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Background Ankle-foot orthoses (AFOs) have been shown to improve gait and static balance in individuals with lower extremity weakness and instability. However, the effects of AFOs on dynamic balance reactions including reactive stepping responses are not well known. Therefore, the purpose of this study was to determine the effects of an AFO on reactive stepping responses in healthy young adults. Research question Does an AFO alter reactive stepping responses in healthy young adults? Methods Twenty healthy young adults completed 10 reactive stepping trials using a lean-and-release system for each of three AFO conditions: 1) no AFO, 2) AFO on left leg and 3) AFO on right leg. Trials were recorded using 3D motion capture and force plates. Stepping limb preference and temporal, spatial, and kinematic variables were measured. Differences between conditions were determined by a one-way ANOVA with a Tukey post-hoc. Results With no AFO, participants demonstrated a preference for stepping with the right leg, 7.0 ± 3.9 of 10 trials. With an AFO on the right leg, this preference decreased to 5.7 ± 4.4 (p = 0.03). With an AFO on the left leg, this preference increased to 8.1 ± 3.3 (p = 0.03). Reaction times were not significantly different between conditions, but participants took a significantly shorter reactive step with the leg wearing the AFO. Peak ankle, knee, and hip joint angles were significantly less with the AFO on the stepping limb compared to the stance limb. Significance This study shows that AFO use can influence reactive stepping limb preference and stepping limb kinematics in healthy young adults. These results can inform future research on AFO users with gait impairments. These finding may also be helpful in developing interventions to address the specific effects of an AFO on reactive stepping responses.

Muscular manifestations of sarcoidosis are commonly found on biopsy but rare on correlated imaging. We present a rare case of a 36-year-old male patient with sarcoid myositis and image findings of active myositis in the lower back and pelvic girdle musculature. This case suggests considering sarcoidosis as a differential diagnosis in the setting of chest findings and new lower back and lower extremity weakness.

La neuropatía periférica es una complicación presente en menos del 5 % de los casos de intoxicación por monóxido de carbono. El presente artículo describe las características clíni- cas de tres pacientes que acudieron con síntomas de lesión de nervio periférico tras estar expuestos a un incendio. Las variaciones clínicas incluyeron debilidad de miembros inferiores, parestesias y dolor tipo ardor. Se usaron estudios de electrodiagnóstico a los 14 días del evento, los cuales mostraron cambios no específicos. Al año del evento, uno de los pacientes confirmó lesión desmielinizante y axonal de nervio periférico. La presencia de signos y síntomas en conjunto con el antecedente de inhalación de humo, establecen el nexo etiológico con la intoxicación por monóxido de carbono. Este caso demuestra la importancia de considerar la intoxicación por monóxido de carbono como causa de neuropatía periférica. El diagnóstico debe fundamentarse en una historia clínica completa y puede apoyarse de electrodiagnóstico.

Sciatica is a musculoskeletal disease with more than 10 million cases per year in India. It is a lumbar radiculopathy with mild, moderate or intense pain that radiates from lower back into right, left or both the legs. This article is a case report of a patient presenting with lower extremity weakness, lower back pain radiating towards both the legs and cramps in lower extremity. She was diagnosed for Gridhrasi and was admitted in IPD of All India Institute of Ayurveda. She was given Panchakarma treatment like Abhyanga, Rooksha Churna Pinda Swedana, Patra Pinda Swedana and Abhyantara Basti for a period of 18 days. There was 56.5% relief in her symptoms according to Rolland and Morris scale and on an average percentage according to subjective symptoms assessment criteria calculating relief in symptoms. On the basis of result it was observed that Panchakarma with proper Pathya Apathya can give satisfactory results in addition to it, if this intervention is given in acute stage then it may enhance the results.

Background We have previously shown that older adults discharged from the emergency department (ED) experience an increased disability burden within a 6-month time period after ED discharge. The objective of this study was to identify risk factors associated with increased disability burden among older adults discharged from the ED. Methods This study is part of an ongoing longitudinal study of 754 community-living persons aged ≥70 years. The analytic sample included 813 ED visits without hospitalization from 430 participants who had ≥1 visit to an ED during a 14-year follow-up period (1998-2012). Information on ED visits and disability burden in 13 functional activities was collected during monthly interviews. Twenty-nine candidate risk factors were evaluated for their independent associations with increased disability burden using a longitudinal multivariable model. Results In the multivariable analyses, age ≥ 85 (adjusted risk ratio [aRR] 1.14, 95% confidence interval [CI] 1.05 - 1.24), being unmarried (aRR 1.15, 95% CI 1.05 - 1.27), lower extremity weakness (aRR 1.20, 95% CI 1.07 - 1.34), and physical frailty (aRR 1.25, 95% CI 1.13 - 1.37) were associated with increased disability burden. As the number of risk factors increased, the predicted mean disability burden (on a scale 0-13) also increased, ranging from a value of 1.80 (95% CI 1.43 - 2.27) for 0 risk factors to a value of 8.59 (95% CI 7.93 - 9.29) for 4 risk factors. Conclusion Among older adults discharged from the ED, several risk factors were associated with increased disability burden over the following 6 months, including age ≥ 85, being unmarried, lower extremity weakness, and physical frailty. Further research is needed to evaluate whether risk stratification based on non-modifiable factors or interventions targeting modifiable risk factors improve functional outcomes for older adults discharged from the ED.

Purpose: To report a case of chronic intermittent spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) and its successful treatment using hypogastric artery stenting. Case Report: A 79-year-old patient presented in May 2013 with a thoracic aortic aneurysm (TAA) and a contained rupture. He urgently underwent TEVAR that covered 274 mm of descending thoracic aorta without immediate postoperative signs of acute SCI. At 3-month follow-up, he reported repeating incidents of sudden lower extremity weakness leading to a fall with a humerus fracture. A neurological consultation revealed the tentative diagnosis of intermittent SCI caused by TEVAR and initially recommended a conservative approach. During the following year there was no clinical improvement of the symptoms. Computed tomography angiography showed a high-grade stenosis of the right hypogastric artery, which was stented in November 2014 to improve the collateral network of spinal cord perfusion. Following treatment, the patient had no further neurological symptoms; at 32 months after the reintervention, the imaging follow-up documented a patent stent and continued exclusion of the TAA. Conclusion: Intermittent neurological symptoms after TEVAR should be suspected as chronic intermittent SCI. The improvement of collateral networks of the spinal cord by revascularization of the hypogastric artery is a viable treatment option.

The authors report a pathologically confirmed case of primary malignant melanoma located in the intradural lumbosacral area, which is extremely rare due to its atypical location and manifestation. However rare, primary malignant melanoma could present as an intradural tumor and cause neurological deficit.

Solitary fibrous tumors (SFTs) are rare, spindle cell neoplasms of the mesenchymal origin. Lesions localized to the spine are exceptionally uncommon, only described in the literature in case reports and small case series. While these lesions are typically benign, there are a few reports in which they recur or present as malignancies. The patient presented in the case herein was a 72-year-old male, who presented with a 1-year history of lower extremity weakness, pain, and numbness and was found to have a cervical, intradural extramedullary tumor. In addition to the case report, the authors perform a thorough review of all previously published cases of spinal SFT.

This study determined the frequency and impact of symptoms on quality of life (QoL) in patients diagnosed with limb girdle muscular dystrophy (LGMD). Participants with a diagnosis of LGMD in registries based at the Coalition to Cure Calpain-3, the Jain foundation, and the Global FKRP Registry competed a survey to report the frequency and relative impact of themes and symptoms of LGMD. Frequency, mean impact, and population impact scores were calculated, and responses were categorized by age, symptom duration, gender, employment status, use of assistive devices, and LGMD subtypes. 134 participants completed the survey. The most prevalent themes included an inability to do activities (100%), limitation with mobility (99.3%), and lower extremity weakness (97.0%). Themes with the greatest impact were: limitations with mobility, lower extremity weakness, and an inability to do activities. Symptom duration and the use of assistive devices were associated with the presence of multiple themes. Employment was associated with the impact of several themes with no differences in frequency. The prevalence and impact of these themes vary in the LMGD population. The most prevalent and impactful themes were related to weakness, but additional concerns related to emotional challenges should also be considered in clinical and research settings.

We present a case of new onset bilateral lower extremity weakness, paresthesia, urinary retention and bowel incontinence in a 51-year-old man. He had a complicated history of acute myelogenous leukemia with known central nervous system (CNS) and leptomeningeal involvement status post allogenic stem cell transplant complicated by chronic graft versus host disease (GVHD). We review the differential diagnosis as the physical exam and diagnostic results evolved. We also provide a review of the relevant literature supporting our favored diagnosis, as well as other competing diagnoses in this complicated case. The ultimate differential diagnosis included viral myelitis, treatment-related myelopathies, and CNS GVHD. The case provides a sobering reminder that even with an appropriate diagnostic workup, some cases remain refractory to therapeutic efforts. It also underscores the importance of a sensitive neurologic exam, given the significant clinico-radiological delay, and reviews the complex differential diagnosis for myelopathy.

The purpose of this report is to examine the features of cauda equina syndrome (CES) presenting as bladder and bowel dysfunction in the absence of lower extremity weakness. Between July 2015 and July 2016, we experienced four cases of massive LDH causing CES that presented as bladder and bowel dysfunction in the absence of lower extremity weakness. Herein, we describe the clinical features of these four patients (two males and two females) who were followed for a minimum of two years postoperatively. The mean age at the time of surgery was 46.8 years (range, 37-71 years). The disc herniation lesion was at the L4/5 level in one patient, and the L5/S1 level in three. The mean interval between the onset of CES and complete surgical decompression was 10.5 days (range, 1-18 days). Postoperative outcomes were better than poor in three of four cases, while one case had residual sphincter dysfunction. LDH causing CES is considered an indication for immediate surgical decompression; however, diagnosis of CES is likely to be delayed in atypical cases of CES that present as bladder and bowel dysfunction in the absence of lower extremity weakness. Diagnosis of CES tended to be delayed in cases without lower extremity weakness. Clinicians should recognize even sensory impairment alone of the dominant area supplied by S2-4 is an important diagnostic sign of CES in the early stage.

Giant aortic aneurysms are rare entities with a high mortality, and only a few cases have been described. Spinal cord ischemia secondary to an aortic aneurysm occurs even more rarely. We present the case of a giant aneurysm of the infrarenal abdominal aorta that was initially manifested through bilateral lower limb weakness.

Objective/background It has previously been shown that post-operative lower extremity weakness (LEW) is associated with elevated blood and cerebrospinal fluid (CSF) glucose levels after branched endovascular aneurysms repair (BEVAR) of extensive aortic aneurysms. The purpose of this study was to determine whether a post-operative insulin infusion protocol (IIP) to achieve tight blood glucose control decreases the rate of LEW. Methods From October 2013, blood and CSF samples were collected pre-operatively, immediately post-operatively, and on post-operative day one in asymptomatic patients undergoing BEVAR. In July 2016, an IIP was initiated to maintain post-operative blood glucose levels Results Between October 2013 and April 2018, 43 patients underwent BEVAR. Twenty-two (group A) underwent BEVAR before initiation of the IIP. Of these, seven (32%) developed LEW within 48 h of repair. This was temporary in five (23%) and permanent in two (9%) patients. Post-operative blood glucose levels were significantly higher in patients with LEW compared with those without LEW (140 ± 27 mg/dL vs. 117 ± 16 mg/dL; p = .02). Post-operative CSF glucose levels were significantly higher in patients with LEW compared with those without LEW (102 ± 15 mg/dL vs. 77 ± 15 mg/dL; p = .001). The subsequent 21 patients (group B) underwent BEVAR after initiation of the IIP. No patient in group B developed LEW while on the IIP, but one (5%) developed paraplegia on post-operative day four. The rate of early LEW ( Conclusion An IIP to control blood glucose after BEVAR is associated with a decreased rate of post-operative LEW. Tight control of blood glucose should be considered after any extensive aortic reconstruction to minimise the risk of post-operative LEW.

CASE REPORT A 67-year-old man presented with signs of acute periprosthetic infection after total hip arthroplasty (THA). Surgical debridement, antibiotics, and a head and liner exchange were performed. After showing no improvement, a single-stage revision was conducted. Postoperatively, he developed back pain and lower extremity weakness. Electrodiagnostic studies showed a Guillain-Barre syndrome (GBS) variant. Intravenous immunoglobulin was administered to halt disease progression. After 1 year, he still demonstrated neuromuscular deficits and required a cane for ambulation. CONCLUSION This case highlights GBS after THA. A high degree of clinical suspicion is essential to prevent misinterpretation as a postsurgical complication. LEVEL OF EVIDENCE V, case report.

Lower limb orthoses are used in individuals with a wide range of conditions resulting in impaired functional mobility and loss of independence. These devices are most commonly utilized to enhance stability in both standing and walking when lower extremity weakness is present, but may also be indicated when correction of a lower limb deformity is the desired outcome. Lower limb orthoses can also be used in order to stabilize a joint in the setting of ligamentous deficiency as well as provide pain relief in the setting of joint deterioration. Lower limb orthoses encompass a broad spectrum of devices ranging from simple and inexpensive devices such as a knee sleeve or accommodative foot orthotic to sophisticated and expensive devices such as a computerized knee-ankle-foot orthosis. Significant advances have occurred in the materials and fabrication techniques used for lower limb orthoses allowing braces to be both more lightweight and durable. Orthoses incorporating microprocessor joint control are available, and it is anticipated that further advances will continue in the future. Despite these technology advances and the wide variety of available lower limb orthoses, clinical decision-making remains challenging because of the lack of comparative effectiveness research to guide orthosis selection. .

Spinal cord injury has been described in only 2% to 5% of electrical injuries. When its presentation is delayed for several days to weeks after the initial injury, recovery is not the rule. Herein, we describe two patients who developed spinal cord injury from electrical burns. Case 1: A 60-year-old male presented with a 40% TBSA after contacting a power line. On hospital day 6, he developed lower extremity weakness that progressed to flaccid paralysis. Case 2: A 58-year-old male sustained a 9% TBSA high-voltage injury. On hospital day 2, he started to have progressive weakness of his lower extremities that progressed to flaccid paralysis. Neither case was judged to have experienced additional significant trauma. Neurological complications after electrical injuries are protean. Delayed spinal cord injury is rare and associated with variable degrees of recovery. Neurological follow-up with rehabilitation is essential for a successful recovery.

Teratomas of the spinal cord are rare tumors, particularly in adults, but there is an increasing body of literature documenting both their diagnosis and successful treatment with surgical resection. However, to date, the literature has largely characterized spinal teratomas as single solitary lesions. Here, we report on an adult patient who presented with signs of progressive lower extremity weakness. Imaging demonstrated two simultaneous lesions of the spine, an extramedullary lesion in the upper thoracic region and an intramedullary lesion in the mid-thoracic region. Both lesions were resected and pathologically determined to be mature spinal teratomas. To our knowledge, this is only the second report of this tumor presenting simultaneously at more than one location in the spine and the first time it has presented both as an intra-axial and extra-axial lesion. Our results suggest that the presence of more than one simultaneous lesion does not necessarily increase the risk of a more aggressive immature pathology.

Background This study was aimed at investigating the causes of lower extremity weaknesses after posterior lumbar spine fusion surgery and looking at subsequent treatment strategies. Methods Patients who underwent posterior lumbar spine fusion surgery in the Peking University First Hospital between January 2009 and December 2018 were counted. Those who needed secondary surgery because of subsequent lower extremity weaknesses were selected. CT scans and MRIs were used to evaluate the reasons for weaknesses before secondary surgery. Muscle strength was evaluated after surgery. Results Thirty patients (30/4078, 0.74%) required a secondary surgery because of lower extremity weaknesses after posterior lumbar spine fusion surgery. The main causes of weakness were (1) internal fixation malposition and loosening (11 patients, 36%), (2) epidural hematomas (9 patients, 30%), (3) insufficient decompression (5 patients, 17%), and (4) nerve root edemas (5 patients, 17%). Weakness occurred on average 2.9 days after surgery (1–9 days). Twenty-seven patients (90%) got improved muscle strength after their secondary surgery. Conclusions Iatrogenic neurologic deficits and lower extremity weaknesses were rare complications after posterior lumbar spine fusion surgeries, but important to recognize and manage. The main causes of weakness were internal fixation malposition and loosening, epidural hematomas, insufficient decompression, or root edemas. There may be positive, therapeutic effects to subsequent, active surgical exploration.

Thyrotoxic periodic paralysis (TPP) is a rare presentation of thyrotoxicosis most commonly associated with Graves' disease. It is rare in Caucasians, but it affects approximately 2% of Asians (occurring in those of Chinese, Japanese, Vietnamese, Filipino, and Korean descent) with thyrotoxicosis of any cause. Typical thyrotoxic features may be absent despite biochemical thyrotoxicosis. Hypokalemia and muscle paralysis are the result of an acute intracellular shift of potassium and not due to total body potassium deficiency. TPP is a self-limiting condition that is easily corrected by treatment of the thyrotoxicosis. We present a case of a Filipino man, aged 47 years, who presented to the emergency department with acute bilateral lower extremity weakness and hypokalemia who was subsequently diagnosed with TPP due to Graves' disease.

This article reviews the common lower extremity postpartum neuropathies, including their incidence, risk factors, clinical features, and treatment. In addition, the rarer complications from neuraxial anesthesia are also discussed.

A 59-year-old woman with a history of stage 3 immunoglobulin G (IgG) lambda multiple myeloma (MM) on treatment with bortezomib and dexamethasone, chronic lower back pain, and chronic but improving bilateral lower extremity weakness and numbness presented with 2 to 3 weeks of worsening lower extremity weakness and numbness. Prior to presentation, the patient had been hospitalized for sepsis and cardiac arrest. Weakness affected the left lower extremity before progressing to the right lower extremity, whereas numbness was present in both feet. There was no bowel or bladder incontinence, saddle anesthesia, preceding trauma, or history of radiation therapy. The bilateral lower extremity weakness and numbness resulted in gait impairment and falls, which prompted admission for further investigation. Notably, bortezomib had been started 4 months prior to presentation.

Cervical disc herniations most often present with neck and arm pain resulting from direct nerve root compression from a paramedian or foraminal disc herniation. It is unusual to encounter unilateral lower extremity symptoms in the absence of other neurological symptoms due to a centrally herniated cervical disc. Because this clinical presentation is uncommon, there can be misdiagnosis, or delay in treatment of patients who suffer from debilitating pain or weakness. We treated a patient who presented with acute progressive unilateral lower extremity weakness and paresthesia from a large herniated cervical disk. His lower extremity symptoms resolved post-operatively after undergoing anterior cervical discectomy and fusion. This case provides an example of the importance of neuroanatomical knowledge in surgical decision-making; clinicians should recognize that unilateral leg weakness can result from cervical disc herniation in absence of other neurological symptoms.

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Foreign bodies in the spine are most commonly traumatic and managed in an acute setting. A few case reports describe foreign bodies resulting in delayed neurologic dysfunction, most commonly iatrogenic or from penetrating injury. We present a 30-year old man with lower extremity weakness from an intradural extramedullary foreign body granuloma secondary to a thorn, which was initially thought to represent an aggressive malignant process with intra and extramedullary involvement on MR. Postoperatively, the patient endorsed a causative trauma several years prior. We also present a review of the few similar published cases as well as the described prototypical imaging features and pathologic process.

A 25-year-old female presented to an emergency department complaining of atraumatic back pain and lower extremity weakness. An extensive laboratory and radiographic evaluation, including thoracic and lumbar MRIs, demonstrated rhabdomyolysis. Her creatinine kinase peaked at 17,991 U/L. Upon further questions the patient admitted to using marijuana the night before but urine drug screen was negative for cannabinoids. Liquid chromatography—quadrupole time-of-flight mass spectrometry of her serum—detected methyl 2-(1-(4-fluorobenzyl)-1H-indazole-3-carboxamido)-3-methylbutanoate (AMB-FUBINACA or FUB-AMB) at a concentration of 4.2 ng/mL. No other cause of rhabdomyolysis was found. She improved with hydration and was discharged after a 3-day hospitalization.

Background and purpose: Enteral nutrition via nasogastric tube in acute stroke patients with dysphagia is an important determinant of patient outcomes. It is unclear whether intermittent or continuous feeding is more efficacious. The aim of this review is to examine the current evidence comparing the effectiveness of intermittent versus continuous feeding in stroke patients in terms of nutritional status, gastrointestinal intolerance and other complications.\ud \ud Methods: A systematic review of randomized controlled studies comparing intermittent with continuous nasogastric feeding in acute stroke patients was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Metaanalyses) guidance using predefined search terms. The search was conducted in MEDLINE and EMBASE up to 1st March 2019. Two independent reviewers assessed study quality using the Joanna Briggs Institute Critical Appraisal Tool. Meta-analyses were conducted, where appropriate, using a random-effects model to pool risk ratio with corresponding 95% CI.\ud \ud Results: Three studies including a total of 184 patients were identified. All three were medium to low quality. The definition of intermittent enteral nutrition within each study varied considerably in terms of volume, rate and mode of delivery. Achievement of nutritional targets was the same for both feeding patterns in the one study it was reported. Only aspiration pneumonia and diarrhea were measured by all three studies. There was no significant difference in the incidence of aspiration pneumonia (RR 0.91, 95% CI 0.53-1.57, p=0.74, I2=50%) and diarrhea (RR 1.74, 95% CI 0.70-4.30, p=0.23, I2=42%) between the two patterns of feeding. Other outcomes including, vomiting, gastric retention, mortality, pre-albumin and nasogastric tube complications showed no significant differences.\ud \ud Conclusion: There is very little and low-quality evidence to inform patterns of enteral feeding after stroke. The available evidence shows no significant difference in nutritional achievement and complications between intermittent and continuous nasogastric tube feeding in acute stroke patients.

A 69-year-old woman was admitted to the hospital with double vision, weakness in the lower extremities, sensory loss, pain, and falls. Her symptoms started with sudden onset of horizontal diplopia 6 weeks before, followed by gradually worsening lower-extremity weakness, as well as ataxia and patchy

We report a case of autoimmune necrotizing myopathy related to statin use in a 70-year-old woman who came to the hospital because of progressive lower extremity weakness. Laboratory, electromyography and muscle biopsy results were consistent with autoimmune necrotising myopathy. The patient was treated with intravenous immunoglobulin with improvement in muscle strength.

Schwannomas are relatively rare tumours. They occur in approximately 1 of 40,000 hospital admissions. Usually asymptomatic unless very big in size. They may present with symptoms of visceral compression viz. constipation, urinary frequency and urgency, or the nerve compression like sciatica, lower extremity weakness, tingling and numbness. We here highlight the various clinical, radiological and pathologic features the tumour and importance of proper pre-operative imaging, planning regarding surgery and the type of consent required before the surgery in a 30 years old male with a large pelvic mass, diagnosed and supposed to be Schwannoma arising from the S2 sacral foramina. We were able to enucleate the mass intact without any visceral or neuro-vascular injury with minimal blood loss.

A 20-year-old woman presented with subacute progressive lower extremity weakness and spasticity. Examination findings were consistent with Brown-Sequard syndrome. Thoracic spine MRI/magnetic resonance angiography showed an intramedullary mass (figure 1). During gross total resection, the mass had a pearlescent appearance, while histopathologic examination was consistent with epidermoid cyst (figure 2).

Transcranial motor-evoked potentials (TcMEPs) are used to monitor the descending motor pathway during scoliosis surgery. By comparing potentials before and after correction, surgeons may prevent postoperative functional loss in distal muscles. There is currently no consensus as to which muscles should be monitored. The purpose of this study is to determine the least invasive monitoring protocol with the best localization of potential neurologic deficit. A retrospective review of 125 patients with TcMEP monitoring during surgery for thoracolumbar scoliosis between 2008 and 2015 was conducted. 18 patients had postoperative neurologic consult due to deficit. The remaining 107 patients were a consecutive cohort without postoperative neurologic consult. TcMEPs were recorded from vastus lateralis (VL), tibialis anterior (TA), peroneus longus (PL), adductor hallucis (AH) and abductor pollicis brevis (APB) bilaterally. The effectiveness of each muscle combination was evaluated independently and then compared to other combinations using Akaike Information Criterion (AIC). Monitoring of VL, TA, PL, and AH yielded sensitivity of 77.8% and specificity of 92.5% (AIC=66.7). Monitoring of TA, PL and AH yielded sensitivity of 77.8% and specificity of 94.4% (AIC=62.4). Monitoring of VL, TA and PL yielded sensitivity of 72.2% and specificity of 93.5% (AIC=70.1). Monitoring of TA and PL yielded sensitivity of 72.2% and specificity of 96.3% (AIC=63.9). TcMEP monitoring of TA, PL, and AH provided the highest sensitivity and specificity and best predictive power for postoperative lower extremity weakness.