Adult brainstem glioma presenting with isolated persistent hemifacial spasm or facial nerve palsy.

OBJECT: Adult brainstem gliomas are a rare group of heterogeneous brain tumors. Classical clinical presentation includes progressive impairment of cranial nerves associated with long tract signs. The prognosis and response to treatment are poor; nevertheless, some patients do have a long survival. The objective of this study was to describe a series of patients with an isolated persistent hemifacial spasm and/or facial nerve palsy as the presenting symptom of a brainstem glioma. METHODS: Fourteen patients from 3 French hospitals (Paris, Caen, Lille) were included. Clinical and radiological features and overall survival were retrospectively analyzed. A review of the literature of similar cases was performed. RESULTS: Mean age at diagnosis was 35 years (range 19-57 years). Mean duration of facial nerve involvement before diagnosis was 17 months (range 1-48 months). Tumors were characterized on MRI by a lateralized location in the pons, a T1-weighted hyposignal, a T2-weighted hypersignal and no contrast enhancement after Gadolinium injection except for 2 cases. Biopsies were performed in 10 cases and showed 8 low-grade and 2 high-grade gliomas. All the patients were initially treated with radiotherapy and 6 patients with chemotherapy after progression. Eleven patients died from tumor progression. Median survival time was 90 months. CONCLUSIONS: Adult brainstem gliomas revealed by a progressive isolated involvement of the facial nerve seem to have particular clinico-radiological features of slow progressive tumors and may be associated with long patient survival.

Multimodal management of ruptured cerebral micro-arteriovenous malformations: A retrospective series of 19 cases and a review of the literature.

BACKGROUND: Micro-arteriovenous malformations (micro-AVMs) are defined as AVMs just visible on angiography with a nidus size between 0.5 and 1cm. Their principal manifestation is intracranial hemorrhage and their diagnosis and therapeutic management are still unclear. METHODS: The aim of our work was to show the clinical presentation, treatment and outcome of ruptured cerebral micro-AVMs in a retrospective cohort study of 19 patients and a systematic review of the literature. RESULTS: We obtained a total of 20 micro-AVMs in 19 patients. The mean age was 47.3 years. Clinical presentation was acute bleeding. The mean volume of hematoma was 12.9 mm3 (0 - 60.4), with topographic distribution as follows: 64% cortical with supratentorial bleeding, 26% deep, and 10% in the posterior fossa. Among the 20 micro-AVMs of the series, 11 (55%) had endovascular management, 6 (30%) had surgical treatment and 3 (15%) had GK radiosurgery alone. All of our patients have been cured at the end of the follow up without re-permeabilization. In our series, clinical outcome showed good recovery with a mean score of 4.6 on Glasgow Outcome Scale (GOS). In the literature, 88% of patients had a GOS of 4 or 5. DISCUSSION: Intracerebral hematoma (ICH) was the main clinical manifestation. In the case of negative initial angiographic assessment, patients must have supraselective angiographic exploration. In the case of conservative treatment of hematoma, endovascular obliteration and microsurgical exclusion seems to be reasonable therapeutic options, according to our observations.

[Neurosurgical treatment of chronic pain]. / Traitement neurochirurgical de la douleur chronique.

Neurosurgical treatment of pain used two kind of techniques: 1) Lesional techniques interrupt the transmission of nociceptive neural input by lesionning the nociceptive pathways (drezotomy, cordotomy, tractotomy…). They are indicated to treat morphine-resistant cancer pain and few cases of selected neuropathic pain. 2) Neuromodulation techniques try to decrease pain by reinforcing inhibitory and/or to limit activatory mechanisms. Chronic electrical stimulation of the nervous system (peripheral nerve stimulation, spinal cord stimulation, motor cortex stimulation…) is used to treat chronic neuropathic pain. Intrathecal infusion of analgesics (morphine, ziconotide…), using implantable pumps, allows to increase their efficacy and to reduce their side effects. These techniques can improve, sometimes dramatically, selected patients with severe and chronic pain, refractory to all other treatments. The quality of the analgesic outcome depends on the relevance of the indications.

From "mechanical" to "neuropathic" back pain concept in FBSS patients. A systematic review based on factors leading to the chronification of pain (part C).

INTRODUCTION: Beyond initial lesions, any form of spinal (re)operation can cause direct potential aggression to the nervous system by contact with neural tissue or by imprinting a morphological change on the neural tissue. The potential consequences of nerve root injury affect both peripheral and axial dermatomal distribution. The hypothesis of a possible neuropathic aspect associated with the back pain component of failed back surgery syndrome (FBSS) therefore appears to be reasonable. Its pathophysiology remains unclear due to the permanent interplay between nociceptive and neuropathic pain components, resulting in the coexistence of physiological and pathological pain at the same anatomical site. This paper is designed to extensively review the fundamental mechanisms leading to chronification of pain and to suggest considering the emerging concept of "neuropathic back pain". METHODS: Literature searches included an exhaustive review of 643 references and 74 book chapters updated by searching the major electronic databases from 1930 to August 2013. RESULTS: Inflammatory and neuropathic back pain could be distinguished from pure nociceptive pain as a result of an increased activity and responsiveness of sensitized receptors at the peripheral nervous system and also as a consequence of increased afferent inflow to the central nervous system, moving to a new, more excitable "wind-up" state. This can be clinically translated to an amplified response to a moderate/intense stimulus (primary hyperalgesia) or an aversive sensation provoked by the activation of low-threshold mechanoreceptors through non-noxious stimuli, which defines allodynia. Activated non-neuronal cells including microglia have been found to be cellular intermediaries in mechanical allodynia. Major changes in the spinal cord are the loss of inhibitory mechanisms, resulting in an increased activity of interneurons or projection neurons and a structural reorganization of the central projection pattern. This abnormal excitability of sensory neurons is coupled to changes in the neurotransmitter phenotype, which could induce a resistance to conventional analgesic treatments. CONCLUSION: A clear understanding of the factors leading to the chronification of back pain should help us to move to the choice of mechanism related pain treatments to improve outcomes in FBSS chronic condition.

Anatomy, physiology and neurobiology of the nociception: a focus on low back pain (part A).

INTRODUCTION: The treatment of Failed Back Surgery Syndrome (FBSS) remains a challenge for pain medicine due to the complexity in the interactions between [1] a residual mechanical pain after surgery and, [2] a progressive transition into chronic pain involving central nervous system plasticity and molecular reorganization. The aim of this paper is to provide a fundamental overview of the pain pathway supporting the nociceptive component of the back pain. METHODS: Literature searches included an exhaustive review of 643 references and 74 book chapters updated by searching the major electronic databases from 1930 to August 2013. RESULTS: Pain input is gathered by the peripheral fibre from the innervated tissue's environment and relayed by two contiguous central axons to the brain, via the spinal cord. At this level, it is possible to characterize physical pain and emotional pain. These are supported by two different pathways, encoding two dimensions of pain perception: In Neo-spino-thalamic pathway, the wide dynamic range neuron system is able to provide the information needed for mapping the "sensory-discriminative" dimension of pain. The second projection system (Paleo-spino-thalamic pathway) also involves the ventromedial thalamus but projects to the amygdala, the insula and the anterior cingulate cortex. These areas are associated with emotionality and affect. CONCLUSION: The mechanical component of FBSS cannot be understood unless the functioning of the pain system is known. But ultimately, the highly variable nature of back pain expression among individuals would require a careful pathophysiological dissection of the potential generators of back pain to guide pain management strategies.

Endoscopic versus stereotactic procedure for pineal tumour biopsies: Comparative review of the literature and learning from a 25-year experience.

BACKGROUND AND PURPOSE: Pineal tumours account for 1% to 4% of brain tumours in adults and for around 10% in children. Except in a few cases where germ cell markers are elevated, accurate histological samples are mandatory to initiate the treatment. Open surgery still has a high morbidity and is often needless. Biopsies can either be obtained by endoscopic or stereotactic procedures. METHODS: Following an extensive review of the literature (PubMed 1970-2013; keywords pineal tumour, biopsy; English and French), 33 studies were analysed and relevant data compared regarding the type of procedure, diagnosis rate, cerebrospinal fluid diversion type and rate, perioperative mortality, morbidity. RESULTS: Endoscopic and stereotactic biopsies showed a diagnosis rate of 81.1% (20%-100%) and 93.7% (82%-100%), respectively. Endoscopic biopsies involved 21.0% of minor and 2.0% of major complications whereas stereotactic biopsies involved 6.4% of minor and 1.6% of major complications. The most frequently reported complication was haemorrhage for both endoscopic and stereotactic procedures, accounting for 4.8% and 4.3%, respectively. Mortality rate was low for both endoscopic and stereotactic procedures, equal to 0.4% and 1.3%, respectively. Local experience of stereotactic biopsies was also reported and corroborated the previous data. CONCLUSIONS: The difference between both procedures is not statistically significant (p>0.05) across large series (≥20patients). Nevertheless, tissue diagnosis appears less accurate with endoscopic procedures than with stereotactic procedures (81.1% versus 93.7%, weighted mean across all series). In our opinion, the neuroendoscopic approach is the best tool for managing hydrocephalus, whereas stereotactic biopsies remain the best way to obtain a tissue diagnosis with accuracy and low morbidity.

Multicolumn spinal cord stimulation for significant low back pain in failed back surgery syndrome: design of a national, multicentre, randomized, controlled health economics trial (ESTIMET Study).

BACKGROUND: Many studies have demonstrated the efficacy of spinal cord stimulation (SCS) for chronic neuropathic radicular pain over recent decades, but despite global favourable outcomes in failed back surgery syndrome (FBSS) with leg pain, the back pain component remains poorly controlled by neurostimulation. Technological and scientific progress has led to the development of new SCS leads, comprising a multicolumn design and a greater number of contacts. The efficacy of multicolumn SCS lead configurations for the treatment of the back pain component of FBSS has recently been suggested by pilot studies. However, a randomized controlled trial must be conducted to confirm the efficacy of new generation multicolumn SCS. Évaluation médico-économique de la STImulation MEdullaire mulTi-colonnes (ESTIMET) is a multicentre, randomized study designed to compare the clinical efficacy and health economics aspects of mono- vs. multicolumn SCS lead programming in FBSS patients with radicular pain and significant back pain. MATERIALS AND METHODS: FBSS patients with a radicular pain VAS score≥50mm, associated with a significant back pain component were recruited in 14 centres in France and implanted with multicolumn SCS. Before the lead implantation procedure, they were 1:1 randomized to monocolumn SCS (group 1) or multicolumn SCS (group 2). Programming was performed using only one column for group 1 and full use of the 3 columns for group 2. Outcome assessment was performed at baseline (pre-implantation), and 1, 3, 6 and 12months post-implantation. The primary outcome measure was a reduction of the severity of low back pain (bVAS reduction≥50%) at the 6-month visit. Additional outcome measures were changes in global pain, leg pain, paraesthesia coverage mapping, functional capacities, quality of life, neuropsychological aspects, patient satisfaction and healthcare resource consumption. TRIAL STATUS: Trial recruitment started in May 2012. As of September 2013, all 14 study centres have been initiated and 112/115 patients have been enrolled. Preliminary results are expected to be published in 2015. TRIAL REGISTRATION: Clinical trial registration information-URL: www.clinicaltrials.gov. Unique identifier NCT01628237.

Pathophysiological characterisation of back pain generators in failed back surgery syndrome (part B).

INTRODUCTION: Low back surgery, including as many type of spine procedures as the multitude of failed back surgery syndrome (FBSS) etiologies, is not always the answer for patients with chronic low back pain. Paradoxically, although a patient is considered to present FBSS because he has already undergone spinal surgery, any new symptom in the back or deterioration of back pain must not be immediately attributed to FBSS, but could be related to another cause independently of the initial mechanical problem. The aim of this paper is to extensively review the potential back pain generators in FBSS patients and to discuss their respective roles and interactions in back pain pathophysiology. METHODS: Literature searches included an exhaustive review of 643 references and 74 book chapters updated by searching the major electronic databases from 1930 to August 2013. RESULTS: Nociceptive fibres innervating any of the back anatomical structures can all play a part in the pathogenesis of the low back pain component in FBSS. The main spinal pain generators are not only myofascial syndrome or muscle spasm but also the facets, the disc complex or a sagittal imbalance and should therefore be carefully reviewed. Only after these steps and appropriate imaging, would it be justified to irremediably diagnose the patient with a refractory chronic condition, requiring no further spine surgery and to propose "palliative" pain treatment options. CONCLUSION: Clinical investigations of the low back pain component in FBSS patients should be based on meticulous dissection of all potential triggers that could be a source of the nociceptive pain characteristics and possibly amenable to further aetiological treatment. Clinicians should therefore refine pain management strategies to ensure that the chronic nature of the pain becomes the guiding principle for multidisciplinary assessment.

Role of radiosurgery in the management of pineal region tumours: indications, method, outcome.

Numerous tumour types can occur in the pineal region. Because these tumours are uncommon and heterogeneous, it is often difficult to establish optimal treatment strategies based on comparative clinical trials. To date, the role of radiosurgery for the treatment of pineal region tumours remains controversial. This report of a 10-year single-department experience and review of the literature focuses on the spectrum of pathologic features found in these pineal parenchymal tumours and on the interest of radiosurgery in their management. Considering pineocytomas, although these tumours have been considered to be radioresistant to fractionated radiotherapy, our results are in agreement with similar results reported in the literature in suggesting that radiosurgery may be an alternative to surgical resection or an adjuvant therapy when the resection is not optimal. When dissemination occurs after radiosurgery, however, craniospinal radiation and chemotherapy are necessary. Radiosurgery has also proven its interest in the treatment of germinomas as an alternative to encephalic radiotherapy with limited long-term damage. Regarding the other pathologies, radiosurgery can be considered as part of a multimodal treatment including surgery, chemo-radiotherapy and its role still has to be clearly defined.

[Auditory evaluation in the management of acoustic neurinoma]. / Mesure de l'audition dans la prise en charge du neurinome de l'acoustique.

OBJECTIVE: The hearing level is a major point to take into account for managing a patient with an acoustic neuroma. The Gardner-Robertson classification is the most frequently reported as well as the AAO-HNS classification. It combines the use of pure tone audiometry and speech audiometry. The goal of this study is to determine the effect of the level of presentation for the speech material and the effect of the type of list selected for the determination of the speech discrimination score. METHODS: The speech determination score has been determined for 94 patients with different type of lists of 20 items: sentences, bi and monosyllabic words at two levels of presentation: at speech recognition threshold level plus 35dB and at the most comfortable level. The impact of the choice of the frequencies selected to determine the pure tone average, especially 3000Hz or 4000Hz has been also evaluated. RESULTS: There is a statistical difference when the frequency 4000Hz is selected rather than 3000Hz in the determination of the pure tone average. The speech discrimation score obtained with the use of monosyllabic word lists is statistically different than those obtained with bisyllabic words. CONCLUSION: To classify a patient's hearing whatever the classification, the speech discrimination score should be determined using monosyllabic word lists. Any other type of lists (sentences, spondees) leads to a significantly different score.

[Radiosurgery for brain arteriovenous malformations]. / Radiochirurgie stéréotaxique des malformations artérioveineuses cérébrales.

Radiosurgery as treatment for arteriovenous malformations has shown a good efficacy in reducing intracranial bleeding due to rupture. The choice of therapeutic modalities is based on evolutive risk and arteriovenous malformations volume, patient profile and risks stratification following therapeutic techniques (microsurgery, radiosurgery, embolization). Nidus size, arteriovenous malformations anatomical localization, prior embolization or bleeding, distributed dose are predictive factors for radiosurgery's good results and tolerance. This review article will highlight arteriovenous malformations radiosurgery indications and discuss recent irradiation alternatives for large arteriovenous malformation volumes.

[Medical devices needed for stereotactic radiosurgery and intracranial stereotactic radiotherapy]. / Équipements requis pour la mise en œuvre de la radiochirurgie et de la radiothérapie en conditions stéréotaxiques intracrânienne.

Since the previous special issue of Cancer Radiothérapie dedicated to radiosurgery in 1998, many important technological and computer developments have improved external beam radiotherapy treatment device performances. Whereas the Gamma Knife(®) was the gold standard for intracranial radiosurgery, new linear accelerator developments have led to new possibilities for the clinicians. This article describes quickly the different devices available for cranial radiosurgery or fractionated stereotactic radiotherapy.

[Stereotactic and diagnostic imaging in radiosurgery]. / Imagerie stéréotaxique et diagnostique en radiochirurgie.

Constant progress in medical imaging and particularly magnetic resonance imaging has profound impact in planning for stereotactic radiosurgery and radiotherapy. The purpose of this paper is to discuss the integration of medical imaging modalities in the planning process. Principles of generic algorithms to calculate stereotactic coordinates are treated for tomographic imaging and digital substraction angiography, and their accuracies are analyzed in a review of the literature. The algorithmic foundations and performance of automatic intermodality co-registration methods are developed. Finally, the MRI sequences useful in planning and follow-up are discussed and the role of MR angiographic sequences compared to conventional X-ray angiography in the particular case of the arteriovenous malformation planning.

[Place of stereotactic techniques in the modern management of lateral ventricle tumors. Stereotactic biopsies and radiosurgery]. / Place de la stéréotaxie dans la prise en charge des tumeurs du ventricule latéral. Biopsies stéréotaxiques et radiochirurgie.

The authors make an overview about the use of stereotactic techniques in the management of lateral ventricle tumors. If stereotactic techniques are not in the foreground for the management of lateral ventricle tumors, stereotactic biopsies can be very useful in case of atypical, clinical or radiological presentation of the tumors and radiosurgery can help in case of evolution or re-evolution of tumors after resection. In these cases, stereotactic procedures are very safe. Modern technical evolutions allow the optimization of the stereotactic procedure but also to mix robotic with endoscopic techniques in order to offer new surgical perspectives.

Stereotactic robot-guided biopsies of brain stem lesions: Experience with 15 cases.

BACKGROUND AND PURPOSE: Biopsies of brain stem lesions are useful for histopathological analysis, which guide appropriate treatment. The frame-based stereotactic procedure is the gold standard technique for biopsies of the brain stem. For the past few years, a frameless stereotactic robot, the NeuroMate robot (Renishaw, UK) has also been used for brain biopsies. We report a retrospective study of 15 patients who underwent NeuroMate robot-guided biopsies of brain stem lesions to evaluate the efficiency and safety of the system. METHODS: From January 2004 to March 2006, 15 patients (five children and ten adults) underwent 17 biopsies of brain stem lesions. The lesions were located in the mesencephalon in two cases, in the pons in seven cases, in the pons and the medulla oblongata in five cases, and in the whole midbrain in one case. The biopsy procedure comprised four stages: image acquisition, preoperative planning, patient-to-image registration, and operative procedure. A transcerebellar approach was used in 12 cases and a double oblique anterior frontal approach in five cases. RESULTS: Two adults underwent a second procedure because the first biopsy was not contributive. There was no operative mortality. We observed two cases of transient morbidity and one case of permanent morbidity. CONCLUSIONS: The frameless NeuroMate robot is an efficient and safe instrument for biopsies of brain stem lesions. We believe that the use of frameless stereotactic techniques for brain stem biopsies could increase the number of biopsies and therefore improve the diagnostic yield and accuracy of the technique.

Reduced levodopa-induced complications after 5 years of subthalamic stimulation in Parkinson's disease: a second honeymoon.

The purpose of this paper is to describe the effect of 5 years of subthalamic nucleus deep brain stimulation (STN DBS) on levodopa-induced complications, both in everyday life and during an acute challenge with levodopa. Thirty three patients were evaluated during an acute levodopa challenge before surgery and then 1 and 5 years afterwards (both off stim and on stim), using the UPDRS III scale and the CAPSIT-PD scales for dystonia and peak-dose dyskinesia. The UPDRS IV scale was used to assess motor complications in everyday life. The levodopa daily dose and DBS parameters were also recorded. Levodopa-induced complications in everyday life (UPDRS IV) and during an acute levodopa challenge had improved markedly after 1 year (both on and off stim) and still further at 5 years. Peak-dose dyskinesia decreased between the 1- and 5-year measurements. STN DBS decreases levodopa-induced motor complications over the long term. This phenomenon may be explained by (a) overall stabilization of the basal ganglia network and (b) striatal synaptic changes. Our results suggest that DBS leads to both qualitative and quantitative modulations in the corticostriatal loops.

[Isolated intracranial relapse in previously treated Hodgkin's disease]. / Rechute intracérébrale isolée dans la maladie de Hodgkin.

UNLABELLED: Isolated brain relapse is uncommon in Hodgkin's lymphoma and often linked with advanced or refractory disease. CASE REPORTS: We report two patients with stage IV Hodgkin's disease, previously treated with chemotherapy, who later developed neurological symptoms. Brain MRI demonstrated two different types of lesions. Histological findings were consistent with intracranial location of Hodgkin lymphoma. Both of the patients presented only with isolated CNS relapse of the lymphoma. CONCLUSION: The two cases demonstrated the MRI appearance of intracranial involvement can be varied and mimic other disease processes in patients with a previous history of Hodgkin's lymphoma. Thus, a biopsy is necessary for diagnosis and correct treatment.

[Neurostimulation procedures in refractory pain]. / Techniques de neurostimulation et douleurs réfractaires.

In the context of chronic pain, the technics of neuromodulation have a significative place especially when they are neuropathic with a precise selection of the indications according to the neurophysiological, anatomical and clinical data. The choice is essentially based upon the severity and the site of pain. They are totally conservative, adaptable and reversible but it is necessary to organize a very rigorous clinical and technical follow-up according to a multidisciplinary approach.

TSH-secreting adenoma improved with cabergoline.

TSH-secreting adenomas are rare tumors, representing only 0.5 to 2.5% of pituitary adenomas. Their main clinical characteristics include signs of thyrotoxicosis, diffuse goiter and a compressive syndrome. Biologically, free T4 and T3 serum levels are elevated, contrasting with inadequate serum TSH levels and increased alpha chains. Magnetic resonance (MR) imaging shows a pituitary tumor, the main differential diagnosis being resistance to thyroid hormones. Treatment is based on surgery, possibly associated with somatostatin analogs and radiotherapy. Though the long-term evolution of this rare pathology seems to have improved, some clinical situations are still a challenge to treat. We report one such case that was resistant to both stereotactic radiotherapy and somatostatin analogs, but surprisingly improved with cabergoline. We suggest that cabergoline should be considered as an alternative treatment in cases of pituitary adenomas that resist traditional treatments.

Anatomical bases of tibial neurotomy for treatment of spastic foot.

Spastic pes equines, possibly associated with varus posture or spastic claw of the toes, can require neurosurgical treatment. In these cases, a selective fascicular neurotomy can be proposed, which consists of a partial section of some motor collateral branches of the tibial nerve. In order to avoid sensory and trophic complications after surgery due to an excessive manipulation of the nerve, accurate anatomical data must be collected. Therefore, biometric, histological and ultrastructural studies were carried out. A total of 50 dorsal compartments of the leg were dissected. The distance between the emergence of each muscular branch of the tibial nerve and anatomical landmarks were measured. Complementary histological study was processed on three specimens with slices stained by Masson's trichromatic method. Eventually, electronic microscopy observation was processed on two other specimens. In 16 cases (32%), we found a common muscular branch for all the muscles of the dorsal leg compartment, which emerged from the nerve trunk near the tendinous arch of the soleus (67 +/- 29 mm from the femorotibial articular line). In the other cases, muscular branches of the nerve emerged from its ventral lateral aspect, with variable origins (inferior nerve for the soleus: 82 +/- 31 mm from the femorotibial articular line, nerve for flexor digitorum longus: 116 +/- 41 mm, nerve for tibialis posterior: 106 +/- 51 mm, with a second nerve in 9/50 cases, nerve for flexor hallucis longus: 129 +/- 48 mm, with a second nerve in 6 cases). Histological and ultrastructural analysis confirmed the presence of the motor nervous fibers in the ventral lateral part of the nerve trunk. These new anatomical findings allow a more precise dissection during operative procedure, in order to avoid sensory or trophic complications.