Multiple locations of nerve compression: an unusual cause of persistent lower limb paresthesia

Role of electromyography and ultrasonography in the diagnosis of double crush lumbar radiculopathy and common fibular injury: illustrative cases

BACKGROUND

Double crush syndrome consists of two compression sites along a peripheral nerve and is rare in the lower extremities. Electrodiagnostic and ultrasound (US) studies may be helpful in evaluating foot drop involving overlapping pathologies.

OBSERVATIONS

Case 1 involved a man who presented with left dorsiflexor weakness and left foot numbness. Electromyography (EMG) revealed a left common fibular nerve entrapment neuropathy and left L5 radiculopathy. US and magnetic resonance imaging (MRI) revealed a large cystic lesion of the left common fibular nerve treated by cyst removal. The left foot drop persisted postoperatively. Lumbar computed tomography myelography revealed severe left foraminal stenosis at L5–S1. Multilevel lumbar laminectomies and facetectomies with an L5–S1 fusion were performed. Within 1 month postoperatively, the left foot drop had improved. Case 2 involved a man who developed a right foot drop caused by right lumbar foraminal stenosis at L4–5 and L5–S1. EMG and US of the right common fibular neuropathy showed large fascicles involving the right common fibular nerve. MRI revealed a hyperintense signal of the right common fibular nerve. Spontaneous improvement occurred within 6 months without surgery.

LESSONS

Spine surgeons should recognize double crush in the lower extremities. EMG and US are valuable in detecting peripheral nerve abnormalities, especially in cases with overlapping lumbar pathology.

Surgical treatment of common peroneal neuropathy in schwannomatosis: illustrative cases

BACKGROUND

Neurofibromatosis syndromes such as neurofibromatosis type 1, neurofibromatosis type 2, and schwannomatosis often result in painful symptoms related to tumor burden.

OBSERVATIONS

Painful symptoms classically associated with common points of peripheral nerve entrapment, such as common peroneal neuropathy at the fibular tunnel, may present in patients both with and without focal tumor involvement.

LESSONS

Surgical decompression at the point of entrapment, with or without resection of tumor, may provide symptomatic relief. Examples of surgical decompression at the point of entrapment, both with and without resection of tumor, are presented.

Nerve entrapments related to muscle herniation

BACKGROUND

Muscle herniation is a muscle protrusion through a fascial defect. It is a rarely reported cause of nerve entrapment.

METHODS

We present a case of superficial fibular (peroneal) neuropathy associated with a fibularis (peroneus) brevis muscle herniation and a review of the literature on nerve entrapments secondary to muscle herniation unrelated to compartment syndrome.

RESULTS

Eleven cases of nerve entrapments secondary to muscle herniation were identified. The superficial fibular nerve (SFN) was the most commonly entrapped nerve by fibularis muscle herniation. Patients presented with pain, numbness, or paresthesias, and an often tender, small palpable mass with a Tinel sign. Muscle MRI or ultrasound identified the lesion, and patients responded well to fasciotomy.

CONCLUSIONS

The most commonly reported nerve entrapped by muscle herniation is the SFN secondary to fibularis muscle herniation. Characteristic clinical and imaging (MRI or ultrasound) features are diagnostic, and there is a salutary response to fasciotomy.

The immediate effect of osteopathic cervical spine mobilization on median nerve mechanosensitivity: A triple-blind, randomized, placebo-controlled trial

BACKGROUND

Neurodynamics is a clinical medium for testing the mechanical sensitivity of peripheral nerves which innervate the tissues of both the upper and lower limb. Currently, there is paucity in the literature of neurodynamic testing in osteopathic research, and where there is research, these are often methodologically flawed, without the appropriate comparators, blinding and reliability testing.

AIMS

This study aimed to assess the physiological effects (measured through Range of Motion; ROM), of a commonly utilized cervical mobilization treatment during a neurodynamic test, with the appropriate methodology, i.e., compared against a control and sham. Specifically, this was to test whether cervical mobilization could reduce upper limb neural mechanical sensitivity.

METHODOLOGY

Thirty asymptomatic participants were assessed and randomly allocated to either a control, sham or mobilization group, where they were all given a neurodynamic test and ROM was assessed.

RESULTS

The results showed that the mobilization group had the greatest and most significant increase in ROM with Change-Left p < 0.05 and Change-Right p < 0.05 compared against the control group, and Change-Left p < 0.01 and Change-Right p < 0.05 compared against the sham group.

CONCLUSIONS

This study has highlighted that, as expected, cervical mobilization has an effect at reducing upper limb neural mechanical sensitivity. However, there may be other factors interacting with neural mechanosensitivity outside of somatic influences such as psychological expectation bias. Further research could utilize the methodology employed here, but with other treatment areas to help develop neural tissue research. In addition to this, further exploration of psychological factors should be made such as utilizing complex top-down cognitive processing theories such as the neuromatrix or categorization theories to help further understand cognitive biases such as the placebo effect, which is commonly ignored in osteopathic research, as well as other areas of science, and which would further complete a holistic perspective.

Decompression of the superficial peroneal nerve: clinical outcomes and anatomical study

OBJECTIVE

The authors of this study sought to determine the outcomes of patients undergoing superficial peroneal nerve (SPN) release to treat lower-extremity pain and describe consistent anatomical landmarks to direct surgical planning.

METHODS

This retrospective cohort study examined 54 patients with pain in the SPN distribution who were treated with decompression between 2011 and 2014. Patients rated pain and the effect of pain on quality of life (QOL) on the visual analog scale (VAS) from 0 to 10. Scores were then converted to percentages. Linear regression analysis was performed to assess the impact of the preoperative effect of pain on QOL, age, body mass index (BMI), and preoperative duration of pain on the postoperative effect of pain on QOL. Measurements were made intraoperatively in 13 patients to determine the landmarks for identifying the SPN.

RESULTS

A higher BMI was a negative predictor for improvement in the effect of pain on QOL. A decrease in pain compared with the initial level of pain suggested a nonlinear relationship between these variables. A minority of patients (7 of 16) with a preoperative pain VAS score ≤ 60 reported less pain after surgery. A large majority (30 of 36 patients) of those with a preoperative pain VAS score > 60 reported improvement. Intraoperative measurements demonstrated that the SPN was consistently found to be 5 ± 1.1, 5 ± 1.1, and 6 ± 1.2 cm lateral to the tibia at 10, 15, and 20 cm proximal to the lateral malleolus, respectively.

CONCLUSIONS

A majority of patients with a preoperative pain VAS score > 60 showed a decrease in postoperative pain. A higher BMI was associated with less improvement in the effect of pain on QOL. This information can be useful when counseling patients on treatment options. Based on the intraoperative data, the authors found that the SPN can be located at reliable points in reference to the tibia and lateral malleolus.

Entrapment of the superficial peroneal nerve: an anatomical insight

Entrapment of the superficial peroneal nerve is an uncommon neuropathy that may occur because of mechanical compression of the nerve, usually at its exit from the crural fascia. The symptoms include sensory alterations over the distribution area of the superficial peroneal nerve. Clinical examination, electrophysiologic findings, and imaging techniques can establish the diagnosis. Variations in the superficial peroneal sensory innervation over the dorsum of the foot may lead to variable results during neurologic examination and variable symptomatology in patients with nerve entrapment or lesions. Knowledge of the nerve's anatomy at the lower leg, foot, and ankle is of essential significance for the neurologist and surgeon intervening in the area.