P. Rigoard

Back pain: a real target for spinal cord stimulation?

BACKGROUND Failed back surgery syndrome represents one of the most frequent etiologies of chronic back pain and is a major public health issue. Neurostimulation has currently not been validated in the treatment of back pain because of technological limitations in implantable spinal cord stimulation (SCS) systems. New-generation leads using several columns of stimulation can generate longitudinal and/or transverse stimulation fields into the spinal cord. OBJECTIVE To investigate, through extensive stimulation testing, the capacity of multicolumn tripolar leads to achieve back territory paresthesia coverage in refractory failed back surgery syndrome patients. METHODS Eleven patients implanted with a 16-contact spinal cord stimulation lead (Specify 5-6-5, Medtronic Inc) were assessed with a systematic exploration of 43 selected stimulation configurations to generate bilateral back paresthesia in addition to leg territory coverage. RESULTS The tripolar lead successfully generated paresthesia in both bilateral back and leg territories in 9 patients (81.8%). Success rates of multicolumn stimulation patterns were significantly higher than for longitudinal configurations for lombodorsal paresthesia coverage. Six months after implantation, significant pain relief was obtained compared with preoperative evaluation for global pain (Visual Analog Scale, 2.25 vs 8.2 preoperatively; P < .05), leg pain (Visual Analog Scale, 0.5 vs 7.6 preoperatively; P < .05), and back pain (Visual Analog Scale, 1.5 vs 7.8 preoperatively; P < .05). CONCLUSION These results suggest that multicolumn leads can reliably generate back pain coverage and favor pain relief outcomes. This may lead physicians to reconsider new indications for spinal cord stimulation. Expanding neurostimulation perspectives to intractable back pain syndromes could become realistic in the near future.

The Accumbofrontal Fasciculus in the Human Brain: A Microsurgical Anatomical Study

BACKGROUND:The fiber-dissection technique provides unique 3-dimensional anatomic knowledge of the white matter. OBJECTIVE:To better identify the frontostriatal pathways in the human brain, we used a fiber-dissection technique to reconstruct neural connections between the frontal cortex and the nucleus accumbens (NAcc), which is the most ventral extent of the striatum. METHODS:Thirty previously frozen, formalin-fixed human brains were dissected under the operating microscope using a modified fiber-dissection technique, primarily reported by Klingler. RESULTS:Our serial dissections of 30 human brain specimens clearly demonstrated that projection fibers form a connection between the NAcc and the frontal lobe. We evidenced this newly described subcortical tract as an accumbofrontal fasciculus. This focal projection was concentrated at the level of the ventromedial part of the NAcc and characterized by an elective and specific projection from the orbitomedial prefrontal cortex, particularly the gyrus rectus and the medial orbital gyrus situated between the H-shaped and the medial orbital sulcus. CONCLUSION:The accumbofrontal fasciculus is an elective and specific projection from the orbitoprefrontal cortex. This fasciculus is part of a corticostriatothalamocortical loop and a putative target for deep-brain stimulation in the treatment of obsessive-compulsive disorder and major depression. The analysis of in vivo diffusion tractography, used today as a standard in the investigation of many brain disorders, could potentially take advantage of complementary anatomic correlations and functional extrapolations, as described in this study.

Lidocaine Hyperselective Motor Blocks of the Triceps Surae Nerves : Role of the Soleus Versus Gastrocnemius on Triceps Spasticity and Predictive Value of the Soleus Motor Block on the Result of Selective Tibial Neurotomy

Buffenoir K, Rigoard P, Lefaucheur J-P, Filipetti P, Decq P: Lidocaine hyperselective motor blocks of the triceps surae nerves: role of the soleus versus gastrocnemius on triceps spasticity and predictive value of the soleus motor block on the result of selective tibial neurotomy. Am J Phys Med Rehabil 2008;87:292–304. Objectives:This prospective study was designed to evaluate the clinical and gait parameter changes induced by two types of hyperselective motor blocks of the triceps surae nerves (superior soleus and gastrocnemius nerves) and their ability to predict the results of selective tibial neurotomy. Design:Seven adult patients (four males and three females, mean age of 41 yrs old) with spastic foot were included in this study. Clinical (equinus foot score, ankle range of motion, spasticity, pain, and comfort wearing shoes), and gait analysis (kinematic and electromyographic parameters) assessment were performed before and after each motor block (superior soleus nerve and gastrocnemius nerve) and 1 mo after selective tibial neurotomy. Results:The superior soleus nerve block was effective on clinical parameters (triceps surae stretch reflex scores decreased from 2.57 to 0.9, and mean walking time decreased from 44 to 32.1 secs) and on kinematics parameters (the total duration of the gait cycle was decreased because of a reduction of the R3 and swing phases). The same results are observed after soleus neurotomy. Conclusion:This work confirms the practical value of selective superior soleus nerve motor block and that this block provides a useful prediction of the effect of selective soleus neurotomy. It constitutes an additional argument in favor of the predominant role of the soleus in spastic foot.

Abnormalities of the gallbladder, clinical effects.

The aim of this review of the literature was to present and discuss the anatomical and embryological basis of congenital abnormalities of the gallbladder, based on a case of volvulus. In the rare cases of ectopic gallbladder, diagnosis of a biliary disease could be difficult. In such cases surgery can also be dangerous, especially when it is associated with abnormalities of the intra-hepatic biliary and vascular tree. This study, based on the embryology of the extra hepatic bile duct, focused on the most frequent gallbladder abnormalities to keep them in mind.

The Neurostimulation Appropriateness Consensus Committee (NACC) Safety Guidelines for the Reduction of Severe Neurological Injury

Neurostimulation involves the implantation of devices to stimulate the brain, spinal cord, or peripheral or cranial nerves for the purpose of modulating the neural activity of the targeted structures to achieve specific therapeutic effects. Surgical placement of neurostimulation devices is associated with risks of neurologic injury, as well as possible sequelae from the local or systemic effects of the intervention. The goal of the Neurostimulation Appropriateness Consensus Committee (NACC) is to improve the safety of neurostimulation.

Multicolumn spinal cord stimulation lead implantation using an optic transligamentar minimally invasive technique.

BACKGROUND A new generation of neurostimulation surgical leads is used to increase the success of spinal cord stimulation in difficult-to-treat indications such as failed back surgery syndrome. Minimal access spinal technologies (MASTs) have previously been used for surgical lead implantation. However, only a unilateral approach was possible, causing difficulties for median lead placement, and not always preventing laminectomy. A recent MAST technique was used to implant spinal cord stimulation leads without these limitations. OBJECTIVE To describe the MAST technique used in a pilot study. METHODS Twenty-four consecutive patients were implanted with a multicolumn surgical lead for refractory chronic back and leg pain by using the optic transligamentar MAST technique. RESULTS The MAST technique allowed median lead placement, facilitated visualization of the spine, and permitted transligamentar insertion that minimized scarring and muscle damage. No technique-related adverse events or lead revisions were reported. CONCLUSION Use of a MAST approach could be useful in safe implantation of multicolumn surgical leads in difficult-to-treat, refractory lower back pain conditions such as failed back surgery syndrome.

Successful treatment of pudendal neuralgia with tricolumn spinal cord stimulation: case report.

BACKGROUND AND IMPORTANCE There is large variation in the success of decompressive surgery for pudendal neuralgia (PN), the most chronic, disabling form of perineal pain. We attempt to determine whether spinal cord stimulation using new-generation multicolumn leads could form part of the treatment algorithm for refractory PN. CLINICAL PRESENTATION A man with PN that was unresponsive to conventional treatment demonstrated a neuropathic component and had a negative response to nerve infiltrations (so he was not indicated for decompressive surgery) and a positive response to perianal transcutaneous electrical nerve stimulation and was implanted with a 16-contact surgical lead at the level of conus medullaris, allowing multicolumn stimulation. Using transverse combinations, it was possible to obtain 100% paresthesia over the perineal area without unwanted dorsal root stimulation. Perineal and radicular pain was successfully relieved for up to 12 months (80% and 60% reduction in the visual analogue scale scores, respectively), with an improvement in all quality of life domains and a reduction in drug consumption. CONCLUSION Spinal cord stimulation using a 16-contact lead may be a viable therapeutic option for patients with refractory PN for whom decompressive surgery is contraindicated.

The significance of the Rete mirabile in Vesalius's work : An example of the dangers of inductive inference in medicine. Commentary

IN HIS BOOK, De Humani Corporis Fabrica, published in 1543, Andreas Vesalius refuted the existence of the rete mirabile in humans. At the same time, it was through dissection of sheep that he continued to demonstrate its existence in some animals, thereby proving that its absence in humans was not owing to erroneous dissection. Radically breaking with Galenic dogma, Vesalius would not accept the idea that some scientific expositions are resignedly accepted as true because dogmatic reasons rendered their being subjected to anatomic verification impossible. He epitomized the awakening of the critical spirit and the onset of modern anatomy. In this study, we aimed to comprehend the approach that led Andreas Vesalius to his denial that the rete mirabile existed in humans.We attempted to restore Vesaliuss verification procedures through our dissection “à la Vesalius” of the rete mirabile in sheep. Was it not utterly imperative for him to dare to believe more of what is seen than what is written? In the same spirit, wishing to verify inherited ideas and to avoid meaningless phrases, we have taken it upon ourselves to translate the Latin commentaries to Figures 16 and 17 of the seventh book of the Fabrica.

Étude rétrospective du résultat à long terme des neurotomies sélectives périphériques dans le traitement du membre supérieur spastique

BACKGROUND/OBJECTIVE Peripheral selective neurotomy is commonly used to treat the equinus spastic foot (tibial nerve), but is less frequently used in treating upper limb spasticity, because of the complexity of the articular deformities and the complex innervations of the different muscles. We present our experience and the long-term results of this surgery based on a retrospective series of 22 patients with a disabling spasticity of the upper limb. METHODS Between 2003 and 2006, neurotomies were performed in 22 patients with disabling spasticity of the upper limb despite optimal medical treatment. Patients were evaluated before and after the surgical procedure. Twelve clinical parameters were studied for describing deformity (resting position and amplitude of each joint), spasticity (Ashworth and Tardieu scores), and the functional impacts of the spasticity. RESULTS At long-term follow-up, all parameters were improved from the surgery, both in terms of spastic symptoms (highly significantly decreased in Ashworth and Tardieu scores) and the deformity of the upper limb (e.g., 60 degrees increase in the extension of the elbow). Pain, active amplitude, and functional impact scores were also statistically significantly improved after surgery. The mean satisfaction index was 7/10 (+/-1.6). CONCLUSIONS Selective neurotomy is an effective treatment for patients with a disabling and excessive spasticity in the upper limb. It provides a long-term, objective improvement based on analytical and functional parameters. We emphasize the importance of accurate clinical evaluation and surgical planning. Finally, excessive time to treatment seems to be an important factor for recurrence or incomplete efficiency of the procedure.

Designing an operating theatre for awake procedures: A solution to improve multimodality information input.

Objective. Many neurosurgical procedures are now performed with the patient aware in order to allow interactions between the patient and healthcare professionals. These procedures include awake brain surgery and spinal cord stimulation (SCS), lead placement for treatment of refractory chronic back and leg pain. Neurosurgical procedures under local anaesthesia require optimal intraoperative cooperation of the patient and all personnel involved in surgery. In addition to accommodating this extra source of intraoperative information all other necessary sources of data relevant to the procedure must be presented. The concept of an operating room dedicated to neurosurgical procedures performed aware and accommodating these concepts is presented, and some evidence for improvements in outcome presented, deriving from a series of patients implanted with spinal cord stimulators before and after the operating theatre was brought into service. Results and discussion. In addition to the description, two videos demonstrate the facility online. Beyond this qualitative evidence, quantitative improvement in patient outcome is evidenced by the series presented: 91.3% of patients operated in the awake anaesthesia-dedicated theatre obtained adequate low back pain coverage, versus 60.0% for patients operated before (p = 0.028). Conclusion. The concept of such an operating room is a step in improving the outcome by improving the presentation of all types of information to the operating room staff most notably in the example of aware procedures.