Adult-onset hypophosphatemic osteomalacia as a cause of widespread musculoskeletal pain: A retrospective case series of single center experience

BACKGROUND

Osteomalacia (OM) is frequently confused with various musculoskeletal or other rheumatic diseases, especially in patients with adult-onset widespread musculoskeletal pain because of its low prevalence and non-specific manifestations.

AIM

To facilitate the early diagnosis and etiology-specific treatment of adult-onset hypophosphatemic OM.

METHODS

A retrospective review of medical records was performed to screen adult patients who visited a physiatry locomotive medicine clinic (spine and musculoskeletal pain clinic) primarily presenting with widespread musculoskeletal pain at a single tertiary hospital between January 2011 and December 2019. We enrolled patients with hypophosphatemia, high serum bone-specific alkaline phosphatase levels, and at least one imaging finding suggestive of OM.

RESULTS

Eight patients with adult-onset hypophosphatemic OM were included. The back was the most common site of pain. Proximal dominant symmetric muscle weakness was observed in more than half of the patients. Bone scintigraphy was the most useful imaging modality for diagnosing OM because radiotracer uptake in OM showed characteristic patterns. Six patients were diagnosed with adefovir (ADV)-induced Fanconi syndrome, and the other two patients were diagnosed with tumor-induced OM and light-chain nephropathy, respectively. After phosphorus and vitamin D supplementation and treatment for the underlying etiologies, improvements in pain, muscle strength, and gait were observed in all patients.

CONCLUSION

Mechanical pain characteristics, hypophosphatemia, and distinctive bone scintigraphy patterns are the initial diagnostic indicators of adult-onset hypophosphatemic OM. ADV-induced Fanconi syndrome is the most common etiology of hypophosphatemic OM in hepatitis B virus-endemic countries.

Intraneural ganglion cysts originating from the hip joint: A single-center experience

INTRODUCTION/AIMS

Intraneural ganglion cysts (INGCs) are non-neoplastic mucinous cysts within the epineurium of peripheral nerves. Characteristics of INGCs around the hip joint have not been adequately described. We aimed to describe clinical features, imaging findings, and treatment outcomes in patients with INGCs originating from the hip joint.

METHODS

We retrospectively included cystic lesions around the hip joint satisfying the following inclusion criteria over 6 years: (1) multilocular elongated hyperintense cystic mass on T2-weighted imaging; and (2) distribution along the course of the peripheral nerve and its branches on magnetic resonance imaging (MRI).

RESULTS

Six patients with an INGC around the hip joint were identified. Parent peripheral nerves were the sciatic nerve (four patients), the superior gluteal nerve (one patient), and the nerve to quadratus femoris (one patient). Buttock, groin, or lower extremity pain/paresthesias were the initial symptoms in all patients. INGCs within the articular branches of the hip joint were identified on MRI. Four patients underwent arthroscopic debridement and capsulotomy. All patients showed generally favorable outcome regardless of treatment.

DISCUSSION

Physicians should consider the possibility of INGCs originating from the hip joint as a cause of nontraumatic hip, buttock, or lower extremity pain. This can occur in any nerve innervating the hip joint, and usually it originates in the posterior capsule of the hip joint. Arthroscopic surgery shows promising results; however, more information about the surgical technique and long-term follow-up results are needed.

Deep vein thrombosis of the common iliac vein caused by neurogenic heterotopic ossification in the anterior lower lumbar spine of a patient with complete paraplegia due to radiation-induced myelopathy

Context: Deep vein thrombosis (DVT), a frequent complication of spinal cord injury, is occasionally caused by neurogenic heterotopic ossification (NHO). In most cases of NHO, the hip joint is affected. Herein, we present a case of paraplegia following radiation-induced myelopathy that presented with left leg swelling due to DVT in the common iliac vein (CIV) caused by venous compression by NHO on the anterior lower lumbar spine.Findings: A 28-year-old man with complete paraplegia due to radiation-induced myelopathy presented with left lower extremity swelling 6 years after the onset of paraplegia. DVT in the left CIV was observed on computed tomography venography. The left CIV was significantly compressed between the NHO at the anterior longitudinal ligament of the lumbar spine and the right common iliac artery, suggestive of May-Thurner syndrome. Slightly distal to that compressed area, the left CIV was significantly compressed by the large NHO at the anterior longitudinal ligament of the lumbar spine.Conclusions: We believe that such compression of the left CIV would have contributed to the development of DVT. This case shows that DVT might be caused by NHO at the anterior aspect of the lumbar vertebral body, and this may help clinicians identify the main cause of DVT in the leg.

Hereditary Spastic Paraplegia in Koreans: Clinical Characteristics and Factors Influencing the Disease Severity

Background and Purpose

Hereditary spastic paraplegia (HSP) progresses over time and is associated with locomotive dysfunction. Understanding the factors affecting disease severity and locomotive function is important in HSP. This study investigated the factors influencing disease severity and ambulation status of HSP.

Methods

We consecutively enrolled 109 Korean patients (64 males, and 45 females)from 84 families with a clinical diagnosis of HSP. HSP was primarily diagnosed based on clinical criteria including clinical findings, family history, and supported by genetic studies. Epidemiological and clinical features of the patients were analyzed, and the Spastic Paraplegia Rating Scale (SPRS) score and ambulatory status were used to evaluate disease severity.

Results

Ninety-two (84.4%) patients had pure HSP, and 55 (50.4%) had a dominant family history. Thirty-one (28.4%) patients required a mobility aid for locomotion. A Kaplan-Meier analysis showed that HSP patients lost their independent gait ability after a median disease duration of 34 years. Those with an age at onset of ≤18 years had a longer median independent walking time. Pure HSP is characterized by predominant bilateral lower extremity weakness and spasticity, whereas complicated HSP presents more complex neurological findings such as ocular and bulbar symptoms, ataxia, and cognitive impairment. Complicated HSP was significantly correlated with the SPRS mobility score (β=3.70, 95% confidence interval=0.45–6.94). The age at onset and disease duration were significantly correlated with disease severity, and they were significant predictors of the use of a mobility aid (p<0.05).

Conclusions

These findings suggest that a later age at onset and longer disease duration are significant factors affecting the disease severity and ambulatory function in patients with HSP. These findings can help clinicians to identify subjects at risk of locomotive impairment.

The emerging genetic diversity of hereditary spastic paraplegia in Korean patients

Hereditary Spastic Paraplegias (HSP) are a group of rare inherited neurological disorders characterized by progressive loss of corticospinal motor-tract function. Numerous patients with HSP remain undiagnosed despite screening for known genetic causes of HSP. Therefore, identification of novel genetic variations related to HSP is needed. In this study, we identified 88 genetic variants in 54 genes from whole-exome data of 82 clinically well-defined Korean HSP families. Fifty-six percent were known HSP genes, and 44% were composed of putative candidate HSP genes involved in the HSPome and originally reported neuron-related genes, not previously diagnosed in HSP patients. Their inheritance modes were 39, de novo; 33, autosomal dominant; and 10, autosomal recessive. Notably, ALDH18A1 showed the second highest frequency. Fourteen known HSP genes were firstly reported in Koreans, with some of their variants being predictive of HSP-causing protein malfunction. SPAST and REEP1 mutants with unknown function induced neurite abnormality. Further, 54 HSP-related genes were closely linked to the HSP progression-related network. Additionally, the genetic spectrum and variation of known HSP genes differed across ethnic groups. These results expand the genetic spectrum for HSP and may contribute to the accurate diagnosis and treatment for rare HSP.

Focal vasculitic myositis as a primary manifestation of Behçet's disease: a case series of 10 Korean patients in a locomotive medicine clinic

OBJECTIVES

Muscle involvement in Behçet's disease (BD) is rare, and several cases have been reported in the literature. Therefore, this study aimed to describe the clinical, laboratory and imaging findings in adult patients presenting with BD-associated myositis before the diagnosis of BD.

METHODS

We retrospectively screened patients who visited a locomotive medicine clinic presenting with myalgia, local swelling, or tenderness of extremities without an established diagnosis of BD. We enrolled patients whose pain in the extremities was proven to be suggestive of focal vasculitic myositis and who were eventually diagnosed as having BD at the initial visit or during follow-up. We thoroughly reviewed the clinical, histological and imaging findings and treatment outcomes in patients who presented with focal vasculitic myositis as the primary manifestation of BD.

RESULTS

Ten adult patients with focal vasculitic myositis as the primary manifestation of BD were enrolled. The lower and upper extremities were affected in eight and two patients, respectively. The affected lower extremities were the calf (n = 6) and thigh muscles (n = 2). The common findings of MRI included high signal intensity of the affected muscles and intermuscular fascia on fat-suppressed images, suggestive of myofascitis and oedematous changes in the subcutaneous layer. The results of skin or muscle biopsy were suggestive of vasculitis. All the patients were pain-free at the short-term follow-up (1-3 weeks) after oral steroid therapy.

CONCLUSION

Focal vasculitic myositis can be a primary manifestation of BD warranting medical attention. BD-associated myositis responds well to oral steroid therapy.

Case Report: Neurogenic Thoracic Outlet Syndrome Without Electrophysiologic Abnormality

Neurogenic thoracic outlet syndrome (N-TOS) is a chronic compressive brachial plexopathy that involves the C8, T1 roots, and/or lower trunk. Medial antebrachial cutaneous (MABC) nerve conduction study (NCS) abnormality is reportedly one of the most sensitive findings among the features of N-TOS. The aim of the present study was to report clinical features, imaging findings, treatment, and prognoses of two N-TOS patients with no abnormalities in electrophysiological studies. Both patients presented with paresthesia of unilateral arm, and examination revealed no neurologic deficits. Electrophysiologic studies including MABC NCS were normal. Computed tomography (CT) angiography and brachial plexus magnetic resonance imaging (MRI) of the patients showed compression and displacement of the neurovascular bundle in the thoracic outlet by causative structures. Due to their sensory symptoms and CT angiography and brachial plexus MRI findings, after excluding other diseases, we diagnosed them with N-TOS. With the development of imaging techniques, more patients presenting with clinical features of lower trunk brachial plexopathy and anomalous structures compressing the neurovascular bundle on imaging studies can be diagnosed with N-TOS, even if electrophysiologic studies including MABC NCS do not show abnormalities.

Neurolymphomatosis: a single-center experience of neuromuscular manifestations, treatments, and outcomes

OBJECTIVES

Neurolymphomatosis (NL) is a disease characterized by the infiltration of malignant lymphocytes into the peripheral nervous system. We report clinical features, radiographic findings, modes of treatment, and outcomes of patients with NL.

METHODS

We retrospectively investigated patients with NL. We extracted data, including clinical features, magnetic resolution imaging (MRI), ¹⁸F-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scans, cerebrospinal fluid cytology findings, the results of electrodiagnostic studies, as well as patient treatments and outcomes.

RESULTS

Ten NL patients were identified. All patients reported pain/paresthesia and weakness in the affected area. The MRI scans were abnormal in eight out of nine patients with an enhancement of the spinal nerve root, plexus, peripheral nerve trunk, and cranial nerve. The FDG PET/CT scans were positive in all patients. Radiculopathy or radiculoplexopathy was the most common electrodiagnostic finding. Neurological improvement was observed in only three patients. The condition of the nine patients who underwent multimodality treatments for cancer eventually deteriorated and the patients died.

CONCLUSIONS

NL should be considered in the differential diagnosis of any type of neuropathy in patients with lymphoma. Because it could be confused with other neuropathies in lymphoma and various musculoskeletal diseases, a high index of suspicion and familiarity with clinical manifestation of NL are key. FDG PET/CT was the most sensitive diagnostic imaging modality to detect relevant neural invasion. The root within the spinal neural foramen was the most frequently affected neural structure. Early diagnosis of this rare neurologic manifestation of lymphoma may improve treatment outcomes.

Radial neuropathy caused by intraneural leiomyoma: A case report

INTRODUCTION

Leiomyoma of peripheral nerve is a rare condition characterized by neuropathy of affected nerve. We herein report a rare presentation of leiomyoma of radial nerve which presented with wrist drop.

PATIENT CONCERNS

A 37-year-old man visited our clinic with a history of sudden onset weakness of the wrist dorsiflexion/finger extension of the right side.

DIAGNOSIS

T2-weighted with fat saturation image of MRI demonstrated a well-defined, intra-neural, round mass of about 0.8 cm × 0.5 cm within the radial nerve. Excision of mass established the pathological diagnosis of intra-neural leiomyoma.

INTERVENTIONS

The patient underwent excision of mass and attached nerve tissue, followed his medial antebrachial nerve graft for repair of the defected radial nerve.

OUTCOMES

As of the 1-year follow-up, no symptoms of recurrence have been observed. Also, the strength of wrist dorsiflexion improved to grade 4/5 CONCLUSION:: This rare case demonstrates the importance of MR imaging to differentiate intra-neural leiomyomas from other benign peripheral nerve sheath tumors. Surgical treatment plays an important role in the treatment of patient with intraneural leiomyoma with neurologic deficits.

Diagnosis of Hourglass-Like Constriction Neuropathy of the Radial Nerve Using High-Resolution Magnetic Resonance Neurography: A Report of Two Cases

Hourglass-like constriction neuropathy is a neurological condition caused by fascicular constriction of one or more peripheral nerves, unrelated to intrinsic or extrinsic compression. It is often neglected in clinical practice, and its diagnosis is challenging. Here, we report two cases of hourglass-like constriction neuropathy in the radial nerve diagnosed using high-resolution magnetic resonance neurography (MRN). Two men, aged 47 and 19 years, developed sudden weakness in the left wrist and finger extensors. They were diagnosed with radial neuropathy between the left mid-humerus level and the elbow joint, using the electrodiagnostic test. To evaluate the cause of the nerve lesion and the lesion location, high-resolution MRN was performed. Patient 1 showed an hourglass-like constriction of the left posterior interosseous nerve within the epineurium of the left radial nerve, 8.9 cm proximal to the lateral epicondyle. Patient 2 showed two focal constrictions of the left radial nerve, 8.0 and 6.9 cm proximal to the lateral epicondyle, respectively, and distal to the radial groove. Additionally, bull’s eye signs were observed juxta-proximal to constrictions of the left radial nerve. The findings were indicative of hourglass-like constriction neuropathy. Both of the patients underwent surgery. However, at the 6-month follow-up, their motor weakness showed no improvement. MRN can be beneficial for diagnosing hourglass-like constriction neuropathy and locating the lesion.

Significance of Sufficient Neck Flexion During Magnetic Resonance Imaging in the Diagnosis of Hirayama Disease: Report of Two Cases

It is difficult to distinguish Hirayama disease (HD) from other mimicking disorders in adolescent patients with distal upper limb weakness. The prevailing theory of HD postulates that the lower cervical cord is susceptible to compression during neck flexion because of insufficient growth of the dura relative to the spinal column. Confirmation of a dynamic change in the dorsal epidural space on magnetic resonance imaging (MRI) during neck flexion is essential for diagnosing HD. However, neck flexion MRI has not been routinely performed in juvenile patients with distal upper limb weakness in the absence of suspected HD. We report two cases of HD that were initially confused with other diseases because of insufficient or absent cervical flexion during MRI. Full-flexion MRI showed typical findings of HD in both cases. Our cases suggest that dynamic cervical MRI in the fully flexed position is necessary for evaluating suspected HD.

Nonsurgical treatments for patients with radicular pain from lumbosacral disc herniation

BACKGROUND CONTEXT

Lumbosacral disc herniation (LDH) is one of the most frequent musculoskeletal diseases causative of sick leave in the workplace and morbidity in daily activities. Nonsurgical managements are considered as first line treatment before surgical treatment.

PURPOSE

This clinical practice guideline (CPG) is intended to provide physicians who treat patients diagnosed with LDH with a guideline supported by scientific evidence to assist in decision-making for appropriate and reasonable treatments.

STUDY DESIGN/SETTING

A systematic review.

PATIENT SAMPLE

Studies of human subjects written in Korean or English that met the following criteria were selected: patients aged ≥18 years, clinical presentation of low back and radicular leg pain, diagnosis of LDH on radiological evaluation including computed tomography or magnetic resonance imaging.

OUTCOMES MEASURES

Pain and functional evaluation scales such as visual analogue scale, numeric rating scale, and Oswestry disability index METHODS: The MEDLINE (PubMed), EMBASE, Cochrane Review, and KoreaMed databases were searched for articles regarding non-surgical treatments for LDH published up to July 2017. Of the studies fulfilling these criteria, those investigating clinical results after non-surgical treatment including physical and behavioral therapy, medication, and interventional treatment in terms of pain control and functional improvements were chosen for this study.

RESULTS

Nonsurgical treatments were determined to be clinically effective with regards to pain reduction and functional improvement in patients with LDH. Nevertheless, the evidence level was generally not evaluated as high degree, which might be attributed to the paucity of well-designed randomized controlled trials. Exercise and traction were strongly recommended despite moderate level of evidence. Epidural injection was strongly recommended with high degree of evidence and transforaminal approach was more strongly recommended than caudal approach.

CONCLUSIONS

This CPG provides new and updated evidence-based recommendations for treatment of the patients with LDH, which suggested that, despite an absence of high degrees of evidence level, non-surgical treatments were clinically effective.

Clinical, electrodiagnostic and imaging features of true neurogenic thoracic outlet syndrome: Experience at a tertiary referral center

OBJECTIVE

True neurogenic thoracic outlet syndrome (TN-TOS) is an extremely rare neuromuscular disease. We report clinical, electrodiagnostic and radiologic features of patients with TN-TOS.

METHODS

Retrospective chart review of patients satisfying criteria was done. Nerve conduction study (NCS) and needle electromyography (EMG) of upper extremity were reviewed. Brachial plexus MRI and computed tomography angiography (CTA) were also reviewed.

RESULTS

Thirteen TN-TOS patients were identified. The most common neurologic signs were hypesthesia in the medial forearm or ulnar digits and weakness of the abductor pollicis brevis (APB) muscle. In NCS, medial antebrachial cutaneous (MABC) sensory nerve action potential amplitude was decreased in all tested patients. The APB muscle was most commonly involved in EMG. Among radiologic criteria, focal stenosis of subclavian artery in CTA was the most common finding.

CONCLUSION

We confirmed that TN-TOS is T1 predominant lower roots/trunk brachial plexopathy with clinical and electrodiagnostic features. Radiologic studies may be used to detect structural abnormalities.

SIGNIFICANCE

As MABC NCS showed abnormal results in all tested patients, it should be added to electrodiagnostic study as screening method. If present, structural abnormalities might be confirmed with radiologic studies.

Intraneural Ganglion Cyst of the Sciatic Nerve Treated Using Arthroscopic Hip Surgery: A Case Report

This is a rare case of sciatic neuropathy in a 46-year-old man secondary to an intraneural ganglion cyst from the hip joint extending upward to the lumbar plexus and the L5 nerve root. Magnetic resonance neurography showed that the joint fluid passed through a labral tear and extended rostrally along the articular branch and the peroneal portion of the sciatic nerve to near the L5 nerve root. The condition was treated by arthroscopic disruption of the joint connection to the nerve with resolution of the intraneural cyst and partial neurological recovery.

Ultrasound measurements of axillary recess capsule thickness in unilateral frozen shoulder: study of correlation with MRI measurements

OBJECTIVE

The aims of this study were to compare the ultrasound thickness of the affected axillary recess capsule (ARC) with that of the unaffected ARC in patients with frozen shoulder (FS), to analyze whether the ultrasound measurements of the ARC thickness correlate with those obtained using MRI, and to assess whether the ultrasound thickness of the ARC correlates with the patterns of range of motion limitation.

MATERIALS AND METHODS

Forty-four patients with clinically diagnosed unilateral FS and MRI evaluation performed ultrasound measurement of ARC. The ultrasound measurement of the ARC thickness was performed with the patients in a supine position with their shoulder abducted by 40°. The ARC thickness was also measured by MRI on oblique coronal images by another physician blinded to the ultrasound measurements. With both ultrasound and MRI, ARC thickness was determined at the widest portion of the capsule.

RESULTS

The ultrasound thickness of ARC was significantly higher in the affected shoulder (4.4 ± 1.1 mm) than in the unaffected one (2.2 ± 0.5 mm) (p < 0.001). The ultrasound thickness of the ARC in the affected shoulder correlated with that measured by MRI (8.9 ± 1.9 mm) (p < 0.001, r = 0.83). The ARC thickness, whether measured by ultrasound or MRI, was not significantly related to the limitation of movement in specific directions.

CONCLUSION

Ultrasound can demonstrate the difference in ARC thickness between affected and unaffected shoulders in patients with unilateral FS. The ARC thickness measured by ultrasound correlates with that measured by MRI.

Characteristics of Korean Patients with Polymyalgia Rheumatica: a Single Locomotive Pain Clinic Cohort Study

BACKGROUND

Polymyalgia rheumatica (PMR) is a common systemic inflammatory disease of the elderly; however, the clinical characteristics and therapeutic response of PMR in Korea have been rarely studied.

METHODS

We reviewed the medical records of 54 Korean patients diagnosed with PMR between January 2009 and February 2017 in a locomotive pain clinic of one tertiary referral hospital. We analyzed epidemiologic and clinical characteristics, therapeutic responses, and prognostic factors for remission-failure at one-year after oral prednisolone treatment.

RESULTS

In 54 patients with PMR, 32 (59.3%) were female. The average age at diagnosis was 65.0 ± 10.5 years. Duration of symptoms before diagnosis was 8.1 ± 8.6 months. All patients had shoulder pain (54 patients, 100.0%); 49 patients (90.7%) had hip girdle pain, while 19 patients (35.2%) had peripheral joint pain. Four patients (7.4%) were accompanied by the giant cell arteritis (GCA). There was no seasonal preference for symptom development. Only 19 patients were diagnosed with PMR at initial symptom presentation. At one-year follow-up after oral prednisolone treatment, the remission rate was 35.3% (12/34). Multivariate analysis showed that history of relapse (odds ratio, 6.81; 95% confidence interval, 1.035-44.804) was a significant predictor of remission-failure.

CONCLUSION

The rate of remission (35.3%) after oral prednisolone treatment was similar to previous reports in western countries; and GCA is not a rare condition in Korean PMR patients. Misdiagnosis of PMR is common, and heightened consideration for PMR is needed in elderly patients who present inflammatory features of bilateral shoulder pain.

Missense mutation of SPAST protein (I344K) results in loss of ATPase activity and prolonged the half-life, implicated in autosomal dominant hereditary spastic paraplegia

The spastin protein (SPAST) contains an ATPase with diverse cellular activities (AAA) domain and regulates microtubule dynamics. Missense mutations of the SPAST gene are frequently detected in patients with hereditary spastic paraplegias (HSPs) and represent the main reason of loss of SPAST function; however, the pathogenicity of mutant SPAST is heterogeneous. Here, SPAST variant with an I344K mutation (I344K-SPAST) was identified in a Korean family with autosomal dominant-type HSP. We investigated the role of the I344K-SPAST in HSP to provide a therapeutic mechanism. The I344K-SPAST mutation prolonged the half-life of the protein compared to wild-type SPAST (WT-SPAST) in cells by modulating post-translational modifications for proteasomal degradation. I344K-SPAST was localized in microtubule but defective in microtubule severing and ATPase activity compared to WT-SPAST in vitro and in cells. Mutant M87 isoform harboring the same mutation with I344K-M1 SPAST also increased protein stability and loss of MT severing activity, but the pathogenicity was not stronger than I344K-M1 SPAST in neurite outgrowth. Overexpression of I344K-SPAST resulted in microtubule accumulation following inhibited neurite growth in neuroblastoma, neural progenitor cells and mouse primary cortical neurons. Conversely, these pathogenic effects of I344K-SPAST were reduced by overexpression of WT-M1 SPAST in a dose dependent manner since WT-SPAST could interact with I344K-SPAST. Our data therefore provide proof-of-concept that gene transfer of WT-M1 SPAST may serve as a valid therapeutic option for HSPs.

Clinical correlation of metabolic parameters on 18F-FDG PET/CT in idiopathic frozen shoulder

Objective

Because positron emission tomography/computed tomography (PET/CT) using fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) can be used to visualize inflammation of the musculoskeletal system, it may help elucidate the pathophysiology of frozen shoulder (FS). The purpose of this study was to characterize the uptake pattern on ¹⁸F-FDG PET/CT in patients with idiopathic FS and to determine if there is a correlation between its metabolic parameters and clinical findings.

Methods

¹⁸F-FDG PET/CT was conducted to 35 patients with unilateral idiopathic FS. Clinical data including pain, functional scores, and passive range of motion (ROM) were collected. Maximum standardized uptake values (SUVmax) were measured at the four regions of interest (ROIs): rotator interval (RI), anterior joint capsule (AJC), axillary recess (AR), and posterior joint capsule (PJC) from the attenuation-corrected axial images.

Results

Mean SUVmax values for four ROIs of the affected shoulder were significantly higher than those of the unaffected shoulder. Mean SUVmax values of RI and AR were significantly higher than those of AJC and PJC and mean SUVmax of AJC was significantly higher than that of PJC in the affected side. Three recognizable patterns of increased uptake were noted: (1) AR dominant type (15 patients); (2) RI dominant type (9 patients); (3) both RI and AR dominant type (11 patients). The SUVmax of AR showed negative correlation with abduction and forward flexion. The SUVmax of RI showed negative correlation with external rotation and internal rotation. The SUVmax of AJC showed negative correlation with all ROMs. However, there was no significant correlation between the SUVmax of PJC and any ROM.

Conclusion

Our study demonstrates that the anterior–inferior capsular portion, including RI and AR, is the main pathologic site of idiopathic FS and reveals significant correlations between ROM and metabolic parameters on ¹⁸F-FDG PET/CT. These results imply that AR and RI lesions are related to elevational limitations and rotational limitations, respectively.

Acute Paraplegia After Lumbar Steroid Injection in Patients With Spinal Dural Arteriovenous Fistulas: Case Reports

Spinal dural arteriovenous fistulas (SDAVFs) are the most common type of spinal vascular malformations. However, SDAVFs are still underdiagnosed entities because their clinical symptoms are usually non-specific, as they include low back pain or radiating pain to the limb. There have been several reports of acute paraplegia after lumbar epidural steroid injections in patients with SDAVFs. We present 4 patients with SDAVFs who received lumbar steroid injection. Among the 4 cases, acute paraplegia developed in 2 cases that received a larger volume of injectate than the other cases. Thus, we are suggesting that the volume of injectate may be a contributing factor for acute paraplegia after lumbar steroid injection in patients with SDAVFs.

Reliability, Validity, and Responsiveness of the Korean Version of the Shoulder Disability Questionnaire and Shoulder Rating Questionnaire

Objective

To translate, adapt, and test the reliability, validity, and responsiveness of the Korean version of the Shoulder Disability Questionnaire (SDQ) and the Shoulder Rating Questionnaire (SRQ).

Methods

The international guideline for the adaptation of questionnaires was referenced for the translation and adaptation of the original SDQ and SRQ. Correlations of the SDQ-K and SRQ-K with the Shoulder Pain and Disability Index (SPADI) and the Numeric Rating Scale (NRS) were assessed to determine the reliability and validity of the questionnaires. To evaluate reliability, surveys were performed at baseline and a mean of 6 days later in 29 subjects who did not undergo any treatment for shoulder problems. To evaluate responsiveness, assessments were performed at baseline with 4-week intervals in 23 subjects with adhesive capsulitis who were administered triamcinolone injection into the glenohumeral joint.

Results

Fifty-two subjects with shoulder-related problems were surveyed. Cronbach alpha for internal consistency was 0.82 for the summary SDQ-K and 0.75 for the summary SRQ-K. The test-retest reliability of the SDQ-K, SRQ-K, and domains of the SRQ-K ranged from 0.84 to 0.95. The SDQ-K and SRQ-K summary scores correlated well with the SPADI and NRS summary scores. Generally, the effect sizes and standardized response means of the summary scores of the SDQ-K, SRQ-K, and domains of the SRQ-K were large, reflecting their responsiveness to clinical changes after treatment.

Conclusion

The reliability, validity, and responsiveness of the SDQ-K and SRQ-K were excellent. The SDQ-K and SRQ-K are feasible for Korean patients with shoulder pain or disability.

Clinical Characteristics and Genotype-Phenotype Correlation of Korean Patients with Spinal and Bulbar Muscular Atrophy

PURPOSE

Spinal and bulbar muscular atrophy (SBMA) is an X-linked motor neuron disease characterized by proximal muscle weakness, muscle atrophy, and fas-ciculation. Although SBMA is not uncommon in Korea, there is only one study reporting clinical characteristics and genotype-phenotype correlation in Korean patients.

MATERIALS AND METHODS

In this study, age at the onset of symptoms, the score of severity assessed by impairment of activities of daily living milestones, and rate of disease progression, and their correlations with the number of CAG repeats in the androgen receptor (AR) gene, as well as possible correlations among clinical characteristics, were analyzed in 40 SBMA patients.

RESULTS

The median ages at onset and at diagnosis were 44.5 and 52.5 years, respectively, and median interval between onset and diagnosis and median rate of disease progression were 5.0 years and 0.23 score/year, respectively. The median number of CAG repeats in the AR gene was 44 and the number of CAG repeats showed a significant inverse correlation with the age at onset of symptoms (r=-0.407, p=0.009). In addition, patients with early symptom onset had slower rate of disease progression.

CONCLUSION

As a report with the largest and recent Korean cohort, this study demonstrates clinical features of Korean patients with SBMA and reaffirms the inverse correlation between the age at disease onset and the number of CAG repeats. Interestingly, this study shows a possibility that the rate of disease progression may be influenced by the age at onset of symptoms.

Ullrich Congenital Muscular Dystrophy Possibly Related With COL6A1 p.Gly302Arg Variant

Ullrich congenital muscular dystrophy (UCMD) is characterized by congenital weakness, proximal joint contractures, and hyperlaxity of distal joints. UCMD is basically due to a defect in extra cellular matrix protein, collagen type VI. A 37-year-old woman who cannot walk independently visited our outpatient clinic. She had orthopedic deformities (scoliosis, joint contractures, and distal joint hyperlaxity), difficulty of respiration, and many skin keloids. Her hip computed tomography showed diffuse fatty infiltration and the 'central shadow' sign in thigh muscles. From the clinical information suggesting collagen type VI related muscle disorder, UCMD was highly considered. COL6A1 gene sequencing confirmed this patient as UCMD with novel c.904G>A (p.Gly302Arg) variant. If musculoskeletal and dermatologic manifestations and radiologic findings imply abnormalities in collagen type VI network, COL6A related congenital muscular dystrophy was to be suspected.

Magnetic resonance neurographic findings in classic idiopathic neuralgic amyotrophy in subacute stage: a report of four cases

Neuralgic amyotrophy (NA) is characterized by acute onset of severe pain, followed by muscular weakness and wasting of the shoulder girdle. While the diagnosis of NA mainly relies on the clinical history and examination, some investigations including electrophysiologic study and radiologic study may help to confirm the diagnosis. Magnetic resonance neurography (MRN), a new technique for the evaluation of peripheral nerve disorders, can be helpful in the diagnosis of NA. MRN presents additional benefits in comparison to conventional magnetic resonance imaging in the diagnosis of idiopathic NA (INA). In this report, we present the first four cases of classic INA diagnosed with MRN in subacute stage. MRN imaging modality should be considered in patients clinically suspected of INA.

Metabolic patterns of the shoulder joint on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in adhesive capsulitis

OBJECTIVE

The purpose of our study was to demonstrate metabolic patterns on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in patients with adhesive capsulitis (AC).

METHODS

We retrospectively reviewed (18)F-FDG PET/CT performed on 22 shoulders of 21 patients diagnosed with AC: 2 shoulders with stage I, 14 with stage II, and 6 with stage III. A clinical diagnosis of AC was retrospectively made based on clinical examination, clinical course, and imaging. The pattern of radiotracer uptake was analyzed. Standardized uptake values in rotator interval (RI), anterior joint capsule (AJC), axillary recess (AR), and greater tuberosity were measured and compared to those of the contralateral side and the control group consisting of 40 shoulders in 20 subjects without shoulder pain.

RESULTS

Four patterns of uptake were noted: (1) glenoid type I (n = 16), with uptake in RI, AJC, and AR; (2) glenoid type II (n = 2),with uptake in AJC and AR; (3) glenoid type III (n = 2), with uptake in RI and AJC; (4) focal type (n = 2), with uptake in RI or AR. Affected side SUVmax for RI, AJC, and AR was significantly higher compared with the unaffected side and the control group. Two shoulders with stage I AC had patterns similar to the ones with stage II or III.

CONCLUSION

Specific patterns of (18)F-FDG uptake with dominant uptake in RI, AJC, or AR may be related to AC.

Incidence of deep vein thrombosis after spinal cord injury in Korean patients at acute rehabilitation unit

Deep vein thrombosis (DVT) and subsequent pulmonary embolism (PE) remain significant causes of morbidity, mortality in patients with spinal cord injury (SCI). Since incidence of DVT after SCI in Korean population has not been much studied, we retrospectively analyzed the medical records of 185 SCI patients admitted for acute rehabilitation unit to investigate the incidence of DVT. Color Doppler ultrasonography was performed to screen for the occurrence of DVT at the time of initial presentation to acute rehabilitation unit. Primary study outcome was the incidence of DVT. Possible risk factors for DVT including the epidemiologic characteristics, completeness of motor paralysis, cause of injury, spasticity, surgery, and active cancer were analyzed. The incidence of DVT after SCI was 27.6%. In multiple logistic regression analysis, absence of spasticity was a significant independent risk factor (P<0.05) for occurrence of DVT. Symptomatic pulmonary embolism was evident in 7 patients without an episode of sudden death. Therefore, it is concluded that the incidence of DVT after SCI in Korean patients is comparable with that in Western populations. This result suggests that pharmacologic thromboprophylaxis should be considered in Korean patients with SCI.

Brachial Plexopathy due to Myeloid Sarcoma in a Patient With Acute Myeloid Leukemia After Allogenic Peripheral Blood Stem Cell Transplantation

Myeloid sarcoma is a solid, extramedullary tumor comprising of immature myeloid cells. It may occur in any organ; however, the invasion of peripheral nervous system is rare. Herein, we report the case of myeloid sarcoma on the brachial plexus. A 37-year-old woman with acute myelogenous leukemia achieved complete remission after chemotherapy. One year later, she presented right shoulder pain, progressive weakness in the right upper extremity and hypesthesia. Based on magnetic resonance images (MRI) and electrophysiologic study, a provisional diagnosis of brachial plexus neuritis was done and hence steroid pulse therapy was carried out. Three months later the patient presented epigastric pain. After upper gastrointestinal endoscopy, myeloid sarcoma of gastrointestinal tract was confirmed pathologically. Moreover, 18-fluoride fluorodeoxyglucose positron emission tomography showed a fusiform shaped mass lesion at the brachial plexus overlapping with previous high signal lesion on the MRI. Therefore, we concluded the final diagnosis as brachial plexopathy due to myeloid sarcoma.

Hypophosphatemic osteomalacia induced by low-dose adefovir therapy: focus on manifestations in the skeletal system and literature review

Osteomalacia is a metabolic bone disease that leads to softening of the bones and can be caused by hypophosphatemia. Large clinical studies of low-dose adefovir dipivoxil (adefovir) have found no evidence of renal tubular dysfunction leading to hypophosphatemia after 48 weeks of treatment. We report two cases of low-dose adefovir-induced hypophosphatemic osteomalacia that initially presented with diffuse musculoskeletal pain. The first patient was a 62-year-old man with a 2-year history of bone pain involving the dorsal mid-thorax, lower anterior chest wall, right sacroiliac joint area, and both knees. The patient had been receiving adefovir for 5 years before confirmation of hypophosphatemia and urinary phosphate wasting. Bone scintigraphy revealed multifocal lesions including multiple ribs, costochondral junctions, costovertebral junctions, sacrum, both posterior iliac bones, both proximal tibia, right calcaneus, and the left second metatarsophalangeal joint area, which were suggestive of metabolic bone disorder. Bone pain was significantly reduced within 3 months after supplementation with phosphate and calcitriol. The second patient was a 54-year-old male who presented with an 18-month history of severe bone pain of the right medial knee and low back. The patient had been taking adefovir for approximately 40 months before the development of bone pain. Laboratory data revealed hypophosphatemia and vitamin D deficiency. Bone scintigraphy showed increased uptake in bilateral ribs, sternum, both scapulae, both costovertebral junctions, both pelvic bones, medial cortex of the right proximal femur, right proximal tibia, and the left lateral tarsal bone. The symptoms improved by changing the antiviral agent from adefovir to entecavir. Because osteomalacia often presents with diffuse bone pain, non-specific radiologic findings and non-characteristic routine serum biochemical changes, the disease can be confused with various musculoskeletal diseases and a high index of suspicion is necessary for an early diagnosis in patients receiving adefovir therapy.

Clinical, Electrophysiological Findings in Adult Patients with Non-traumatic Plexopathies

Objective

To ascertain the etiology of non-traumatic plexopathy and clarify the clinical, electrophysiological characteristics according to its etiology.

Method

We performed a retrospective analysis of 63 non-traumatic plexopathy patients that had been diagnosed by nerve conduction studies (NCS) and needle electromyography (EMG). Clinical, electrophysiological, imaging findings were obtained from medical records.

Results

We identified 36 cases with brachial plexopathy (BP) and 27 cases with lumbosacral plexopathy (LSP). The causes of plexopathy were neoplastic (36.1%), thoracic outlet syndrome (TOS) (25.0%), radiation induced (16.7%), neuralgic amyotrophy (8.3%), perioperative (5.6%), unknown (8.3%) in BP, while neoplastic (59.3%), radiation induced (22.2%), neuralgic amyotrophy (7.4%), psoas muscle abscess (3.7%), and unknown (7.4%) in LSP. In neoplastic plexopathy, pain presented as the first symptom in most patients (82.8%), with the lower trunk of the brachial plexus predominantly involved. In radiation induced plexopathy (RIP), pain was a common initial symptom, but the proportion was smaller (50%), and predominant involvements of bilateral lumbosacral plexus and whole trunk of brachial or lumbosacral plexus were characteristic. Myokymic discharges were noted in 41.7% patients with RIP. Abnormal NCS finding in the medial antebrachial cutaneous nerve was the most sensitive to diagnose TOS. Neuralgic amyotrophy of the brachial plexus showed upper trunk involvement in all cases.

Conclusion

By integrating anatomic, pathophysiologic knowledge with detailed clinical assessment and the results of ancillary studies, physicians can make an accurate diagnosis and prognosis.

Comparison between (18)F-FDG PET/CT and EMG Mapping for Identifying Dystonic Superficial Muscles in Primary Cervical Dystonia: Preliminary Results

PURPOSE

This study was conducted to compare (18)F-FDG PET/CT and electromyography (EMG) mapping in patients with primary cervical dystonia (PCD) to find dystonic superficial cervical muscles.

METHODS

Ten consecutive patients with PCD (M:F = 5:5, age 44 ± 13 years) whose dystonic posture was not relieved with conventional muscle relaxant therapy were included. Target cervical muscles for the comparison between (18)F-FDG PET/CT and EMG mapping were four representative superficial bilateral cervical muscles: splenius capitis muscle, sternocleidomstoid muscle, upper trapezius muscle, and leavator scapulae muscle. The diagnostic efficacy was compared between (18)F-FDG PET/CT and EMG mapping using physical exam and measurement of rotation angle as the gold standard.

RESULTS

Among 80 muscles evaluated, there were 21 (26%) dystonic superficial cervical muscles assessed with physical exam and motion analysis. The sensitivity, specificity, and accuracy for localizing dystonic muscles were 76, 92, and 88% for (18)F-FDG PET/CT, and 95, 66, and 74% for EMG mapping, respectively. The sensitivity of EMG mapping was significantly higher than that of (18)F-FDG PET/CT. In contrast, (18)F-FDG PET/CT was significantly superior to EMG mapping for specificity and accuracy.

CONCLUSIONS

(18)F-FDG PET/CT is more specific and accurate than EMG mapping for finding superficial dystonic cervical muscles. The high sensitivity of EMG mapping suggests that (18)F-FDG PET/CT and EMG mapping are complementary for finding dystonic superficial cervical muscles.

Clinical and genetic analysis of a Korean family with hereditary spastic paraplegia type 3

Hereditary spastic paraplegia (HSP) is a neurodegenerative disease characterized by progressive spasticity in the lower extremities. Mutations in the atlastin GTPase 1 (ATL1) gene cause approximately 10% of autosomal dominantly inherited HSP. For many subjects with an ATL1 mutation, spastic gait begins in early childhood and does not significantly worsen, even over many years; such cases resemble spastic diplegic cerebral palsy. Herein we report a heterozygous R239C mutation in the ATL1 gene in a Korean family. The family members exhibited early onset pure spastic paraplegia and had been previously diagnosed with the diplegic form of cerebral palsy. We suggest that spastic paraplegia type 3 (SPG3A) be included in the differential diagnosis of early onset spastic paraplegia. To the best of our knowledge, this is the first report of a genetically confirmed family affected with SPG3A in Korea.

Haplotype analysis of the myotonic dystrophy type 1 (DM1) locus in the Korean population

Myotonic dystrophy type 1 (DM1) is caused by unstable expansion of the CTG repeat in the DMPK gene. According to the hypothesis that expanded CTG repeat alleles originated from larger normal alleles, a correlation exists between prevalence of DM1 and frequency of large normal alleles. We examined the number of CTG repeats in a group of 481 non-DM1 individuals and 116 DM1 patients. Among these subjects, we analyzed the haplotype in 76 unrelated non-DM1 individuals and 14 unrelated DM1 patients using 8 bialleleic markers on the DM1 locus. Different CTG repeats from 5 to 36 and variable allele frequencies were observed. The most common allele was 12 CTG repeats (27.3%), and the frequency of larger normal alleles (>19 CTG repeats) was 3.7%. Haplotype analysis revealed that 100% of alleles with 5 and >19 CTG repeats were haplotype A. In this study, we provide the first haplotypic molecular evidence for a founder effect of DM1 mutations in Korea, and reinforce the hypothesis that out-of-Africa DM1 alleles were derived by expansion from a pool of non-DM1 alleles with haplotype A.

Mitochondrial GTPase mitofusin 2 mutations in Korean patients with Charcot-Marie-Tooth neuropathy type 2

Charcot-Marie-Tooth disease (CMT) is classified into two types, the demyelinating (CMT1) and axonal forms (CMT2). CMT2 is further subdivided by linkage analysis into eight subgroups. Recently, mutations in the MFN2 gene, which encodes the mitochondrial GTPase mitofusin 2 (Mfn2) that regulates the mitochondrial network architecture by fusing the mitochondria, were identified in CMT2A patients. This study carried out mutation analysis of the MFN2 gene in 12 unrelated Korean patients suspected of having CMT2 and identified four mutations (Arg94Trp, His165Arg, Ser263Pro, and Ser350Pro). Three mutations were found within the highly conserved GTPase domain that is essential for the function of Mfn2, and one mutation (Ser350Pro) was observed between the GTPase domain and the downstream coiled-coil domain. This suggests that mutations in the MFN2 gene are an important causative gene underlying Korean patients with CMT2, and screening for a mutation in the MFN2 gene is strongly recommended for making a molecular diagnosis of CMT2.

Mutation analysis of the GNE gene in Korean patients with distal myopathy with rimmed vacuoles

Distal myopathy with rimmed vacuoles (DMRV; MIM 605820) is an autosomal recessive neuromuscular disorder characterized by weakness of the anterior compartment of the lower limbs, sparing the quadriceps muscles. Recently, mutations in the UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (GNE) gene have been identified as the genetic basis of DMRV. To investigate the mutation spectrum of the GNE gene in Korean patients with DMRV, we performed clinical and genetic analysis of nine unrelated patients suspected to have DMRV. Direct sequencing analysis revealed that eight out of nine patients (88.9%) were either homozygous or compound heterozygous for GNE gene mutations, including three known (C13S, R129Q, and V572L) and two novel mutations (M29T and A591T) [corrected] The allelic frequencies of the V572L and C13S mutations were 68.8% (11/16) and 12.5% (2/16), respectively. These results suggest that screening for GNE gene mutations in patients suspected to have DMRV would be helpful for molecular diagnosis of DMRV in the Korean population.

Cervical Radiculopathy Caused by Neural Foraminal Migration of a Herniated Calcified Intervertebral Disk in Childhood: A Case Report

Childhood intervertebral disk calcification is a rare clinical entity. Although its clinical course is usually benign, nerve root irritation or spinal cord compression can occasionally occur. We present the clinical and radiologic findings of a 9-year-old boy with cervical radiculopathy due to a herniated calcified intervertebral disk, which developed suddenly after swimming for 1 hour. Radiologic findings indicated that a calcified nucleus pulposus at the C6-7 level herniated into the spinal canal and migrated far into the right C6-7 neural foramen. Surgical management was performed 8 weeks after the onset of symptoms, because the initial presenting symptoms persisted despite conservative treatment. In children, calcified intervertebral disks can cause cervical radiculopathy that requires surgical management when they herniate and migrate far into the neural foramen.

Mutation analysis of SPG4 and SPG3A genes and its implication in molecular diagnosis of Korean patients with hereditary spastic paraplegia

BACKGROUND

Hereditary spastic paraplegia (HSP), a genetically and clinically heterogeneous group of neurodegenerative disorders, is characterized by progressive lower limb weakness and spasticity. Among the 8 loci associated with the autosomal dominant uncomplicated HSP (AD-HSP), the spastin (SPG4) and atlastin (SPG3A) genes have been known to account for approximately 40% and 10% of all cases, respectively.

OBJECTIVE

To investigate the contribution of these 2 genes in the occurrence of HSP in Korean patients.

DESIGN

Clinical and genetic study.

SETTING

Tertiary care center.

PATIENTS

Eighteen patients with uncomplicated HSP (11 AD and 7 sporadic) underwent screening for gene mutation.

MAIN OUTCOME MEASURES

Mutations in the SPG4 and SPG3A genes as detected by direct sequencing of all coding exons and flanking intronic sequences.

RESULTS

We identified 8 different SPG4 mutations, 7 of which have not been reported elsewhere. Among the detected mutations were 3 missense mutations, 2 in-frame deletions, 2 frameshift mutations, and 1 splice-site mutation. No mutation was found in the SPG3A gene.

CONCLUSION

Compared with previous studies, a higher frequency of SPG4 gene mutations in AD-HSP (7/11; 64%) was observed, suggesting that a mutation analysis for the SPG4 gene might be helpful for molecular diagnosis of AD-HSP in Korean patients.

Locating the target nerve and injectate spread in rabbit sciatic nerve block

BACKGROUND AND OBJECTIVES

The purpose of this study is to determine how close the needle tip is placed to the target nerve using a nerve stimulator and to determine how far the injectate spreads in percutaneous nerve blocks.

METHODS

Twenty-four sciatic nerves of New Zealand white rabbits were located with a 2-dimensional needle manipulator and a nerve stimulator (pulse width: 100 micros for group I, 250 micros for group II). The stimulation current required to elicit a motor response for each insertion depth of the needle and the nerve-needle distance at which the required current reached the minimum were measured. Another 10 sciatic nerves were located manually using a nerve stimulator and neurolyzed with a mixed solution of 5% phenol and Indian ink (100 microL).

RESULTS

The nerve-needle distance was in the range of -1.2 mm to +2.8 mm in group I (1.1 +/- 0.9 mm [mean +/- standard error] in absolute value) and -0.2 mm to +4.8 mm (2.2 +/- 1.7 mm [mean +/- standard error] in absolute value) in group II (positive values signify the center of the beveled surface is past the nerve), when the stimulation current reached the minimum (average minimum current: 0.47 mA in group I, 0.37 mA in group II). Indian ink spread over a significant distance (25.4 +/- 0.5 mm [mean +/- standard error]; range, 19-31 mm) longitudinally within the perineural tissue, and axonal degeneration was observed linearly at the peripheral portion of the nerve fascicle in a similar pattern as Indian ink spread.

CONCLUSIONS

The target nerve was located within 5 mm from the needle with less than 0.5-mA stimulation current. The injectate spread to more than 20 mm on average even when a small volume (100 microL) of the injectate was injected in rabbit sciatic nerves.

Motor branch of the rectus femoris: anatomic location for selective motor branch block in stiff-legged gait

OBJECTIVE

To determine the ideal target point for selective motor branch block of the rectus femoris to treat stiff-legged gait.

DESIGN

Descriptive study.

SETTING

Anatomic institute of a university school of medicine in Korea.

CADAVERS

Twenty-two preserved adult cadavers.

INTERVENTION

The anterior thigh of the cadaver was dissected below the inguinal ligament. The motor branches of the 4 heads of the quadriceps were identified and traced from just below the inguinal ligament to the motor points.

MAIN OUTCOME MEASURES

The point T, where the motor branch of the rectus femoris is divided into smaller subbranches, was identified. Its location in relation to the surface anatomic landmarks was determined on the basis of the 2 anatomic lines that connect the anterior superior iliac spine to the medial femoral condyle, and the issuing spot of the femoral nerve below the inguinal ligament to the middle of the superior pole of the patellar.

RESULTS

The motor branch of the rectus femoris was divided into 2 subbranches at point T just before it reached the muscle. It nearly touched the medial margin of the rectus femoris at a proximal one-fourth to one-fifth point on 2 anatomic lines. The superior subbranch penetrated the muscle fascia at the posterior surface of the proximal one third of the muscle, whereas the inferior subbranch penetrated the muscle fascia at the medial border of the muscle.

CONCLUSION

The point T is the most suitable target point to selectively block the motor branch of the rectus femoris without affecting the other 3 motor branches of the femoral nerve in the treatment of stiff-legged gait.

A novel missense mutation (I344K) in the SPG4gene in a Korean family with autosomal-dominant hereditary spastic paraplegia

Hereditary spastic paraplegia (HSP) is a group of clinically and genetically heterogeneous neurodegenerative disorders characterized by slowly progressive spasticity and weakness of the lower extremities. Among eight loci linked with autosomal-dominant (AD)-HSP, the SPG4 locus on chromosome 2p22 accounts for about 40% of all patients. Recently, mutations in a new member of the AAA protein family, called spastin, have been identified as responsible for SPG4-linked AD-HSP. Here, we describe a novel missense mutation (c.1031T>A; I344K) in exon 7 of the SPG4 gene identified in a Korean family with typical clinical features of pure AD-HSP. The mutation affects the third amino acid of the highly conserved AAA cassette domain, which is the most fore part of the domain altered by a missense mutation reported so far. Clinical presentations of affected individuals carrying the I344K mutation were not different from those of pure AD-HSP with SPG4 mutations reported previously. However, it is noteworthy that neither urinary dysfunction nor involvement of upper extremities was noticed in this family. To our knowledge, this is the first report of genetically confirmed AD-HSP in Korea.

Phenol block of peripheral nerve conduction: Titrating for optimum effect

OBJECTIVES

To verify the dose-response relationship in phenol nerve block and to determine the concentration and volume of phenol injectate required for effective nerve conduction block.

DESIGN

Before-after, experimental study.

SETTING

A research institute laboratory.

ANIMALS

Seventy-one New Zealand white rabbits.

INTERVENTIONS

Group I (n = 48) received tibial nerve block by perineural injection (phenol, n = 40; saline, n = 8), group II (n = 21) by submerging the nerve in phenol solution. The 6 subgroups of group I each received different concentrations (3%, 4%, 5%) and volumes (0.1mL, 0.2mL, 0.3mL). The 2 subgroups of group II received 3% (n = 8) and 5% (n = 13) phenol.

MAIN OUTCOME MEASURES

Compound muscle action potential (CMAP) and tension of triceps surae muscles by electric stimulation of the sciatic nerve were measured preintervention and at day 1, and weeks 1, 2, 4, and 8 postblock. Histologic studies were performed on 2 animals from group I.

RESULTS

Two rabbits in group I died before results were obtained. In the remaining animals, CMAP amplitude reduced significantly (p <.05) as the volume of 5% phenol solution increased from 0.1mL, 0.2mL, to 0.3mL. A high concentration of phenol produced a more pronounced conduction block; however, no significant (p =.0589) difference existed among the 3 concentrations. Submerged tibial nerve had a greater degree of conduction block than perineurally injected nerve. Depth of the degeneration area in nerve fascicle varied with distance from the injection point.

CONCLUSIONS

The nerve block effect of phenol can be titrated by adjusting the concentration and volume of phenol solution if the technique of application and localization of a block site are standardized.

Motor branch block of the rectus femoris: its effectiveness in stiff-legged gait in spastic paresis

OBJECTIVE

To verify the efficacy of motor branch block of the rectus femoris for stiff-legged gait in spastic patients.

DESIGN

Before-after treatment trial.

SETTING

University hospital physical medicine and rehabilitation department outpatient clinic.

PATIENTS

Thirty-one adult spastic patients with stiff-legged gait.

INTERVENTION

Motor branch block of the rectus femoris with 2% lidocaine and 5% phenol.

OUTCOME MEASURES

Subjective assessment of gait performance by patients themselves and objective assessment of gait speed and sagittal knee kinematics.

RESULTS

Seventy-four percent (23/31) of patients felt an improvement (improved knee bending, disappeared toe dragging) after nerve block with lidocaine. Sixteen of 17 patients with an abnormal swing phase activity of the rectus femoris without that of the vastus medialis or lateralis and 20 of 23 patients with a sufficient hip flexor strength expressed an improvement subjectively. Gait analysis showed increased maximal knee flexion at swing phase and increased slope of knee flexion curve at toe off (p < .05). Phenol block was performed in 19 of 23 patients who had had a subjective improvement in their gait performance after nerve block with lidocaine. Gait speed, maximal knee flexion angle at swing phase, and slope of knee flexion curve at toe off increased significantly after phenol block (p < .05).

CONCLUSION

Motor branch block of the rectus femoris can be an effective treatment in stiff-legged gait. Its effect is varied with hip flexor strength and dynamic electromyographic findings of quadriceps.

Expression of myometrial activation and stimulation genes in a mouse model of preterm labor: myometrial activation, stimulation, and preterm labor

Myometrial contractions of labor result from an increase in myometrial activation and stimulation. Activation develops through the expression of contraction associated proteins (CAPs), including oxytocin receptors (OTR), connexin-43 (Cx-43), and prostaglandin F2 alpha, receptors (FP). Stimulation involves increases in contractile agonists including prostaglandin E2 (PGE2) and prostaglandin F2 alpha. (PGF2 alpha) that may result from increases in prostaglandin endoperoxide H synthase (PGHS)-2. A mouse model of preterm birth was used to study gene expression involved in myometrial activation and stimulation. To induce preterm birth, pregnant C57BL/6J mice were intubated with 6 g/kg ethanol on gestational day 16 and were killed every 6 h from treatment until birth. RIA was used to measure uterine PGE2 and PGF2 alpha, while PGHS-2, OTR, Cx-43, and FP messenger RNA levels were measured by ribonuclease protection assay. Increases in CAP mRNA were associated with term and preterm birth. There were differences in stimulation effectors associated with preterm and term birth. Uterine PGF2 alpha values were increased only at the time of term birth, but PGE2 was elevated during both preterm and term labor. These data suggest that existing levels of PGF2 alpha are sufficient for preterm birth when CAP expression is increased, but term labor requires increases in PGE2, PGF2alpha, and CAPs. The PGHS-2 messenger RNA expression pattern suggests that it is a CAP.