Daniel Le Gars

Percutaneous vertebroplasty for pain management in malignant fractures of the spine with epidural involvement.

PURPOSE To evaluate the feasibility, efficacy, and safety of percutaneous vertebroplasty (PV) in the treatment of pathologic fractures owing to malignancy with epidural involvement, with or without neurologic symptoms of spinal cord or cauda equina compression. MATERIALS AND METHODS This study was approved by the local ethics committee; informed consent was obtained from all patients. This retrospective review was performed for 51 consecutive patients with metastatic disease or multiple myeloma treated by means of vertebroplasty, who presented with at least one vertebral lesion with epidural involvement, with or without clinical symptoms of spinal cord or cauda equina compression. All patients with neurologic deficit were terminally ill. A neurologic examination was performed before and after treatment in all patients. All imaging examinations and treatments were reviewed, and chi(2), Mann Whitney, or Fisher exact testing was performed for univariate analysis of variables. RESULTS A total of 74 vertebrae were treated in 51 patients, 22 women and 29 men with a mean age of 62.5 years (range, 28-85 years). Fifteen (29%) patients presented symptoms of complete or incomplete spinal cord or cauda equina compression before vertebroplasty and no further clinical deterioration was observed after treatment. The analgesic efficacy of vertebroplasty was satisfactory for 94% (48 of 51) of patients after 1 day, 86% (31 of 36) patients after 1 month, and 92% (11 of 12) patients after 1 year. One patient with no clinical neurologic deficit before treatment experienced symptoms of cauda equina compression 2 days after vertebroplasty. No other major complication was observed. CONCLUSION The feasibility, efficacy, and safety of PV were confirmed in patients experiencing pain related to malignant spinal tumors with epidural extension, with a low complication rate. PV should become part of the palliative analgesic treatment for such patients. (c) RSNA, 2010.

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.

Epistaxis revealing the rupture of a carotid aneurysm of the cavernous sinus extending into the sphenoid: treatment using an uncovered stent and coils. Review of literature

True carotid aneurysms with sphenoid extension and revealed by epistaxis are rare. A review of the literature shows the mortality risk of this pathology and the different therapeutic options. A 41-year-old female presented with a cavernous carotid aneurysm with sphenoid extension revealed by massive epistaxis. We propose a combined treatment of the affected vessel using coils and an uncovered stent. The first stage to stop the hemorrhages and occlude the aneurysm using the coil and the second stage several days later after anticoagulation using the stent to prevent revascularization. This treatment has been shown to be effective in producing immediate hemostasis and stable long-term occlusion.

MRI location of the distal dural ring plane: anatomoradiological study and application to paraclinoid carotid artery aneurysms

The distal dural ring plane (DDRP) separates the intradural from the extradural paraclinoid internal carotid artery. The purpose of this study was to evaluate its position with MR imaging. The protocol used a T2-weighted sequence in two orthogonal planes: diaphragmatic (DIA-P) and carotid (CAR-P). The DDRP passes through four anatomoradiological reference points (RefP). We developed on a cadaveric model a correlation method supported by correlation lines and angles (CA) projecting the RefP toward the DDRP. RefP were correlated to the DDRP in 65–84% of cases in the DIA-P and 60–76% of cases in the CAR-P. CA were identified and correlated to the DDRP, respectively, in 87% and 60% of cases in the DIA-P, and 60% and 51% of cases in the CAR-P (failure often related to a lack of visibility of just one RefP). A higher tissular contrast in living subjects allowed the identification of CA in 90% and 80% of cases, respectively, in the DIA-P and the CAR-P. We propose that CA, when identified, should be considered as an approximation of the inferior radiological limit of the DDRP curve. In difficult angiographical cases, this MRI protocol could help to locate paraclinoid aneurysms on both sides of the cavernous sinus roof.

The inter-optic course of a unique precommunicating anterior cerebral artery with aberrant origin of an ophthalmic artery: an anatomic case report

Background and importanceSome variations of the cerebral arterial circle of Willis, such as an inter-optic course of the anterior cerebral artery are exceedingly rare. Imaging of very rare anatomical features may be of interest.Clinical presentationIn a 67-year-old male individual, the unique precommunicating part of the left anterior cerebral artery was found to course between both optic nerves. There was an agenesis of the right precommunicating cerebral artery. This variation was associated with an aberrant origin of the ophthalmic artery, arising from the anterior cerebral artery. The anatomic features, the possible high prevalence of associated aneurysms of the anterior communicating artery complex as well as implications for surgical planning or endovascular treatments are outlined and embryologic considerations are discussed.ConclusionTo the best of our knowledge, this is a very rare illustrated case of an inter-optic course of a unique precommunicating anterior cerebral artery with aberrant origin of an ophthalmic artery.

Microsurgical Anatomy of the Anterior Commissure: Correlations With Diffusion Tensor Imaging Fiber Tracking and Clinical Relevance

BACKGROUND Detailed anatomy of the anterior commissure is unknown in the literature. OBJECTIVE To describe the anterior commissure with the use of a fiber dissection technique by focusing on the morphology (length and breadth of the 2 portions), the course, and the relations with neighboring fasciculi, particularly in the temporal stem. METHODS We dissected 8 previously frozen, formalin-fixed human brains under the operating microscope using the fiber dissection described by Klingler. Lateral, inferior, and medial approaches were made. RESULTS The anterior olfactive limb of the anterior commissure was sometimes absent during dissection. The cross-sectional 3-dimensional magnetic resonance rendering images showed that fibers of the anterior commissure curved laterally within the basal forebrain. The tip of the temporal limb of the anterior commissure was intermingled with other fasciculi in various directions to form a dense 3-dimensional network. CONCLUSION Functional anatomy and comparative anatomy are described. The anterior commissure can be involved in various pathologies such as diffuse axonal injury, schizophrenia, and cerebral tumoral dissemination.

A Phase-Contrast MRI Study of Acute and Chronic Hydrodynamic Alterations after Hydrocephalus Induced by Subarachnoid Hemorrhage

To determine acute intracranial hydrodynamic changes after subarachnoid hemorrhage (SAH) via phase‐contrast MRI (PC‐MRI) analysis of the CSF stroke volume in the aqueduct (SVaq) and the foramen magnum (SVfm).

The duodenal fossae: anatomic study and clinical correlations.

The aim of this study was to present anatomic macroscopic aspects and the relationship between the duodenum and the posterior abdominal wall. The authors describe anatomic types of peritoneal duodenal fossae and stress some points of surgical importance. Twenty-four cadavers, fixed in formalin, were dissected. Ten peritoneal fossae were given prominence and the authors show the anatomical structures topographically, from a superficial plane to a deep viscerae level. There is usually a complete fusion of the duodenal loop with the posterior parietal peritoneum except the duodenojejunal flexure. The study reveals three right retroduodenal fossae, three left retroduodenal fossae, two inferior duodenal fossae, one left paraduodenal fossa and one superior duodenal fossa. These peritoneal recesses mostly result from an incomplete adhesion of the Treitz’s fascia. This work provides some explanation of paraduodenal hernias that represent a rare case of intestinal obstruction. Two cases of these internal hernias are illustrated and their pathophysiology and embryologic basis are discussed.

Apport de l'IRM de flux dans les hydrocéphalies à pression normale de l'adulte: intérêt prédictif dans les indications chirurgicales

The diagnosis and management of patients with idiopathic normal-pressure hydrocephalus (NPH) remain somewhat controversial and there is no clear guideline for assessing the post-shunt outcome. The objective of this study was to investigate whether cerebrospinal fluid (CSF) flow dynamics is linked to post-shunt improvement. Fourteen NPH patients (nine males and five females; mean age, 68 years) investigated by magnetic resonance imaging (MRI) before surgical diversion of CSF were retrospectively reviewed. Phase-contrast sequences were added to the morphological clinical protocol for quantification of CSF oscillations, which were recorded at the level of the cerebral aqueduct and the C2 and C3 subarachnoid spaces (SAS). The phase-contrast images were analysed with custom-designed dedicated flow segmentation software. The oscillations measured in this hydrocephalus population were compared to a previously studied healthy population. A difference of at least two standard deviations was used to define a hyperdynamic or hypodynamic state of CSF flow. The cervical CSF flow of the hydrocephalus patients was not significantly different from those of the volunteer population. Of the 14 hydrocephalus patients, 12 had a good response to the shunt. Of these, 10 presented an increased ventricular CSF flow, one a low ventricular CSF flow, and the last one had a normal ventricular CSF flow. Phase-contrast MRI can help develop guidelines for surgical management of NPH. The shunt responders appear to be the patients with hyperdynamic ventricular CSF flow and normal cervical CSF flow.

Prevalence and profile of cognitive impairment in adult glioma: a sensitivity analysis

Cognitive impairment has been reported in 27–83 % of adults with World Health Organization (WHO) grade I–III glioma. However, the few studies in this field used different methods for cognitive assessment. The objective of the present study was to establish the prevalence of cognitive impairment in patients with WHO grade I–III primary brain tumors and determine the effect sizes of a comprehensive battery of tests. This study used a comprehensive neuropsychological battery to examine 27 patients. To control for false positives, prevalence was estimated from the overall neuropsychological score. Size effects were determined using Cohen’s d. Cognitive impairment was observed in 51.9 % (95 % CI 33−70.7 %) of the patients; the impairment affected action speed (38.5 %), cognitive (33 %) and behavioral (21.7 %) executive functions, oral expression (29.6 %), episodic memory (29.6 %) and visuoconstructive abilities (19.2 %). The largest effect sizes (d ≥ 1.645) were observed for the Digit Symbol Substitution test, global hypoactivity, free recall, Stroop time, the Boston Naming test (BNT), the Trail Making test B (TMTB), verbal fluency and the Rey–Osterrieth Complex Figure Test. Four of these scores (global hypoactivity, the Digit Symbol Substitution test, the TMTB perseveration, and the BNT) were combined to make a shortened battery (AUC 0.872; 95 % CI 0.795–0.949). The overall neuropsychological score was the sole factor associated with the functional outcome. Our results suggest that about half of survivors with a grade I–III primary brain tumor suffer from cognitive impairment. Tests with a large effect size should be included in future large-scale studies.