidence intervals) of 0.35 (0.10-1.12) for MMI and 2.77 (0.84-10.43) for 3-month favorable outcome occurrence. CONCLUSIONS: Early successful reperfusion performed in patients with AIS with clinical and imaging predictors of MMI was associated with decreased MMI occurrence. Reperfusion status might be considered in evaluating the need for craniectomy in patients with early predictors of MMI.

Diagnosis of primary hemifacial spasm.

The diagnosis of primary hemifacial spasm (pHFS), due to a benign compression of the facial motor nerve by a vessel, within or close to its root exit zone, is often made with delay. Misdiagnosis includes psychogenic spasm, tics, facial myokymia or blepharospasm, but in fact post-facial palsy synkinesis (post-paralytic HFS) is the closest clinical condition, because it is limited to the territory of the facial nerve of a single hemiface. The differential diagnosis between these two entities, whose pathophysiological mechanisms are very different, can be made by electroneuromyographic (ENMG) examination. In addition, magnetic resonance imaging (MRI) is essential to show the offending vessel at the origin of pHFS and the absence of other causes of nerve compression. However, the diagnosis cannot be made on MRI basis alone, since a neurovascular conflict can be present in clinically asymptomatic subjects. This article reviews the clinical, MRI, and ENMG features in favour of a pHFS diagnosis as well as the various differential diagnoses of this involuntary facial movement disorder.

Soft tissue expansion and cranioplasty: For which indications?

PURPOSE: The aim of this study was to better define indications for scalp tissue expansion before cranioplasty, and to describe our methodology for calculate the surface of tissue needed, by combining a preoperative analysis of both the size of the defect and the quality of skin above. MATERIAL AND METHODS: A retrospective analysis of patients who underwent expansion before cranioplasty between 2009 and 2015 was conducted. Information was collected on the etiology, size and location of the defect, and reasons of skin contracture. Data concerning expansion and cranioplasty were reviewed. RESULTS: Among 47 patients who underwent operation for cranioplasty, five (10.6%) required previous scalp tissue expansion. The etiology of the bone defect was tumoral in three cases, posttraumatic in one case, and a decompressive craniectomy in one case. The mean surface of the bone defect was 69.6 ± 18.7 cm(2). The locations of the defects were fronto-temporo-parietal, frontal, temporo-frontal, on the vertex, and occipital. The cause associated with the skin contracture was an infection in four cases and a delayed cranioplasty in one case. A round-profile expander and a custom-made porous hydroxyapatite implant were used for all patients. CONCLUSIONS: The accurate assessment of tissue needed before cranioplasty is as essential as the choice of the material used for bone reconstruction. After previous infected cranioplasty or delayed reconstruction of large defects, scalp tissue expansion should be proposed.

A reappraisal of the value of lateral spread response monitoring in the treatment of hemifacial spasm by microvascular decompression.

BACKGROUND: Lateral spread response (LSR) to the electrical stimulation of a facial nerve branch is a specific electrophysiological feature of primary hemifacial spasm (HFS). The curative treatment of HFS is based on surgical microvascular decompression (MVD). However, the outcome of this procedure is not always satisfactory. OBJECTIVE: To evaluate the correlation between intraoperative LSR changes and the short- and long-term postoperative clinical outcome following MVD. METHODS: Thirty-two consecutive patients with primary HFS treated by MVD performed with intraoperative LSR monitoring were retrospectively included. The patients were assessed for the presence of HFS and surgical complications at 1 day, 1 month and 6 months after surgery. The long-term clinical result was assessed between 1 and 10 years (mean 5.4 years) using a self-report questionnaire. RESULTS: Patients were divided into three groups based on intraoperative LSR changes: (1) in 15 patients, LSRs were present before incision and disappeared after MVD (47%); (2) in nine patients, LSRs were present before incision but persisted despite MVD (28%); (3) in eight patients, LSRs were absent before surgery and remained so after the procedure (25%). Intraoperative LSR abolition during the MVD procedure correlated with HFS relief in the long term (p<0.0001, Fisher exact test), but not on the first day after surgery (p = 0.3564). CONCLUSIONS: Monitoring MVD by recording LSRs intraoperatively could be of value not only to indicate the resolution of the vasculonervous conflict at the end of surgery, but also to predict a successful clinical outcome in the long term after the surgical intervention.

[Cranial nerve functional neurosurgery: evaluation of surgical practice]. / La neurochirurgie fonctionnelle des nerfs crâniens Evaluation de l'activité

We report the results of an investigation carried out on the activity of functional neurosurgery of the cranial nerves in the French-speaking countries, based on the analysis of a questionnaire addressed to all the members of the SNCLF. Eighteen centers responded to this questionnaire, which showed that activities and indications varied greatly from one unit to another. The results appear homogeneous and comparable with those reported in the literature. The questionnaire sought to provide a global perspective, open to the comments and questions of all responders on the various techniques raised, with the objective of establishing a common decisional tree for these pathologies and providing if possible to a consensus for better dissemination of these therapies.

[Treatment of trigeminal neuralgia with microvascular decompression]. / Traitement de la névralgie trigéminale par décompression vasculaire microchirurgicale.

Pure microvascular decompression (MVD) can cure (that is, no pain, no medication) primary trigeminal neuralgia (TN) caused by vascular compression in 75% of patients (90% when compression is pronounced), according to a Kaplan-Meier survival study at 15 years. MRI with high resolution evidences neurovascular conflicts with good reliability. The results were found to be significantly better when the prosthesis implanted to maintain the compressive vessel away was not touching the nerve. This argues in favor of a real decompressive mechanism of the MVD procedure, rather than a conduction block. Because pure MVD generally does not produce hypoesthesia in the painful territory, MVD is the first surgical therapeutic option for patients with neuralgia resistant to anticonvulsive medications.

[Balloon compression for the treatment of trigeminal neuralgia]. / Traitement de la névralgie trigéminale par la compression par ballon.

The authors present a retrospective study of 121 patients treated with balloon compression of the rootlets behind the Gasser ganglion from 1995 to 2007. The inclusion criteria were drug-resistant idiopathic trigeminal neuralgia. The authors described the surgical technique and compared their results with results from the literature. The following parameters were compared: technical success, pain relief and recurrence, and complications. Balloon compression is considered in the literature to be a safer procedure than other percutaneous surgeries, especially for postoperative sensitive disorders. The best indications seem to be trigeminal neuralgia in older patients or pain due to multiple sclerosis and neuralgia involving the V1 territory. These conclusions should be confirmed by larger series, a longer follow-up (> 5 years) and statistically better analysis.

[Early diagnosis of bacterial brain abscesses: interest of diffusion-weighted MRI]. / Diagnostic précoce des abcès cérébraux bactériens: intérêt de l'IRM en séquences de diffusion.

Three cases of bacterial brain abscesses, in immunocompetent patients, are reported. In all these cases, the diffusion-weighted magnetic resonance (MRI) with apparent diffusion coefficient (ADC) map has permitted an early diagnosis and a rapid treatment. This emergency MRI showed in the three cases a low signal on TI-weighted images, a high signal on T2-weighted and echo-planar images, and a decrease of ADC (0.36- 0.49 x 10(-3) mm2/s). So, this new MRI technique provides an available and rapid element in the brain abscess diagnosis which often remains a complex clinical and radiological diagnosis.

Chiari I malformation: a rare cause of noncommunicating hydrocephalus treated by third ventriculostomy.

OBJECT: Hydrocephalus associated with Chiari I malformation is a rare entity related to an obstruction in the flow of cerebrospinal fluid (CSF) in the foramen of Magendie. Like all forms of noncommunicating hydrocephalus. it can be treated by endoscopic third ventriculostomy (ETV). The object of this study is to report a series of five cases of hydrocephalus associated with Chiari I malformation and to evaluate the use of ETV in the treatment of this anomaly. METHODS: Five patients (four women and one man with a mean age of 29.6 years) underwent ETV for hydrocephalus associated with Chiari I malformation between April 1991 and February 1997. All patients had presented with paroxysmal headaches, which in two cases were associated with visual disorders. All patients had also presented with hydrocephalus (mean transverse diameter of the third ventricle 12.79 mm; mean sagittal diameter of the fourth ventricle 18.27 mm) with a mean herniation of the cerebellar tonsils at 13.75 mm below the basion-opisthion line. Surgery was performed in all patients by using a rigid endoscope. No complications occurred either during or after the procedure, except in one patient who experienced a wound infection that was treated by antibiotic medications. The mean duration of follow up in this study was 50.39 months. Four patients became completely asymptomatic and remained stable throughout the follow-up period. One patient required an additional third ventriculostomy after I year, due to secondary closure, and has remained stable since that time. Postoperative magnetic resonance images demonstrated a significant reduction in the extent of hydrocephalus in all patients (mean transverse diameter of the third ventricle 6.9 mm [p = 0.0035]; mean sagittal diameter of the fourth ventricle 10.32 mm [p = 0.007]), with a mean ascent of the cerebellar tonsils from 13.75 mm below the basion-opisthion line to 7.76 mm below it (p = 0.01). In addition, CSF flow was identified on either side of the orifice of the third ventriculostomy in all patients postoperatively. CONCLUSIONS: Results in this series confirm the efficacy of ETV in the treatment of hydrocephalus associated with Chiari I malformation. It is a reliable, minimally invasive technique that also provides a better understanding of the pathophysiology of this malformation.

Migration pathways of human glioblastoma cells xenografted into the immunosuppressed rat brain.

Diffuse invasion of the brain by tumor cells is a hallmark of human glioblastomas and a major cause for the poor prognosis of these tumors. This phenomenon is only partially reproduced by rodent models of gliomas that display a very high rate of proliferation and limited cell migration. We have analyzed the development of human glioblastoma cells (GL15) xenografted into the brain of immunosuppressed rats, in order to define the characteristics of tumor cell invasion. As identified by the specific immunolabeling of the tumor cells for the human HLA-ABC antigen, GL15 tumors reproduced the three types of intraparenchymal invasion observed in patients. First, a majority of multipolar tumor cells intermingled rapidly and profusely with host neural cells in the margin of the injection site. This progressively enlarging area was principally responsible for the tumor growth over time. Second, in the gray matter, columns of thin bipolar tumor cells aligned along capillary walls. Third, in the white matter, elongated bipolar isolated tumor cells were observed scattered between axonal fibers. The maximum migration distances along white matter fibers remained significantly higher than the maximum migration distances along blood vessels, up to two months after injection. Development of the tumor was associated with a significant increase of vascularization in the area of tumor spread. Xenografting of human GL15 glioblastoma cells into the immunosuppressed rat brain allowed to differentiate between the three classical types of invasion identified in the clinic, to quantify precisely the distances of migration, and to evaluate cell morphology for each of these routes. The present results support the existence of host/tumor cells interactions with specific characteristics for each type of invasion.

[Treatment of central and neuropathic facial pain by chronic stimulation of the motor cortex: value of neuronavigation guidance systems for the localization of the motor cortex]. / Traitement des douleurs centrales et neuropathiques faciales par stimulation chronique du cortex moteur. Intêret des systèmes de neuronavigation pour le repérage du cortex moteur]

Thirty two patients with refractory central and neuropathic pain of peripheral origin were treated by chronic stimulation of the motor cortex between May 1993 and January 1997. The mean follow-up was 27. 3 months. The first 24 patients were operated according to the technique described by Tsubokawa. The last 13 cases (8 new patients and 5 reinterventions) were operated by a technique including localization by superficial CT reconstruction of the central region and neuronavigator guidance. The position of the central sulcus was confirmed by the use of intraoperative somatosensory evoked potentials. The somatotopic organisation of the motor cortex was established peroperatively by studying the motor responses at stimulation of the motor cortex through the dura. Ten of the 13 patients with central pain (77%) and nine of the 12 patients with neuropathic facial pain had experienced substantial pain relief (75%). One of the 3 patients with post-paraplegia pain was clearly improved. A satisfactory result was obtained in one patient with pain related to plexus avulsion and in one patient with pain related to intercostal herpes zoster. None of the patients developed epileptic seizures. The position of the stimulating poles effective on pain corresponded to the somatotopic representation of the motor cortex. The neuronavigator localization and guidance technique proved to be most useful identifying the appropriate portion of the motor gyrus. It also allowed the establishment of reliable correlations between electrophysiological-clinical and anatomical data which may be used to improve the clinical results and possibly to extend the indications of this technique.

Motor cortex stimulation in the treatment of central and neuropathic pain.

BACKGROUND: Motor cortex stimulation has been proposed for the treatment of central pain. METHODS: Thirty-two patients with refractory central and neuropathic pain of peripheral origin were treated by chronic stimulation of the motor cortex between May 1993 and January 1997. The mean follow-up was 27.3 months. The first 24 patients were operated on according to the technique described by Tsubokawa. The last 13 cases (8 new patients and 5 reinterventions) were operated on by a technique including localization by superficial CT reconstruction of the central region and neuronavigator guidance. The position of the central sulcus was confirmed by the use of intraoperative somatosensory evoked potentials. The somatotopic organization of the motor cortex was established preoperatively by studying the motor responses at stimulation of the motor cortex through the dura. RESULTS: Ten of the 13 patients with central pain (77%) and 10 of the 12 patients with neuropathic facial pain experienced substantial pain relief (83.3%). One of the three patients with post-paraplegia pain was clearly improved. A satisfactory result was obtained in one patient with pain related to plexus avulsion and in one patient with pain related to intercostal herpes zoster. None of the patients developed epileptic seizures. CONCLUSIONS: Our results confirm that chronic stimulation of the motor cortex is an effective method in treating certain forms of refractory pain.

A new device for endoscopic third ventriculostomy.

Since its description by Dandy in 1922, several techniques have been used to perform third ventriculostomy under endoscopic control. Except for the blunt technique, in which the endoscope is used by itself to create the opening in the floor of the third ventricle, the other techniques require more than one instrument to perforate the floor of the ventricle and enlarge the ventriculostomy. The new device described is a sterilizable modified forceps that allows both the opening of the floor and the enlargement of the ventriculostomy in a simple and effective way. The new device has the following characteristics: 1) the tip of the forceps is thin enough to allow the easy perforation of the floor of the ventricle; 2) the inner surface of the jaws is smooth to avoid catching vessels of the basal cistern; and 3) the outer surface of the jaws has indentations that catch the edges of the opening to prevent them from slipping along the instrument's jaws. The ventricle floor is opened by gentle pressure of the forceps, which is slowly opened so that the edges of the aperture are caught by the distal outer indentation of the jaws, leading to an approximately 4-mm opening of the floor. This device has been used successfully in 10 consecutive patients. This new device allows surgeons to perform third ventriculostomy under endoscopic control in a very simple, quick, and effective way, avoiding the need for additional single-use instruments.

[Endoscopic anatomy of the third ventricle]. / Anatomie endoscopique du troisieme ventricule.

According to the development of neurosurgical endoscopy (and especially for third ventriculostomy), the endoscopic anatomy in hydrocephalus should be well known and utilized for orientation. The endoscopic pictures are obtained with a 30; telescope, acquired by a digitalized camera and visualized on a video monitor. The pictures are then numerized on a DKR system. Endoscopic anatomy of the third ventricle is described with a particular focus on the anatomical landmarks and their variations around the foramen of Monro, the anterior and posterior walls of the third ventricle. The knowledge of this anatomy is essential for the safety and the reliability of intraventricular endoscopic procedures.

[Endoscopic surgery of third ventricle lesions]. / Approche endoscopique des lésions du troisième ventricule.

The endoscopic approach of the tumors of the third ventricle interests mainly the colloid cysts but also offers the possibilities of biopsies. Twenty two patients (16 men and 6 women, average age 41 years) presenting with hydrocephalus related to a tumor of the pineal area were treated by a ventriculostomy with attempt at biopsy : they are outside of the limits of this report. Twenty two other patients (15 men, 7 women, average age 39 years) were operated on from 1994 to 1999 for a colloid cyst, and 2 of them were admitted in emergency in sudden coma. The CT scan showed a colloid cyst (hyperdense in 16 patients) associated with an hydrocephalus, except for a patient previously shunted. The diameter of the cyst varied from 4 to 50 mm (average of 20 mm). All the patients were operated on using a rigid endoscope. Among the 20 patients presenting a tumor of the pineal area, a biopsy was possible only in 4 cases (20%). There were no hemorrhage nor neurological disorders. In all the cases, the size and the number of the specimens were sufficient to allow the histological diagnosis. For the patients presenting with colloid cyst, the average follow-up is 2 years. All the preoperative symptoms disappeared except for the memory disorders which were improved. The post-operative Evans index decreased significantly. No residual cyst was observed on the post-operative MRI in 14 patients (63%). Among these patients, an asymptomatic recurrence was observed and remained stable after 44 months of follow-up. A residual cyst was observed in 8 patients (36%), with a diameter from 5 to 25 mm (average 9 mm). No patient required a shunt procedure, and no patient presented hemorrhagic complication. Endoscopy is especially useful in the first line treatment of the colloid cysts of the third ventricle.

Recurrent central neurocytoma with marked increase in MIB-1 labelling index.

Central neurocytomas (CNs) are characterized by an indolent growth and a low recurrence rate. Cell proliferation has been rarely studied in recurrent CNs despite the growing awareness of its prognostic value. We present a CN that recurred rapidly after a prolonged relapse-free interval showing a 4-fold increase of MIB-1 labelling index.