Evaluation of the long-term effect of selective tibial neurotomy for the treatment of spastic foot using a personal goal-centered approach.

OBJECTIVE: The objective of this study was to evaluate the long-term effectiveness of selective tibial neurotomy (STN) for the treatment of the spastic foot using a goal-centered approach. METHODS: Between 2011 and 2018, adult patients with a spastic foot (regardless of etiology) who received STN followed by a rehabilitation program were included. The primary outcome was the achievement of individual goals defined preoperatively (T0) and compared at 1-year (T1) and 5-year (T5) follow-up by using the Goal Attainment Scaling methodology (T-score). The secondary outcomes were the presence of spastic deformities (equinus, varus, and claw toes), modified Ashworth scale (MAS) score for the targeted muscles, and modified Rankin Scale (mRS) score at T0, T1, and T5. RESULTS: Eighty-eight patients were included. At T5, 88.7% of patients had achieved their goals at least "as expected." The mean T-score was significantly higher at T1 (62.5 ± 9.5) and T5 (60.6 ± 11.3) than at T0 (37.9 ± 2.8) (p < 0.0001), and the difference between T1 and T5 was not significant (p = 0.2). Compared to T0, deformities (equinus, varus, and claw toes; all p < 0.0001), MAS score (p < 0.0001), and mRS score (p < 0.0001) were significantly improved at T1 and T5. Compared to T1, MAS score increased slightly only at T5 (p = 0.05) but remained largely below the preoperative value. There was no difference between T1 and T5 regarding other clinical parameters (e.g., deformities, walking abilities, mRS score). CONCLUSIONS: This study found that STN associated with a postoperative rehabilitation program can enable patients to successfully achieve personal goals that are sustained within a 5-year follow-up period.

Anatomical damages in the spinal nerve roots and the spinal cord after brachial plexus injury: descriptive study from a cohort of consecutive patients who underwent DREZ-lesioning for pain-practical implications.

BACKGROUND: Systematic descriptions of anatomical damage after brachial plexus injury (BPI) at the intradural level have been scarcely reported in detail. However, considering these damages, not only in the spinal nerve roots but also in the spinal cord itself, is crucial in determining the appropriate surgical approach to restore upper limb function and address refractory pain. Therefore, the authors present a descriptive study focusing on intradural findings observed during microsurgical DREZ-lesioning. METHODS: This study enrolled 19 consecutive patients under the same protocol. Microsurgical observation through exposure of C4 to Th1 medullary segments allowed to describe the lesions in spinal nerve roots, meninges, and spinal cord. Electrical stimulation of the ventral roots checked the muscle responses. RESULTS: Extensive damage was observed among the 114 explored roots (six roots per patient), with only 21 (18.4%) ventral (VR) and 17 (14.9%) dorsal (DR) roots retaining all rootlets intact. Damage distribution varied, with the most frequent impairments in C6 VRs (18 patients) and the least in Th1 VRs (14 patients), while in all the 19 patients for the C6 DRs (the most frequently impaired) and in 14 patients for Th1 DRs (the less impaired). C4 roots were found damaged in 12 patients. Total or partial avulsions affected 63.3% and 69.8% of DRs and VRs, respectively, while 15.8% and 14.0% of the 114 DRs and VRs were atrophic, maintaining muscle responses to stimulation in half of those VRs. Pseudomeningoceles were present in 11 patients but absent in 46% of avulsed roots. Adhesive arachnoiditis was noted in 12 patients, and dorsal horn parenchymal alterations in 10. CONCLUSIONS: Knowledge of intradural lesions post-BPI helps in guiding surgical indications for repair and functional neurosurgery for pain control.

Evaluation of Selective Tibial Neurotomy for the Spastic Foot Treatment Using a Personal Goal-Centered Approach: A 1-Year Cohort Study.

BACKGROUND: Selective tibial neurotomy (STN) has already demonstrated its effectiveness to reduce foot deformities and spasticity, but assessment according to a goal-centered approach is missing. OBJECTIVE: To evaluate the effectiveness of STN associated with a postoperative rehabilitation program for the treatment of the spastic foot, according to a goal-centered approach. METHODS: Interventional study (before-after STN and rehabilitation program) with observational design including consecutive adult patients with spastic foot, who received STN followed by a rehabilitation program, was performed. The primary outcome measure was the achievement of individual goals at the 1-year follow-up using the Goal Attainment Scaling methodology (with T-score). The secondary outcomes measures were the Modified Ashworth Scale and the modified Rankin Score. RESULTS: A total of 104 patients were included. At the 1-year follow-up, 228/252 (90.5%) goals were achieved: 62/252 (24.6%) were achieved as initially expected, 86/252 (34.1%) were achieved better than initially expected, and 80 (31.7%) were achieved much better than initially expected. The mean T-score was significantly increased at the 1-year follow-up (61.5 ± 10.5) compared with the preoperative period (38.1 ± 2.9, P < .00001), and 95/104 (91.3%) patients had a T-score ≥50, meaning that these patients have achieved their goals. At follow-up, spastic deformities were all significantly decreased ( P < .0001), the Modified Ashworth Scale was significantly lower for each muscle targeted ( P < .0001), and the modified Rankin Score was significantly decreased ( P < .0001) allowing the patient population to improve from a moderate to a slight disability status. CONCLUSION: This study showed that STN, associated with a postoperative rehabilitation program, successfully achieve personal goals in patients with spastic foot.

Excitability of the radiculo-medullary circuitry in spastic cerebral palsy: An intraoperative neurophysiological study in children undergoing selective dorsal rhizotomy.

AIM: To explore - through intraoperative neurophysiology mapping and recordings - the comparative distribution of the reflexive excitability of the L2 to S2 radiculo-metameric segments of the spinal cord in a series of children with bilateral spastic cerebral palsy (CP) who underwent selective dorsal rhizotomy (SDR). METHOD: Our series included 46 consecutive children (36 males, 10 females; aged 5-16 years, mean 8 years) who underwent SDR, using keyhole interlaminar dorsal rhizotomy. The procedure allowed access to all L2 to S2 roots independently, while preserving the posterior architecture of the lumbar spine. Dorsal roots were stimulated selectively to test reflexive excitability of the corresponding radiculo-metameric levels. Stimulation parameters were identical for all roots for optimal comparison between root levels, with an intensity just above threshold to avoid excessive diffusion. The responses in the main muscular groups in each lower limb were clinically observed and electromyograms recorded. Degrees of excitability were quantified according to Fasano's scale. RESULTS: The difference between root levels was highly significant. Median values of excitability were 1, 2, 3, 3, 3, and 3 for the L2, L3, L4, L5, S1, and S2 levels respectively. Lower root levels exhibited significantly more excitability. INTERPRETATION: In addition to insight into the spasticity of children with CP, the profile of segmental excitability can be useful in establishing surgical planning when programming SDR. WHAT THIS PAPER ADDS: Keyhole interlaminar dorsal rhizotomy modality allowed selective stimulation of all L2-S2 dorsal roots for testing excitability. There were significant differences in reflexive excitability of L2-S2 radiculo-medullary segments. Lower segments of L2-S2 medullary levels have higher excitability. Interindividual variability in excitability of lumbosacral segments justifies intraoperative neurophysiology. This original article is commented on by Young on pages 9-10 of this issue.

The Pierre Wertheimer Neurological and Neurosurgical Hospital in Lyon: history of its development and contributions to neurosurgery.

At the end of the 1950s, at the direction of Pierre Wertheimer, the first French professor of neurosurgery, the treatment of neurological and neurosurgical diseases for Lyon's 2 million people was concentrated in a single center functioning as not only a hospital but also a campus for neuroscience. The ideas behind the structure revolve around concepts such as spatial unity, comprehensive specialized fields, a critical mass of patients, a structured training program, and essential cross-communication between areas in the same field. Through several generations of doctors, researchers, and professors, the Pierre Wertheimer Neurological and Neurosurgical Hospital in Lyon (NHL) has had an important impact on clinical practice, fundamental neuroscientific research, and specialist training. Under Wertheimer's stewardship, functional neurosurgery became one of the fields of excellence at the NHL with contributions in pain surgery and physiology but also epilepsy surgery and surgery for spasticity. Typically, these contributions were the result of the collaboration of separate teams, ultimately laying the groundwork for a neuroscientific doctoral school. The large mass of patients treated at the NHL provided opportunities for other, more isolated insights, such as the classification of pineal tumors and contributions to interventional neuroradiology. The present work endeavors to illustrate the contributions of the NHL to neuroscience and discuss the background allowing for their occurrence.

Management of cavernous sinus meningiomas: Consensus statement on behalf of the EANS skull base section.

Introduction: The evolution of cavernous sinus meningiomas (CSMs) might be unpredictable and the efficacy of their treatments is challenging due to their indolent evolution, variations and fluctuations of symptoms, heterogeneity of classifications and lack of randomized controlled trials. Here, a dedicated task force provides a consensus statement on the overall management of CSMs. Research question: To determine the best overall management of CSMs, depending on their clinical presentation, size, and evolution as well as patient characteristics. Material and methods: Using the PRISMA 2020 guidelines, we included literature from January 2000 to December 2020. A total of 400 abstracts and 77 titles were kept for full-paper screening. Results: The task force formulated 8 recommendations (Level C evidence). CSMs should be managed by a highly specialized multidisciplinary team. The initial evaluation of patients includes clinical, ophthalmological, endocrinological and radiological assessment. Treatment of CSM should involve experienced skull-base neurosurgeons or neuro-radiosurgeons, radiation oncologists, radiologists, ophthalmologists, and endocrinologists. Discussion and conclusion: Radiosurgery is preferred as first-line treatment in small, enclosed, pauci-symptomatic lesions/in elderly patients, while large CSMs not amenable to resection or WHO grade II-III are candidates for radiotherapy. Microsurgery is an option in aggressive/rapidly progressing lesions in young patients presenting with oculomotor/visual/endocrinological impairment. Whenever surgery is offered, open cranial approaches are the current standard. There is limited experience reported about endoscopic endonasal approach for CSMs and the main indication is decompression of the cavernous sinus to improve symptoms. Whenever surgery is indicated, the current trend is to offer decompression followed by radiosurgery.

How I do it: Selective dorsal rhizotomy, using interlaminar approaches, for spastic diplegia/quadriplegia in children with cerebral palsy.

BACKGROUND: Dorsal rhizotomy is considered the gold standard for treating spastic diplegia/quadriplegia in children with cerebral palsy, when rehabilitation programs reveal insufficient to control excess of spasticity. METHOD: The Keyhole Interlaminar Dorsal rhizotomy modality has been developed to access-individually-all L2-S2 roots, intradurally at the corresponding dural sheath, and preserve the posterior spine architecture. Intraoperative neuromonitoring consists of stimulating each ventral root, to verify its myotomal innervation, and dorsal roots, to explore their reflexive muscular responses in order to help determination of the proportion of rootlets to be cut. CONCLUSION: This modality, which requires 5 ± 1 h duration, offers tailored accuracy.

How to Do It: Microsurgical DREZotomy for Pain After Brachial Plexus Injury: 2-Dimensional Operative Video.

More than three-quarters of victims of brachial plexus injury suffer from refractory neuropathic pain.1-6 Main putative mechanism is paroxysmal hyperactivity in the dorsal horn neurons at the dorsal root entry zone (DREZ) as demonstrated by microelectrode recordings in animal models7 and patients.8 Pain relief can be achieved by lesioning the responsible neurons in the spinal cord segments with avulsed rootlets.9,10 This video illustrates the technique for microsurgical DREZotomy.11,12 A C3-C7 hemilaminectomy is performed to access the C4-Th1 medullary segments. After opening the dura and arachnoid, and freeing the cord from arachnoid adhesions, the dorsolateral sulcus is identified. Identification can be difficult when the spinal cord is distorted and/or has a loss of substance. The dorsolateral sulcus is then opened with a microknife, so that microcoagulations are performed: 4 mm deep, at 35° angle in the axis of the dorsal horn, every millimeter in a dotted fashion along the avulsed segments. Care should be taken not to damage the corticospinal tract, laterally, and the dorsal column, medially. The patient consents to the procedure. In the presented case, surgery led to complete disappearance of the paroxysmal pain and reduced the background of burning pain to a bearable level without the need of opioid medication. There was no motor deficit or ataxia in the ipsilateral lower limb postoperatively. According to Kaplan-Meier analysis at 10 yr follow-up, in our overall series, microsurgical DREZotomy achieved total pain relief without any medication in 60% of patients, and in 85% without the need for opioids.10,13-15 Microelectrode recording at 1:26 reproduced from Guenot et al7 with permission from JNSPG.

Microsurgical DREZotomy for Treatment of Brachial Plexus Avulsion Pain.

A 63-year-old man with a history of motorcycle accident 42 years ago suffered a left brachial plexus avulsion (BPA). Neuropathic pain in his left upper limb was felt in the C6-C7-C8 dermatomes. The rationale for performing "DREZotomy" is to preferentially interrupt the nociceptive inputs in the lateral part of the dorsal root entry zone (DREZ).1-3 For pain with complete deafferentation, as observed in BPA, the aim is to destroy the hyperactive nociceptive neurons deep in the apex of the dorsal horn (DH).4 Surgery is performed under general anesthesia, with the patient in prone position. Once the dura mater is opened, the arachnoid needs extensive dissection to open the dorsolateral and lateral spinal cisterns.5 In cases of BPA, the dorsolateral sulcus may be difficult to identify. Three anatomic elements can facilitate its recognition. Firstly, the remaining intact rootlets (above and below the avulsed segments) allow us to roughly localize the dorsolateral sulcus by joining these cranial and caudal normal rootlets. Secondly, blood vessels running on the spinal cord penetrate into the dorsolateral sulcus and often delineate the sulcus. Thirdly, scarring can be seen along the sulcus with small holes where the rootlets used to penetrate the cord. DREZotomy is performed using a graduated sharp bipolar instrument to allow precise microcoagulations of the DH. Preoperative surgical planning helps the surgeon by giving the angle between the DH and median plane.6 In the immediate postoperative period, the patient described the complete disappearance of neuropathic pain in his left upper limb, persistent at last follow-up (1 year) (Video 1).

Usefulness of external anal sphincter EMG recording for intraoperative neuromonitoring of the sacral roots-a prospective study in dorsal rhizotomy.

BACKGROUND: In conus medullaris and cauda equina surgery, identification of the sacral nerve roots may be uncertain in spite of their anatomical/radiological landmarks. Mapping the sacral roots by recording the muscular responses to their stimulation may benefit from EMG recording of the External Anal sphincter (EAS) in addition to the main muscular groups of the lower limbs. METHOD: In a consecutive series of 27 lumbosacral dorsal rhizotomy (DRh), authors carried out a prospective study on the reliability of the EMG recording of the EAS for identification of the S1 and S2 sacral roots. RESULTS: An EAS-response was recorded in all the 27 (bilaterally) explored individuals, testifying good sensitivity and selectivity of the method. EAS-responses were obtained in 96.3% of the 54 stimulated sides of the S2 root versus in only 16.66% for the S1 root, so that an absence of response would indicate S1 rather than S2 level. Furthermore, comparison between myotomal distribution of the S1 and S2 roots showed a significant difference (p < 0.00001), so that myotomal profile may help to identify root level. CONCLUSIONS: EMG recording of the EAS can be recommended for current intraoperative neuromonitoring. This simple method also provides-indirectly by extrapolation-information on the sacral motor pathways of the external urethral sphincter (EUS), as the later has the same somatic innervation via the pudendal nerve and related S2, S3, and S4 roots. Method can be helpful not only for DRh, of all varieties, but also for spine surgery, correction of dysraphisms, lipomas and/or tethered cord, and tumor resection.

How I do it: selective tibial neurotomy.

BACKGROUND: Selective neurotomy is known as an effective method to reduce focal spasticity when medical treatment including botulinum toxin is not sufficient. The tibial nerve can be targeted to treat spastic equinovarus foot with (or without) claw toes. METHOD: Tibial nerve trunk is dissected in the popliteal fossa. Sensitive and motor branches are identified using electrical stimulation to monitor motor responses. The muscular nerves corresponding to the targeted muscles are partially sectioned according to a preoperative chart. A postoperative rehabilitation program is mandatory. CONCLUSION: Precise and rigorous selective neurotomy provided a definitive and safe treatment for spastic equinovarus foot.

Muscle responses to radicular stimulation during lumbo-sacral dorsal rhizotomy for spastic diplegia: Insights to myotome innervation.

OBJECTIVE: Most of knowledge on muscle radicular innervation was from explorations in root/spinal cord pathologies. Direct and individual access to each of the lumbar-sacral -ventral and dorsal- nerve roots during dorsal rhizotomy for spastic diplegia allows precise study of the corresponding muscle innervation. Authors report the lumbo-sacral segmental myotomal organization obtained from recordings of muscle responses to root stimulation in a 20-children prospective series. METHODS: Seven key-muscles in each lower limb and anal sphincter were Electromyography (EMG)-recorded and clinically observed by physiotherapist during L2-to-S2 dorsal rhizotomy. Ventral roots (VR), for topographical mapping, and dorsal roots (DR), for segmental excitability testing, were stimulated, just above threshold for eliciting muscular response. RESULTS: In 70% of the muscles studied, VR innervation was pluri-radicular, from 2-to-4 roots, with 1 or 2 roots being dominant at each level. Overlapping was important. Muscle responses to DR stimulation were 1.75 times more extended compared to VR stimulation. Inter-individual variability was important. CONCLUSIONS: Accuracy of root identification and stimulation with the used method brings some more precise information to radicular functional anatomy. SIGNIFICANCE: Those neurophysiological findings plead for performing Intra-Operative Neuromonitoring when dealing with surgery in the lumbar-sacral roots.

Topography of the pain in classical trigeminal neuralgia: insights into somatotopic organization.

Trigeminal neuralgia is defined by its clinical characteristics of paroxysmal unilateral facial pain in a well-defined territory. Distribution of the pain may be in one or several of the cutaneous and/or mucous territories of the three divisions with V2 pain being the most frequent territory followed by V3 and V1. Factors determining the distribution of pain have not yet been systematically investigated. It is now well recognized that vascular compression factor is a predominant aetiology of classical trigeminal neuralgia. In this study we aimed to find whether there is a relation between the location of the vascular compression and the peripheral distribution of the pain. Patients with classical trigeminal neuralgia in whom microvascular decompression was performed were included. Data recorded pertained to the nature of the conflict, its degree and, most importantly, location around the root: supero-median, supero-lateral or inferior. Equally, clinical data for the distribution of pain were recorded. Most of the patients 318 (89.3%) had the compression coming from above, i.e. 220 (61.7%) had compression from a supero-medial direction and 98 (27.5%) from a supero-lateral direction; inferior compression was present in 38 patients (10.7%). Distribution of the pain was significantly different according to the location of the conflict (P = 0.0005, Fisher Exact test). Odds ratios were computed for each location of compression and painful territory involved. According to the overall distribution of pain, patients with supero-medial compression had an odds ratio of 2.7 [95% confidence interval (CI) 1.66-4.41] of manifesting with V1 pain. Conversely V3 pain was less likely to occur with supero-median compression than the other types of pain (odds ratio 0.53, 95% CI 0.34-0.83). Inferior compression on the other hand was more likely to manifest with V3 pain with an odds ratio of 2.56 (95% CI 1.21-5.45). Overall V2 pain had an odds ratio close to 1 regardless of the type of compression. These findings suggest an association between the location of the neurovascular conflict with its resulting insult and the distribution of pain supporting a somatotopic view of the organization of the trigeminal root and a role of the conflict in the clinical manifestation of trigeminal neuralgia.

Microsurgical DREZ lesions for the control of cancer-related pain.

Pain in patients with cancer is a major problem, and sometimes it is necessary to surgically interrupt pain pathways to effectively control refractory pain. Surgical lesion of the dorsal root entry zone (DREZ) was first performed in 1972 for the treatment of pain related to a Pancoast-Tobias tumor. The rationale of DREZotomy is to preferentially interrupt the nociceptive inputs in the lateral part of the DREZ and the ventrolateral (excitatory) part of the dorsal horn. Microsurgical DREZotomy is one technique for DREZ lesioning that is suited for tailored control of pain in patients in good general condition who are experiencing pain in a well-defined territory. The video can be found here: https://youtu.be/JtLQDP7gYSQ.

Correction to: Arachnoiditis as an outcome factor for microvascular decompression in classical trigeminal neuralgia.

Figure 3 corrected.