Spinal epidural abscess from group A Streptococcus after varicella infection: a case report and review of the literature.

INTRODUCTION: Spinal epidural abscess (SEA) is a very rare condition in pediatric patients. Varicella zoster infection could be a predisposing factor, and SEA should be suspected in patients with signs of secondary bacterial infection and even mild neurological signs. CLINICAL CASE: We describe here a case of a 30-month-old girl with a history of remitting varicella infection, diagnosed for a lumbar epidural abscess and sacro-ileitis, secondary to group A Streptococcus (GAS). DISCUSSION: This is the third case of SEA from GAS reported in the literature in a pediatric population with varicella infection. We discuss here the clinical presentation and the diagnostic challenges for SEA in childhood through a review of the literature.

Upregulation of the GABA transporter GAT-1 in the gracile nucleus in the spared nerve injury model of neuropathic pain.

Neuropathic pain is a major health issue and is frequently accompanied by allodynia (painful sensations in response to normally non-painful stimulations), and unpleasant paresthesia/dysesthesia, pointing to alterations in sensory pathways normally dedicated to the processing of non-nociceptive information. Interestingly, mounting evidence indicate that central glial cells are key players in allodynia, partly due to changes in the astrocytic capacity to scavenge extracellular glutamate and gamma-aminobutyric acid (GABA), through changes in their respective transporters (EAAT and GAT). In the present study, we investigated the glial changes occurring in the dorsal column nuclei, the major target of normally innocuous sensory information, in the rat spared nerve injury (SNI) model of neuropathic pain. We report that together with a robust microglial and astrocytic reaction in the ipsilateral gracile nucleus, the GABA transporter GAT-1 is upregulated with no change in GAT-3 or glutamate transporters. Furthermore, [(3)H] GABA reuptake on crude synaptosome preparation shows that transporter activity is functionally increased ipsilaterally in SNI rats. This GAT-1 upregulation appears evenly distributed in the gracile nucleus and colocalizes with astrocytic activation. Neither glial activation nor GAT-1 modulation was detected in the cuneate nucleus. Together, the present results point to GABA transport in the gracile nucleus as a putative therapeutic target against abnormal sensory perceptions related to neuropathic pain.

Intérêt de l'échographie du diamètre de l'enveloppe du nerf optique pour la détection non invasive de l'hypertension intracrânienne [Interest of optic nerve sheath diameter ultrasonography in dectecting non-invasively raised intracranial pressure].

Intracranial hypertension is an emergency suspected from clinical symptoms, imaging data and ophthalomologic signs. Intracranial hypertension is confirmed by invasive intracranial monitoring, which is the gold standard technique to measure intracranial pressure (ICP). Because of complications, hemorrhage or infection, non-invasive methods have been developed such as neuroimaging, transcranial Doppler sonography and optic nerve sheath diameter (ONSD) ultrasonography. We have reviewed ONSD technique that detects intracranial hypertension related volume variations of subarachnoid space along the retro bulbar segment of the optic nerve. Technique, indications and prospects are discussed.

Ulnar nerve transposition at the elbow : local anesthesia should be preferred to general anesthesia

Après la compression du nerf médian au niveau du tunnel carpien, la compression du nerf ulnaire au niveau du coude est le deuxième syndrome compressif le plus fréquent des nerfs périphériques. La chirurgie des nerfs périphériques consiste dans une décompression nerveuse et est caractérisée par un suivi post¬opératoire parfois très douloureux avec des douleurs qui peuvent chroniciser si insuffisamment traitées. Le traitement chirurgical de décompression nerveuse se fait traditionnellement sous anesthésie générale ou régionale. Une analgésie post-opératoire plus efficace et durable avec moindre risque de chronicisation avait justifié ce choix jusqu'à ce jour. Grâce au développement de la chirurgie ambulatoire ces dernières années, un grand nombre d'interventions chirurgicales au niveau de la main sont effectués sous anesthésie locale. Au vu d'une meilleure connaissance de cette technique d'anesthésie, son rôle dans la chirurgie des nerfs périphériques a été remis en question. Alors que plusieurs études ont démontré que l'anesthésie locale est aussi efficace que l'anesthésie générale et régionale au sujet de la chirurgie du tunnel carpien, son utilisation pour la chirurgie du nerf ulnaire reste peu connue. La raison de l'hésitation à l'utilisation de l'anesthésie locale pour le traitement du tunnel ulnaire est due au fait que dans plus de la moitié des cas, une simple décompression n'est pas suffisante et qu'il est souvent nécessaire de transposer le nerf ulnaire devant l'épicondyle ulnaire. La seule publication disponible au sujet de l'utilisation de l'anesthésie locale dans le traitement du tunnel ulnaire considère comme irréalisable d'utiliser cette méthode dans le cas d'une transposition. Malgré cette mise en garde, nous avons, depuis plusieurs années, des excellents résultats avec la transposition du nerf ulnaire sous anesthésie locale. Avec le but d'objectiver notre expérience dans ce domaine nous avons souhaité analyser nos résultats de façon rétrospective avec particulière attention aux douleurs post-opératoires et à la satisfaction des patients. Les dossiers de cinquante patients Consécutifs (26F, 24M) opérés par le même chirurgien dans notre service de 2002 à 2012 ont été analysés rétrospectivement. Les critères suivants ont été récoltés: l'âge du patient, la profession, la main dominante, les détails des techniques opératoires utilisées, le type d'anesthésie, l'intensité du suivi ainsi que les complications, le niveau de douleur dans l'immédiat post-opératorie ainsi que à une année de l'intervention. Les patients ont été divisés en 4 groupes: les opérés sous anesthésie générale avec transposition du nerf (n=17) ou sans transposition (n=10) et les opérés sous anesthésie locale avec transposition (n=12) ou sans transposition (n=11). Au premier jour la douleur était comparable dans tous les groupes. A une semaine, elle était deux fois plus importante lorsque la transposition avait été réalisée sous anesthésie générale par rapport à si une anesthésie locale avait été effectuée (p=0.03). La satisfaction s'est révélée plus élevée mais non significative chez les patients opérés sous anesthésie locale. Ces derniers étaient significativement plus enclins à répéter la chirurgie comparé a ceux opérés sous anesthésie générale (p=0.04). En conclusion, les résultats de cette étude suggèrent que l'anesthésie locale est au moins autant efficace que l'anesthésie générale en termes de complications et de douleurs post-opératoires indépendamment du fait qu'une transposition nerveuse soit effectuée ou pas. Un meilleur contrôle des douleurs à une semaine post-opératoire a contribué à une haute satisfaction des patients de notre étude.

Percutaneous radiofrequency ablation of primary intraosseous spinal glomus tumor.

The glomus tumor is a rare, benign, but painful vascular neoplasm arising from the neuromyoarterial glomus. Primary intraosseous glomus tumor is even rarer, with only about 20 cases reported in the literature so far, 5 of which involved the spine. Surgical resection is currently considered the treatment of choice. We herewith present an uncommon case of primary intraosseous spinal glomus tumor involving the right pedicle of the eleventh thoracic vertebra (T11). To our knowledge, this is the first case of primary intraosseous spinal glomus tumor successfully treated by percutaneous CT-guided radiofrequency ablation (RFA).

Secular changes of spinal canal dimensions in Western Switzerland: a narrowing epidemic?

STUDY DESIGN: Computed tomography-based anatomical study. OBJECTIVE: To study the secular changes in lumbar spinal canal dimensions. SUMMARY OF BACKGROUND DATA: Development of symptomatic lumbar spinal stenosis, among other factors, is related to the dimensions of the bony canal. The canal reaches its adult size early on in life. Several factors, including protein intake, may influence its final dimensions. As with increases in human stature from improvements of socioeconomic conditions, we hypothesized that adult bony canal size has also grown larger in recent generations. METHODS: This study analyzes computed tomographic reconstructions from 184 subjects performed for either trauma (n = 81) or abdominal pathologies (n = 103) and born either between 1940 and 1949 (n = 88) or 1970 and 1979 (n = 96). The cross-sectional area of the bony canal was digitally measured at the level of the pedicle (i.e., at a level not influenced by degenerative changes) for each lumbar vertebra. Intra- and interobserver reliability was assessed. RESULTS: Intra- and interobserver measurement reliability were excellent (interclass correlation coefficient = 0.87) and good (interclass correlation coefficient = 0.61), respectively. Contrary to our hypothesis, the 1940-1949 generation patient group exhibited larger lumbar canals at all levels as compared with the 1970-1979 group. Statistically this difference was highly significant (P < 0.001) and particularly pronounced in the trauma subgroup. CONCLUSION: Given that human stature evolution has stabilized and adult height is established during the first 2 years of long bone growth, it is possible that antenatal factors are responsible for this surprising finding. Maternal smoking and age may be possible explanations. This finding may have significant implications. An increasing number of patients may emerge with lumbar spinal stenosis as degenerative changes develop, putting a strain on health resources. Further studies in different population groups and countries will be important to further confirm this trend. LEVEL OF EVIDENCE: 3.

Vagus nerve stimulator treatment in adult-onset Rasmussen's encephalitis.

We describe a patient with adult-onset Rasmussen's encephalitis (RE) responsive to vagus nerve stimulation. This previously healthy woman developed RE in the right hemisphere at the age of 27. Despite antiepileptic drug polytherapy, she continued to experience subcontinuous, simple-partial left-sided motor seizures and slowly progressive cognitive impairment. Resective surgery was not considered owing to the preservation of left motor skills. She was implanted with a vagus nerve stimulator at the age of 41; after 6 months she experienced a greater than 50% reduction in seizure frequency, which persisted over 2 years together with improvement of her neurological and cognitive status.

Nerve growth factor (NGF) stimulation of cholinergic telencephalic neurons in aggregating cell cultures.

The addition of nerve growth factor (2.5S NGF) to serum-free aggregating cell cultures of fetal rat telencephalon greatly stimulated the developmental increase in choline acetyltransferase activity. Two other neuronal enzymes, acetylcholinesterase and glutamic acid decarboxylase, showed only slightly increased activities after NGF treatment whereas the total protein content of the cultures and the activity of 2',3'- cyclic nucleotide phosphodiesterase remained unchanged. The stimulation of choline acetyltransferase was dependent on the NGF media concentrations, showing a 50% maximum effect (120% increase) at approximately 3 ng/ml (10-10 M 2.5S NGF). NGF treatments during different culture periods showed that the cholinergic neurons remained responsive for at least 19 days. The continued treatment was the most effective; however, an initial treatment for only 5 days still caused a significant stimulation of choline acetyltransferase on day 19. The observed stimulation appeared to be specific to NGF. Univalent antibody fragments (Fab) against 2.5S NGF completely abolished the NGF-dependent increase in choline acetyltransferase activity, whereas Fab fragments of control IgG were ineffective. Furthermore, angiotensin II, added in high amounts to the cultures, showed no stimulatory effect. The present results suggest that certain populations of rat brain neurons are responsive to nerve growth factor.

Pilomyxoid astrocytoma of the spinal cord in an adult.

We report a 45-year old woman with a pilomyxoid astrocytoma (PMA) of the cervical spinal cord with a rapid clinical course and fatal outcome. Moreover, two family members of the patient were reported to have brainstem tumours with similar histopathological features. This may be the first report of familial PMAs.

Interspinous distraction in lumbar spinal stenosis: a neurophysiological perspective.

STUDY DESIGN: Prospective neurophysiological study. OBJECTIVE: To identify and quantify the neurophysiological effects of interspinous distraction during spine surgery for lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: Interspinous devices have been introduced as an alternative treatment of LSS in selected patients aiming at obtaining indirect decompression. Nevertheless, there is no data on the immediate neurophysiological effect of distraction. METHODS: Thirty patients with LSS undergoing decompression (14 at single level, 16 at multiple levels) were enrolled, resulting in a total of 48 levels to be analyzed. Before decompression, calibrated incremental distraction simulating interspinous device implantation of 8, 10, 12, 14, and 16 mm was performed. Intraoperative motor evoked potentials were acquired before any distraction, during distraction at each incremental value and after bilateral decompression. We evaluated relative changes of motor evoked potentials normalized to hand muscles and related them to the number of affected levels, LSS radiological severity based on the A to D grading, lordosis, and disc height. RESULTS: For single-level disease, 8-mm distraction and open decompression yielded similar improvement in motor evoked potentials not only in levels with morphological grades A or B, but also in levels with morphological grades C or D (i.e., severe or extreme stenosis) (P = 0.32). In contrast, distraction superior to 8 mm was less effective (P ≤ 0.05). In multiple-level stenosis, decompression was significantly more effective than any degree of distraction (P < 0.001). No correlation of those results to disc height or lordosis was observed. Using χ trend test to analyze the effect of distraction, a linear trend favoring moderate over severe stenotic morphology was observed (P = 0.0349). CONCLUSION: Interspinous distraction of 8 mm is sufficient to replicate electrophysiological improvements obtained during full decompression even in severe single-level stenosis but not in multilevel disease. Interspinous distraction has therefore an immediately measurable neurophysiological effect. Level of Evidence: 4.

Does the physical disector method provide an accurate estimation of sensory neuron number in rat dorsal root ganglia?

The physical disector is a method of choice for estimating unbiased neuron numbers; nevertheless, calibration is needed to evaluate each counting method. The validity of this method can be assessed by comparing the estimated cell number with the true number determined by a direct counting method in serial sections. We reconstructed a 1/5 of rat lumbar dorsal root ganglia taken from two experimental conditions. From each ganglion, images of 200 adjacent semi-thin sections were used to reconstruct a volumetric dataset (stack of voxels). On these stacks the number of sensory neurons was estimated and counted respectively by physical disector and direct counting methods. Also, using the coordinates of nuclei from the direct counting, we simulate, by a Matlab program, disector pairs separated by increasing distances in a ganglion model. The comparison between the results of these approaches clearly demonstrates that the physical disector method provides a valid and reliable estimate of the number of sensory neurons only when the distance between the consecutive disector pairs is 60 microm or smaller. In these conditions the size of error between the results of physical disector and direct counting does not exceed 6%. In contrast when the distance between two pairs is larger than 60 microm (70-200 microm) the size of error increases rapidly to 27%. We conclude that the physical dissector method provides a reliable estimate of the number of rat sensory neurons only when the separating distance between the consecutive dissector pairs is no larger than 60 microm.

Rituximab treatment in non-malignant inflammatory sensory polyganglionopathy

Non-malignant inflammatory sensory polyganglionopathy (NISP) is the most common form of acquired ganglionopathies, a rare and distinct subgroup of peripheral nerve diseases characterized by a primary degeneration of sensory neurons in dorsal root ganglia. There is a rational for the use of immune modifying agents (IMA) in NISP since an underlying auto-immune process is demonstrated or suspected. However, commonly used IMA such as corticosteroids, azathioprine, methotrexate or IVIG do not prevent disease's progression in the majority of patients. The use of newer IMA, especially those directed against B-cells, may be a therapeutic alternative. An interesting candidate is rituximab, a mouse-human chimeric anti CD20 antibody that specifically eliminates B-cells and B-cells precursors.Objectives: This is a prospective open label pilot study to determine the efficacy of rituximab treatment in NISP patients, who did not respond to commonly used IMA.Methods: Five patients (40% male) with a mean age of 55 years (range 49-67), diagnosed with NISP after extensive work-up, were treated (schema used for one cure: 2 9 1gr within 15 days interval). Neurological scores (NIS, ISSS, ODSS) and B cell counts were assessed at baseline and during clinical follow-up at 2 and 6 monthsto assess treatment efficacy.Results: The treatment was generally well tolerated. Minor adverse events reported were transient arterial hypotension during the infusions in two patients and intermittent mild leucopenia in one patient. Clinical evolution during the follow-up period was characterized by a stability of the functional scores in four patients (80%) and the continuation of disability progression of one patient (20%). CD4 cells disappeared in all patients after the second infusion, an effect that lasted until the follow up at 6 months.Conclusion: The preliminary results of this pilot study indicate that rituximab is generally well tolerated and prevents progression of disability during the 6-month observation period in NISP patients. Inclusion of additional patients and extending of the follow-up period are intended to further investigate the efficacy of rituximab in NISP.