Lixun Wang

Electrophysiological differences between Hirayama disease, amyotrophic lateral sclerosis and cervical spondylotic amyotrophy

BackgroundHirayama disease (HD), amyotrophic lateral sclerosis (ALS) or cervical spondylotic amyotrophy (CSA) may result in atrophy of intrinsic hand and forearm muscles. The incidence of HD is low, and it is rarely encountered in the clinical setting. Consequently, HD is often misdiagnosed as ALS or CSA. It is important to differentiate these diseases because HD is caused by a benign focal lesion that is limited to the upper limbs.MethodsThe thenar and hypothenar compound muscle action potential (CMAP) amplitude of the upper limbs of 100 HD, 97 ALS and 32 CSA cases were reviewed; 35 healthy individuals were included as controls. Seventy-eight percent, 38% and 69% of patients with HD, ALS or CSA had unilateral involvement; the remaining patients were affected bilaterally. Thenar and hypothenar CMAP amplitude evoked by ulnar stimulation was compared with CMAP evoked by median stimulation.ResultsThe ulnar/median CMAP ratio was found to be lower in HD (0.55 ± 0.41, P < 0.0001), higher in ALS (2.28 ± 1.15, P < 0.0001) and no different in CSA (1.21 ± 0.53, P > 0.05) compared with the normal range from previous studies (0.89-1.60) and with the healthy controls (1.15 ± 0.23). Conduction velocities of the sensory and motor nerves, the amplitude of the sensory nerve action potential, and the CMAP amplitude of the unaffected limb were all normal.ConclusionsThe hand muscles were differentially affected between patients with HD, ALS and CSA. The ulnar/median CMAP ratio could be used to distinguish these three diseases.

Efficacy of anterior cervical decompression and fusion procedures for monomelic amyotrophy treatment: a prospective randomized controlled trial: clinical article.

OBJECT Monomelic amyotrophy (MMA) is a benign, self-limiting lower motor neuron disease. Optimal surgical strategies-discectomy decompression and fusion (DDF) or corpectomy decompression and fusion (CDF)-for patients with aggravated symptoms (within 6 months of presentation) are controversial, particularly in those who are ineligible for conventional treatment. These 2 methods of anterior cervical decompression and fusion for MMA in patients unwilling or unable to wear a conventional cervical collar long term were evaluated. METHODS Anterior cervical decompression and fusion were performed in 48 male patients with MMA between September 2007 and September 2010. Patients were randomly treated with anterior cervical discectomy decompression with autologous iliac crest bone grafting and internal plate fixation (DDF group: 24 patients) or anterior cervical corpectomy, posterior longitudinal ligament resection, autologous iliac crest bone grafting, and internal plate fixation (CDF group: 24 patients). Subjective symptom assessments and electromyography (EMG) examinations were conducted both preoperatively and postoperatively. RESULTS Subjective assessments and EMG studies (mean follow-up duration 25.9 months) indicated improvement in 64.6% and 60% of patients, respectively. No significant correlations between the effectiveness of surgery and age at symptom onset, preoperative symptom duration, or postoperative follow-up time were found. CONCLUSIONS The lack of a significant difference in effectiveness between DDF and CDF favors DDF as more clinically applicable because of its lower procedural risks. As a second-line alternative to cervical collar treatment, surgical anterior cervical decompression and fusion via DDF or CDF may prevent further deterioration and produce good short-term therapeutic effects in patients with MMA; however, cervical collar treatment is recommended for eligible patients because of its lower associated risks.

Lumbar spinal stenosis induced by rare chronic tophaceous gout in a 29-year-old man.

Spinal gout is rare in patients younger than 45 years, occurring most commonly between ages 45 and 80 years. This article describes a 29-year-old man with a history of gout initially observed more than 20 years previously who presented with lower back pain and left lower limb weakness. Computed tomography and magnetic resonance imaging revealed severely damaged facet joints and laminae surrounding L4-S1, and materials with a granular, yellow, cheese-like appearance were observed under direct vision. Postoperative histological examination confirmed spinal gout. Complete posterior decompression was performed concurrently with interbody fusion at L4-L5 and L5-S1. Seventeen-month follow-up revealed good recovery.The mechanism by which urate crystals form preferentially in the spine as opposed to more common soft tissue sites is not well understood. Most reported spinal gout cases were located at L4-S1, which were believed to be the segments with high stresses. These cases occurred in older patients with degenerative spinal diseases and had trauma as indicators. The current authors presume that gout is more likely to exist in the mobile regions with high pressure, such as L4-S1, even in individuals with an initially healthy spine, especially with a long period of abnormal renal dysfunction. Although it is often overlooked in young patients, this condition may be more common than the literature suggests due to the high potential for misdiagnosis in relatively young patients.

Stab wound with lodged knife tip causing spinal cord and vertebral artery injuries: case report and literature review.

Study Design. Case report and literature review. Objective. To report the case of a young patient who sustained a penetrating wound with a knife tip retained in his cervical vertebrae and to review the literature. Summary of Background Data. Stab wound with foreign body retained, associated with spinal cord injury and vertebral artery injury, is not commonly reported. The timing and approach of surgical intervention are still controversial. Methods. A 17-year-old boy with a wound in the neck presented with diminishing feeling and dysfunction of the left leg and arm. Radiographs demonstrated a foreign body at the C4 level, and possible spinal cord and vertebral artery injuries were detected by computed tomography. Digital subtracted angiography showed a small lateral opening of the injured artery, which was successfully embolized. The knife tip was removed from the original wound without severe cerebrospinal fluid leakage or bleeding, Results. The patient achieved immediate improvement after the operation. Conclusion. Cases of simultaneous spinal cord injury and vertebral artery injury in which the foreign body is retained are uncommonly reported. Digital subtracted angiography is necessary for cervical penetrating wounds and surgical approach should be individualized.

Mast Quadrant-assisted Minimally Invasive Modified Transforaminal Lumbar Interbody Fusion: Single Incision Versus Double Incision

Background: The concept of minimally invasive techniques is to make every effort to reduce tissue damage. Certainly, reducing skin incision is an important part of these techniques. This study aimed to investigate the clinical feasibility of Mast Quadrant-assisted modified transforaminal lumbar interbody fusion (TLIF) with a small single posterior median incision. Methods: During the period of March 2011 to March 2012, 34 patients with single-segment degenerative lumbar disease underwent the minimally invasive modified TLIF assisted by Mast Quadrant with a small single posterior median incision (single incision group). The cases in this group were compared to 37 patients with single-segment degenerative lumbar disease in the double incision group. The perioperative conditions of patients in these two groups were statistically analyzed and compared. The Oswestry Disability Index (ODI) scores, Visual Analog Scale (VAS) scores, and sacrospinalis muscle damage evaluation indicators before operation and 3, 12 months postoperation were compared. Results: A total of 31 and 35 cases in the single incision and double incision groups, respectively, completed at least 12 months of systemic follow-up. The differences in perioperative conditions between the two groups were not statistically significant. The incision length of the single incision group was significantly shorter than that of the double incision group (P < 0.01). The ODI and VAS scores of patients in both groups improved significantly at 3 and 12 months postoperation. However, these two indicators at 3 and 12 months postoperation and the sacrospinalis muscle damage evaluation indicators at 3 months postoperation did not differ significantly between the two groups (P ≥ 0.05). Conclusions: Mast Quadrant-assisted modified TLIF with a small single posterior median incision has excellent clinical feasibility compared to minimally invasive TLIF with a double paramedian incision.

Abnormal flexor carpi radialis H-reflex as a specific indicator of C7 as compared with C6 radiculopathy.

Objective: The H-reflex of the flexor carpi radialis (FCR H-reflex) has not been commonly used for the diagnosis of cervical radiculopathy when compared with the routinely tested soleus H-reflex. Although both S1 and S2 roots innervate the soleus, the H-reflex is selectively related to S1 nerve root function clinically. Flexor carpi radialis is also innervated by two nerve roots which are C6 and C7. Although they are among the most common roots involved in cervical radiculopathy, few studies reported if the attenuation of the FCR H-reflex is caused by lesions affecting C7 or C6 nerve roots, or both. We aimed to identify whether an abnormal FCR H-reflex was attributed to the C7 or C6 nerve root lesion, or both. The sensitivities of needle electromyography, FCR H-reflex, and provocative tests in unilateral C7 or C6 radiculopathy were also compared in this study. Methods: A concentric needle electrode recorded bilateral FCR H-reflexes in 41 normal subjects (control group), 51 patients with C7 radiculopathy, and 54 patients with C6 radiculopathy. Clinical, radiological, and surgical approaches identified the precise single cervical nerve root involved in all patient groups. The H-reflex and M-wave latencies were measured and compared bilaterally. Abnormal FCR H-reflex was defined as the absence of the H-reflex or a side-to-side difference over 1.5 milliseconds which was based on the normal side-to-side difference of the H-reflex latency of 16.9 milliseconds (SD = 1.7 milliseconds) from the control group. We also determined standard median and ulnar conduction and needle electromyography. The provocative tests included bilateral determination of the Shoulder Abduction and Spurlings tests in all radiculopathy group patients. Results: Abnormal FCR H-reflexes were recorded in 45 (88.2%) of C7 radiculopathy group patients, and 2 (3.7%) of C6 radiculopathy group patients (P < 0.05). Needle electromyography was abnormal in 41 (80.4%) of C7 radiculopathy patients and 43 (79.6%) of C6 radiculopathy patients. Provocative tests were positive in 15 (29.4%) of C7 radiculopathy patients and 25 (46.3%) of C6 radiculopathy patients. Conclusions: Flexor carpi radialis H-Reflex provides a sensitive assessment of evaluating the C7 spinal reflex pathway. Clinically, a combination of the FCR H-reflex with needle electromyography may yield the highest level of diagnostic information for evaluating clinical cases of C7 radiculopathy.

Multifocal Osteolytic Lesions Within Lumbar Spine in a Middle-aged Chinese Woman: A Benign Metastasizing Leiomyoma?

Study Design. Case report. Objective. To describe a case presented as osteolytic lesions involving 2 inconsecutive lumbar, which was pathologically proved to be of smooth muscular origin. Summary of Background Data. Smooth muscle tumor of uncertain malignant potential (STUMP) could be diagnosed when the neoplasm showed some malignant behavior, whereas its histologic image revealed very low malignance. A 47-year-old woman presented with low back pain and numbness of the left lower extremity attributable to osteolytic lesions in the second and fourth lumbar vertebral bodies, which was subsequently diagnosed as STUMP. A benign metastasizing leiomyoma was highly suspected. Methods. Clinical, pathologic, and radiologic characters of the patient with STUMP confined within the lumbar spine were retrospectively reviewed. A mini review was also conducted. Results. We describe the first spine-confined case of STUMP. Conclusion. Significant new information in the growing literature of this rare and newly identified diagnosis has addressed the need for orthopedists to consider the STUMP diagnosis.

Factors Affecting Postoperative Neurological Deficits After Nerve Root Resection for the Treatment of Spinal Intradural Schwannomas.

Study Design. A retrospective clinical data analysis. Objective. To investigate the factors related to postoperative neurological deficits after nerve root resection in the treatment of spinal intradural schwannoma. Summary of Background Data. Neurological deficits could be observed after resection of tumor-involved nerve roots in spinal intradural schwannoma. Thus, it is important to find the factors related to postoperative neurological deficits. Methods. Clinical and pathological data were selected from patients underwent total resection of the solitary spinal intradural schwannoma from T11 to S. Patients were divided into the postoperative neurological deficits positive group (PND group, n = 12) and negative group (non-PND group, n = 52). Clinical features including age, sex, duration of disorders, diabetes, preoperative visual analogue scale (VAS) and SF-36 score, preoperative symptoms, tumor size, tumor location, and immunostaining results were analyzed. Results. Age, sex, duration of disorders, diabetes, preoperative VAS and SF-36 score, tumor length, and tumor-occupied ratio were not significantly different between the two groups (P > 0.05). Lower extremity pain, sensory disturbance, and motor disturbance were found in 25.0%, 50.0%, and 75.0% of patients in the PND group and 76.9%, 17.3%, and 7.7% of patients in the non-PND group, respectively, and the results were significantly different (P < 0.05). The rate of postoperative neurological deficits was higher when the tumor was located in the thoracolumbar junction (T11–L2) than other segments (L2–S; P = 0.009). For immunostaining study, CD34-positive rate was significantly different between the two groups (P = 0.013). Conclusion. The absence of preoperative lower extremity pain, presence of sensory and motor disturbances, and tumor location in the thoracolumbar junction (T11–L2) are the predictors of postoperative neurological deficits. Age, sex, duration of the disorders, diabetes, preoperative VAS score, preoperative SF-36 score, tumor length, and tumor-occupied ratio are not related to postoperative neurological deficits. On immunostaining of tumors, CD34-negative results are related to the development of postoperative neurological deficits. Level of Evidence: 4

Magnetic Resonance Neurography in Analysis of Operative Safety of Transforaminal Lumbar Interbody Fusion in Chinese Subjects

To measure relevant anatomical variables of lumbosacral nerve root and adjacent structures by magnetic resonance neurography (MRN) and analyze operative safety of transforaminal lumbar interbody fusion (TLIF) in Chinese subjects.