Sciatic neuropathy: clinical and prognostic features in 73 patients

Five Cases of Idiopathic Sciatic Mononeuropathy: Clinical, Electrophysiological, Radiological, and Histological Features

Background

Common etiologies of sciatic mononeuropathy are compressive, infiltrative, traumatic, or diabetic. However, in a proportion of patients, the etiology remains elusive despite extensive serological, electrophysiological, radiological, and histological investigations.

Methods

Patients with unexplained sciatic mononeuropathy were studied with regard to their clinical, radiological, pathological, and treatment aspects.

Results

We could identify five cases of sciatic mononeuropathy wherein the etiology remained unknown even after a comprehensive evaluation. The compressive, metabolic, hematological, and immune causes were ruled out with necessary investigations. The clinical, electrophysiological, radiological, and histological features of these patients are discussed.

Conclusion

The etiology of sciatic mononeuropathy can remain obscure in certain instances in spite of the comprehensive workup. The role of investigations and the exclusion process of various diagnostic entities are discussed.

Spontaneous ischemic neuropathy of the sciatic nerve due to arterial occlusion – a rare cause of acute neuropathy not to be missed, a report of two cases

Background

Ischemic neuropathy of the sciatic nerve without preceding vascular surgical procedures is a rare condition and may be due to arterial occlusion in one limb.

Case presentations

We present two cases with acute onset of pain and sensory symptoms such as pins and needles and numbness in the foot with no or mild motor symptoms. In the neurological work-up, electrophysiological signs of axonal neuropathy of both peroneal and tibial nerves were demonstrated and T2 hyperintensity was seen in the distal sciatic nerves on MR neurography as well as signs indicating arterial thrombosis in the corresponding vessels. Recanalization was obtained in both patients angiographically with significant improvement in one patient.

Conclusions

Spontaneous arterial occlusion of major or peripheral arteries is a rare but important cause of acute onset of single or multiple axonal mononeuropathies of one extremity. Recognition of this infrequent cause is essential since it requires immediate and specific therapeutic options.

Bilateral foot drop after COVID-19-related acute respiratory distress syndrome: A case report

In these days of the pandemic, we have faced with the locomotor system problems following severe acute respiratory syndrome-coro- navirus 2 (SARS-CoV-2) infection. While some of these problems are related to the disease itself, some of them are associated with the prolonged immobilization during the infection. Long-term intensive care unit admissions of patients may also lead to various types of neuropathies, extending the recovery period. The real burden of the novel coronavirus-2019 (COVID-19) is still unclear. In particular, after a prolonged hospitalization period, the duration of rehabilitation may be longer to gain independence in daily living activities. In this report, we present a different aspect of the COVID-19 with bilateral foot drop in a 53-year-old female patient. To the best of our knowledge, this case is the first report of both peroneal and sciatic nerve damage following COVID-19.

[Endoscopic sciatic nerve decompression]

OBJECTIVE

To improve treatment outcomes in patients with sciatic nerve neuropathy.

MATERIAL AND METHODS

The first results of endoscopic sciatic nerve decompression in 6 patients with sciatic neuropathy (mean age 47±6.7 years) are presented. The authors developed and described new and unique technique for this procedure. All patients suffered severe neuropathic pain syndrome with neurologic disorders. All patients underwent endoscopic sciatic nerve decompression in prone position.

RESULTS

Mean VAS score of preoperative pain syndrome was 7.8±0.37. In 3 months after surgery, this value decreased up to 1.5 scores. Complete regression of pain syndrome and significant reduction of neurologic symptoms were noted in 5 out of 6 patients (83%).

CONCLUSION

Primary data characterize the developed method as an easy, minimally invasive and effective procedure for pain relief and fast recovery of lower extremity function in these patients.

Electrodiagnostic Assessment of Uncommon Mononeuropathies

Carpal tunnel syndrome, ulnar neuropathy at the elbow, and peroneal neuropathy are the most common mononeuropathies; however, other individual nerves may also be injured by various processes. These uncommon mononeuropathies may be less readily diagnosed owing to unfamiliarity with the presentations and vague symptoms. Electrodiagnostic studies are essential in the evaluation of uncommon mononeuropathies and can assist in localization and prognostication. However, they can also be challenging; stimulation at the proximal sites is difficult and well-validated reference values are not available. This article reviews the electrodiagnostic assessment of several uncommon upper and lower extremities mononeuropathies.

The Effect of Alpha Lipoic Acid on the Recovery of Sciatic Nerve Injury in Rats: A Prospective Randomized Controlled Trial

OBJECTIVE

The aim of this study was to investigate the regenerative effects of alpha lipoic acid on the recovery of sciatic nerve crush injury (SNCI) in rats.

DESIGN

This was a randomized, experimental, and sham-controlled study. The sciatic nerves of 28 rats in four groups were traumatized for 60 secs: G1, sham operated + saline; G2, SNCI + saline; G3, SNCI + alpha lipoic acid 50 mg/kg/day; and G4, SNCI + alpha lipoic acid 100 mg/kg/day. Sciatic functional index values were measured on day 0, 1, 7, 14, 21, and 28. Sciatic nerve stimulation threshold values were recorded on day 1, 14, and 28. End-point histopathologic evaluation was conducted.

RESULTS

The mean sciatic functional index value of G2 but not G3/G4 on day 7 was significantly lower than on day 0 (P = 0.035, P = 0.447/P = 0.800). The mean sciatic functional index value of G2 but not G3/G4 increased significantly between day 7 and 14 (P = 0.035, P = 0.447/P = 0.438). The day 14 mean sciatic nerve stimulation threshold values of G3/G4 but not G2 were decreased significantly compared with those on day 1 (P = 0.022/P = 0.022, P = 0.933). The mean sciatic nerve stimulation threshold values of G3/G4 on day 14 were similar to those on day 0 (P = 0.106/P = 0.418). Regeneration in muscle and nerve connective tissues and nerve structures was observed in G3/G4. Inflammation in the muscle and nerve tissues of G4 was suppressed down to similar levels of G1. Myelinated nerve fibers were less degenerated in G3/G4.

CONCLUSION

Alpha lipoic acid has the potential to accelerate the process of nerve healing in the context of SNCI in rats.

Peripheral Neuropathy in the Lower Limbs of Individuals With Spinal Cord Injury or Disease: A Retrospective Study

PURPOSE

This study investigated the frequency and types of peripheral neuropathy in the lower limbs of patients undergoing rehabilitation after traumatic spinal cord injury or spinal cord disease.

METHODS

This study included consecutive patients with spinal cord injury/spinal cord disease who had electrophysiological assessments during their admission in a rehabilitation center from October 2015 to July 2019. Patients with traumatic spinal cord injury were compared with patients with nontraumatic spinal cord disease.

RESULTS

There were 67 patients (52 male patients, 15 female patients; mean age = 56.5 yrs) of whom 36 patients had spinal cord injury and 31 patients had spinal cord disease. Most of the patients were middle-aged men with at least one preexisting medical comorbidity, who were mostly admitted for rehabilitation of cervical, incomplete spinal cord injury/spinal cord disease. Most patients (86.6%) had abnormal electrophysiological studies representing 5.57% of all admissions. A length-dependent polyneuropathy was diagnosed in 0.77% of all admissions (n = 8). The group of patients with spinal cord injury was comparable with the group of patients with spinal cord disease regarding the other baseline data, clinical, and electrophysiological findings.

CONCLUSIONS

Diseases of the peripheral nervous system were similarly found among patients undergoing rehabilitation for either spinal cord injury or spinal cord disease. A length-dependent polyneuropathy was diagnosed in 0.77% of all admissions. Timely diagnosis and proper treatment of the cause of peripheral neuropathies in the lower limbs in these patients may potentially influence rehabilitation protocols and improve patient outcomes.

Post-operative extra-spinal etiologies of sciatic nerve impingement

Sciatica is a highly prevalent cause of morbidity, commonly resulting from intra-spinal pathological processes. Many cases can have extra-spinal etiologies and can be clinically challenging. Certain scenarios should suggest an extra-spinal etiology, particularly total and revision hip arthroplasty, surgical hip dislocation, hip arthroscopy, and surgery in the lithotomy position. We review the post-operative clinical scenarios where sciatic neuropathy may occur, along with the pertinent imaging findings.

Iatrogenic lesions of peripheral nerves

Iatrogenic nerve lesions (INLs) are an integral part of peripheral neurology and require dedicated neurologists to manage them. INLs of peripheral nerves are most frequently caused by surgery, immobilization, injections, radiation, or drugs. Early recognition and diagnosis is important not to delay appropriate therapeutic measures and to improve the outcome. Treatment can be causative or symptomatic, conservative, or surgical. Rehabilitative measures play a key role in the conservative treatment, but the point at which an INL requires surgical intervention should not be missed or delayed. This is why INLs require close multiprofessional monitoring and continuous re-evaluation of the therapeutic effect. With increasing number of surgical interventions and increasing number of drugs applied, it is quite likely that the prevalence of INLs will further increase. To provide an optimal management, more studies about the frequency of the various INLs and studies evaluating therapies need to be conducted. Management of INLs can be particularly improved if those confronted with INLs get state-of-the-art education and advanced training about INLs. Management and outcome of INLs can be further improved if the multiprofessional interplay is optimized and adapted to the needs of the patient, the healthcare system, and those responsible for sustaining medical infrastructure.

Compression and entrapment neuropathies

Peripheral nerve entrapments are frequent. They usually appear in anatomical tunnels such as the carpal tunnel. Nerve compressions may be due to external pressure such as the fibular nerve at the fibular head. Malignant or benign tumors may also damage the nerve. For each nerve from the upper and lower limbs, detailed clinical, electrophysiological, imaging, and therapeutic aspects are described. In the upper limbs, carpal tunnel syndrome and ulnar neuropathy at the elbow are the most frequent manifestations; the radial nerve is less frequently involved. Other nerves may occasionally be damaged and these are described also. In the lower limbs, the fibular nerve is most frequently involved, usually at the fibular head by external compression. Other nerves may also be involved and are therefore described. The clinical and electrophysiological examination are very important for the diagnosis, but imaging is also of great use. Treatments available for each nerve disease are discussed.

Clinical and electrodiagnostic features of sciatic neuropathies

Sciatic neuropathy is the second most common neuropathy of the lower extremity and a common cause of foot drop. This article reviews the anatomy, clinical features, pathophysiology, and electrodiagnostic assessment of sciatic neuropathies. There are multiple potential sites of pathology, determined in part by the mechanism of insult, including trauma, compression, masses, inflammation, and vascular lesions. Diagnosis is augmented by careful electrodiagnostic studies and imaging to help distinguish sciatic neuropathy from other sources of pathology. Electrodiagnostic studies may also help in assessing for early recovery and in determining prognosis.

Piriformis syndrome surgery causing severe sciatic nerve injury

Piriformis syndrome is a controversial entrapment neuropathy in which the sciatic nerve is thought to be compressed by the piriformis muscle. Two patients developed severe left sciatic neuropathy after piriformis muscle release. One had a total sciatic nerve lesion, whereas the second had a predominantly high common peroneal nerve lesion. Follow-up studies showed reinnervation of the hamstrings only. We conclude that piriformis muscle surgery may be hazardous and result in devastating sciatic nerve injury.

Clinical, electrophysiological, and prognostic study of postinjection sciatic nerve injury: An avoidable cause of loss of limb in the peripheral medical service

BACKGROUND

Post injection sciatic nerve injury is a common cause of sciatic nerve mononeuropathy in the developing world largely due to inadequate health care facilites in the rural regions.

OBJECTIVE

The study was conducted to analyse the pattern of this nerve lesion in clinical and electrophysiological parameters and also to study the outcome in a conservatively treated cohort.

MATERIALS AND METHODS

One hundred and six patients who underwent evaluation at our laboratory from 2000 to 2006 for post injection sciatic neuropathy formed the study population. Twenty two of these were followed up (mean 6.6 months) for the outcome.

RESULTS

In the cases with full data, common peroneal division of the sciatic nerve was affected alone or predominantly. On follow up, 72% cases showed little or partial recovery. Thirty two percent patients had residual trophic changes and causalgia at their last visit.

CONCLUSION

The majority of cases of postinjection sciatic nerve injury have poor prognosis on conservative treatment.

[Sciatic neuropathy after pelvic floor repair]

After the surgical treatment of a recurrent enterocele and rectocele using a polypropylene implant, a patient developed a reversible paralysis. Haematoma was excluded. To search for the cause of the paralysis, polypropylene implants were inserted in four ethanol-preserved cadavers. Their dissection showed a safe distance at all points between the implant and the sciatic nerve. The patient's paralysis was most likely due to the lithotomy position, with an overstretching of the sciatic nerve during the intraoperative flexion of the hip joint.

Sciatic nerve injury associated with acetabular fractures

Sciatic nerve injuries associated with acetabular fractures may be a result of the initial trauma or injury at the time of surgical reconstruction. Patients may present with a broad range of symptoms ranging from radiculopathy to foot drop. There are several posttraumatic, perioperative, and postoperative causes for sciatic nerve palsy including fracture-dislocation of the hip joint, excessive tension or inappropriate placement of retractors, instrument- or implant-related complications, heterotopic ossification, hematoma, and scarring. Natural history studies suggest that nerve recovery depends on several factors. Prevention requires attention to intraoperative limb positioning, retractor placement, and instrumentation. Somatosensory evoked potentials and spontaneous electromyography may help minimize iatrogenic nerve injury. Heterotopic ossification prophylaxis can help reduce delayed sciatic nerve entrapment. Reports on sciatic nerve decompression are not uniformly consistent but appear to have better outcomes for sensory than motor neuropathy.

Pediatric sciatic neuropathies due to unusual vascular causes

Four cases of pediatric sciatic neuropathies due to unusual vascular mechanisms are reported. Pediatric sciatic neuropathies were seen after umbilical artery catheterization, embolization of arteriovenous malformation, meningococcemia, and hypereosinophilic vasculitis. Electrophysiologic studies demonstrated abnormalities in motor studies of peroneal and tibial nerves. Sensory studies demonstrated abnormalities of sural and superficial peroneal nerves. Results of needle electromyography were abnormal in sciatic-innervated muscles. Prognosis was variable and depended on the severity of the initial nerve injury.

Importance of Electromyography and the Electrophysiological Severity Scale in Forensic Reports

Forensic reports on traumatic peripheral nerve injuries include dysfunction degrees of extremities, which are arranged according to the Turkish Penalty Code. The aim of this study is to discuss the role and importance of electromyography while preparing forensic reports in the cases of traumatic peripheral nerve injuries and the usefulness of scoring systems. A modified global scale, recommended by Mondelli et al., was used to assess the electrophysiological impairment of each peripheral nerve. Forensic reports of 106 patients, reported between 2002 and 2004, were evaluated. Thirty-four percent of the cases were reported as "total loss of function," 41.5% were reported as "functional disability," and there were no dysfunctions in the other cases in forensic reports that were prepared based on Council of Social Insurance Regulations of Health Processes and Guide prepared by the Council of Forensic Medicine and profession associations of forensic medicine. When we rearranged these forensic reports based on the electrophysiological severity scale (ESS), it was clearly found that all of the score 2 cases and 86.7% of the score 3 cases corresponded to "functional disability" and 91.4% of the score 4 cases correspond to "total loss of function." We found a significant correlation between the ESS and functional evaluation in peripheral nerve injury cases. Evaluation of functional disabilities in peripheral nerve injuries with the ESS represents a standardized and objective method used for forensic reports.

Sciatic neuropathy: case report and discussion of the literature on postoperative sciatic neuropathy and sciatic nerve tumors

Sciatic nerve injury and dysfunction is not an uncommon cause of lower extremity symptoms in a musculoskeletal practice. We present the case of a man who presented with lower extremity weakness, pain, and cramps, and was initially diagnosed at an outside institution with bilateral S1 radiculopathies and recommended for spine surgery. He came to us for a second opinion. Electrodiagnostic testing revealed an isolated sciatic neuropathy and the patient was referred for imaging, which showed a sciatic nerve sheath tumor. Review of the literature on sciatic neuropathies shows that there can be many possible etiologies of sciatic nerve dysfunction, but that hip arthroplasty continues to be the leading risk factor. Sciatic nerve tumors are not commonly described in the literature and their definitive management remains unclear.

Nerve injuries following intramuscular injections: a clinical and neurophysiological study from Northwest India

In developing countries, injections are frequently used to treat common ailments. Intramuscular injections (IMI) may damage peripheral nerves at the site of injection. Our objectives were to study the clinical features, neurophysiological findings, and outcome in patients with nerve injuries (NI) following IMI and to determine the factors affecting prognosis. We conducted a retrospective review of patients with NI following IMI, who were referred to our Neurophysiology Laboratory at Christian Medical College, Ludhiana, India, between January 1990 to December 2003. There were 36 (55%) patients with sciatic nerve palsy, 29 (44%) patients with radial nerve injury, and 1 (1%) patient with posterior femoral cutaneous nerve injury. In 57 (86%) patients, the IMI were given by uncertified medical practitioners. Needle electromyography (EMG) was analyzed in 36 patients (>or=60 days after onset). In 12 (33%) patients, there was EMG evidence of axonal damage with reinnervation, while in the other 24 (67%) patients, there was axonal damage without reinnervation. Only 18 (28%) patients had a good recovery. In conclusion, NI following IMI is a preventable iatrogenic hazard, which carries a poor prognosis.

Gait characteristics of sciatic nerve palsy--a report of four cases

There are few reports concerning the gait characteristics of sciatic nerve palsy. Four cases, one with complete palsy and three with incomplete palsy, are presented. Complete palsy (case 1) was due to sacrifice of the sciatic nerve in a wide excision for chondrosarcoma in the left ischium. Incomplete palsy (cases 2, 3, and 4) was due to contusion incurred in traffic accidents. It is noteworthy that all four patients could walk with or without a short-leg brace. But the patients with complete loss of proprioception distal to the ankle (cases 1 and 2) had to watch their steps while walking to maintain their walking balance. This clinical analysis revealed that proprioceptive impairment of the sciatic nerve caused a walking disability even though the palsy was incomplete.

Electrodiagnostic approach to the patient with suspected mononeuropathy of the lower extremity

Lower extremity mononeuropathies are less common than those affecting the upper limb. Yet, they are often challenging and more difficult to diagnose. The electrodiagnostic (EDX) studies play a pivotal role in diagnosis. Well planned and executed studies are very useful, although limiting factors such as age, foot swelling or prior lumbar spine surgery may hinder making a definite diagnosis. In this section, the author emphasizes the EDX studies of most lower extremity mononeuropathies and discusses, briefly, their anatomical and clinical aspects.

Use of enhanced stimulation voltage to determine the severity of compressive peripheral nerve injury

BACKGROUND

The aim of this study was to investigate whether enhanced stimulation voltage could be a predictor of the extent of injury in acute compressive peripheral nerve trauma.

METHODS

The femoral nerves were exposed on both sides, in 11 anesthetized rabbits. Supramaximal stimulation voltage was used to produce a maximal-amplitude compound muscle action potential (CMAP) from the quadriceps femoris muscle. Afterward, the left femoral nerve was clipped for 1 minute, and the right femoral nerve for 5 minutes to produce an acute compressive injury. Immediately after removal of the clip, the proximal and distal sides of the clippage site were stimulated by gradually increased voltage until CMAPs were obtained. The same procedure was repeated at the 30th and 60th minutes. The ratio of the CMAP amplitudes obtained from proximal and distal stimulation was measured to establish a classification.

RESULTS

The stimulation voltages and amplitudes of the CMAPs before clippage were similar with the after-clippage values obtained from distal stimulation (p > 0.05), but the after-clippage values obtained from proximal stimulation were different in both sides (p < 0.05). Doubled stimulation voltage was enough to obtain CMAPs on the left side, but eightfold the initial level was required on the right side. The amplitude ratios recovered to preinjury levels in all of the subjects on the left side, but only two showed recovery on the right side (p < 0.001). Histopathologically, there was axonal compression without discontinuity on the left side, whereas the fibers were dispersed on the right side.

CONCLUSION

Stimulation voltage was found to discriminate the severity of the lesion in experimental peripheral nerve injury. Proximal to distal amplitude ratio seems to be a prognostic factor when the injury is less severe.

Idiopathic sciatic mononeuropathy

Sciatic nerve lesions are usually painful and secondary to compression, trauma, infarction or part of a systemic illness. The etiology is usually defined by radiographic or blood studies, or by exploratory surgery. In rare cases, as the one being presented, there is clear clinical and electrophysiological evidence for a lesion of the sciatic nerve, but no morphological correlate or defined etiology. These idiopathic sciatic mononeuropathies seem to occur in the nerves of the legs in young adults.

Sciatic neuropathy secondary to total hip arthroplasty wear debris

Sciatic neuropathy after total hip arthroplasty can result from several causes. We present a case in which a large cystic mass developed around a failed total hip arthroplasty. The lesion extended through the greater sciatic notch and into the pelvis producing sciatic nerve compression. The diagnosis was delayed, and the patient underwent a laminectomy without relief of symptoms before an abdominopelvic computed tomography (CT) scan revealed the mass. After revision of the components and excision of the accessible portion of the lesion, the symptoms improved. Resolution of the intrapelvic portion of the mass was demonstrated on follow-up CT scan, suggesting that retroperitoneal resection of this type of lesion may not be required at the time of revision of the components.

Sciatic neuropathy

Injuries to the sciatic nerve cause neurologic deficits in the peroneal and tibial nerve distributions. Interestingly, most injuries result in more severe deficits to the peroneal division compared to the tibial division. Thus, it can sometimes be difficult to distinguish sciatic neuropathy from peroneal neuropathy. The long course of the sciatic nerve leaves it vulnerable to nerve injury from a variety of causes. Most sciatic neuropathies are acute in onset, such as from hip arthroplasty and hip fracture or dislocation, but some occur from prolonged compression, such as during coma. Entrapment of the sciatic nerve by mass lesions or by the piriformis muscle is relatively rare.

Recovery of sciatic nerve injuries in association with total hip arthroplasty in 27 patients

We analyzed 27 sciatic nerve injuries associated with total hip arthroplasty (THA). The patients were 23 women and 4 men, and their median age was 55 years (range, 28-75 years). In 1987 to 1995, 4,339 THAs were performed. Primary arthroplasties accounted for 3,471 and 868 were revisions. Nine patients had developmental dysplasia of the hip. Six operations were revisions. Radiologic lengthening was median 1.4 cm (range, -1 to 4.1 cm); in 8 cases, lengthening was greater than 2 cm. The median follow-up period was 58 months (range, 24-110 months). Eight patients recovered fully, the recovery of 7 patients was fair, and 12 patients had a considerable permanent disability. The risk of nerve injury was not related to the extent of lengthening. The recovery of the nerve injury was only weakly correlated to its primary postoperative extent. The sciatic nerve injury rate was 0.6%.

Tardy sciatic nerve palsy following apophyseal avulsion fracture of the ischial tuberosity. Case report

This 4 1-year-old man presented with a 2-year history of symptoms and signs of sciatic nerve compression. Imaging studies revealed a large ossified fragment within the biceps muscle of the thigh abutting the sciatic nerve at the level of the lesser trochanter. The bony fragment resulted from an unrecognized apophyseal avulsion fracture of the ischial tuberosity, which the patient had sustained while sprinting 27 years earlier. External neurolysis of the sciatic nerve and excision of the mass led to a successful outcome.

Clinical and prognostic features in unilateral femoral neuropathies

We have examined the clinical features of patients with femoral neuropathy and the factors that influence the prognosis. Of 80 consecutive patients referred for neurophysiological evaluations of proximal lower limb weakness, 32 fulfilled strict inclusion criteria and had adequate information, including estimates of axon loss (AxL) by stimulation of the bilateral femoral nerve. In 31, the Kaplan-Meier method was used to describe the time course of the outcome, while logistic regression was employed to determine the contributing factors. Excellent, satisfactory, and poor outcomes were seen in 10 (31%), 11 (34%), and 10 (31%) patients, respectively. Logistic regression analysis of seven factors demonstrated that the estimate of AxL was the only significant variable. The best prognostic factor was an estimate of AxL < or = 50%, with all patients fulfilling this criterion showing improvement with 1 year; fewer than half the patients with AxL > 50% should be expected to improve. This study clearly shows that, irrespective of the cause of femoral neuropathy, functional improvement is seen in 2 out of 3 patients within 2 years and that the estimate of AxL is the only factor influencing prognosis.

The electrophysiologic features of sciatic neuropathy in 100 patients

We reviewed the electrophysiologic data of 100 consecutive patients with sciatic neuropathy in order to better understand this disorder. Most patients (93%) had electrodiagnostic signs of significant axonal loss. Seven patients had predominantly signs of demyelination; 6 were due to compression and 1 was idiopathic. The peroneal division was more severely affected than the tibial division in 64% of patients. Tibialis anterior EMGs were abnormal in 92%, and the EDB CMAP was low in amplitude or absent in 80%. CMAP and SNAP amplitudes and EMGs were all normal in the tibial division in 12%. In contrast, the tibial division was more severely affected in only 8 patients. Of those, 5 were due to thigh trauma (gunshot wounds or femur fracture), 2 from gunshot wounds to the hip, and the other was chronic and idiopathic. Sciatic neuropathies are commonly, but not always, axonal loss lesions that affect the peroneal greater than tibial division.