Cyrille Capel

Frameless robotic stereotactic biopsies: a consecutive series of 100 cases

OBJECT Stereotactic biopsy procedures are an everyday part of neurosurgery. The procedure provides an accurate histological diagnosis with the least possible morbidity. Robotic stereotactic biopsy needs to be an accurate, safe, frameless, and rapid technique. This article reports the clinical results of a series of 100 frameless robotic biopsies using a Medtech ROSA device. METHODS The authors retrospectively analyzed their first 100 frameless stereotactic biopsies performed with the robotic ROSA device: 84 biopsies were performed by frameless robotic surface registration, 7 were performed by robotic bone fiducial marker registration, and 9 were performed by scalp fiducial marker registration. Intraoperative flat-panel CT scanning was performed concomitantly in 25 cases. The operative details of the robotic biopsies, the diagnostic yield, and mortality and morbidity data observed in this series are reported. RESULTS A histological diagnosis was established in 97 patients. No deaths or permanent morbidity related to surgery were observed. Six patients experienced transient neurological worsening. Six cases of bleeding within the lesion or along the biopsy trajectory were observed on postoperative CT scans but were associated with transient clinical symptoms in only 2 cases. Stereotactic surgery was performed with patients in the supine position in 93 cases and in the prone position in 7 cases. The use of fiducial markers was reserved for posterior fossa biopsy via a transcerebellar approach, via an occipital approach, or for pediatric biopsy. CONCLUSIONS ROSA frameless stereotactic biopsies appear to be accurate and safe robotized frameless procedures.

Effect of surgery on periventricular white matter in normal pressure hydrocephalus patients: comparison of two methods of DTI analysis

Background Diffusion tensor imaging (DTI) is a useful tool for assessing changes that occur in microstructures. We have developed a novel method for region of interest (ROI) delineation in the assessment of DTI parameters in patients with normal pressure hydrocephalus (NPH). Purpose To compare the standard method and our novel method in an evaluation of the impact of surgery on periventricular white matter in patients with NPH. Material and Methods Ten patients with NPH underwent 3T magnetic resonance imaging (MRI; including 12-direction DTI sequences) before and after surgery. We recorded diffusion parameters (λi, the fractional anisotropy [FA], the apparent diffusion coefficient, and Dr) in the internal capsule (IC) and the body of the corpus callosum (BCC). Using the standard delineation technique, regions of interest (ROIs) were positioned according to anatomical and functional considerations and then filled with several sub-ROIs. The ROIs delineated with our novel technique (extracted as the six sub-ROIs with the lowest standard deviation for the FA) were arranged in two rows (medial and lateral), from the ventricle to the brain surface. Results The within-ROI homogeneity was higher with the novel method than with the conventional method (P < 10−4). When the conventional delineation method was applied to the IC data, only λ2 was found to be significantly greater after surgery; in contrast, application of our novel method evidenced a significant decrease in FA and λ1 and a significant increase in λ2 (P < 0.05). Both before and after surgery, the FA in the medial row of ROIs was greater than the FA in the lateral row (P < 0.01). In the BCC, only λ2 and Dr varied significantly (when evaluated with the novel method). Conclusion Our results show that use of a novel method of DTI data analysis may be more sensitive to local changes induced by surgical procedures. Furthermore, this novel method was able to detect the transmantle pressure gradient related to the regional stress distribution.

Interactions between Flow Oscillations and Biochemical Parameters in the Cerebrospinal Fluid.

The equilibrium between the ventricular and lumbar cerebrospinal fluid (CSF) compartments may be disturbed (in terms of flow and biochemistry) in patients with chronic hydrocephalus (CH). Using flow magnetic resonance imaging (MRI) and CSF assays, we sought to determine whether changes in CSF were associated with biochemical alterations. Nine elderly patients with CH underwent phase-contrast MRI. An index of CSF dynamics (Idyn) was defined as the product of the lumbar and ventricular CSF flows. During surgery, samples of CSF were collected from the lumbar and ventricular compartments and assayed for chloride, glucose and total protein. The lumbar/ventricular (L/V) ratio was calculated for each analyte. The ratio between measured and expected levels (Ibioch) was calculated for each analyte and compared with Idyn. Idyn varied from 0 to 100.103μl2.s2. In contrast to the L/V ratios for chloride and glucose, the L/V ratio for total protein varied markedly from one patient to another (mean ± standard deviation (SD): 2.63 ± 1.24). The Ibioch for total protein was strongly correlated with the corresponding Idyn (Spearman’s R: 0.98; p < 5 × 10−5).We observed correlated alterations in CSF flow and biochemical parameters in patients with CH. Our findings also highlight the value of dynamic flow analysis in the interpretation of data on CSF biochemistry.

Should we fear cement leakage during kyphoplasty in percutaneous traumatic spine surgery? A single experience with 76 consecutive cases

OBJECTIVE Although kyphoplasty is widely used to repair osteoporotic and pathologic vertebral fractures, balloon kyphoplasty and vertebral body stenting are new treatment options in cases of traumatic spinal injury. To our knowledge, there are no literature data on the incidence of cement leakage whereas these two percutaneous techniques are commonly used to repair non-pathologic fractures. The aim of this study was to evaluate and compare the clinical characteristics and the incidence of cement leakage associated with balloon kyphoplasty and vertebral body stenting in the percutaneous treatment of traumatic spinal injury. METHODS A series of 76 consecutive kyphoplasties (50 with vertebral body stenting and 26 balloon kyphoplasties) were retrospectively reviewed. Preoperative and postoperative computed tomography scans were analyzed in order to detect cement leakage and grade it as minor, moderate or major. RESULTS The overall leakage rate was 50%. None of the leakages gave rise to clinical symptoms. Although balloon kyphoplasty and vertebral body stenting did not differ in terms of the leakage rate, the latter technique was associated with a lower leakage volume. The Magerl type, fracture level and use of concomitant osteosynthesis did not appear to significantly influence the leakage rate. CONCLUSION Vertebral body stenting can reduce the amount of cement leakage due to a better cohesion of the bone fragments after kyphosis correction and maintenance.

Robot-Assisted Radiofrequency Ablation of a Sacral S1-S2 Aggressive Hemangioma

BACKGROUND Aggressive vertebral hemangiomas are rare tumors of the spine. The treatment management strategy usually consists of vertebroplasty, radiation therapy, or, in rare cases of surgical strategy. CASE DESCRIPTION We present a case of a bulging sacral S1-S2 hemangioma in the spinal canal that could not be managed in the usual manner. CONCLUSION Here we demonstrate the usefulness of radiofrequency ablation technique as an alternative treatment, as well as robotic assistance for optimal placement of the ablation probe within the lesion.

Normal‐Pressure Hydrocephalus, Sleep Apnea Syndrome, and Quality of Life in an Octagenarian

heimers-and-dementia-the-conversation-with -children/Accessed 2015. 7. Huvent-Grelle D, Pagniez C, Puisieux F. La maladie d’Alzheimer expliqu ee aux petits: La souffrance psychologique des petits-enfants confront es a la maladie d’Alzheimer d’un grand-parent. How to explain Alzheimer’s disease to children: Psychological stress in grandchildren faced with Alzheimer’s disease affecting a grandparent. La Revue Francophone de G eriatrie et de G erontologie 2011;XVIII:490–492. [In French] 8. Sakai EY, Carpentier BD, Rieger RE. “What’s wrong with grandma?” Depiction of Alzheimer’s disease in children storybooks. Am J Alzheimers Dis Other Demen 2012;27:584–591. 9. Costa Ponce C, Nascimento Odonez T, Lima-Silva TB et al. Effects of a psychoeducational intervention in family caregivers of people with Alzheimer’s disease. Dement Neuropsychol 2011;5:226–237. 10. Dunkin JJ, Anderson-Hanley C. Dementia caregiver burden: A review of the literature and guidelines for assessment and intervention. Neurology 1998;1(Suppl 1):S53–S60; discussion S65–S67.

Cerebrospinal Fluid and Cerebral Blood Flows in Idiopathic Intracranial Hypertension

OBJECTIVES Cerebrospinal fluid (CSF) and blood flows have a strong relationship during a cardiac cycle. Idiopathic intracranial hypertension (IIH) is a pathology that seems to present hemodynamic and hydrodynamic disturbance. The aim of this study was to establish CSF and blood interaction in IIH. MATERIAL AND METHODS We retrospectively studied cerebral hydrodynamic and hemodynamic flows by phase-contrast MRI (PCMRI) in 13 IIH subjects (according Dandys criteria) and 16 controls. We analyzed arterial peak flow, pulsatility index, and resistive index in arterial and venous compartments (PFart, PIart, RIart, PFvein, PIvein, RIvein) and measured arteriovenous and CSF peak flow and stroke volume (PFav, SVVASC, PFCSF, SVCSF). RESULTS We found no significant difference between IIH and control groups in arterial and venous parameters. Arteriovenous flow analysis showed higher PFav and SVVASC in the IIH group than in the control group (respectively 369 ± 27 mL/min and 286 ± 47 mL/min, p = 0.02; and 1085 ± 265 μL/cardiac cycle and 801 ± 226 μL/cardiac cycle, p = 0.007). PFCSF and SVCSF were higher in the IIH group than in the control group (respectively 206 ± 50 mL/min and 126.6 ± 24.8 mL/min, p = 0.04; and 570 ± 190 μL/cardiac cycle and 430 ± 100 μL/cardiac cycle, p = 0.0007). CONCLUSION Although no significant change was found in arterial and venous flows, we showed that a small phase shift of venous outflow might cause an increase in the arteriovenous pulsatility and an increasing brain expansion during the cardiac cycle. This arteriovenous flow increase would result in an increase of CSF flushing through the foramen magnum and an increased ICP.

A case of Erdheim-Chester disease with spinal cord compression and sphenoid sinus involvement

Erdheim-Chester disease is a rare form of non-Langerhans cell histiocytosis. It is an inflammatory disorder associated with BRAF V600E mutation in 50% of cases. This multisystem disease is rarely associated with spinal involvement. Neurological involvement is an independent predictive factor of poor prognosis. The diagnosis is histopathological based on CD68-positive and CD1A-negative histiocytes. Treatment with interferon-alpha is an independent predictor of survival in Erdheim-Chester disease and vemurafenib has also been shown to be effective for BRAF V600E mutation. We report a clinical case of a 51-year-old patient with multiple and rare locations of Erdheim-Chester disease, particularly at the sphenoid sinus.

CSF protein variations correlates with CSF oscillations in hydrocephalus patients

There are no previous reports comparing CSF biochemistry and its flow dynamics. As suggested by Milhorat, the complex system of CSF circulation through the brain may help to maintain a balance between the CSF flow rate and the CSF biochemical composition between different compartments. We hypothesize that this equilibrium may be disturbed in hydrocephalus patients and by using flow-MRI and CSF biological assessment, we could determine if alterations of CSF flow found in hydrocephalus patients affects their CSF biochemistry.

Unexpected ruptured aneurysm during posterior fossa surgery

BACKGROUND AND IMPORTANCE Surgery is the recommended treatment for unique significant cerebellar metastasis, particularly in cases of hydrocephalus. Complications of posterior fossa surgery are associated with high risk of morbidity and mortality. We present a unique case of unexpected peroperative rupture of a cerebellar superior artery aneurysm during posterior fossa surgery. CLINICAL PRESENTATION During posterior cranial fossa surgery, severe arterial bleeding occurred in front of the medulla oblongata. Immediate postoperative computed tomographic (CT) angiography revealed a fusiform aneurysm from a distal branch of the left superior cerebellar artery. CONCLUSION To our knowledge, this is the first reported operative case of unexpected infratentorial ruptured aneurysm during posterior fossa surgery.