Ventral Nerve Roots Research Articles

Magnetic resonance imaging of the cervical spinal cord in spinal muscular atrophy.

ObjectiveIn this study we investigated the potential value of magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) in characterizing changes in the cervical spinal cord and peripheral nerve roots in vivo in patients with spinal muscular atrophy (SMA).MethodsWe developed an MRI protocol with 4 sequences to investigate the cervical spinal cord and nerve roots on a 3 Tesla MRI system. We used 2 anatomical MRI sequences to investigate cross-sectional area (CSA) at each spinal segment and the diameter of ventral and dorsal nerve roots, and two diffusion tensor imaging (DTI) techniques to estimate the fractional anisotropy (FA), mean (MD), axial (AD) and radial diffusivity (RD) in 10 SMA patients and 20 healthy controls.ResultsThere were no significant differences in CSA (p > .1), although an 8.5% reduction of CSA in patients compared to healthy controls was apparent at segment C7. DTI data showed a higher AD in grey matter of patients compared to healthy controls (p = .033). Significantly lower MD, AD and RD values were found in rostral nerve roots (C3-C5) in patients (p < .045).ConclusionsWe showed feasibility of an advanced 3 T MRI protocol that allowed differences to be determined between patients and healthy controls, confirming the potential of this technique to assess pathological mechanisms in SMA. After further development and confirmation of findings in a larger sample, these techniques may be used to study disease course of SMA in vivo and evaluate response to survival motor neuron (SMN) augmenting therapy.

Effect of lentiviral vector-mediated overexpression of hypoxia-inducible factor 1 alpha delivered by pluronic F-127 hydrogel on brachial plexus avulsion in rats

Brachial plexus avulsion often results in massive motor neuron death and severe functional deficits of target muscles. However, no satisfactory treatment is currently available. Hypoxia-inducible factor 1α is a critical molecule targeting several genes associated with ischemia-hypoxia damage and angiogenesis. In this study, a rat model of brachial plexus avulsion-reimplantation was established, in which C5-7 ventral nerve roots were avulsed and only the C6 root reimplanted. Different implants were immediately injected using a microsyringe into the avulsion-reimplantation site of the C6 root post-brachial plexus avulsion. Rats were randomly divided into five groups: phosphate-buffered saline, negative control of lentivirus, hypoxia-inducible factor 1α (hypoxia-inducible factor 1α overexpression lentivirus), gel (pluronic F-127 hydrogel), and gel + hypoxia-inducible factor 1α (pluronic F-127 hydrogel + hypoxia-inducible factor 1α overexpression lentivirus). The Terzis grooming test was performed to assess recovery of motor function. Scores were higher in the hypoxia-inducible factor 1α and gel + hypoxia-inducible factor 1α groups (in particular the gel + hypoxia-inducible factor 1α group) compared with the phosphate-buffered saline group. Electrophysiology, fluorogold retrograde tracing, and immunofluorescent staining were further performed to investigate neural pathway reconstruction and changes of neurons, motor endplates, and angiogenesis. Compared with the phosphate-buffered saline group, action potential latency of musculocutaneous nerves was markedly shortened in the hypoxia-inducible factor 1α and gel + hypoxia-inducible factor 1α groups. Meanwhile, the number of fluorogold-positive cells and ChAT-positive neurons, neovascular area (labeled by CD31 around avulsed sites in ipsilateral spinal cord segments), and the number of motor endplates in biceps brachii (identified by α-bungarotoxin) were all visibly increased, as well as the morphology of motor endplate in biceps brachil was clear in the hypoxia-inducible factor 1α and gel + hypoxia-inducible factor 1α groups. Taken together, delivery of hypoxia-inducible factor 1α overexpression lentiviral vectors mediated by pluronic F-127 effectively promotes spinal root regeneration and functional recovery post-brachial plexus avulsion. All animal procedures were approved by the Institutional Animal Care and Use Committee of Guangdong Medical University, China.

Two Cases of Guillain-Barré Syndrome Variants Presenting With Dysautonomia.

We describe 2 pediatric cases presenting with posterior reversible encephalopathy syndrome secondary to autonomic dysfunction preceding the onset of motor symptoms in Guillain-Barré syndrome variants. Patient 1 presented acutely with encephalopathy, cerebellar signs, hypertension, lower limb weakness, and respiratory decompensation. Magnetic resonance imaging (MRI) brain showed occipital lesions consistent with posterior reversible encephalopathy syndrome. Nerve conduction studies were consistent with Miller-Fisher syndrome. After intravenous immunoglobulin and plasmapheresis, he improved clinically with radiological resolution. Patient 2 presented with headache, leg pain, seizures, and significant hypertension. Brain MRI was normal but spine MRI revealed enhancement of the cauda equina ventral nerve roots. She was areflexic with lower limb weakness a few days after intensive care unit admission and made a significant improvement after treatment with intravenous immunoglobulin. In children presenting with posterior reversible encephalopathy syndrome in the absent of other causes of primary hypertension, Guillain-Barré syndrome variants are an important differential etiology, presenting with autonomic dysfunction, even before signs of motor weakness become evident.

Dynamic magnetic resonance imaging parameters for objective assessment of the magnitude of tethered cord syndrome in patients with spinal dysraphism.

Dynamic magnetic resonance imaging (MRI)-based criteria for diagnosing magnitude of tethered cord syndrome (TCS) in occult spinal dysraphism are proposed. In this prospective, case-control design study, MRI lumbosacral spine was performed in 51 subjects [pilot group (n = 10) without TCS (for defining radiological parameters), control group (n = 10) without TCS (for baseline assessment), and study group (n = 31) with spinal dysraphism (thick filum terminale [n = 12], lumbar/lumbosacral meningomyelocoele [n = 6], and lipomyelomeningocoele [n = 13])]. The parameters compared in control and study groups included oscillatory frequency (OF), difference in ratio, in supine/prone position, of distance between posterior margin of vertebral body and anterior margin of spinal cord (oscillatory distance [OD]), with canal diameter, at the level of conus as well as superior border of contiguous two vertebrae above that level; delta bending angle (ΔBA), difference, in supine/prone position, of angle between longitudinal axis of conus and that of lower spinal cord; and sagittal and axial root angles, subtended between exiting ventral nerve roots and longitudinal axis of cord. An outcome assessment at follow-up was also done. In the study group (cord tethered), significantly less movement at the level of conus (OF0, p = 0.013) and one level above (OF1, p = 0.03) and significant difference in ΔBA (p = 0.0) were observed in supine and prone positions, compared to controls. Ventral nerve root stretching resulted in sagittal/axial root angle changes. Median OF (0.04) in the lipomyelomeningocoele group was significantly less than that in control group (0.23). Median OF was also lesser in patients with thick filum terminale or meningomyelocele. Difference in median sagittal and axial root angles among the study and control groups was statistically significant (p = 0.00). New dynamic MRI-based parameters to establish the presence and magnitude of TCS have been defined. OF measured the extent of loss of translational cord displacement in supine and prone positions; ΔBA defined the relative angulation of conus with lower spinal cord, and sagittal and axial root angles represented ventral nerve root stretching. The difference in OF or ΔBA was minimum in the group with thick filum terminale and progressively increased in the groups with lipomyelomeningocele and meningomyelocele.

The focus of the cervical radiculopathy by dermatomal pain in comparison with results of electrodiagnosis and imaging

Objectives The dermatomal pain related to a cervical radiculopathy is often misunderstanded by physicians because in most cases there is a discordance between it, imaging and electromyography (EMG). The aim of this study is to compare trajectory of dermatomal pain, imaging and EMG findings. Methods It's a retrospective study over a year that regrouped patients referred to the department of functional explorations of Sfax for electrodiagnostic test. These patients had clinical signs of cervical radiculopathy and underwent a cervical imaging (MRI or CT) that confirmed it. They underwent a nerve conduction study with a needle EMG examination that examined one muscle from the affected root and others upper and lower depending on its result and clinical finding. The Fisher's exact test was used for comparison of different clinical, imaging and EMG signs. Results Sixteen patients (sex-ratio 1/3) were collected with a mean age of 54.8 ± 11.15 year. These patients had not yet motor signs. In 6 patients the pain was not dermatomal. When the pain was dermatomal, there was a concordance between clinic and respectively imaging and EMG in 3 cases and 8 cases. Dermatomal pain was not correlated with imaging (P = 0.8) nor with EMG (P = 0.9). There was a correlation between imaging and EMG (P = 0.05). Conclusion Because the radiculopathy is due to a motor ventral nerve root compression, the most important symptom is the myotomal weakness [1] , [2] . However, dermatomal pain was the most sensitive symptom but less specific in Hassan's study [2] . In fact this symptom can be due to a combination of mechanical and inflammatory mechanisms. Imaging and EMG are often in concordance with the affected nerve root but EMG gives more evidence of the functional lesions and a more specificity [3] .

Cell- and stage-specific localization of galectin-3, a β-galactoside-binding lectin, in a mouse model of experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease in which pathogenic T cells play an important role, and an experimental autoimmune encephalomyelitis (EAE) is used as an animal model of MS. Galectins are β-galactoside-binding lectins and involved in various physiological and pathological events. Among fifteen members of galectins, galectin-1, -8, and -9 play immunosuppressive roles in MS and EAE; however, the role of galectin-3 (gal-3) is complex and controversial. We examined expression of gal-3 in the spinal cord and nerve roots of EAE mice. No immunohistochemical signals were detected in naïve mice, whereas gal-3 appeared at lower lumbar levels of the spinal cord and nerve roots in EAE mice. In the spinal cord, gal-3-positive cells were activated microglia and/or infiltrating macrophages, which were round in shape and intensified for the lysosomal enzyme, cathepsin D, indicating elevated phagocytic activity. Gal-3-positive cells in the spinal cord were most abundant during the peak symptomatic period. In the recovery period, they disappeared from the spinal parenchyma but remained at moderate levels in the pia mater. Interestingly, gal-3-positive cells selectively appeared in ventral, but not dorsal, nerve roots running through the spinal canal, with expression peaking during the recovery period. In ventral nerve roots, the major cell type expressing gal-3 was a specific population of Schwann cells that surround unmyelinated axons and express the biosynthetic enzyme for l-serine, a potent neurotrophic amino acid. Gal-3 was also induced in Iba1/F4/80-positive macrophages, which engulf damaged myelin and axon debris. Thus, gal-3 is induced in distinct cell types that are engaged in removal of damaged axons and cell debris and axon regeneration and remyelination, suggesting a potential neuroprotective role of gal-3 in EAE mice.

ScAAV9-VEGF-165 inhibits neuroinflammatory responses and invasion of macrophages into the peripheral nervous system of ALS transgenic mice

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that leads to paralysis and death within 3–5 years. Although the vast majority of studies have focused on vulnerable neurons, growing evidence has shown that non-neuronal cells contribute to the pathogenesis and disease progression. Here, we showed that intrathecal injection of scAAV9-VEGF at 60 days of age significantly reduced the number of microglia and inhibited the neuroinflammatory response in the CNS. Meanwhile, we found that administration of VEGF inhibited the invasion of macrophages into the PNS, including ventral nerve roots, sciatic nerves and muscles. Overall, our study indicated the anti-inflammation effect of VEGF in the CNS and PNS of ALS mice when delivered by intrathecal injection.

T25. Changes in central motor conduction time and its implication in the pathogenesis of distal-type cervical spondylotic amyotrophy

The true pathogenesis of cervical spondylotic amyotrophy (CSA) remains controversial. One of the current hypotheses for the etiology of CSA mainly involves selective compression of the ventral nerve roots and/or anterior horn cells by a bony spur or herniated disc. Some scholars have proposed that CSA may be ascribed to ischemia of anterior horn cells caused by compressive injury of anterior spinal artery. Recently published studies demonstrated that chronic incomplete cervical cord compression can cause the loss of motor neurons in the spinal anterior horn caudal to the level of the compressive injury, which was described as trans-synaptic damage. Although CSA was previously considered a neurological disease involving only lower motor neurons (LMNs), some authors revealed that approximately 28.6–66.7% of distal-type CSA patients had significant lower limb hyperreflexia, which is consistent with upper motor neuron (UMN) lesions. Therefore, trans-synaptic damage may be involved in the pathogenesis of distal-type CSA. The present study has been undertaken to evaluate central motor conduction in distal-type CSA patients and to analyze the role of trans-synaptic damage in the pathogenesis of distal-type CSA. Central motor conduction time (CMCT) to both upper and lower limbs was measured in 28 distal-type CSA patients and 21 controls, and all subjects underwent further motor unit number estimation (MUNE), handgrip strength examination (HGS) and magnetic resonance imaging evaluation. Prolonged CMCT was recorded in 9/28 (32.1%) CSA patients, and both lower MUNE values and smaller HGS were observed in these 9 cases (P < 0.05). Imaging analysis demonstrated that 5 of these 9 cases had cervical compression both proximally and distally, and severe proximal cervical compression without distal selective compression was found in the other two cases (2/9, 22.2%). There was an inverse correlation between CMCT and both MUNE values and HGS on symptomatic side (P < 0.05), and a positive relationship between CMCT and amplitude of single motor unit potentials was found on less-symptomatic side (P < 0.05). Distal-type CSA patients may have substantial corticospinal tract lesions, and trans-synaptic damage caused by these lesions may be involved in the pathogenesis of distal-type CSA. Therefore, clinicians should be cautious when evaluating and managing distal-type CSA patients, especially the cases with additional proximal cervical compression, because severe muscular atrophy may be caused by both trans-synaptic damage and selective compression.

Novel method for restoration of anorectal function following spinal cord injury via nerve transfer in rats

ObjectivesNerve transfer has been developed to restore partial function after serious nerve injuries, for example, restoring bladder control after spinal cord injury (SCI). Our aim here was to establish a preclinical proof-of-concept model using nerve transfer for restoring anorectal function after SCI.SettingWe used laminectomy to model SCI, and bilateral spinal ventral and dorsal nerve root anastomosis to re-establish connectivity to the anorectal musculature.MethodsMultidisciplinary methods were used to assess the anatomical and functional integrity of the alternative spinal-to-anorectal nerve circuit. Adult rats were used to establish the model. Bilateral anterior and posterior L5 nerve roots were surgically matched with anterior and posterior of S1 nerve roots by microscopic anastomosis to establish an artificial rectal reflex arc with complete sensory and motor pathways. Twelve weeks later, we used retrograde nerve tracing and neurohistomorphological analysis to assess anatomical integrity of the new artificial rectal reflex arc. Anorectal manometry was used to assess the function of the new nerve circuit.ResultsRetrograde tracing with recombinant attenuated pseudo rabies virus indicated that the new neural pathway was successfully established to the anorectal musculature after experimental SCI. Toluidine blue-stained sections of the anastomosis site revealed normal-appearing nerve fiber morphology and regeneration, and transmission electron microscopy revealed myelinated axons. Anorectal manometry revealed significant anorectal functional recovery.ConclusionThese results suggest that our model is a feasible first step in developing an alternative reflex pathway after laminectomy at L4 to S2 and shows promise for effective restoration of anorectal function.

Post-mortem diffusion MRI of the cervical spine and its nerve roots

Abstract Purpose The aim of this work is to examine the architectural configuration and the microstructural substrate of the cervical spine and its nerve roots with post-mortem (PM) diffusion tensor imaging (DTI) in non-fixed subjects and to compare these findings with histology. Methods Magnetic resonance imaging (MRI) data were acquired on a 1.5 T MRI scanner in five non-fixed non-trauma deaths. Two different areas were evaluated: 1) the cervical spinal cord and ventral and dorsal nerve roots with a “high in-plane” DTI and a multi-echo fast field echo protocol, and 2) the cervical peripheral nerves with an “isotropic” DTI and a 3D turbo spin echo protocol. Histology samples were obtained matching the anatomical level of the slices of the ‘high in-plane’ DTI protocol. Results We were able to show detailed reconstructions of the dorsal and ventral nerve roots with the ‘high in-plane’ protocol and identified a low fractional anisotropy (FA = 0.30 ± 0.08) in the grey matter and a high FA (0.51 ± 0.13) in the white matter. Both grey and white matter configurations correlated with the anatomical MRI, the diffusion MRI, and with the histological sections. Using the ‘isotropic’ DTI protocol, it was feasible to reconstruct the spinal cord, cervical nerves, and nerve roots in all PM subjects. Conclusion We were able to generate detailed architectural configurations of the ventral and dorsal nerve roots. Anatomical and diffusion MR scans showed good qualitative agreement with histology. We believe that PMDTI will be helpful in the assessment of head and neck injuries in a forensic setting.

A numerical investigation of intrathecal isobaric drug dispersion within the cervical subarachnoid space.

Intrathecal drug and gene vector delivery is a procedure to release a solute within the cerebrospinal fluid. This procedure is currently used in clinical practice and shows promise for treatment of several central nervous system pathologies. However, intrathecal delivery protocols and systems are not yet optimized. The aim of this study was to investigate the effects of injection parameters on solute distribution within the cervical subarachnoid space using a numerical platform. We developed a numerical model based on a patient-specific three dimensional geometry of the cervical subarachnoid space with idealized dorsal and ventral nerve roots and denticulate ligament anatomy. We considered the drug as massless particles within the flow field and with similar properties as the CSF, and we analyzed the effects of anatomy, catheter position, angle and injection flow rate on solute distribution within the cerebrospinal fluid by performing a series of numerical simulations. Results were compared quantitatively in terms of drug peak concentration, spread, accumulation rate and appearance instant over 15 seconds following the injection. Results indicated that solute distribution within the cervical spine was altered by all parameters investigated within the time range analyzed following the injection. The presence of spinal cord nerve roots and denticulate ligaments increased drug spread by 60% compared to simulations without these anatomical features. Catheter position and angle were both found to alter spread rate up to 86%, and catheter flow rate altered drug peak concentration up to 78%. The presented numerical platform fills a first gap towards the realization of a tool to parametrically assess and optimize intrathecal drug and gene vector delivery protocols and systems. Further investigation is needed to analyze drug spread over a longer clinically relevant time frame.

The Effects of Minocycline on Spinal Root Avulsion Injury in Rat Model.

The neuroprotective role of minocycline in the treatment of brachial plexus injury is controversial. To study the neuroprotective effect of minocycline via different routes in adult Sprague Dawley rats with brachial plexus injury. The C7 nerve roots of the animals were avulsed via an anterior extravertebral approach. Traction force was used to transect the ventral motor nerve roots at the preganglionic level. Intraperitoneal and intrathecal minocycline (50 mg/kg for the first week and 25 mg/kg for the second week) were administered to promote motor healing. The spinal cord was harvested six weeks after the injury, and structural changes following the avulsion injury and pharmacological intervention were analysed. Motor neuron death and microglial proliferation were observed after the administration of minocycline via two different routes (intraperitoneal and intrathecal) following traumatic avulsion injury of the ventral nerve root. The administration of intraperitoneal minocycline reduced the microglia count but increased the motor neuron count. Intrathecal minocycline also reduced the microglial count, with a greater reduction than in the intraperitoneal group, but it decreased the motor neuron count. Intraperitoneal minocycline increased motor neuron survival by inhibiting microglial proliferation following traumatic avulsion injury of the nerve root. The inhibitory effect was augmented by the use of intrathecal minocycline, in which the targeted drug delivery method increased the bioavailability of the therapeutic agent. However, motor neuron survival was impaired at a higher concentration of minocycline via the intrathecal route due to the more efficient method of drug delivery. Microglial suppression via minocycline can have both beneficial and damaging effects, with a moderate dose being beneficial as regards motor neuron survival but a higher dose proving neurotoxic due to impairment of the glial response and Wallerian degeneration, which is a pre-requisite for regeneration.

Predisposing factors for poor outcome of surgery for cervical spondylotic amyotrophy: a multivariate analysis.

The purpose of this study was to characterize risk factors for poor surgical outcome in patients with cervical spondylotic amyotrophy (CSA). We retrospectively reviewed 88 cases of CSA surgery and investigated age, sex, duration of symptoms, atrophy type, preoperative muscle power, signal changes on MRI, anterior horn (AH) or ventral nerve root (VNR) compression, compression levels, surgical approach and postoperative recovery. Fifty (56.8%) patients had good surgical outcome. Logistic regression, with poor outcome as dependent variable, showed independent risks associated with duration of symptoms (OR; 1 for symptom duration less than 3 months versus 3.961 [95% CI; 1.203–13.039, p = 0.024] for symptom duration of 3–6 months versus 18.724 [95% CI; 3.967–88.367, p < 0.001] for symptom duration greater than 6 months), compression type (OR; 1 for VNR versus 4.931 [95% CI; 1.457–16.685, p = 0.010] for AH versus 5.538 [95% CI; 1.170–26.218, p = 0.031] for VNR + AH), and atrophy type (OR; 1 for proximal type versus 6.456 [95% CI; 1.938–21.508, p = 0.002] for distal type). These findings suggest that a long duration of symptoms, AH or both AH and VNR compression, and distal type are risk factors for poor surgical outcome in patients with CSA.

MRI of Conus Medullaris, Cauda Equina, and Filum Terminale Lesions

Cauda equina is the Latin name for horse's tail because the cauda equina resembles a horse tail. The cauda equina is a set of 10 paired dorsal and ventral nerve roots (20 nerve roots in total), corresponding to four lumbar (second to fifth), five sacral, and one coccygeal segments that originate from the conus medullaris. These nerve roots are contained by the thecal sac, which is an enclosed space formed by dura mater and arachnoid extending from the head to the sacrum. The conus medullaris is an expansion of the terminating distal thoracic spinal cord, typically located at the T12-L1 level.

Infra-Conus Single-Level Laminectomy for Selective Dorsal Rhizotomy: Technical Advance

Background/Aims: Selective dorsal rhizotomy for spastic cerebral palsy is an effective and well-validated surgical approach. Multiple techniques have been described in the past including multiple laminectomies and a single-level laminectomy at the level of the conus. There is considerable technical challenge involved with a single-level laminectomy approach. Methods: We report here a modification of the single-level laminectomy that selectively analyzes each individual nerve root with electromyography to separate dorsal and ventral nerve roots through comparison of stimulus responses. Results: In 18 children with cerebral palsy who underwent this operation there was a mean improvement in the Modified Ashworth Scale of 2.0 with no reported incidence of muscle weakness, sensory loss, or neurogenic bladder. Conclusion: This approach allows for a modification of selective dorsal rhizotomy through a single-level laminectomy and tailors the selection of nerve root sectioning to the individual patient of interest while still maintaining its effectiveness.

DIC imaging for identification of motor and sensory nerves

Identification of motor and sensory nerves is important in applications such as nerve injury repair. Conventional practice relies on time consuming staining methods for this purpose. Here, we use laser scanning infrared differential interference contrast (IR-DIC) microscopy for label-free observation of the two types of nerve. Ventral and dorsal nerve roots of adult beagle dogs were collected and sections of different thicknesses were imaged with an IR-DIC microscope. Different texture patterns of the IR-DIC images of the motor and sensory nerve can be distinguished when the section thickness increases to 40[Formula: see text][Formula: see text]m. This suggests that nerve fibers in motor and sensory nerves have different distribution patterns. The result hints a potential new way for more rapid identification of nerve type in peripheral nerve repair surgery.

Abstracts from The 34(th) Annual National Neurotrauma Symposium June 26-29, 2016 Lexington, Kentucky.

Abstracts from The 34(th) Annual National Neurotrauma Symposium June 26-29, 2016 Lexington, Kentucky.

Lower Extremity Weakness in a Soccer Athlete

HISTORY: A 14-year-old male soccer player presented with bilateral lower leg pain and weakness. Ten days prior, he was at a lake cottage in Indiana, where he had an acute onset of bilateral leg pain, fatigue, and headache. He had a difficult time walking with a wide-based gait. Family attributed the symptoms to fatigue from intensive soccer conditioning. Over the next few days, leg pain and weakness improved, but, at soccer, he had a difficult time running and increased leg pain. He denied fevers, chills, neck pain, nausea, vomiting, diarrhea, rash, insect bites, bowel or bladder dysfunction, or upper extremity weakness. He had recent exposure to lake water, but no family members with similar symptoms. Family history was negative for neurologic, cardiac, or rheumatologic disease. PHYSICAL EXAMINATION: Well-appearing child with normal vital signs. Difficulty getting off the examination table with antalgic, wide-based gait. Diminished 4/5 strength of the bilateral proximal quadriceps, but otherwise with normal strength of the upper and lower body. Tender to palpation of the bilateral calf and quadriceps muscles without muscle or joint swelling. Neurological exam with normal deep tendon reflexes (DTRs), negative clonus, and negative Babinski. Skin without lesions. DIFFERENTIAL DIAGNOSIS: 1. Viral myositis 2. Inflammatory myopathy 3. Guillain-barré syndrome 4. Neuroparasitic infection 5. Muscular dystrophy 6. Rhabdomyolysis TEST AND RESULTS: Labs: CK 486 U/L at presentation, decreased to 66 U/L. CBC, electrolytes, TSH, ESR, CRP, urinalysis, myoglobin, CSF, ANA, and Lyme serology all normal. Imaging: Spine MRI with prominent ventral nerve root enhancement of the caudal equina (a common finding seen in Guillain-barré syndrome although not specific). EMG: Motor nerve conduction with significant reduction in compound muscle action potential amplitude. FINAL/WORKING DIAGNOSIS: Guillain-barré syndrome (GBS) with likely subacute/acute motor axonal neuropathy TREATMENT & OUTCOMES: 1. Referred to neuromuscular disorders clinic with progressive loss of DTRs. 2. Admitted to the hospital following EMG suggestive of GBS and received intravenous immunoglobulin. 3. Discharged on 60 mg of oral prednisone daily with the plan to taper. 4. Currently in weekly physical therapy with complete resolution of pain and weakness.

Developmental nicotine exposure alters cholinergic control of respiratory frequency in neonatal rats

Prenatal nicotine exposure with continued exposure through breast milk over the first week of life (developmental nicotine exposure, DNE) alters the development of brainstem circuits that control breathing. Here, we test the hypothesis that DNE alters the respiratory motor response to endogenous and exogenous acetylcholine (ACh) in neonatal rats. We used the brainstem-spinal cord preparation in the split-bath configuration, and applied drugs to the brainstem compartment while measuring the burst frequency and amplitude of the fourth cervical ventral nerve roots (C4VR), which contain the axons of phrenic motoneurons. We applied ACh alone; the nicotinic acetylcholine receptor (nAChR) antagonist curare, either alone or in the presence of ACh; and the muscarinic acetylcholine receptor (mAChR) antagonist atropine, either alone or in the presence of ACh. The main findings include: (1) atropine reduced frequency similarly in controls and DNE animals, while curare caused modest slowing in controls but no consistent change in DNE animals; (2) DNE greatly attenuated the increase in C4VR frequency mediated by exogenous ACh; (3) stimulation of nAChRs with ACh in the presence of atropine increased frequency markedly in controls, but not DNE animals; (4) stimulation of mAChRs with ACh in the presence of curare caused a modest increase in frequency, with no treatment group differences. DNE blunts the response of the respiratory central pattern generator to exogenous ACh, consistent with reduced availability of functionally competent nAChRs; DNE did not alter the muscarinic control of respiratory motor output. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1138-1149, 2016.

MRI-based determination of convex or concave surgical approach for lateral lumbar interbody fusion in lumbar degenerative scoliosis: a retrospective radiographic comparative analysis

We determined the optimal approach to perform lateral lumbar interbody fusion (LLIF) to treat lumbar degenerative scoliosis (LDS) by comparing the safe zone and psoas muscle on the concave and convex sides. Patients without scoliosis (N.=52) and those with levoscoliosis (N.=55) and dextroscoliosis (N.=53) were included. Vertebral anteroposterior diameter, overlap between the retroperitoneal vessels and the anterior edge of the vertebra, and overlap between the ventral nerve roots and the posterior edge of the vertebra were measured, and safe zones were calculated. The cross-sectional area (CSA) and fatty infiltration (FI) rate of the bilateral psoas muscle were measured, and the convex and concave sides were compared. The ventral overlap on the convex side decreased at the L3-4 and L4-5 levels in the levoscoliosis group (P=0.05 and P=0.01, respectively) and at the L2-3 and L3-4 levels in the dextroscoliosis group (P=0.01 and P=0.03, respectively). The convex side at the L3-4 and L4-5 levels presented a greater safe zone in the levoscoliosis group (76.11% vs. 74.00% at L3-4, P=0.02; 69.37% vs. 63.16% at L4-5, P=0.00). The convex side at the L2-3, L3-4, and L4-5 levels in the dextroscoliosis group showed greater safe zones compared to those in the group without scoliosis (77.78% vs. 74.40% at L2-3, P=0.02; 72.15% vs. 69.87% at L3-4, P=0.03; and 58.45% vs. 54.39% L4-5 level, P=0.01). CSA of the psoas muscle on the concave side was significantly higher at the L2-3 and L3-4 levels (P=0.02 and 0.01, respectively). The psoas muscle on the concave side was significantly thicker (P=0.00 at all levels) with a higher FI rate. The convex retroperitoneal vessels were positioned more anteriorly, whereas the ventral nerve roots lacked significant positional alterations, increasing the convex safe zone and providing optimal disc space access and less psoas muscle injury.