Diagnostic Roots Radiofrequency Sensory Stimulation Looking for Symptomatic Injured Roots in Multiple Lumbar Stenosis / 대한신경손상학회지

Objective@#We present how to perform radiofrequency sensory stimulation (RFSS) and whether RFSS could be helpful in identifying symptomatic injured roots in multilevel lumbar stenosis. @*Methods@#Consecutive patients who underwent RFSS from 2010 to 2012 were enrolled. To identify pathologic lesions, RFSS was performed for suspicious roots, as determined using lumbar magnetic resonance imaging (MRI). The RFSS procedure resembled transforaminal root block. During RFSS of the suspicious root, patients could indicate whether stimulation induced their usual pain and/or sensory changes and could indicate whether the same leg area was affected. The number of possible symptomatic roots on MRI was evaluated before and after RFSS. Based on the RFSS results, we confirmed the presence of symptomatic nerve root(s) and performed surgical decompression. Surgical results, such as numeric rating scale (NRS) scores for low back pain (LBP) and leg pain (LP), and Oswestry disability index (ODI), were evaluated. @*Results@#Ten patients were enrolled in the study. Their mean age was 70.1±9.7 years. Clinically, NRS-LBP, NRS-LP, and ODI before surgery were 5.1%, 7.5%, and 53.2%, respectively. The mean number of suspicious roots was 2.6±0.8. After RFSS, the mean number of symptomatic roots was 1.6±1.0. On average, 1.4 lumbar segments were decompressed. The follow-up period was 35.3±12.8 months. At the last follow-up, NRS-LBP, NRS-LP, and ODI were 3.1%, 1.5%, and 35.3%, respectively. There was no recurrence or need for further surgical treatment for lumbar stenosis. @*Conclusion@#RFSS is a potentially helpful diagnostic tool for verifying and localizing symptomatic injured root lesions, particularly in patients with multilevel spinal stenosis.

Gender differences in adult traumatic brain injury according to the Glasgow coma scale: A multicenter descriptive study / 中华创伤杂志(英文版)

PURPOSE@#Patients' gender, which can be one of the most important determinants of traumatic brain injury (TBI) outcomes, is also likely to interact with many other outcome variables of TBI. This multicenter descriptive study investigated gender differences in epidemiological, clinical, treatment, mortality, and variable characteristics in adult TBI patients.@*METHODS@#The selection criteria were defined as patients who had been diagnosed with TBI and were admitted to the hospital between January 1, 2016 and December 31, 2018. A total of 4468 adult TBI patients were enrolled at eight University Hospitals. Based on the list of enrolled patients, the medical records of the patients were reviewed and they were registered online at each hospital. The registered patients were classified into three groups according to the Glasgow coma scale (GCS) score: mild (13-15), moderate (9-12), and severe (3-8), and the differences between men and women in each group were investigated. The risk factors of moderated and severe TBI compared to mild TBI were also investigated.@*RESULTS@#The study included 3075 men and 1393 women and the proportion of total males was 68.8%. Among all the TBI patients, there were significant differences between men and women in age, past history, and GCS score. While the mild and severe TBI groups showed significant differences in age, past history, and clinical symptoms, the moderate TBI group showed significant differences in age, past history, cause of justice, and diagnosis.@*CONCLUSION@#To the best of our knowledge, this multicenter study is the first to focus on gender differences of adult patients with TBI in Korea. This study shows significant differences between men and women in many aspects of adult TBI. Therefore, gender differences should be strongly considered in TBI studies.

A Prospective Observational Study of Return to Work after Single Level Lumbar Discectomy

Objective@#: Lumbar disc herniation (LDH) is a common disease, and lumbar discectomy (LD) is a common neurosurgical procedure. However, there is little previous data on return to work (RTW) after LD. This study investigated the period until the RTW after LD prospectively. Clinically, the pain state at the time of RTW also checked. RTW failure rate 6 months after surgery also investigated. @*Methods@#: Patients with daily/regular jobs undergoing LD between September 2014 and December 2018 were enrolled. Pain was assessed by the Oswestri Disability Index (ODI) and the Numeric Rate Scale (NRS). Employment type was divided into self-employed, regular and contracted. Monthly telephone interviews were conducted to check RTW status and self-estimated work capability after surgery. @*Results@#: Sixty-seven patients enrolled in this study. Three patients failed to RTW, and three others resigned within 6 months after surgery. The preoperative NRS and ODI were 7.2±1.2 and 22.1±7.9, respectively. The average time to RTW was 5.1±6.0 weeks. At RTW, NRS was 1.5±1.8 and ODI was 6.3±3.9. Amongst patients that successfully returned to work were 16 self-employed workers, 42 regular employees, and three contracted workers. The time to RTW of self-employed, regular, and contracted workers were 5.9±8.8, 4.2±4.3 and 13.3±2.3 weeks, respectively (p=0.011). Thirty-six of the patients that returned to work self-reported a 22.8±15.6% reduction in work capability at 6 months. @*Conclusion@#: RTW may vary depending on the employment status. In this study, we found that while employment type may affect the length to RTW, most patients were able to RTW and >40% of patients reported no loss of work capabilities 6 months postoperatively, hopefully alleviating some patient hesitation towards LD.

Rapid Healing and Remodeling Process of Pediatric Seat-Belt Fracture without Surgical Treatment / 대한신경손상학회지

Pediatric seat-belt fracture is a rare condition, and its management has not been well defined. The authors report a case of pediatric Chance fracture that was managed conservatively and that demonstrated rapid bone healing. A 7-year-old boy presented with back pain after a motor vehicle accident. Plain lumbar spine radiography, three-dimensional computed tomography (CT), and magnetic resonance imaging revealed a seat-belt fracture type C (classified by Rumball and Jarvis), and the patient's condition was managed conservatively. The patient started to ambulate with a brace 2 weeks after the injury. Spine CT performed 100 days after the injury revealed a remodeled fracture, and dynamic radiography did not show any evidence of instability or kyphotic deformity. We suggest that if there are no neurological deficits or severe deformities, then a pediatric seat-belt fracture should be managed conservatively, because the bone healing process is far more rapid in children than it is in adults and because of possible growth problems after surgery.

Osteoblast and Bacterial Culture from Cryopreserved Skull Flap after Craniectomy: Laboratory Study

OBJECTIVE: Cranioplasty using a cryopreserved skull flap is a wide spread practice. The most well-known complications of cranioplasty are postoperative surgical infections and bone flap resorption. In order to find biological evidence of cryopreserved cranioplasty, we investigated microorganism contamination of cryopreserved skulls and cultured osteoblasts from cryopreserved skulls. METHODS: Cryopreserved skull flaps of expired patients stored in a bone bank were used. Cryopreserved skulls were packaged in a plastic bag and wrapped with cotton cloth twice. After being crushed by a hammer, cancellous bone between the inner and outer table was obtained. The cancellous bone chips were thawed in a water bath of 30°C rapidly. After this, osteoblast culture and general microorganism culture were executed. Osteoblast cultures were done for 3 weeks. Microorganism cultures were done for 72 hours. RESULTS: A total of 47 cryopreserved skull flaps obtained from craniectomy was enrolled. Of the sample, 11 people were women, and the average age of patients was 55.8 years. Twenty four people had traumatic brain injuries, and 23 people had vascular diseases. Among the patients with traumatic brain injuries, two had fracture compound comminuted depressed. The duration of cryopreservation was, on average, 83.2 months (9 to 161 months). No cultured osteoblast was observed. No microorganisms were cultured. CONCLUSION: In this study, neither microorganisms nor osteoblasts were cultured. The biological validity of cryopreserved skulls cranioplasty was considered low. However, the usage of cryopreserved skulls for cranioplasty is worthy of further investigation in the aspect of cost-effectiveness and risk-benefit of post-cranioplasty infection.

Review of Cranioplasty after Decompressive Craniectomy / 대한신경손상학회지

Cranioplasty is an in evitable operation conducted after decompressive craniectomy (DC). The primary goals of cranioplasty after DC are to protect the brain, achieve a natural appearance and prevent sinking skin flap syndrome (or syndrome of the trephined). Furthermore, restoring patients' functional outcome and supplementing external defects helps patients improve their self-esteem. Although early cranioplasty is preferred in recent year, optimal timing for cranioplasty remains a controversial topic. Autologous bone flaps are the most ideal substitute for cranioplasty. Complications associated with cranioplasty are also variable, however, post-surgical infection is most common. Many new materials and techniques for cranioplasty are introduced. Cost-benefit analysis of these new materials and techniques can result in different outcomes from different healthcare systems.

Delayed Infarction of Medullar and Cerebellum 3 Months after Vertebral Artery Injury with C1-2 Fracture: Case Report / 대한신경손상학회지

The clinical manifestations of vertebral artery (VA) injury (VAI) after cervical trauma range from asymptomatic to fatal cerebral infarction. Thrombotic occlusion and embolization to the distal arteries can cause cerebellar and brain stem infarction within days after trauma. We report a 64-year-old man who underwent arthrodesis surgery for C1 and C2 fractures. He had left VAI at the C2 transverse foramen site but was asymptomatic. The patient experiences brainstem and cerebellar infarction 3 months after injury to the VA, and we are here to discuss the treatment of VAI after cervical trauma.

A Novel Association between Lysyl Oxidase Gene Polymorphism and Intracranial Aneurysm in Koreans

PURPOSE: Lysyl oxidase (LOX) controls the cross-linking and maturation of elastin and collagen fibers. In this study, we investigated the association between LOX gene polymorphisms and intracranial aneurysm (IA) formation in a homogeneous Korean population. MATERIALS AND METHODS: This cross-sectional study involved 80 age-sex matched patients with IA and controls. Fisher's exact test was performed to analyze allelic associations between ten single nucleotide polymorphisms (SNPs) and IA, including 41 ruptured and 39 unruptured cases. Haplotype-specific associations were analyzed using the omnibus test estimating asymptotic chi-square statistics. RESULTS: Of ten SNPs, three SNPs (rs2303656, rs3900446, and rs763497) were significantly associated with IA (p<0.01). The C allele of rs3900446 was significantly related to increased IA risk with a significant threshold [odds ratio (OR)=20.15, p=4.8×10⁻⁵]. Meanwhile, the A allele of rs2303656 showed a preventive effect against IA formation (p=8.2×10⁻⁴). Seventeen of 247 haplotype structures showed a suggestive association with IA (asymptotic p<0.001). Of ten SNP haplotype combinations, the CG combination of rs3900446 and rs763497 reached Bonferroni-adjusted significant threshold in IA patients (minor haplotype frequency=0.113, asymptotic p=1.3×10⁻⁵). However, there was no association between aneurysm rupture and the LOX gene. CONCLUSION: This preliminary study indicated that LOX gene polymorphisms, such as rs2303656, rs3900446, and rs763497, may play crucial roles in IA formation in the Korean population. Our novel findings need to be validated in a large-scale independent population.

Delayed Consecutive Contralateral Thalamic Hemorrhage after Spontaneous Thalamic Hemorrhage

Simultaneous or subsequent bilateral thalamic hemorrhagic events have ranged from 12 to 19 in prior reports, with a time lag between bilateral thalamic hemorrhage of up to two days. Herein, we report the first case of delayed (17 days) consecutive contralateral thalamic hemorrhage after spontaneous first thalamic hemorrhage. A 65-year-old female initially presented with a drowsy mentality with a left-side motor weakness (grade II/III). Brain computed tomography (CT) demonstrated right side thalamic and intraventricular hemorrhage. She regained alertness with mild residual motor weakness (grade III/IV) under medical management. Seventeen days later, a sudden and generalized tonic-clonic seizure developed. Brain CT scans revealed a new contralateral thalamic hemorrhage coincident with microbleeds. Neurologic status remained unchanged, consisting of a stuporous mentality with quadriparesis of grade II/II. We report the first case of delayed consecutive contralateral thalamic hemorrhage up to 17 days after first thalamic hemorrhage. The case highlights the need for close monitoring of patients with thalamic hemorrhage who experience microbleeds on the contralateral side, due to the possibility of delayed hemorrhage.

Delayed Consecutive Contralateral Thalamic Hemorrhage after Spontaneous Thalamic Hemorrhage

Simultaneous or subsequent bilateral thalamic hemorrhagic events have ranged from 12 to 19 in prior reports, with a time lag between bilateral thalamic hemorrhage of up to two days. Herein, we report the first case of delayed (17 days) consecutive contralateral thalamic hemorrhage after spontaneous first thalamic hemorrhage. A 65-year-old female initially presented with a drowsy mentality with a left-side motor weakness (grade II/III). Brain computed tomography (CT) demonstrated right side thalamic and intraventricular hemorrhage. She regained alertness with mild residual motor weakness (grade III/IV) under medical management. Seventeen days later, a sudden and generalized tonic-clonic seizure developed. Brain CT scans revealed a new contralateral thalamic hemorrhage coincident with microbleeds. Neurologic status remained unchanged, consisting of a stuporous mentality with quadriparesis of grade II/II. We report the first case of delayed consecutive contralateral thalamic hemorrhage up to 17 days after first thalamic hemorrhage. The case highlights the need for close monitoring of patients with thalamic hemorrhage who experience microbleeds on the contralateral side, due to the possibility of delayed hemorrhage.

Neuralgic Amyotrophy Manifesting as Mimicking Posterior Interosseous Nerve Palsy

The upper trunk of the brachial plexus is the most common area affected by neuralgic amyotrophy (NA), and paresis of the shoulder girdle muscle is the most prevalent manifestation. Posterior interosseous nerve palsy is a rare presentation in patients with NA. It results in dropped finger on the affected side and may be misdiagnosed as entrapment syndrome or compressive neuropathy. We report an unusual case of NA manifested as PIN palsy and suggest that knowledge of clinical NA phenotypes is crucial for early diagnosis of peripheral nerve palsies.

Radiologic Determination of Corpus Callosum Injury in Patients with Mild Traumatic Brain Injury and Associated Clinical Characteristics

OBJECTIVE: To investigate the incidence of corpus callosum injury (CCI) in patients with mild traumatic brain injury (TBI) using brain MRI. We also performed a review of the clinical characteristics associated with this injury. METHODS: A total of 356 patients in the study were diagnosed with TBI, with 94 patients classified as having mild TBI. We included patients with mild TBI for further evaluation if they had normal findings via brain computed tomography (CT) scans and also underwent brain MRI in the acute phase following trauma. As assessed by brain MRI, CCI was defined as a high-signal lesion in T2 sagittal images and a corresponding low-signal lesion as determined by axial gradient echo (GRE) imaging. Based on these criteria, we divided patients into two groups for further analysis : Group I (TBI patients with CCI) and Group II (TBI patients without CCI). RESULTS: A total of 56 patients were enrolled in this study (including 16 patients in Group I and 40 patients in Group II). Analysis of clinical symptoms revealed a significant difference in headache severity between groups. Over 50% of patients in Group I experienced prolonged neurological symptoms including dizziness and gait disturbance and were more common in Group I than Group II (dizziness : 37 and 12% in Groups I and II, respectively; gait disturbance : 12 and 0% in Groups I and II, respectively). CONCLUSION: The incidence of CCI in patients with mild TBI was approximately 29%. We suggest that brain MRI is a useful method to reveal the cause of persistent symptoms and predict clinical prognosis.

Pullout Strength after Expandable Polymethylmethacrylate Transpedicular Screw Augmentation for Pedicle Screw Loosening

OBJECTIVE: Pedicle screw fixation for spine arthrodesis is a useful procedure for the treatment of spinal disorders. However, instrument failure often occurs, and pedicle screw loosening is the initial step of a range of complications. The authors recently used a modified transpedicular polymethylmethacrylate (PMMA) screw augmentation technique to overcome pedicle screw loosening. Here, they report on the laboratory testing of pedicle screws inserted using this modified technique. METHODS: To evaluate pullout strengths three cadaveric spinal columns were used. Three pedicle screw insertion methods were utilized to compare pullout strength; the three methods used were; control (C), traditional transpedicular PMMA augmentation technique (T), and the modified transpedicular augmentation technique (M). After control screws had been pulled out, loosening with instrument was made. Screw augmentations were executed and screw pullout strength was rechecked. RESULTS: Pedicle screws augmented using the modified technique for pedicle screw loosening had higher pullout strengths than the control (1106.2+/-458.0 N vs. 741.2+/-269.5 N; p=0.001). Traditional transpedicular augmentation achieved a mean pullout strength similar to that of the control group (657.5+/-172.3 N vs. 724.5+/-234.4 N; p=0.537). The modified technique had higher strength than the traditional PMMA augmentation technique (1070.8+/-358.6 N vs. 652.2+/-185.5 N; p=0.023). CONCLUSION: The modified PMMA transpedicular screw augmentation technique is a straightforward, effective surgical procedure for treating pedicle screw loosening, and exhibits greater pullout strength than traditional PMMA transpedicular augmentation. However, long-term clinical evaluation is required.

Acute Myelopathy Caused by a Cervical Synovial Cyst

Synovial cysts of the cervical spine, although they occur infrequently, may cause acute radiculopathy or myelopathy. Here, we report a case of a cervical synovial cyst presenting as acute myelopathy after manual stretching. A 68-year-old man presented with gait disturbance, decreased touch senses, and increased sensitivity to pain below T12 level. These symptoms developed after manual stretching 3 days prior. Computed tomography scanning and magnetic resonance imaging revealed a 1-cm, small multilocular cystic lesion in the spinal canal with cord compression at the C7-T1 level. We performed a left partial laminectomy of C7 and T1 using a posterior approach and completely removed the cystic mass. Histological examination of the resected mass revealed fibrous tissue fragments with amorphous materials and granulation tissue compatible with a synovial cyst. The patient's symptoms resolved after surgery. We describe a case of acute myelopathy caused by a cervical synovial cyst that was treated by surgical excision. Although cervical synovial cysts are often associated with degenerative facet joints, clinicians should be aware of the possibility that these cysts can cause acute neurologic symptoms.

Sensory Complications in Patients after Scalp Mass Excision and Its Anatomical Considerations

OBJECTIVE: To evaluate the incidence of postsurgical sensory complications in patients with scalp masses and classify the locations of them from a surgical standpoint according to anatomical considerations. METHODS: A total of 121 patients who underwent surgery for scalp mass were included in this study. The authors reviewed medical records and preoperative radiologic images. We investigated the complications related to sensory changes after procedure. Enrolled patients have been divided into three groups. Group A included patients with tumors above the superior nuchal line (SNL), Group B with tumors within the trapezius muscle area and patients who had tumors on the lateral trapezius muscle area were assigned to Group C. We compared the incidence related to postoperative sensory complications and summarized their additional treatments for these with clinical outcome. RESULTS: There were 12 patients (10%) with sensory complications related on the mass excision site (Group A: 1 patient, Group B: 2 patients, Group C: 9 patients). Six patients were affected with lesser occipital nerve (LON), 2 patients on greater occipital nerve (GON) and 4 patients on GON and LON. Over 6 months after surgery, two of the twelve patients with sensory complications did not have complete recovered pain in spite of proper medications and local chemical neurolysis with 1.0% lidocaine and dexamethasone. CONCLUSION: Occipital neuropathy should be considered as a complication related excision of scalp mass. The sensory complications are more frequent in Group C because of the anatomical characteristics of the occipital nerves and there were no statistical difference for other variables.

Demographic and Clinical Characteristics of Patients with Restless Legs Syndrome in Spine Clinic

OBJECTIVE: The restless legs syndrome (RLS) is a common disorder affecting up to 5% to 15% of the general population, in which the incidence increases with age, and includes paresthesia in the legs. The purpose of this study is to investigate the incidence of RLS in spine center and to review clinical manifestations of this syndrome and its current treatments. METHODS: Over a period of a year, retrospective medical record review and lumbar magnetic resonance images were performed on 32 patients with RLS in spine clinic who were diagnosed by National Institutes of Health criteria. Affected limbs were classified as five. Two grading systems were used in the evaluation of neural compromises. RESULTS: The incidence of RLS was 5.00% (32/639). There were 16 males (50%) and 16 females (50%). The median age at diagnosis was 55.4 years (range, 25-93 years). There are no correlation between the affected limbs of RLS and neural compromises on the lumbar spine. CONCLUSION: The RLS is a clearly common neurologic disorder of the limbs, usually the legs. The awareness of this syndrome can help reduce diagnostic error; thereby, avoiding the morbidity and expense associated with unnecessary studies or inappropriate treatments in RLS patients.

Clinical Features of Wrist Drop Caused by Compressive Radial Neuropathy and Its Anatomical Considerations

OBJECTIVE: Posture-induced radial neuropathy, known as Saturday night palsy, occurs because of compression of the radial nerve. The clinical symptoms of radial neuropathy are similar to stroke or a herniated cervical disk, which makes it difficult to diagnose and sometimes leads to inappropriate evaluations. The purpose of our study was to establish the clinical characteristics and diagnostic assessment of compressive radial neuropathy. METHODS: Retrospectively, we reviewed neurophysiologic studies on 25 patients diagnosed with radial nerve palsy, who experienced wrist drop after maintaining a certain posture for an extended period. The neurologic presentations, clinical prognosis, and electrophysiology of the patients were obtained from medical records. RESULTS: Subjects were 19 males and 6 females. The median age at diagnosis was 46 years. The right arm was affected in 13 patients and the left arm in 12 patients. The condition was induced by sleeping with the arms hanging over the armrest of a chair because of drunkenness, sleeping while bending the arm under the pillow, during drinking, and unknown. The most common clinical presentation was a wrist drop and paresthesia on the dorsum of the 1st to 3rd fingers. Improvement began after a mean of 2.4 weeks. Electrophysiologic evaluation was performed after 2 weeks that revealed delayed nerve conduction velocity in all patients. CONCLUSION: Wrist drop is an entrapment syndrome that has a good prognosis within several weeks. Awareness of its clinical characteristics and diagnostic assessment methods may help clinicians make diagnosis of radial neuropathy and exclude irrelevant evaluations.

Effect of Pulsed Radiofrequency Neuromodulation on Clinical Improvements in the Patients of Chronic Intractable Shoulder Pain

OBJECTIVE: The aim of this study was to evaluate effect of pulsed radiofrequency (PRF) neuromodulation of suprascpaular nerve (SSN) in patients with chronic shoulder pain due to adhesive capsulitis and/or rotator cuff tear. METHODS: The study included 11 patients suffering from chronic shoulder pain for at least 6 months who were diagnosed with adhesive capsulitis (n=4), rotator cuff tear (n=5), or adhesive capsulitis+rotator cuff tear (n=2) using shoulder magnetic resonance imaging or extremity ultrasonography. After a favorable response to a diagnostic suprascapular nerve block twice a week (pain improvement >50%), PRF neuromodulation was performed. Shoulder pain and quality of life were assessed using a Visual Analogue Scale (VAS) and the Oxford Shoulder Score (OSS) before the diagnostic block and every month after PRF neuromodulation over a 9-month period. RESULTS: The mean VAS score of 11 patients before PRF was 6.4+/-1.49, and the scores at 6-month and 9 month follow-up were 1.0+/-0.73 and 1.5+/-1.23, respectively. A significant pain reduction (p<0.001) was observed. The mean OSS score of 11 patients before PRF was 22.7+/-8.1, and the scores at 6-month and 9 month follow-up were 41.5+/-6.65 and 41.0+/-6.67, respectively. A significant OSS improvement (p<0.001) was observed. CONCLUSION: PRF neuromodulation of the suprascapular nerve is an effective treatment for chronic shoulder pain, and the effect was sustained over a relatively long period in patients with medically intractable shoulder pain.

Pure Intramuscular Osteolipoma

Ossified lipoma or osteolipoma are rarely reported. It is defined as a histologic variant of lipoma that has undergone osseous metaplasia. Osteolipoma presents with a dominant osseous component within a lipoma. We report a case of a histologically confirmed osteolipoma on the nuchal ligament independent of bone. The patient was a 51-year-old female who presented with a 5-year history of a painless, progressively enlarging mass on the posterior neck. Computed tomography and magnetic resonance imaging showed a circumscribed mass compatible with fat between the C2 and C6 spinous processes with a large calcified irregular component. The mass with dual components was totally removed under general anesthesia and no recurrence was observed after 6 months of follow-up. We also reviewed the clinicopathologic features of previously reported osteolipomas in the literature and suggest that although osteolipoma is a rare variant of lipoma, it should be considered in the differential diagnosis when a lipoma of the posterior neck mixed with a bony component is encountered.

Clinical Characteristics of Peroneal Nerve Palsy by Posture

OBJECTIVE: Posture induced common peroneal nerve (CPN) palsy is usually produced during the prolonged squatting or habitual leg crossing while seated, especially in Asian culture and is manifested by the onset of foot drop. Because of its similarity to discogenic foot drop, patients may be diagnosed with a lumbar disc disorder, and in some patients, surgeons may perform unnecessary examinations and even spine surgery. The purpose of our study is to establish the clinical characteristics and diagnostic assessment of posture induced CPN palsy. METHODS: From June 2008 to June 2012, a retrospective study was performed on 26 patients diagnosed with peroneal nerve palsy in neurophysiologic study among patients experiencing foot drop after maintaining a certain posture for a long time. RESULTS: The inducing postures were squatting (14 patients), sitting cross-legged (6 patients), lying down (4 patients), walking and driving. The mean prolonged neural injury time was 124.2 minutes. The most common clinical presentation was foot drop and the most affected sensory area was dorsum of the foot with tingling sensation (14 patients), numbness (8 patients), and burning sensation (4 patients). The clinical improvement began after a mean 6 weeks, which is not related to neural injury times. Electrophysiology evaluation was performed after 2 weeks later and showed delayed CPN nerve conduction study (NCS) in 24 patients and deep peroneal nerve in 2 patients. CONCLUSION: We suggest that an awareness of these clinical characteristics and diagnostic assessment methods may help clinicians make a diagnosis of posture induced CPN palsy and preclude unnecessary studies or inappropriate treatment in foot drop patients.