Comparison of two segmentation software tools for deep brain stimulation of the subthalamic and ventro-intermedius nuclei.

PURPOSE: Deep brain stimulation (DBS) relies on precise targeting of key structures such as the subthalamic nucleus (STN) for Parkinson's disease (PD) and the ventro-intermedius nucleus of the thalamus (Vim) for essential tremor (ET). Segmentation software, such as GuideXT© and Suretune©, are commercially available for atlas-based identification of deep brain structures. However, no study has compared the concordance of the segmentation results between the two software. METHODS: We retrospectively compared the concordance of segmentation of GuideXT© and Suretune© software by comparing the position of the segmented key structures with clinically predicted targets obtained using the newly developed RebrAIn© software as a reference. RESULTS: We targeted the STN in 44 MRI from PD patients (88 hemispheres) and the Vim in 31 MRI from ET patients (62 hemispheres) who were elected for DBS. In 22 STN targeting (25%), the target positioning was not correlating between GuideXT© and Suretune©. Regarding the Vim, targets were located in the segmented Vim in 37%, the posterior subthalamic area (PSA) in 60%, and the STN in 3% of the cases using GuideXT©; the proportions were 34%, 60%, and 6%, respectively, using Suretune©. The mean distance from the centre of the RebrAIn© targeting to the segmented Vim by Suretune© was closer (0.64 mm) than with GuideXT© (0.96 mm; p = 0.0004). CONCLUSION: While there is some level of concordance in the segmentation results of key structures for DBS treatment among software models, differences persist. Therefore, such software should still be considered as tools and should not replace clinician experience in DBS planning.

A long-term follow-up of weight changes in subthalamic nucleus stimulated Parkinson's disease patients.

Deep brain stimulation of the subthalamic nucleus (STN-DBS) constitutes the mainstay treatment in advanced Parkinson's disease (PD) with motor fluctuations. Despite its efficacy on motor signs and quality of life, emergent adverse events have been recently reported. Among them, weight gain (WG) is a recognized adverse event of subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD). Also, WG is poorly known at the long-term and predisposing factors have not yet been identified. We conducted a cross-sectional study of WG in 47 STN-DBS PD patients between 1999-2006. Data on disease history, motor status and dopaminergic drug treatment were retrospectively collected at surgery and 1 year post-surgery. Weight at disease diagnosis and at surgery, as well as the current weight and height were gathered by an autoquestionnaire. Moreover, the weight before surgery was obtained and verified in medical files in more than 90% of our patients. Sixty-six patients who underwent surgery between 1999-2006 were included, but six were deceased, four refused to participate and nine were lost for follow-up. So, 47 (71%) were retained in our analysis. A total of 78.7% of patients gained weight. On average 4.7 years follow up after surgery, the mean weight gain was +7.2±8.1kg compared to the preoperative assessment (p<0.001) and the mean BMI gain was +2.7±3.0kg/m(2) compared to pre-surgery values (p<0.001). The patients gained more weight after surgery than they had lost during disease evolution before surgery. Women and patients with a more severe UPDRS-III "off" drug score before surgery significantly gained more weight. Our study provides further evidence that the WG is a problem after STN-DBS and concerns a majority of patients at the long term. It may expose them to complications that should be considered for prevention and the patient's information before surgery.

[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.

Sensory motor mismatch within the supplementary motor area in the dystonic monkey.

Dystonia, a movement disorder characterized by abnormal postures, is associated in primary forms of the disease with subtle proprioceptive troubles and aberrant somatotopic representation in the somatosensory cortex (SC). However, it is unclear whether these sensory features are a causal phenomenon or a consequence of dystonia. The supplementary motor area proper (SMAp), a premotor cortical region, receives strong inputs from both the SC and basal ganglia. We hypothesized that disruption in sensory-motor integration within the SMAp may play a part in the pathophysiology of dystonia. Using a model of secondary dystonia obtained by 3-nitropropionic acid intoxication in rhesus monkeys, we first provide evidence that the SMAp was overexcitable in dystonic animals. Second, we show that proprioceptive inputs processed by SMAp neurons were dramatically increased with wider sensory receptive fields and a mismatch between sensory inputs and motor outputs. These findings suggest that abnormal sensory inputs impinging upon SMAp neurons play a critical role in the pathophysiology of dystonia.

[Intrathecal baclofen in hereditary spastic paraparesis: benefits and limitations]. / Intérêts et limites du baclofène intrathécal dans les paraparésies spastiques héréditaires.

BACKGROUND: Chronic intrathecal delivery of baclofen has been introduced for treatment of severe spinal spasticity. Very little is known about this treatment in hereditary spastic paraparesis. Here we review the benefits and limitations of pump implantation for baclofen delivery in this population. METHODS: Consecutive patients presenting with hereditary spastic paraparesis were assessed for spasticity (Ashworth and Penn scores), muscular strength and walking (speed, comfort and perimeter length). The effect of intrathecal delivery of baclofen was judged after progressive bolus injections or chronic administration by electrical syringe. The pump implantation was proposed when spasticity scores decreased by 2 or more points, with muscular strength preserved and walking area increased. RESULTS: We investigated 6 patients (3 males; mean age 48 years) with hereditary spastic paraparesis. The mean follow-up was 19 years; for 4 patients who received pump implantation, the mean follow-up was 6.2 years. The mean baclofen daily dose was 75 mug. Satisfaction was high for patients who received implantation early instead of waiting for the natural course of the disease. DISCUSSION: Some patients with hereditary spastic paraparesis have good functional improvement with chronic intrathecal delivery of baclofen if walking is still possible. Despite the natural history of the disease, functional results are stable during the first 5 years of treatment. The data indicate a possible compromise between decreased spasticity and muscular strengthening with the treatment.

Side-effects of subthalamic stimulation in Parkinson's disease: clinical evolution and predictive factors.

Chronic bilateral high-frequency stimulation of the subthalamic nucleus (STN) is an alternative treatment for disabling forms of Parkinson's disease when on-off fluctuations and levodopa-induced dyskinesias compromise patients' quality of life. The aim of this study was to assess the evolution of side-effects during the first year of follow-up and search for clinical predictive factors accounting for their occurrence. We compared the frequency of side-effects at 3 and 12 months after surgery in a cohort of 44 patients. The off-medication scores of Unified Parkinson's Disease Rating Scale (UPDRS) II, III, axial symptoms, disease duration and age at surgery were retained for correlation analysis. Dysarthria/hypophonia, weight gain and postural instability were the most frequent chronic side-effects. Whereas dysarthria/hypophonia remained stable over time, weight gain and postural instability increased during the first year post-op. High axial and UPDRS II scores at surgery were predictive of dysarthria/hypophonia. Age and axial score at surgery were positively correlated with postural instability. Despite the occurrence of side-effects, the benefit/side-effects ratio of STN stimulation was largely positive during the first year of follow-up. Age, intensity of axial symptoms and UDPRS II off-medication score before surgery are predictive factors of dysarthria/hypophonia and postural instability after surgery.

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.

Minimal tissue damage after stimulation of the motor thalamus in a case of chorea-acanthocytosis.

Autopsy findings are reported from a patient with chorea-acanthocytosis treated for 2 years by deep brain stimulation (DBS) of the motor thalamus. Postoperative testing showed a progressive improvement in axial truncal spasms. Although relatively high currents were used for 2 years in this patient, postmortem analysis showed minimal tissue damage in the vicinity of the electrode tip. It is concluded that DBS has little impact on the surrounding tissues.

Syntheses of branched-chain sugars with push-pull functionality.

The reaction of methyl 4,6-O-benzylidene-3(2)-deoxy-alpha-D-erythro- hexopyranosid-2(3)-ulose with carbon disulfide, alkyl iodide, and sodium hydride gave methyl 4,6-O-benzylidene-3(2)-[bis(alkylthio)methylene]-3(2)-deoxy-alpha-D- erythro-hexopyranosid-2(3)-uloses. Methyl 4,6-O-benzylidene-2-[bis(methylthio)-methylene]-2-deoxy-alpha-D- erythro-hexopyranosid-3-ulose (5) reacted with aromatic amines to give, in a rearrangement process, N-aryl-2-aryliminomethyl-4,6-O-benzylidene-2-deoxy- alpha-D-erythro-hex-1-enopy-ranosylamin-3-uloses. The reaction of 5 with hydrazine hydrate afforded 5-methylthio-(methyl 4,6-O-benzylidene-2,3-dideoxy-alpha-D-erythro-hexopyranosido)[3,2- c]pyrazole.

Solid-state conformations of 2,6-cis- and 2,6-trans-substituted dihydropyran-3-ones.

2,6-Dihydropyran-3-ones carrying substituents at C-2 and C-6 in cis-arrangement invariably adopt half-chair conformations in which the ring oxygen and the carbon atom next to the carbonyl group are above and below, respectively, the plane formed by the other four carbon atoms, i.e., the 2Ho or oH2 conformation. In the case of a trans-arrangement of 2,6-substituents, the geometry of the pyranoid ring falls into the Bo,6<-->Eo<-->2Ho or thet inverse o,6B<-->oE<-->oH2 section of the conformational cycle, depending on the absolute configuration of the compound; for two of the dihydropyranones, 4B and 6, a unique skew-boat (SBo,6) conformation, fixed between the Bo,6 and Eo geometries, was ascertained, which previously has only been observed for pyranoid enelactones.

Amyloid angiopathy-related cerebellar hemorrhage.

BACKGROUND: The posterior fossa localization of amyloid angiopathy-related hemorrhage is very unusual. Less than 10 cases have been previously reported. Surgical management of amyloid angiopathy-related hemorrhage is the subject of controversy. RESULTS: Typical aspects of amyloid angiopathy were found within the surgically removed biopsies of 71-year-old nonhypertensive, nondemented woman suffering cerebellar hemorrhage. CONCLUSIONS: Amyloid angiopathy-related hemorrhage could occur in the cerebellum, and diagnosis might be suspected when no past history of mental deterioration and/or arterial hypertension are present and when angiography rules out vascular malformation. Surgical management seems to have the same restricted indications as in other brain areas.

Dental safety needles' effectiveness: results of a one-year evaluation.

BACKGROUND: Some government agencies and state legislatures recently have passed regulations mandating the use of safety-enhanced devices, including dental anesthetic safety needles. Little information exists, however, on the efficacy and utility of these types of needles currently on the market. METHODS: The authors evaluated four types of dental safety needles and syringes for clinical acceptability. Two of these devices were deemed unacceptable owing to inherent features identified during the bench test. The remaining two devices were clinically evaluated using an 11-statement survey. Senior dental students completed the survey at one, two, four, five, six and eight weeks from introduction of the devices to a dental school clinic. Junior dental students joined the senior students using one of the devices for the last six months of the evaluation and joined the senior students in completion of a final survey at 52 weeks. RESULTS: The survey results indicated increasing user dissatisfaction with nine of the safety device features evaluated over the 52 weeks. At eight weeks, use of one of the two devices was discontinued owing to poor clinical performance. A review of the blood exposure incident reports that routinely are collected following an exposure incident revealed a small increase in exposures involving anesthetic needles. The sample size was too small to determine statistical significance of the change in injury rate, but it did show that needlesticks continue to occur in spite of the use of safety devices. CONCLUSIONS: None of the safety devices tested successfully passed the clinical evaluation. Continued evaluation is necessary to ensure that effective safety devices are available to dental practitioners. CLINICAL IMPLICATIONS: Evaluators had significant concerns about the usability of dental safety needles and their ability to adapt to using them effectively. Results of a review and bench tests indicate that the devices tested are no safer than traditional anesthetic needles.

The hepatitis B e-antigen positive dental school applicant.

There are few guidelines available for dental school faculty and administrators in the management of hepatitis B e-antigen positive (HBeAg+) dental school applicants. It is apparent that this serostatus is unique and requires a different approach from that used for applicants with other infectious diseases, such as the human immunodeficiency virus (HIV). The issue is examined from a number of perspectives, including the science, policy, legal, and ethical considerations confronted in establishing a policy for the HBeAg+ dental school applicant.

[How can we define the modalities and clinical levels of coma to wakefulness?]. / Comment définir les modalités et les niveaux cliniques de passage du coma à l'éveil ?

OBJECTIVE: The starting point of the French conference of consensus concerning arousal after coma was to answer the following question: "How can we define the ways of going from coma to arousal and their clinical levels? MATERIALS AND METHOD: A team of readers have picked up in the literature one hundred and fifty papers, out of which fifty six have been analysed. RESULTS: From this analysis, three points emerged: The concepts of coma and arousal; The conditions of evolution from coma to arousal; Various groups of patients depending on their expressing arousal. One could not find any consensual model concerning the different ways of going from coma to arousal. The variability of the technics and the changing validity of all scores did not allow the conditions of arousal to reach a satisfactory level of proof. The Glasgow Coma Scale (GCS) is the recognised standard for severe wakefulness' impairment, but it is not sensitive enough while patients' arousing. The Glasgow Outcome Scale (GOS) takes into account the patients' situations far later and does not include situations such as Minimally Conscious States (MCS). That's why we face multiple scores, either ordinal, or categorial, all tending to evaluate the slow levels of arousal. CONCLUSION: Clinical findings concerning arousal are to be completed by non-clinical data. This would be greatly helpful to define appropriate management concerning individualized groups of patients. At this stage, another challenge for clinicians is to make the difference between emerging wakefulness and growing conscious activity.

[Botulinum toxin and traumatic brain injury]. / Toxine botulique et traumatisme crânien.

Botulinum toxin is a successful focal spasticity therapy. The aim of this article is to study the data of the literature concerning its utilisation in traumatic brain injured patients, whom motor and tonus disturbances are polymorphic, in their clinical presentation as well as in their evolution. Although there are few studies concerning its utilisation in such patients, none of them being controlled, its use seems interesting in focal spasticity treatment. It can contribute to improve functional abilities and comfort for these patients.

[Intrathecal baclofen and traumatic brain injury. A review]. / Le traitement par baclofène intrathécal chez le traumatise crânien grave. Revue de la littérature.

Severe head injury can induce hypertonia. There are two kinds of hypertonia related to severe injury. The most common one is a spasticity that occurs a long time after the head injury; the second is hypertonia that occurs during the early stage of the post-trauma recovery. Hypertonia is associated with other symptoms and defines post-trauma dysautonomia. Intrathecal baclofen can alleviate spasticity in severe head injury with improvement of the Ashworth score, spasm score or reflex score. But it also improves the number of paroxymal dysautonomic episodes. Real functional improvement is more difficult to show. To be effective, intrathecal baclofen therapy in brain injured patients needs high doses per day, through a spinal catheter in the mediothoracic region, and delivered at least continuously for a few hours to achieve a functional improvement.

[Physiopathology of chronic subdural hematoma]. / Physiopathologie de l'hématome sous-dural chronique.

Coagulation, fibrinolysis and kinin-kallicrein system disorders could explain chronic subdural hematoma pathophysiology. The marked decrease in antithrombin III in the hematoma suggest that the decreased levels of clotting factors were caused by excessive coagulation resulting in clotting factors consumption. The decrease in alpha 2-antiplasmin with the increase of fibrin degradation products suggest that hyperfibrinolytic activity of the subdural hematoma. Coagulation and fibrinolysis disorders could explain repetitive hemorrhages from the outer membrane, which cause progressive enlargement of the hematoma. Kinin-kallicrein system disorders raise the hemorrhage by its action on the outer membrane. Nowadays, the earliest osmotic theory should reasonably be abandoned.

[Primary central nervous system lymphomas. Diagnostic and prognostic effect of steroid-induced remission]. / Lymphomes primitifs du système nerveux central. Rôle diagnostique et pronostique des rémissions cortico-induites.

PURPOSE: Non-AIDS primary central nervous system lymphomas may respond totally or partially to corticosteroids. These corticoid-induced remissions seems to be very specific for this disease. They have been proposed as diagnostic test. The effect of these remissions on prognosis remains unknown. METHODS: A retrospective study was conducted. Corticosteroid sensibility, duration of survival, duration of disease free interval and type of treatment were compared between two groups of patients. The first one (group 1) included 44 patients in which exact diagnosis was made by stereotactic biopsy or surgery. The second group (group 2) included 5 patients exhibiting typical neuroradiological aspects of primary lymphoma in whom corticosteroid therapy produced a total regression of the lesions. RESULTS: In group 1, 29.1% of the lymphomas exhibited cortico-sensitivity. Duration of free interval of disease accounted for 75% of the overall duration of survival. Age was the only significant factor predicting remission (p = 0.019). The sole factor influencing total duration of remission was the type of treatment (p = 0.03). Duration of remission was significantly shorter in group 2 versus group 1 patients (p = 0.007). CONCLUSIONS: Duration of the first remission is of paramount importance on survival as well as the quality of first line therapy. In these conditions the absence of precise diagnosis due to corticoid-induced remissions could be dramatically deleterious.