Neurological Weakness Research Articles

Retrospective multicenter study of surgical treatments for osteoporotic vertebral fractures

BackgroundAlthough many surgical procedures are available for treating osteoporotic vertebral fractures, there have been no comprehensive multicenter surveys in Japan focusing on surgical treatments for these fractures. This study aimed at (1) conducting a retrospective multicenter study to survey surgical treatments performed at referral center hospitals in various regions in Japan and (2) analyzing situations and problems related to the surgical treatments of osteoporotic vertebral fractures in Japanese hospitals. MethodsAmong 738 patients who were hospitalized in 13 hospitals in various regions in Japan between 2005 and 2006 for osteoporotic vertebral fractures, 84 patients (11.4%) who underwent spinal surgery were enrolled. These patients were retrospectively analyzed regarding cause of injury, preoperative symptoms, preoperative neurological function, surgical procedures, periods of bed rest, length of hospital stay, and ambulatory status at discharge from hospital. ResultsAs to the cause of spinal fracture, 38 patients (45% of the surgical patients) could not identify a specifi c cause of their spinal fracture. Preoperative neurological motor weakness in legs was observed in 41 (49%). With regard to surgical treatment, posterior spinal reconstruction surgery was performed in 50 patients (60%), vertebroplasty in 26 (31%), anterior reconstruction surgery in 6 (7%), anterior and posterior combined reconstruction surgery in 1, and posterior decompression alone in 1 patient. In all, 70 patients (83.3%), whose periods of hospital stay averaged 52.8 days, could walk by themselves at the time of discharge; 14 (16.7%), whose periods of hospital stay averaged 44.7 days, could not walk by themselves at the time of discharge. ConclusionsEven after a large variety of surgical procedures were tried to treat osteoporotic vertebral fractures and long hospital stays, about 17% of the patients were unable to walk by themselves at the time of discharge from hospital.

Current Perception Threshold in Subacute Myelo-Optico-Neuropathy

ABSTRACTWe report the first current perception threshold (CPT) examination of sensory disturbance in subacute myelo-optico-neuropathy (SMON). SMON patients experience serious neurological symptoms, including dysesthesia, sensory loss, motor weakness, and visual impairment. During CPT examination, 5 Hz, 250 Hz, and 2,000 Hz stimulations were used to stimulate C fibers, A-δ fibers, and A-β fibers, respectively. Ten SMON patients (mean age, 73.8 ± 8.4 years) and ten age-matched controls (72.3 ± 6.3 years) were studied using CPT measured at the index finger and near the external malleolus. The CPTs to 250 Hz and 2,000 Hz stimulations near the external malleolus were significantly higher and the CPT to 5 Hz stimulation was significantly lower in the SMON group than in the control group. Although peripheral nerve impairment is mild in SMON, pathological examination shows a decrease of large fibers. This is thought to increase the CPTs to 250 Hz and 2,000 Hz stimulations. The center of the gate control of pain exists in the posterior horn receiving information from the dorsal root ganglion. The dorsal root ganglion at the lumber cord is strongly impaired in SMON; therefore, the gate control may not work effectively, and decreases CPT to 5 Hz stimulation.

MtDNA T8993G-Augmented Mitochondrial Stresses Upon mCa2+ Overload and its Protection by Melatonin in a NARP Cybrid

Mitochondrial DNA (mtDNA) T8993G mutation inhibits specifically mitochondrial F1F0-ATPase (complex V) for severe ATP deficiency and is clinically associated with neurological muscle weakness, ataxia, and retinitis pigmentosa so called NARP mutation. At present, detail T8993G-associated mitochondrial mechanisms as well as its therapeutic strategies are limited. Using time-lapse laser scanning dual fluorescence imaging microscopy, this study investigated T8993G-altered apoptotic mitochondrial pathology particular upon mCa2+ stress and protection by melatonin, previously reported to protect mCa2+ stress-mediated apoptosis (Hsu et al., 2009 JPR in press). In comparison to its parental osteosarcoma 143B and mtDNA less (ρ0) cells, T8993G induced significant hyperpolarization of mitochondrial membrane potential (ΔΨm) and potentiated greatly ionomycin-induced mCa2+ stress. T8993G-augmented mCa2+ stress subsequently elicited rigorously generation of mitochondrial oxygen species (mROS), depletion of cardiolipin (CL) and activation of the mitochondrial permeability transition (MPT). In contract, ρ0 cells, with much depolarized ΔΨm, suffered less mCa2+ stress, mROS formation, CL depletion and the MPT opening. Interestingly, melatonin reduced significantly peak amplitude of the ionomycin-induced mCa2+ transient and antagonized efficiently mCa2+-augmented mROS generation for a reduced depletion of CL and activation of the MPT. In addition, melatonin prevented “oxidation free mCa2+”-mediated MPT suggesting its direct targeting on the MPT. Melatonin-enhanced tail amplitude of mCa2+ transient possibly due to the reduced MPT-dependent depolarization of ΔΨm, however, did not enhance mCa2+ stress-mediated pathology in NARP cybrids possibly as melatonin-elevated mCa2+ improved mitochondrial respiratory. Thus, the administration of melatonin may provide potential improvement for the treatment of mtDNA T8993G-associated NARP syndromes and diseases.

Successful Treatment of a Southern Pacific Rattlesnake (Crotalus viridis helleri) Bite in a Caracal (Caracal caracal)

A caracal (Caracal caracal) was bitten on the lower lip by a southern Pacific rattlesnake (Crotalus viridis helleri) and quickly developed progressive, severe soft tissue swelling and bruising of this site. Initial laboratory results revealed prolonged clotting times within the first hour of envenomation, followed by signs of vasculitis and anemia. The caracal was successfully treated with intravenous crystalloids, four vials of polyvalent crotalidae antivenom, and transfusions of bovine hemoglobin glutamer-200 (Oxyglobin) and fresh whole blood. The progressive soft tissue swelling and bruising halted and the coagulation parameters improved after administration of antivenom; however, the caracal continued to show neurologic dysfunction, including depression, weakness, muscle fasciculations, anisocoria, and ataxia. Administration of an additional vial of antivenom 72 hr after envenomation quickly corrected the weakness and muscle fasciculations, whereas the anisocoria and mild ataxia persisted for another 24 hr. The caracal remains clinically normal 3 yr after the envenomation.

Erlotinib with sirolimus for advanced renal cell carcinoma: Preliminary efficacy results

e16037 Background: The mammalian target of rapamycin (mTOR) is an important therapeutic target in the treatment of renal cell carcinoma (RCC). Temsirolimus, an analog of rapamycin, prolongs survival when used to treat high-risk RCC patients and is approved for the treatment of advanced RCC. Oral rapamycin (sirolimus/Rapamune) is less expensive than temsirolimus and plasma levels can be routinely monitored. Pre-clinical data indicate that the combined inhibition of the epidermal growth factor receptor (EGFR) and mTOR results in enhanced anti-cancer activity, especially in cell lines with wt-VHL. Methods: All patients on this study had metastatic or unresectable renal cell carcinoma with progression despite sunitinib and/or sorafenib. Treatment was started with erlotinib (Tarceva) 150 mg po daily. On day 8, sirolimus was begun with a single 6 mg loading dose and then given as 2 mg daily. Radiographic assessments were performed every 8 weeks. Results: The current data set was obtained through July of 2008. Enrollment started in July of 2006 with the last patient accrued in March 2008; 25 patients have been treated. The median subject age was 60 years with an average of 2.6 previous medical treatments. The unconfirmed median progression free survival (PFS) was 12 weeks (range 2–52) with 4 patients remaining on active treatment and included in this analysis. No confirmed complete or partial responses were observed, but meaningful stable disease (SD) (e.g., > 6 months) was noted in a small group of patients. The most common adverse events were rash and diarrhea with the majority of these observed as a grade 1 event. Grade 3 and 4 toxicities included rash, mucositis, neurological motor weakness, dehydration, worsening cardiac function, non-ST elevation MI, and anemia. Additional efficacy, toxicity and pharmacokinetic data will be presented. Conclusions: The combination of erlotinib and sirolimus produces a median PFS of 12 weeks in a significantly pretreated RCC population, which is not dissimilar to recent results with other mTOR inhibitors in this setting. The toxicity profile of this combination is consistent with the expectations of this pre-treated patient population with advanced RCC. [Table: see text]

The weak cat. Practical approach and common neurological differentials.

Practical relevanceWeakness is recognized somewhat infrequently in cats, but is an important manifestation of neurological disease. The clinician must perform a complete neurological examination to determine the neuroanatomic basis for the weakness. As for all species, the neuroanatomic diagnosis allows the clinician to generate an appropriate differential diagnosis, to design a diagnostic plan, to prognosticate, and ultimately to develop a treatment plan.Clinical challengesThe cause(s) of neurological weakness in the cat may be difficult to determine without access to advanced imaging modalities, cerebrospinal fluid analysis or electrodiagnostics. However, an accurate neuroanatomic diagnosis allows the clinician to pursue preliminary anomalous (vertebral anomalies), metabolic (eg, diabetes mellitus, electrolyte abnormalities) and neoplastic differentials via blood work, vertebral column and thoracic radiography, and abdominal ultrasound. Subsequently, referral to a specialty veterinary hospital may be warranted to pursue advanced neurodiagnostics.AudienceThis review provides a framework for generating a neuroanatomic and differential diagnosis in the weak cat. It also discusses the pathogenesis and clinical signs associated with the most common neurological differentials for feline paresis. As such, it is aimed at both primary health care and specialty veterinarians.Patient groupThe neurological conditions discussed in this review cause weakness in cats of all age groups.

Artificial nucleus replacement: surgical and clinical experience

Objective: To assess long-term clinical results of prosthetic disc nucleus (PDN) replacement for the treatment of lumbar disc herniation. Methods: Seventy-two patients with lumbar disc herniation were implanted with a single PDN device from March 2002 to December 2003. Fifty-eight (80.6%) patients attended clinical, functional, and radiographic follow-up examinations for more than 48 months. Independent analysis was performed by careful review of the interviews, operative reports, preoperative and postoperative radiographs, and computed tomography scans or magnetic resonance imaging (MRI). Results: After implantation, a significant proportion of patients experienced pain relief. Improvements were noted in pain intensity, walking distance, neurological weakness, Oswestry and Prolo scores, intervertebral disc height and lumbar mobility. Intervertebral disc height was not well maintained, compared with the preoperative height it decreased 18% (P < 0.001). Several complications were associated with the implantation of PDN, including transient low-back pain, implant dislocation, malposition of the implant, damage to the end plates and subsidence of implant. Conclusion: The clinical data show that PDN is preferred and can effectively increase the range of lumbar motion in patients with lumbar disc herniation. However, this study only represents cases in our centre.

Prise en charge anesthésique des patients porteurs de myotonie de Steinert : à propos de deux cas cliniques

Steinert disease, the most common myopathy in adults, is a challenge for anaesthesiologists and critical care physicians during the perioperative time. The risk of myotonic crisis, malign hyperthermia and the increased sensitivity to anaesthetic drugs shouldn't be forgotten. On contrary, Steinert disease is rarely revealed in the postoperative period. It should be evoked in case of postoperative pulmonary complications such as difficult weaning with neurological symptoms like hypotonia or muscular weakness.

Artificial nucleus replacement: surgical and clinical experience

To assess long-term clinical results of prosthetic disc nucleus (PDN) replacement for the treatment of lumbar disc herniation. Seventy-two patients with lumbar disc herniation were implanted with a single PDN device from March 2002 to December 2003. Fifty-eight (80.6%) patients attended clinical, functional, and radiographic follow-up examinations for more than 48 months. Independent analysis was performed by careful review of the interviews, operative reports, preoperative and postoperative radiographs, and computed tomography scans or magnetic resonance imaging (MRI). After implantation, a significant proportion of patients experienced pain relief. Improvements were noted in pain intensity, walking distance, neurological weakness, Oswestry and Prolo scores, intervertebral disc height and lumbar mobility. Intervertebral disc height was not well maintained, compared with the preoperative height it decreased 18% (P < 0.001). Several complications were associated with the implantation of PDN, including transient low-back pain, implant dislocation, malposition of the implant, damage to the end plates and subsidence of implant. The clinical data show that PDN is preferred and can effectively increase the range of lumbar motion in patients with lumbar disc herniation. However, this study only represents cases in our centre.

Syringomyelia-associated Scoliosis With and Without the Chiari I Malformation

Although there may be a hereditary component to true idiopathic scoliosis, the condition has no known cause and is not associated with dysraphism. However, scoliosis with an associated syrinx, with or without the Chiari I malformation, sometimes presents as an idiopathic-type curve. Physical examination findings and subtle clues on diagnostic imaging may help the orthopaedic surgeon diagnose scoliosis associated with syringomyelia. Examination findings include asymmetric reflexes and presentation at ages younger than those of patients who present with adolescent idiopathic curves (i.e., 10 to 14 years). Radiologic findings include kyphosis at the apex of the curve. Indications for surgical decompression include progressive neurologic deficits, weakness, pain, and progressive curves. Most orthopaedic surgeons agree that a syrinx should be evaluated neurosurgically before any planned spinal arthrodesis to decrease the risk of neurologic injury connected with surgical correction. The indications for arthrodesis in these patients compared with those with idiopathic curves are evolving.

Short-term progressive resistance exercise may not be effective at increasing wrist strength in people with tetraplegia: a randomised controlled trial

Is an 8-week progressive resistance exercise program effective for increasing strength in the wrist muscles of people with tetraplegia? Is it effective for improving muscle endurance and participants' perceptions about use of their hands for activities of daily living? Randomised controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis. Thirty-two people with tetraplegia and neurological weakness of their wrist flexor or extensor muscles. The wrist muscles of one randomly-chosen hand were trained 3 times a week for 8 weeks. The control group received no intervention. The primary outcome was strength measured as maximal voluntary isometric torque in Nm. The secondary outcomes were muscle endurance measured as fatigue resistance and participants' perceptions about use of their hands using the Canadian Occupational Performance Measure. The mean effect on maximal voluntary isometric torque was 0.2 Nm (95% CI -0.5 to 0.8). This represents an 8% increase of mean initial strength; less than the 20% deemed clinically worthwhile at the commencement of the study. The mean effect on fatigue resistance was 0.1 (95% CI 0.0 to 0.2). The mean effect on participants' perceptions of performance was -0.3 (95% CI -1.9 to 1.2) and satisfaction was -0.3 (95% CI -1.6 to 1.0). The results indicate that progressive resistance exercise has no effect on participants' perceptions about hand function. However, it is not yet clear whether progressive resistance exercise programs improve strength and endurance in muscles with neurologically-induced weakness following tetraplegia.

Treatment of Osteoporotic Fractures of the Spine

Osteoporosis is a skeletal disease characterized by reduced bone strength due to the loss of bone mass, structural disproportion and reduced calcium level as well as changes in the bone structure caused by trabecular deficit. The loss of bone mass in the vertebrae leads to an increased risk of fractures. Osteoporotic vertebral fractures are two to three times more frequent than hip fractures, especially in women. Osteoporotic compressive fractures of the spine mostly occur in the middle and lower thoracic spine and in the thoracolumbar spine. Common consequences of fractures include long-term pains, decrease in the height and spinal deformity, which significantly correlate with disorders in the gait and mobility, reduced pulmonary function, loss of appetite and in the end increased mortality. Clinical picture in acute conditions manifests itself as a sudden pain in the back following minimal trauma but also often without any trauma at all. Diagnostics is based on a detailed medical history and a thorough clinical examination. Radiological diagnosis relies on standard x-rays. In case of clinical indication (differential diagnosis of tumor or spondylitis, neurological weakness) CT and/or MR imaging is performed. The approach to the treatment of osteoporotic fractures of the spine is individual and is based upon the medical history, localization of symptoms and correlation of the clinical examination with the radiological finding. Open reduction, decompression and fixation are indicated in patients with posttraumatic stenosis and neurological weakness. Current operative methods include vertebroplasty and kyphoplasty, which significantly reduce pain and improve mobility of the patient and consequently, the quality of life.

Paraostéoarthropathie de la hanche sur lésion du nerf sciatique par injection intramusculaire de quinine

Introduction Often occurring in central nerve injuries, paraosteoarthropathic conditions are revealed by a stiffness or ankylosis of the joint. Their occurring during peripheral nerve injuries is rare. Objective To report a case of hip paraosteoarthropathy features after sciatica nerve injury by quinine intramuscular injection. Materials and method We report a case of a 24-year-old patient presenting with pain, oedema of the left buttock, limitation of bending of the left hip, and antalgic limping associated with a small step because of axonal left sciatic nerve injury. Initial pelvis X-ray and laboratory findings were normal. Reviewed 4 months later with important stiffness of the left hip, a second X-ray showed an atypical paraosteoarthropathy (POA). Chemotherapy and physiotherapy alleviated neurological muscle weakness but did not have any effect on the hip functionality. Surgical excision was the only treatment that improved the amplitude of movements. Evolution 7 years later showed the disappearance of the peripheral nerve-injury signs and the conservation of the movement amplitude obtained after excision, without a return to normal. Conclusion–Discussion Factors pointing to this POA were initial œdema, immobilization because of pain, and trauma by quinine intramuscular injection. The interest is the exceptional occurrance of POA on a peripheral nerve injury (sciatica nerve injury by quinine injection) outside the context of length resuscitation and that sciatica nerve injury is frequent in tropical countries but anachronistic in a developed one.

G.P.3 08 Novel mutations in the CHRNB1 gene in three patients affected by a congenital myasthenic syndrome

Mutations of the nicotinic acetylcholine receptor (AChR) cause congenital myasthenic syndromes (CMS) by leading either to endplate AChR deficiency or to altered kinetic properties. Mutations in the alpha, beta and delta subunits of the AChR are less frequent than mutations of the epsilon subunit and often associated with a severe phenotype. So far, only five mutations of the gene encoding the beta subunit (CHRNB1) have been published. Here we present three CMS patients out of two families with mutations in the CHRNB1 gene. Two patients of Serbian origin, mother and daughter, presented with mild myasthenic syndromes in their late twenties. In each case, symptoms appeared during a pregnancy. At a neurological examination, mild ptosis and weakness of facial and upper extremities muscles were noted. A clear decremental response to repetitive nerve stimulation was obtained; repeated prostigmine tests did not show any clear improvement of the symptoms. The third patient, a girl currently 3 years of age, presented with an early-onset CMS associated with muscle hypotonia at birth, respiratory and feeding difficulties in the first weeks of life. Later on, apneic episodes occurred several times, especially during infections. At the age of 2 years, a CMS was diagnosed and acetylcholinesterase inhibitor therapy was started, which was only partially effective. By direct sequencing of the CHRNB1 gene we identified a heterozygous missense mutation (T265S) in the two Serbian patients. This mutation alters a conserved residue of the pore-forming second transmembrane region of the AChR beta subunit. In the third patient we identified two compound heterozygous mutations of the CHRNB1 gene: a nonsense mutation, Y149X, and a missense mutation, R220C. The arginine at position 220 in the extracellular domain of the beta subunit is highly conserved among species and AChR subunits. CHRNB1 mutations shall be considered as a rare cause of CMS. The pathogenic mechanisms of the mutations presented here remain to be investigated.

Foramen Magnum Surgery: Experience With 22 Cases

The foramen magnum is one of the important anatomic structures in the craniovertebral junction. Various tumors and lesions may involve the foramen magnum. Surgery in this region is challenging and a variety of surgical approaches have been advocated for the operation in this area only recently has this surgery been done outside major centers. We report our experience with the surgery of the foramen magnum tumors. This clinical study was done on a series of 22 cases of foramen magnum tumors over a period of 8 years. Surgical approaches were classic midline posterior fossa in 20 cases and lateral approach in 2 cases. The most frequent clinical presentations were suboccipital neck pain, with complaints of weakness and sensory changes. The most frequent neurologic findings were weakness, hyperreflexia, sensory changes, cerebellar signs, and gait disturbance. Pathologies included 7 meningiomas, 4 neurofibromas, 3 schwannomas, 2 hydatid cysts, 2 astrocytomas, and 4 miscellaneous lesions (tuberculoma, syphilis, ependymoma, and choroid plexus papilloma). Gross total resection was performed in 14 (64%) cases, subtotal resection in 4 (18%) cases, and partial resection in 4 (18%) cases. There were 2 (9%) mortality and 4 (18%) patients who developed 6 complications including cerebrospinal fluid leakage, meningitis, lower cranial nerves palsy, gait disturbance, sensory and motor deficits. Foramen magnum tumors are diverse in pathology and clinical manifestations. With the modern diagnostic tools such as magnetic resonance imaging and advances in surgical techniques especially skull base approaches, resection of the lesions could be performed with acceptable and minimum morbidity and mortality. The posterior approach is adequate for the majority.

P94. Use of continous intraoperative electromyographic potential nerve root monitoring during decompression of patients with symptomatic lumbar radiculopathy

BACKGROUND CONTEXT: Symptomatic compressive lumbar radiculopathy and sciatica are very common indications for spinal surgery. Persistent postoperative sciatica and weakness is reported in 5 to 15% of clinical series. Inadequate disc fragment excision, suboptimal bony decompression of the lateral recess, and persistent foraminal/recess compressive lesions are commonly cited causes for persistent symptoms. Additionally, new neurological weakness can complicate up to 2–3% of decompressive surgeries.

Computer modeling of gait abnormalities in cerebral palsy: application to treatment planning

The treatment of gait abnormalities in persons with cerebral palsy is challenging. Theoretically, gait abnormalities can be diminished by decreasing the muscle forces that disrupt normal movement (e.g. via muscle–tendon lengthenings or tone-altering medications) and/or increasing the muscle and ground reaction forces that have the potential to improve movement (e.g. via strengthening exercises, orthoses, or derotational osteotomies). However, different patients exhibit varying degrees of neurologic impairment, spasticity, weakness, and bone deformity, suggesting that gait deviations arise from a variety of sources, each of which requires a different treatment. Treatment planning is further complicated because there is currently no scientific basis for determining how patients’ neuromusculoskeletal impairments contribute to abnormal movement. This paper describes how biomechanical models can be used, in combination with experimental data, to enhance our understanding of gait abnormalities and to provide a theoretical basis for planning treatments. Two examples are presented, and suggestions for future work are discussed.

The effect of localized leg muscle fatigue on tibial impact acceleration

Objective. The objective of this study was to assess the effect of localized leg muscle fatigue on tibial acceleration following impact. Background. Peak tibial accelerations measured just distal to the knee joint during running have been shown to increase with general body fatigue. However, the role that local leg muscle fatigue plays in shock attenuation is not clear. Methods. The unshod, dominant foot of 24 healthy women in two different age groups was impacted into a vertical force plate, using a human pendulum method. Impact velocity and force approximated that found in running. EMG activity of the gastrocnemius and tibialis anterior muscles was monitored during fatiguing isometric exercise to assess fatigue, and quantified at impact as a measure of muscle activation level. A skin-mounted uni-axial accelerometer, was located at the tibial tubercle under pre-load, to measure tibial acceleration at impact. Results. There was a significant decrease in peak tibial acceleration ( P=0.008) and acceleration slope ( P=0.033) following fatigue. There were no significant main effects or interactions for age group or muscle group for all tibial response variables. Conclusion. The reduction in peak tibial acceleration following fatigue (for the test performed) is contrary to the response documented following whole-body fatigue. Relevance A decrease in tibial acceleration transmission may have a protective effect on the weight-bearing joints proximal to the ankle. Thus, local muscle fatigue may not be detrimental to the joints in those people participating in weight-bearing, ballistic activities or for those with neurological peripheral weakness.

Prosthetic Disc Nucleus (PDN) Replacement for Lumbar Disc Herniation

A clinical follow-up study was performed to evaluate lumbar disc nucleus replacement clinically and functionally. The objective was to assess the clinical efficacy of the prosthetic disc nucleus (PDN) for treatment of lumbar disc herniation. The PDN was designed to treat patients suffering from disc herniation and/or degeneration. Clinical trials for PDN were first conducted in 1996, and the results showed that the PDN device was effective in most of the patients who were implanted. These studies had been carried out with patients who were implanted with a pair of the devices. The main complication was device migration. Therefore, a follow-up study based on a single PDN device implantation was designed to evaluate its clinical result. Forty-five patients with lumbar disc herniation were implanted with one PDN device from March 2002 to December 2002. Thirty (66.7%) patients came to the clinical, functional, and radiographic 6-month follow-up examinations. Independent analysis was performed by careful review of the charts, operative notes, preoperative and postoperative radiographs, magnetic resonance images, and follow-up records of all patients. After implantation, significant proportions of patients experienced pain relief. Improvements were noted in pain intensity, walking distance, lumbar mobility, neurologic weakness, Oswestry and Prolo scores, and intervertebral disc height. No difference in work status after PDN implantation could be detected. Compared with the preoperative height, the intervertebral disc had gained 19.7% (P < 0.001). Device migration, failure, and dislocation were not noticed in any patient. A few patients had minor complications such as transient low-grade fever. Clinically, a single PDN is preferred and can effectively increase the height of the intervertebral disc in patients with lumbar disc herniation. However, long-term follow-up of PDN implantation needs to be studied.

Wooden splinter in the foramen magnum

A 20-year-old male patient was involved in a violent conflict and a wound was inflicted upon his suboccipital region by a wooden chopstick. He was sent to our emergency room about 1 h later. He was irritable with fluent and clear speech and complaining of neck pain. On examination, he was conscious and alert. No peripheral neurological abnormalities or weakness of the extremities were noted. Lateral cervical spine and skull X-rays were unremarkable. Emergent nonenhanced computed tomography (CT) of the head and craniocervical junction was performed. The patient had no intracranial lesion. Axial CT at the level of craniocervical junction showed a linear low-density signal represented by a low Hounsfield unit (Hu) number of −68, traversing the spinal canal of the craniocervical junction, which coincided with the location of the chopstick (Fig. 1). A wooden chopstick retained in the foramen magnum was diagnosed. Prophylactic antibiotics and tetanus toxoid were administered. The patient underwent an emergency operation to remove the foreign body. A splinter of wooden chopstick in the foramen magnum was removed. A small dural penetration wound that was found intra-operatively was repaired after debridement. He was well, without neurological deficit or cerebrospinal fluid leakage 1 year after discharge.