Tibial nerve branching pattern and compatibility of branches for the deep fibular nerve

PURPOSE

In individuals who develop drop foot due to nerve loss, several methods such as foot-leg orthosis, tendon transfer, and nerve grafting are used. Nerve transfer, on the other hand, has been explored in recent years. The purpose of this study was to look at the tibial nerve's branching pattern and the features of its branches in order to determine the suitability of the tibial nerve motor branches, particularly the plantaris muscle motor nerve, for deep fibular nerve transfer.

METHODS

There were 36 fixed cadavers used. Tibial nerve motor branches were observed and measured, as were the lengths, distributions, and thicknesses of the common fibular nerve and its branches at the bifurcation region.

RESULT

The motor branches of the tibial nerve that supply the soleus muscle, lateral head, and medial head of the gastrocnemius were studied, and three distinct forms of distribution were discovered. The motor branch of the gastrocnemius medial head was commonly observed as the first branch to divide, and it appeared as a single root. The nerve of the plantaris muscle was shown to be split from many origins. When the thickness and length of the motor branches measured were compared, the nerve of the soleus muscle was determined to be the most physically suited for neurotization.

CONCLUSION

In today drop foot is very common. Traditional methods of treatment are insufficient. Nerve transfer is viewed as an application that can both improve patient outcomes and hasten the patient's return to society. The nerve of the soleus muscle was shown to be the best candidate for transfer in our investigation.

An anomalous pseudoganglion associated with high division of sciatic nerve

Sciatic nerve (SN) is the thickest and longest nerve of the body. Deviations from the normal anatomical origin and level of bifurcation of SN have been frequently reported. In the present case, we are presenting a unique scenario of origin of terminal branches of the SN-tibial nerve (TN) and common peroneal nerve (CPN) in the pelvic region itself from divisions arising directly from the lumbosacral plexus. This variation was associated with origin of posterior femoral cutaneous nerve from the superior division of CPN with anomalous communicating branches between pudendal nerve and TN. The unique characteristics of the present case are the presence of 'pseudoganglion' found on the inferior division of TN. The present case stands out as the first of its kind to mention such pseudoganglion. Knowledge of some unusual findings like presence of pseudoganglion and intercommunications between nerves have clinical implications in anesthesiology, neurology, sports medicine, and surgery.

A case of plexiform schwannoma arising from the sciatic, tibial, and peroneal nerves

Plexiform schwannoma is a rare subtype of schwannoma. In this report, we present a case of plexiform schwannoma arising from the sciatic, tibial, and peroneal nerves. A 54-year-old man presented with a painful palpable mass extending from the left posterior thigh to the calf. Magnetic resonance imaging showed multiple bead-like nodular structures along the sciatic, tibial, and peroneal nerve pathway. The nodular lesions showed uniform signal intensity on T1-weighted imaging. On T2-weighted imaging, each nodule showed an eccentric area of relatively low signal intensity surrounded by an area of higher signal intensity and a low-intensity rim. Plexiform schwannoma or neurofibroma was considered as the preoperative diagnosis. Because of the patient's severe symptoms and strong desire for relief, tumor enucleation of the largest painful nodule was performed, and plexiform schwannoma was confirmed pathologically.

An anatomical approach to the tarsal tunnel syndrome: what can ankle's medial side anatomy reveal to us?

BACKGROUND

The heel is a complex anatomical region and is very often the source of pain complaints. The medial heel contains a number of structures, capable of compressing the main nerves of the region and knowing its anatomical topography is mandatory. The purpose of this work is to evaluate if tibial nerve (TN) and its main branches relate to the main anatomical landmarks of the ankle's medial side and if so, do they have a regular path after emerging from TN.

METHODS

The distal part of the legs, ankles and feet of 12 Thiel embalmed cadavers were dissected. The pattern of the branches of the TN was registered and the measurements were performed according to the Dellon-McKinnon malleolar-calcaneal line (DML) and the Heimkes Triangle (HT).

RESULTS

The TN divided proximal to DML in 87.5%, on top of the DML in 12,5% and distal in none of the feet. The Baxter's nerve (BN) originated proximally in 50%, on top of the DML in 12,5% and distally in 37.5% of the cases. There was a strong and significant correlation between the length of DML and the distance from the center of the medial malleolus (MM) to the lateral plantar nerve (LPN), medial plantar (MPN) nerve, BN and Medial Calcaneal Nerve (MCN) (ρ: 0.910, 0.866, 0.970 and 0.762 respectively, p <  0.001).

CONCLUSIONS

In our sample the TN divides distal to DML in none of the cases. We also report a strong association between ankle size and the distribution of the MPN, LPN, BN and MCN. We hypothesize that location of these branches on the medial side of the ankle could be more predictable if we take into consideration the distance between the MM and the medial process of the calcaneal tuberosity.

Application of new waveform analysis methods reflecting F-wave diversity -classification of F-wave diversity according to differences in the derived muscles

Background

The F wave waveforms show diversity according to the number and size of re-firing cells, but there is still no analytical method that reflects this feature. We previously reported that five classifications of F waves are obtained from the ulnar nerve. However, the diversity of F waves derived from the lower extremities may not be similar. We therefore compared the diversity of F waves in the upper and lower extremities in healthy subjects.

New method

F waves were measured during tibial nerve stimulation in 26 healthy subjects. The amount of amplitude decrease was calculated from the amplitude value after the additive averaging process and based on the average amplitude value of each stimulus, and the relationship between the peak latency and density was examined.

Results

The amount of amplitude decrease due to the additive averaging process was negatively correlated with the density of negative peaks. The diversity of F waves could be categorized into four class based on the histograms.

Comparison with existing method

The new method uses a novel additive average method that reflects the diversity of F waves. Furthermore, it uses a histogram to visualize the cancellation between waveforms.

Conclusion

We developed an analysis method that reflects the diversity of F waves in a novel manner, which visualizes cancellation between waveforms using a histogram.

Canalis cruropopliteus - the overlooked canal of Wenzel Gruber

It is widely known that the popliteal fossa and the lower leg are connected by a canal, containing the neuro-vascular bundle to the posterior leg region, containing the tibial nerve and the posterior tibial artery and veins. The existence of this canal has not been duly recognized in literature, even though it has been named by Wenzel Gruber in 1871, and its contents, walls, entrance, and exits have been extensively described by him in 1878. In the present paper, we would like to pay a homage to the work of this prominent anatomist, which retains its significance for contemporary surgical practice. The cruropopliteal canal, canalis cruropopliteus, as named by him, and having been assigned a multitude of terms in practice, deserves to regain its eponymous name - Gruber's canal. The history, and the anatomy with its clinical implications are discussed herein. We hereby recommend that the original name of this canal be included in anatomical textbooks and specialized literature.

Tarsal tunnel ganglion cyst: intraneural or extraneural site?

Intraneural ganglion cysts are very uncommon lesions, whose diagnosis has increased since the articular theory and the description of the MRI findings were established. We present a case report of a 59-year-old man with symptoms of tarsal tunnel syndrome. Foot and ankle MRI demonstrated the presence of an intraneural cystic lesion in the posterior tibial neve and its connection with the subtalar joint through an articular branch. The identification of the specific radiological signs like the «signet ring sign» allowed establishing an adequate preoperative diagnosis, differentiating it from an extraneural lesion and facilitating the articular disconnection of the nerve branch during surgery.

Anatomical variations of the tibial nerve and their clinical correlation

The tibial nerve is a branch of the sciatic nerve, which innervates the legs and feet. Anatomical variations of this nerve at the ankle are commonly found. The variation of the tibial nerve in its branching point and cross-sectional area (CSA) at the ankle is commonly related to clinical condition such as foot neuropathy. Knowledge of these variations can support the clinician in making appropriate clinical decisions. This review aims at providing knowledge on the anatomical variations of tibial nerve at ankle, as well as its clinical correlation. This review outlined the variation of the terminal branching point and CSA of the tibial nerve at the ankle in cadaveric and clinical studies.

Predictive value of ultrasonography in polyneuropathy diagnosis: electrophysiological and ultrasonographic analysis

Peripheral neuropathy may cause serious complications such as foot ulcers and Charcot joint which can prevent by early diagnosis. We aimed to analyze the diagnostic value of ultrasonographic measurements of nerves and muscles in distal symmetric axonal polyneuropathy (DSAP). Study included 51 DSAP patients and 51 controls. Nerve conduction studies were performed. Median, ulnar, tibial, superficial peroneal, and sural nerves and the abductor pollicis brevis (APB), abductor digiti minimi (ADM), first dorsal interosseous (FDI), extensor digitorum brevis (EDB), abductor hallucis (AH) and tibialis anterior (TA) muscles were evaluated with ultrasound. The Toronto clinical scoring system (TCSS) was used to assess the severity of neuropathy. The median, ulnar, and tibial nerve cross-sectional areas (CSA) were higher in the DSAP group (p = 0.025, p = 0.011, p < 0.001 respectively) while superficial peroneal and sural nerve CSAs were not differed. Only AH and EDB ultrasonographic findings from the muscles differed between the two groups. Effect of diabetes and DSAP on sonographic findings were assessed with two-way ANOVA. Results indicated that only DSAP had a significant effect on sonographic nerve and muscle examination. The area under the ROC curve was 0.831 ± 0.042 for tibial nerve CSA (p < 0.001) with a cut-off value of 15.5 mm2 (sensitivity 74% and specificity 83%). Median, ulnar and tibial nerve CSAs were found to be larger in polyneuropathy patients and they were associated with the clinical and electrophysiological severity of polyneuropathy. ROC analysis showed that tibial nerve CSA may have a predictive value in the diagnosis of DSAP.

Tibial nerve dynamics during ankle dorsiflexion: The relationship between stiffness and excursion of the tibial nerve

Peripheral nerves extend with a gradual increase in stiffness and also with excursion, namely reduction of fiber bundle waviness, to adapt to joint movements. Although the close relationships between the tibial nerve (TN) excursion and stiffness during ankle dorsiflexion in cadaver studies, the precise in vivo their relationships remain unclear. We hypothesized that the excursion of the TN can be estimated from its stiffness in vivo using shear-wave elastography. This study aimed to analyze the relationships between the TN stiffness at the plantarflexion and dorsiflexion and TN excursion during dorsiflexion using ultrasonography. Twenty-one healthy adults participated in constant-velocity movements of the ankle joint with a 20° range from the maximum dorsiflexion, and the TN was imaged using an ultrasound imaging system. The maximum flow velocity value and the TN excursion distance per dorsiflexion were then calculated as indexes of excursion using the application software Flow PIV. The shear wave velocities of the TN at plantarflexion and dorsiflexion were also measured. Based on our single linear regression, the shear wave velocities of the TN at the plantarflexion had the strongest effect on the excursion indexes, followed by the those at dorsiflexion. Ultrasonographic shear wave velocity could predict the TN excursion if measured under mild plantarflexion of the ankle joint, and might have a close biomechanical relation to the total waviness of the TN.

Synovial sarcoma of the tibial nerve - case report of a rare tumor in a rare location requiring early diagnosis

BACKGROUND

We present the case of a patient with a rare synovial sarcoma (SS) of the tibial nerve. So far, only 4 cases of patients with SS originating from the tibial nerve have been described in the literature, and our patient is only the second patient whose limb was saved during treatment. Synovial sarcomas are malignant mesenchymal tumors, i.e., tumors arising from connective tissue. Synovial sarcomas account for 5-10% of all soft tissue sarcomas. However, the name synovial sarcoma is misleading, because the tumor does not originate from synovial cells, but rather from primitive mesenchymal cells. The name most likely originated from the localization around the large joints on the limbs, more often on the lower ones, in the area of the knee joints. We point out the aspects of correct and quick diagnosis and subsequent treatment, which has very important effect on the patient's prognosis. Primary less radical excision without prior biopsy verification leads to a higher risk of local recurrence, even if a proper reexcision was performed immediately after biopsy verification of the sarcoma.

CASE PRESENTATION

A woman born in 1949 began to suffer at the end of 2020 with escalating pain under the left inner ankle with a projection to the sole and fingers. Her personal, family work and social history were insignificant. After the initial neurological examination, the patient was sent for an ultrasound examination of the ankle, which showed a lobular mass measuring 50 × 22 × 16 mm and according magnetic resonance imaging, the finding appeared to be a suspicious neurinoma of the tibial nerve. The tumor was surgically excised, without prior biopsy verification: a 50 × 20 mm tumor was dissected in the distal part of the tarsal canal, which grew through the structure of the tibial nerve and in some places into the surrounding area and appeared intraoperatively as a neurofibroma. But histologically the tumor was classified as monophasic synovial sarcoma. The patient was indicated for a wide reexcision of the skin with the subcutaneous tissue of size 91 × 20 × 15 mm. Now the patient is being treated with external radiotherapy to the tumor bed and she is able to walk.

CONCLUSION

This report draws attention to a rare type of malignant nerve tumor, which both clinically and radiologically can mimic benign peripheral nerve sheath tumors. Synovial sarcoma should be considered in very painful resistances, typically located around the joints of the lower limbs, the growth of which can be slow. Because the size of the tumor is a negative prognostic factor, it is necessary to make a timely diagnosis using MR imaging and a biopsy with histological examination and to start treatment quickly. Surgical treatment should take place only after a biopsy with histological examination of the tumor so that it is sufficiently radical and does not have to undergo an additional reoperation, as happened in the case of our patient.

Utility of the tibial nerve somatosensory evoked potentials in differentiating between neuromyelitis optica spectrum disorders and multiple sclerosis

BACKGROUND

Somatosensory evoked potentials (SEPs) are widely used for the diagnosis and evaluation of neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). However, whether the parameters of tibial nerve SEPs can help to distinguish NMOSD from MS remains unclear. Thus, the aim of this study was to investigate the utility of tibial nerve SEP parameters in differentiating patients with NMOSD and MS.

METHODS

The clinical data of patients with NMOSD or MS treated in our institution between 2005 and 2021 were retrospectively extracted from our electronic database. Additional inclusion criteria were presentation with sensory symptoms in the lower extremities with corresponding lesions in the magnetic resonance images as well as available data on anti-aquaporin-4 antibodies and tibial nerve SEPs. The Z-scores of the N21-P38 interval (central sensory conduction time), P38 latency, and P38 amplitude were compared between the patients with NMOSD and MS. The relationship of disease severity with the parameters of the tibial nerve SEPs was also evaluated.

RESULTS

Twenty patients with NMOSD and 13 patients with MS were enrolled. The Z-scores of the N21-P38 interval and P38 latency were significantly higher in the MS group than in the NMOSD group (p < 0.05 and p < 0.01, respectively), whereas there was no difference in the Z-scores of the P38 amplitude between the two groups. In the MS group, only the N21-P38 interval and P38 latency were significantly correlated with disease severity (p < 0.05 and p < 0.01, respectively). In contrast, none of the tibial nerve SEP parameters were significantly correlated with disease severity in the NMOSD group.

CONCLUSION

Evaluation of the N21-P38 interval and P38 latency in tibial nerve SEPs potentially helps in differentiating between NMOSD and MS.

Tortuosity and Pulsatility of the Tibial Artery - Two Case Reports of a Rare Etiology of Tarsal Tunnel Syndrome

Tarsal tunnel syndrome is a neuropathic compression of the tibial nerve and its branches on the medial side of the ankle. It is a challenging diagnosis that constitutes symptoms arising from damage to the posterior tibial nerve or its branches as they proceed through the tarsal tunnel below the flexor retinaculum in the medial ankle, easily forgotten and underdiagnosed. Neural compression by vascular structures has been suggested as a possible etiology in some clinical conditions. Tibial artery tortuosity is not that rare, but only that it affects the nerve can cause tarsal tunnel syndrome. Therefore, a study care must be taken to avoid false-positive errors.

Skeletal Muscle Denervation: Sciatic and Tibial Nerve Transection Technique

The nerve transection model is an established and validated experimental model of skeletal muscle atrophy prepared by denervating the skeletal muscle in rodents. While a number of denervation techniques are available in rats, the development of various transgenic and knockout mice has also led to the wide use of mouse models of nerve transection. Skeletal muscle denervation experiments expand our knowledge of the physiological role of nerval activity and/or neurotrophic factors in the plasticity of skeletal muscle. The denervation of the sciatic or tibial nerve is a common experimental procedure in mice and rats, as these nerves can be resected without great difficulty. An increasing number of reports have recently been published on experiments using a tibial nerve transection technique in mice. In this chapter, we demonstrate and explain the procedures used to transect the sciatic and tibial nerves in mice.

Evaluation of the clinical value of shear wave elastography for early detection and diagnosis of diabetic peripheral neuropathy: a controlled preliminary prospective clinical study

PURPOSE

This study aims to analyze the clinical application value of shear wave elastography (SWE) technique for early diagnosis of diabetic peripheral neuropathy (DPN).

METHODS

Diabetic patients hospitalized in the Department of Endocrinology of the First Affiliated Hospital of Anhui Medical University from August 2021 to February 2022 were enrolled as DPN group (n=38) and non-DPN group (n=35) based on the neurophysiological examination results. 30 healthy subjects were recruited as the control group during the same period. Ultrasound examination of the tibial nerve and related laboratory tests were examined and collected for the total 103 study subjects. Statistical analysis of the collected data, and the receiver operating characteristic(ROC) curve for determination of the optimal cut-off values of mean stiffness of tibial nerve to detect DPN, with determination of area under curve (AUC), specificity, sensitivity, and Youden index.P value < 0.05 is considered statistically significant.

RESULTS

Gender, age and BMI differences among three groups were insignificant (P>0.05). The difference of serological indicators between DPN and non-DPN groups was also not found (P>0.05), whereas longer duration of diabetes was observed in DPN group as compared to non-DPN group. As to the ultra-sound relevant parameters, the cross-sectional area and elastic modulus of the tibial nerve in both lower extremities among these three groups were not significantly different (Oneway ANOVA analysis) although the differences were indeed observed if we compared DPN group exclusively with non-DPN group, or compared non-DPN group with healthy group, or compared DPN group with healthy group (t test). Additionally, the mean elasticity (Emean) cut-off value for the diagnosis of DPN was preferably taken as 67.55 kPa.

CONCLUSION

SWE has unique advantages in early detection and diagnosis of DPN, which deserve further research.

Anatomy of the tibial nerve in relation to the tarsal tunnel: A cadaveric study

BACKGROUND

Tarsal tunnel syndrome (TTS) is typically caused by an anatomical variant or mechanical compression of the tibial nerve (TN) with variable success after surgical treatment.

METHOD

40 lower-leg specimens were obtained. Dissections were appropriately conducted. Extremities were prepared under formaldehyde solution. The tibial nerve and branches were dissected for measurements and various characteristics.

RESULTS

The flexor retinaculum had a denser consistency in 22.5% of the cases and the average length was 51.9 mm. The flexor retinaculum as an independent structure was absent and 77.2% of cases as an undistinguished extension of the crural fascia. The lateral plantar nerve (LPN) and abductor digiti minimi (ADM) nerve shared same origin in 80% of cases, 34.5% bifurcated proximal to the DM (Dellon-McKinnon malleolar-calcaneal line) line 31.2% distally and 34.3% at the same level.

CONCLUSION

Understanding the tibial nerve anatomy will allow us to adapt our surgical technique to improve the treatment of this recurrent pathology.

Tibial nerve stimulation increases vaginal blood perfusion and bone mineral density and yield load in ovariectomized rat menopause model

INTRODUCTION AND HYPOTHESIS

Human menopause transition and post-menopausal syndrome, driven by reduced ovarian activity and estrogen levels, are associated with an increased risk for symptoms including but not limited to sexual dysfunction, metabolic disease, and osteoporosis. Current treatments are limited in efficacy and may have adverse consequences, so investigation for additional treatment options is necessary. Previous studies have demonstrated that percutaneous tibial nerve stimulation (PTNS) and electro-acupuncture near the tibial nerve are minimally invasive treatments that increase vaginal blood perfusion or serum estrogen in the rat model. We hypothesized that PTNS would protect against harmful reproductive and systemic changes associated with menopause.

METHODS

We examined the effects of twice-weekly PTNS (0.2 ms pulse width, 20 Hz, 2× motor threshold) under ketamine-xylazine anesthesia in ovariectomized (OVX) female Sprague-Dawley rats on menopause-associated physiological parameters including serum estradiol, body weight, blood glucose, bone health, and vaginal blood perfusion. Rats were split into three groups (n = 10 per group): (1) intact control (no stimulation), (2) OVX control (no stimulation), and (3) OVX stimulation (treatment group).

RESULTS

PTNS did not affect serum estradiol levels, body weight, or blood glucose. PTNS transiently increased vaginal blood perfusion during stimulation for up to 5 weeks after OVX and increased areal bone mineral density and yield load of the right femur (side of stimulation) compared to the unstimulated OVX control.

CONCLUSIONS

PTNS may ameliorate some symptoms associated with menopause. Additional studies to elucidate the full potential of PTNS on menopause-associated symptoms under different experimental conditions are warranted.

An update on imaging of tarsal tunnel syndrome

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve (TN) within the tarsal tunnel (TT) at the level of the tibio-talar and/or talo-calcaneal joints. Making a diagnosis of TTS can be challenging, especially when symptoms overlap with other conditions and electrophysiological studies lack specificity. Imaging, in particular MRI, can help identify causative factors in individuals with suspected TTS and help aid surgical management. In this article, we review the anatomy of the TT, the diagnosis of TTS, aetiological factors implicated in TTS and imaging findings, with an emphasis on MRI.

Feasibility and acceptability of transcutaneous tibial nerve stimulation for the treatment of bladder storage symptoms among people with multiple sclerosis

Background

Neurogenic lower urinary tract dysfunction is an abnormality in the presence of underlying neurologic disease. A recent systematic review and meta-analysis demonstrated that storage phase symptoms are the predominant symptoms among people with multiple sclerosis (PwMS). Transcutaneous tibial nerve stimulation (TTNS) is a non-invasive treatment for bladder storage symptoms; however, the potential efficacy of stimulation among PwMS is based on a small number of studies with the absence of high-quality evidence. The aim of this study was to evaluate the feasibility, acceptability, and safety of TTNS in PwMS using an affordable transcutaneous electrical nerve stimulation (TENS) unit.

Methods

A total of 23 participants with MS enrolled in the study. The primary outcomes included recruitment/retention rate, completion of the outcomes and the intervention, adherence to the protocol, adverse events, and acceptability of the intervention. The primary outcomes were assessed using diaries and a satisfaction questionnaire. The secondary outcomes included changes in urinary symptoms and quality of life assessed using a set of validated outcome measures including a 3-day bladder diary, PPIUS, ICIQ-OAB, and KHQ at baseline and post-intervention.

Results

Twenty participants completed the study. Three participants (13.04%) withdrew. All 20 participants completed the 6-week intervention and all the outcome measures (100%), with no reported adverse events. Participants were satisfied and found the unit acceptable. Three-day bladder diary showed changes in urinary frequency from a daily median of 10 times to 8 times and daily median urgency changed from 6 times at baseline to 2 times post-intervention. PPIUS showed changes in daily median sever urgency from 3 points (IQR=4) to 1 point (IQR=1) post-intervention. ICIQ-OAB total scores changed from 8 points (IQR=2.25) to 4 points (IQR=2.5) post-intervention. Median and mean scores of KHQ showed a clinical meaningful change of QoL in part-two and part-three of the questionnaire.

Conclusions

TTNS is feasible, safe, and acceptable for PwMS. Changes of urinary symptoms scores and QoL post-intervention suggested improvements. Future implications need to consider the treatment protocol including frequency of treatment sessions, duration of treatment, and the electrical stimulation parameters as well as the outcome measures followed in the current study for the implementation of the future pilot RCT.

Trial registration

ClinicalTrials.gov NCT04528784. Registered on 27 August 2020. https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=1&cx=-jg9qo4.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-022-01120-1.

Imaging Axonal Transport in Ex Vivo Central and Peripheral Nerves

Neurones are highly polarized cells with extensive axonal projections that rely on transport of proteins, RNAs, and organelles in a bidirectional manner to remain healthy. This process, known as axonal transport, can be imaged in real time through epifluorescent imaging of fluorescently labeled proteins, organelles, and other cargoes. While this is most conveniently done in primary neuronal cultures, it is more physiologically relevant when carried out in the context of a developed nerve containing both axons and glia. Here we outline how to image axonal transport ex vivo in sciatic and optic nerves, and the fimbria of the fornix. These methods could be altered to image other fluorescently labeled molecules, as well as different mechanisms of intracellular transport.

Intracompartmental pressure in lower leg muscles and tibial nerve in healthy volunteers correlate to the stiffness measured using shear wave elastography

BACKGROUND

Acute compartment syndrome in the lower leg is a painful condition characterized by an increase in intracompartmental pressure. To prevent misdiagnosis and delay in the recognition of the condition, which can lead to severe complications, continuous monitoring of intracompartmental pressure for at least 24 h. from the onset of initial symptoms has been recommended. The purpose of the current study was to establish shear wave elastography as a potential imaging biomarker for the observed increase in pressure in four compartments of the lower leg.

METHODS

Eighteen healthy participants (9 males) without any injury in their leg muscles were recruited for the study after internal review board approval. Subjects were instructed to sit on a table and pressures at 60, 90, and 120 mmHg were applied using a pressure cuff placed above the proximal pole of the patella. Shear wave elastography-measured stiffness outcomes at baseline (0 mmHg) and at each cuff pressure level were obtained from the tibialis anterior, the peroneus longs, gastrocnemius medialis, and tibialis posterior muscles, as well as the tibial nerve.

FINDINGS

Spearman's rank correlation coefficient showed strong correlations between shear wave elastography-measured stiffness from all four muscles and cuff pressure levels (r > 0.80, P < 0.05). Stiffness from the tibial nerve was also significantly correlated with cuff pressure levels (r > 0.99, P < 0.05).

INTERPRETATION

Shear wave elastography imaging of lower leg muscles and nerve can be useful to non-invasively monitor intracompartmental pressure in patients suspected of acute compartment syndrome.

Ultrasound evaluation of peripheral nerves of the lower limb in diabetic peripheral neuropathy

PURPOSE

Comparative evaluation of the cross-sectional area (CSA) of the sural and tibial nerves using ultrasound in diabetic peripheral neuropathy (DPN).

METHOD

This study involved 210 participants divided into 3 groups: type 2 diabetics with DPN, type 2 diabetics without DPN, and controls. Ultrasound evaluation of the sural and tibial nerves was done using a 5-17 MHz linear transducer. The CSA of both the nerves was recorded in both lower limbs. Nerve conduction studies (NCS) were also done in all diabetic patients.

RESULTS

There were 70 participants in each group. All the three groups were gender-matched and no significant difference was observed between CSA values of the sural and tibial nerves between males and females and also in right and left lower limbs within a group. The sural nerve CSA was significantly higher in the DPN group than in diabetic patients without DPN and controls. The sensitivity of the sural nerve CSA was higher than the tibial nerve with a cut-off value of 4.41 mm² for CSA of the sural nerve.

CONCLUSION

The sural nerve CSA at the superior border of lateral malleolus can be used for screening DPN. With well-established cut-off values may result in early initiation of the therapy even in NCS negative cases, thus reducing the morbidity associated with the disease. Ultrasound could be used as a first diagnostic tool for detection of DPN which can be followed by NCS in cases where ultrasound is non-diagnostic.

Parasacral versus tibial transcutaneous electrical stimulation to treat urinary urgency in adult women: Randomized controlled clinical trial

INTRODUCTION

Urinary urgency is a very strong urge to urinate that is difficult to postpone and control. One of the physiotherapeutic resources that can be used in the treatment of urinary urgency is electrical nerve stimulation. The objective of this study is to investigate the effects of parasacral and tibial nerve transcutaneous electrical stimulation in improving urinary urgency in adult women.

MATERIAL AND METHODS

Single-blinded randomized controlled clinical trial.

PARTICIPANTS

Ninety-nine adult women with urgency.

INTERVENTIONS

Transcutaneous electrostimulation for 12, 20-min sessions, twice a week. The tibial and parasacral groups received a current of F = 10 Hz and 200 μs pulse duration, while the sham group received a current of F = 100 Hz and 100 μs pulse duration, the active electrode placed over the scapula. Primary and secondary outcome measures: The primary outcome measure was urinary urgency, measured by the International Consultation on Incontinence Questionnaire Overactive Bladder (ICIQ-OAB) and Overactive Bladder questionnaire-Validated 8-Question Awareness Tool (OAB-V8). Secondary outcomes were quality of life with the King's Health Questionnaire (KHQ) and voiding habits with the 24-h voiding diary. Assessments occurred pretreatment, after the sixth and 12th post-treatment sessions and at the 30-day follow-up.

RESULTS

Both parasacral and tibial groups in the post-treatment presented fewer episodes of urgency than the sham group. The parasacral group showed better results than the sham group post-treatment for ICIQ-OAB scores, and in KHQ domains Impact of Incontinence and task limitations. Parasacral group participants had OAB-V8 score lower than 8 in the post-treatment and follow-up.

CONCLUSION

Both tibial and parasacral groups had a positive and similar effect on reducing urinary urgency in adult women. Relative to the quality of life, transcutaneous parasacral electrostimulation was superior to transcutaneous tibial electrostimulation.

CLINICAL TRIAL REGISTRATION

Brazilian Registry of Clinical Trials (ReBEC), http://ensaiosclinicos.gov.br, protocol RBR-9rf33n.

Intra-Rater and Inter-Rater Reliability of Pressure Pain Algometry of the Sural and Tibial Nerves in Asymptomatic Elite Youth Footballers

Ankle injuries are highly prevalent in elite youth footballers and increase the mechanosensitivity of the local neural tissue, which may predispose athletes to re-injury and prolong rehabilitation periods. Increased neural mechanosensitivity presents clinically as altered pain pressure thresholds (PPTs) which are measured with pressure algometry. The purpose of this study was to determine the intra-rater and inter-rater reliability of PPTs of the ankle neural tissue in asymptomatic elite youth football players. Three raters utilised a digital algometer to evaluate the PPTs of the Sural and Tibial nervous tissue at the ankle of elite youth male footballers. Intraclass correlation coefficients (ICCs) with 95% confidence intervals (CI) were calculated to assess intra-rater and inter-rater reliability and Bland-Altman figures were plotted to enable visual evaluation of measurement error with a significance level of p < 0.05. Thirty-four players (16-18 years old) were assessed. Excellent intra-rater (Tibial ICC 0.88 (0.76-0.94); Sural ICC 0.89 (0.79-0.95)) and good inter-rater reliability (Tibial ICC 0.66 (0.40-0.82); Sural 0.71 (0.50-0.85)) was demonstrated. Bland-Altman plots demonstrated low levels of measurement error. Pressure algometry can be utilised clinically to accurately evaluate the PPTs of the Tibial and Sural nervous tissue at the ankle in asymptomatic elite male youth footballers.

Normal response to tibial neurodynamic test in asymptomatic subjects

BACKGROUND

The straight leg raise test (SLR) is one of the most performed physical tests for mechanosensitivity and impairment of the nervous system. According to the anatomy of the tibial nerve, ankle dorsiflexion and eversion movements could be used to perform the tibial neurodynamic test (TNT). To date, no study has documented the normal responses of the TNT.

OBJECTIVE

To document normal responses of the TNT in asymptomatic individuals and to investigate influences from sex and leg dominance.

METHODS

A cross-sectional study with 44 asymptomatic volunteer subjects, a total of 88 lower limbs, was carried out. The range of motion (ROM), quality, and distribution of sensory responses were recorded. The hip flexion ROM was measured when subjects reported an intensity of their symptoms of 2/10 (P1) and 8/10 (P2).

RESULTS

The mean ROM for hip flexion at P1 was 44.22 ± 13.13∘ and 66.73 ± 14.30∘ at P2. Hip flexion was significantly greater at P2 than P1 (p< 0.001). However, it was not different between sex or limbs (p> 0.05). The descriptor of the quality of sensory responses most often used by participants was stretching (88.6% and 87.5% for P1 and P2, respectively) in the popliteal fossa and posterior calf.

CONCLUSIONS

This study describes the sensory responses of asymptomatic subjects resulting from the TNT. Our findings indicate that TNT responses are independent of the influence of sex or leg dominance.

The influence of right-left error in the placement of the Cc electrode in tibial nerve somatosensory evoked potentials (SEPs)

•

The Cz’–Cc lead in tibial nerve SEPs has a merit that it registers a stable P38 wave.

•

Right-left error in the placement of the Cc electrode distorted SEP results.

•

P38 disappeared by this error and a later component was misidentified as P38.

Objective

At our laboratory, we routinely record tibial nerve somatosensory evoked potentials (SEPs) using 5 channels including the second cervical vertebra (C2S)-contralateral central area (Cc) and Cz’ (2 cm posterior to Cz)–Cc derivations. In a man with lumbar spondylotic myelopathy, symptoms improved after surgery, although the N21-P38 interval was markedly prolonged in comparison with that before surgery. We presumed that the Cc electrode was actually placed on the ipsilateral central area (Ci) at the second examination. Inspired by this episode, we investigated the influence of the right-left error in the placement of the Cc electrode.

Methods

Subjects were 20 healthy volunteers. Tibial nerve SEPs were recorded with 8 leads including Cz’–Cc, Cz’-Ci, C2S-Cc and C2S-Ci.

Results

For the Cz’-Ci lead, the P38 potential diminished in amplitude, was absent or became negative. For the C2S-Ci lead, a large negative potential corresponding to the phase reversal of P38 was frequently observed.

Conclusions

Tibial nerve SEPs using the Cz’–Cc or C2S-Cc lead are distorted if the Cc electrode is placed on the opposite side.

Significance

When a strange result is obtained in tibial nerve SEPs, we should check for a right-left error in the Cc electrode placement.

Location of motor branches of tibialis posterior muscle and its relation in treatment of spastic equinovarus foot: a cadaveric study

Background and objectives

Nerve block or neurolysis is an important approach in the treatment of spastic equinovarus foot. To illustrate the accurate location of the nerve branch to the tibialis posterior muscle (TP) in clinical practice, 21 adult cadavers were dissected and 14 complete both lower limb specimens were obtained. A total of 28 lower limbs were included.

Methods

We measured the length of the motor branch nerve (LM) of the tibialis posterior muscle, the length of the fibula (LF), the vertical distance (D1) from the midpoint of LM to the fibula tip as well as the horizontal distance (D2) from the midpoint of LM to the inner edge of the fibula.

Results

The LM was higher (35.74 ± 7.28 mm) in male than in female (30.40 ± 6.88 mm) specimens but there was no significant correlation between LM and gender (p > 0.05). Additionally, among male specimens, the LM on the right side was longer than that on the left (p ≤ 0.05) while among female specimens, the D1 on the left side was longer than that on the right (p ≤ 0.05). The LF in male specimen was significantly longer than that in female (p ≤ 0.05). The midpoint of the nerve to the motor branch of the tibialis posterior muscle was about 50 mm distal to the fibular head and 10 mm at the inner edge of the fibula.

Conclusion

Using this coordinate, the midpoint of the nerve branch to the TP could be accurately located.

MRI features of symptomatic amputation neuromas

OBJECTIVES

To demonstrate the magnetic resonance imaging (MRI) features of amputation neuromas in lower extremity amputees and investigate independent predictive MRI features for symptomatic neuromas.

METHODS

This retrospective study included 45 amputation neuromas in 44 lower extremity amputees. Two radiologists assessed the imaging features, including shape, size, type (end-bulb or spindle), signal intensity (SI), heterogeneity, margins, enlarged fascicles, dark outer rim, tail sign, target sign, enhancement, perilesional fibrosis, and muscle denervation. The neuromas were categorized into symptomatic (n = 24) or asymptomatic (n = 21). Symptomatic neuromas were determined based on neuropathic pain characteristics, the presence of Tinel's sign or tenderness, and response to local anesthetic injection. Univariate and multivariate analyses were performed to identify independent predictive MRI features.

RESULTS

Of 45 neuromas, 80% (36/45) were end-bulb neuromas and 20% (9/45) were spindle-type neuromas. Eighty percent of the neuromas (36/45) were heterogeneous on T2-weighted images (WIs). Enlarged fascicles were present in 42% (19/45) and dark outer rims in 27% (12/45) of the neuromas. Among the 23 neuromas with enhanced images, 78% (18/23) showed enhancement. Heterogeneity on T2-WIs and enhancement ratios were significantly different between the asymptomatic and symptomatic neuroma groups (p < 0.05). The multivariate analyses indicated that heterogeneity on T2-WIs was an independent factor associated with symptomatic neuromas (p < 0.001).

CONCLUSIONS

Heterogeneity on T2-WIs could be a predictive indicator for symptomatic neuromas in lower extremity amputees.

KEY POINTS

• Amputation neuromas are classified as either end-bulb or spindle-type. They can show enlarged fascicles, dark outer rims, and enhancement. • Heterogeneity on T2-weighted images could be a predictive indicator for symptomatic neuromas. • Predicting the symptomatic neuroma on MRI would help in effective management of stump pain.

Tarsal Tunnel Syndrome

Tarsal tunnel syndrome is paresthesia and pain in the foot and ankle caused by entrapment and compression of the tibial nerve within the fibro-osseous tarsal tunnel beneath the flexor retinaculum. The most helpful diagnostic criteria are a positive Tinel sign at the ankle and objective sensory loss along the distribution of the tibial nerve. Treatment is designed to reduce the compression of the nerve, and surgical nerve release is indicated with failure of conservative options. It is important to identify the causative factor of the nerve compression and eliminate it to obtain excellent results.

Defining the popliteal fossa by bony landmarks and mapping of the courses of the neurovascular structures for application in popliteal fossa surgery

Surgical access to the posterior knee poses a high-risk for neurovascular damage. The study aimed to define the popliteal fossa by reliable bony landmarks and comprehensively mapping the neurovascular structures for application in posterior knee surgery. Forty-five (20 male, 25 female) embalmed adult cadaveric knees were included. The position of the small saphenous vein (SSV), medial cutaneous sural nerve (MCSN) and lateral cutaneous sural nerv (LCSN), tibial nerve (TN) and common fibular nerve (CFN) nerves, and popliteal vein (PV) and popliteal artery (PA) were determined in relation to either medial (MFE) or lateral (LFE) femoral epicondyles, medial (MTC) and lateral (LTC) tibial condyles and the midpoint between the MFE and MTC and LFEF and LTC. The distance between the MFE and the PA, PV, TN, MCSN, and SSV was 38.4±12.1 mm, 38.4±12.9 mm, 39.4±10.2 mm, 39.2±14.0 mm and 37.6±12.5 mm respectively for males and 34.6±4.9 mm, 32.8±5.6 mm and 38.0±8.1 mm 38.8±10.1 mm and 37.9±8.2 mm respectively for females. The distance between LFE and the CFN and LCSN was 13.4±8.2 mm and 24.9±7.3 mm respectively for males and 8.4±9.1 mm and 18.4±10.4 mm respectively in females. This study defined the popliteal fossa by reliable bony landmarks and provided a comprehensive map of the neurovascular structures and will help to avoid injuries to the important neurovascular structures.

Acute intermittent hypoxia enhances regeneration of surgically repaired peripheral nerves in a manner akin to electrical stimulation

The intrinsic repair response of injured peripheral neurons is enhanced by brief electrical stimulation (ES) at time of surgical repair, resulting in improved regeneration in rodents and humans. However, ES is invasive. Acute intermittent hypoxia (AIH) - breathing alternate cycles of regular air and air with ~50% normal oxygen levels (11% O₂), considered mild hypoxia, is an emerging, promising non-invasive therapy that promotes motor function in spinal cord injured rats and humans. AIH can increase neural activity and under moderately severe hypoxic conditions improves repair of peripherally crushed nerves in mice. Thus, we posited an AIH paradigm similar to that used clinically for spinal cord injury, will improve surgically repaired peripheral nerves akin to ES, including an impact on regeneration-associated gene (RAG) expression-a predictor of growth states. Alterations in early RAG expression were examined in adult male Lewis rats that underwent tibial nerve coaptation repair with either 2 days AIH or normoxia control treatment begun on day 2 post-repair, or 1 h ES treatment (20 Hz) at time of repair. Three days post-repair, AIH or ES treatments effected significant and parallel elevated RAG expression relative to normoxia control at the level of injured sensory and motor neuron cell bodies and proximal axon front. These parallel impacts on RAG expression were coupled with significant improvements in later indices of regeneration, namely enhanced myelination and increased numbers of newly myelinated fibers detected 20 mm distal to the tibial nerve repair site or sensory and motor neurons retrogradely labeled 28 mm distal to the repair site, both at 25 days post nerve repair; and improved return of toe spread function 5-10 weeks post-repair. Collectively, AIH mirrors many beneficial effects of ES on peripheral nerve repair outcomes. This highlights its potential for clinical translation as a non-invasive means to effect improved regeneration of injured peripheral nerves.

A bilateral third head of the gastrocnemius which is morphologically similar to the plantaris

PURPOSE

An extra muscle was observed on both sides of the popliteal fossa in the cadaver of a 78-year-old Japanese male during dissection. The aim of this case report was to identify whether this variant is a double plantaris or a third head of the gastrocnemius according to its morphological characteristics and innervation.

METHODS

The muscles were displayed by careful dissection and delineation of surrounding structures. The size of each of the muscle bellies and tendons of those extra muscles were measured manually by the vernier caliper.

RESULTS

The origin of each extra muscle was lateral to the tibial nerve and superior to the plantaris, and each extra muscle which transitioned to a descending tendon parallel to the plantaris had a cone-shaped belly. However, the tendon of the extra muscles was fused into the investing fascia of the gastrocnemius with a tendon length of 4.5 cm on the left and 4.6 cm on the right. The extra muscles were innervated by the branch of the tibial nerve to the medial head of the gastrocnemius on both sides.

CONCLUSION

Although they had an origin and shape similar to that of the plantaris, we identified the extra muscles in this case as a third head of the gastrocnemius, because of innervation to the plantaris arises directly from the tibial nerve. This case highlighted that the innervation is essential to understanding the myogenesis of extra muscles, especially in cases which are difficult to categorize based on the morphological features of the muscle.

The determination of safe zones for arthroscopic portal placement into the posterior knee by mapping the courses of neurovascular structures in relation to bony landmarks

PURPOSE

Minimally invasive surgery in the posterior knee is high risk for iatrogenic injury to popliteal neurovascular neurovasculature structures. This study aimed to use reliable landmarks to define safe zones for arthroscopic portal placement into the posterior knee.

METHODS

Distances were measured between bony landmarks and neurovascular structures within the popliteal fossa using 45 formalin-embalmed cadavers: small saphenous vein (SSV), medial (MCSN) and lateral (LCSN) cutaneous sural nerves, tibial nerve (TN), common fibular nerve (CFN), popliteal vein (PV) and artery (PA). The structures were measured in relation to medial (MEF) and lateral (LEF) femoral epicondyle, medial (MCT) and lateral (LCT) tibial condyle and the midpoint between the landmarks.

RESULTS

The mean distance (mm) between MEF and structures was, male and female, respectively: SSV 37.6 + 12.5, 37.9 + 8.2; MCSN 39.2 + 14, 38.8 + 10.1; TN 39.4 + 10.2, 38.0 + 8.1; PV 38.4 + 12.9, 32.8 + 5.6; PA 38.4 + 12.1, 34.6 + 4.9. At midpoint and MCT all structures medialized between 5 and 28%. The mean distance between LEF and structures was, male and female, respectively: CFN 13.4 + 8.2, 8.4 + 9.1; LCSN 24.9 + 7.3, 18.4 + 10.4. At midpoint and LCT the CFN lateralized by 37-42% and the LCSN medialized by 8-9%.

CONCLUSIONS

Results suggest posteromedial portal placement can be safely established < 20 mm from the medial femoral epicondyle, tibial condyle or the midpoint between the two landmarks. Posterolateral portal placement is of higher risk, and entry point is 18 mm from the lateral femoral epicondyle, tibial condyle or the midpoint between the two landmarks in males and 12 mm in females. These landmarks will allow safe portal placement in 99% of cases.

Redefining the Topography of the Tibial Nerve: Updated Treatment Guide for Tibial Nerve Entrapments: An Addendum to Surgical Treatment Protocol for Peripheral Nerve Dysfunction of the Lower Extremity: A Systematic Approach

Dysfunction of the tibial nerve can progress to painful and potentially disabling conditions. There are multiple sites of entrapment along the course of the tibial nerve. Detailed knowledge of the anatomy and anatomic variations is critical for a surgeon to be able to properly diagnose and treat patients with tibial nerve injuries. Repair of tibial nerve injuries involves a thorough history, physical examination, diagnostic studies, and microsurgical techniques. This article discusses sites of tibial nerve entrapment and use of a surgical algorithm that provides a systematic approach that has been successful within the literature in treating chronic tibial neuritic pain.

Anatomical study and branching point of neurovascular structures at the medial side of the ankle

Nerve entrapment and blood circulation impairment associated with the medial side of the ankle are not uncommon. The purpose of this study was to describe the anatomical basis of neurovascular structures of the medial ankle which comprised the number, origin, branching pattern, and branching point. Forty feet of fresh cadavers were examined by using 2 reference lines: the malleolar-calcaneal (MC) and navicular-calcaneal (NC) axes. We recorded number, origin, length of the 2 axes, the locations and widths of neurovascular structures on MC and NC axes, the branching point of neurovascular structures, and the branching pattern of neurovascular structures was recorded and was separated into 5 types. The posterior tibial nerve (PTN) bifurcated to plantar and calcaneal nerves and branched proximally to the tarsal tunnel (TT). The posterior tibial artery bifurcated to plantar and calcaneal arteries and branched inferiorly to PTN and within the TT. The calcaneal nerves and arteries had more variation of number and origin. The most common branching point of calcaneal nerves and arteries is within the TT, except the medial calcaneal nerve. It branched proximally to the TT. The anatomical knowledge from this study is important for the diagnosis and treatment of clinicians.

[Selective ultrasound-guided hydrodissection of gastrocnemius nerve branch after post-surgical entrapment: Apropos of a case]

Chronic or recalcitrant plantar fasciitis is a cause of persistent plantar pain. These cases are usually resistant to conventional treatments consisting of exercises, orthoses, shock waves and infiltrations and require a surgical approach. Proximal medial gastrocnemius release is a surgical option that provides satisfactory results, but is not free of complications, which include injuries and nerve entrapment. We report the first published case of symptomatic medial gastrocnemius branch entrapment in the post-surgical scar of a tenotomy for the treatment of recalcitrant plantar fasciitis. We propose ultrasound-guided hydrodissection with local anesthetic as a treatment with promising results.

Open tendoachilles injuries due to squatting type of toilet seats: Five-year prospective observational study from a tertiary care center in India

BACKGROUND

Open traumatic tendoachilles injuries due to toilet seats are least reported. The exact mechanism of such injuries is debatable. None of the studies have reported associated neurovascular injuries and the need for microvascular tissue transfer.

METHODS

It is a 5-year prospective observational study from Sep 2013 - Aug 2018 at a tertiary care center on 26 patients who had sustained foot injuries due to squatting type toilet seats. All the patients were managed by thorough wound irrigation and debridement followed by repair of cut tendoachilles, other tendons and neurovascular structures. All the complications and secondary procedures required were recorded. Functional outcome was assessed by Boyden clinical outcome score. Follow up ranged from 1 to 5 years.

RESULTS

All the 26 patients reported a particular mechanism of injury. Complete transection of tendoachilles was seen in 23 (88.5%) patients and partial transection in three (11.5%) patients. Microvascular repair of cut posterior tibial artery was undertaken in three and posterior tibial nerve in two cases and microvascular parascapular flap in one case for soft tissue reconstruction. Twenty-three (88.5%) patients had good to excellent Boyden score while three patients (11.5%) had fair to poor score at 1 year. Such severe injuries due to toilet seats have never been reported in literature.

CONCLUSIONS

Squatting toilet seats can cause devastating foot injuries involving tendons and neurovascular structures and may require microvascular tissue transfer for definitive wound management. The risk of such injuries will continue unless some modifications are undertaken in the design of the seat.

[Percutaneous tibial nerve stimulation in urge urinary incontinence: A prospective study]

OBJECTIVE

To assess the efficacy of percutaneous tibial nerve stimulation and its effectiveness over time in urge urinary incontinence.

MATERIALS AND METHODS

We performed a longitudinal, observational, prospective study without a control group that included patients diagnosed with urge urinary incontinence who met the inclusion/exclusion criteria. Patients were treated with 12 sessions of percutaneous tibial nerve stimulation by electroacupuncture. Baseline and post-treatment data were collected from medical records. Patients were assessed by a telephone interview after the treatment. The variables studied were sociodemographic variables, time until interview, the Sandvick and ICIQ-SF questionnaires, daytime urinary frequency, night-time urinary frequency, use of absorbent material and drug treatment. A descriptive analysis of the variables was performed and patient outcomes were analysed with generalised linear mixed models by SPSS v. 25 statistics software.

RESULTS

A total of 32 women were included (mean age 58.69±8.96). All variables significantly improved after treatment: Sandvick by 4.38 points (95% CI: 2.68-6.08, P<.001), ICIQ-SF by 8.55 points (95% CI: 5.89-11.22, P<.001), daytime urinary frequency by 2.10 points (95% CI: 1.04-3.16, P<.001) and night-time urinary frequency by 1.31 points (95%CI: 0.58-2.04, P<.001). However, 16.34±9.72 months after treatment, these improvements diminished but without reaching baseline levels.

CONCLUSIONS

Percutaneous tibial nerve stimulation by electroacupuncture is effective for the treatment of urge urinary incontinence. Although its effect diminishes over time, the improvement over the baseline situation is maintained during the follow-up period.

A propos of a case]

The most frequent pattern of spasticity in the lower limb is equinovarus foot. Patients with central nervous system injury and severe spasticity, conservative treatment and botulinum toxin type A often have a limited effect. In these cases, nerve blocks can be very useful in deciding our therapeutic action. We present a clinical case as an example of a new ultrasound-guided approach to tibial nerve block, as this is the main nerve involved in equinovarus foot pattern, specific for spastic patients and its usefulness for the clinical management of spasticity.

How I do it: selective tibial neurotomy

BACKGROUND

Selective neurotomy is known as an effective method to reduce focal spasticity when medical treatment including botulinum toxin is not sufficient. The tibial nerve can be targeted to treat spastic equinovarus foot with (or without) claw toes.

METHOD

Tibial nerve trunk is dissected in the popliteal fossa. Sensitive and motor branches are identified using electrical stimulation to monitor motor responses. The muscular nerves corresponding to the targeted muscles are partially sectioned according to a preoperative chart. A postoperative rehabilitation program is mandatory.

CONCLUSION

Precise and rigorous selective neurotomy provided a definitive and safe treatment for spastic equinovarus foot.

Percutaneous tibial nerve stimulation maintenance therapy for overactive bladder in women: long-term success rates and adherence

PURPOSE

Our objectives are to (1) identify predictors of treatment success in women with overactive bladder (OAB) after 1 year of percutaneous tibial nerve stimulation (PTNS) maintenance therapy, (2) identify trends in success rates during that 1 year, and (3) assess maintenance treatment adherence.

MATERIALS AND METHODS

A retrospective study of 141 women with OAB was performed with the definition of success based on a Patient Global Impression-Improvement (PGI-I) score of 1 ("very much better") or 2 ("much better") or a PGI-I score of 1, 2, or 3 ("a little better"). Multivariable logistic regression was performed to identify factors associated with treatment response and the Cochrane-Armitage trend test to identify changes in the scores over time.

RESULTS

After completing 12 weekly treatments, 141 women initiated maintenance therapy with a mean treatment interval of 29 days. At 1 year, 75/141 (53.2%) had discontinued treatment. Those adherent with treatment had a sustained treatment response, with 66.2% of women reporting a PGI-I score of 1, 2 and 92.3% reporting a PGI-I score of 1, 2, or 3 at 1 year. Considering those women who discontinued maintenance therapy as treatment failures, the success rate of 1 year of maintenance therapy ranged from 30.7%-42.9%. No clinical factors were found to be predictive of maintenance treatment success or failure.

CONCLUSIONS

Although an effective treatment for those adherent, discontinuation rates of PTNS maintenance therapy at 1 year are high. Given the low numbers of women referred to maintenance therapy, and the high discontinuation rates, long-term PTNS treatment may be feasible for only a minority of women with OAB.

Tibial motor and sural electrophysiological relationship in subjects without and patients with mild axonal peripheral neuropathy

The distal motor fibers of the tibial and sural nerves are predominantly derived from the S1 root. We aimed to describe the electrophysiological relationship of these two nerves. Clinical, radiological and neurophysiological data of patients with mild, length-dependent, peripheral neuropathy (PN) and subjects without PN were retrospectively collected and analyzed. Eighty-eight individuals without PN and 24 patients with mild axonal PN who had no evidence of lumbosacral radiculopathy were included for analysis. Significant positive correlations were observed for the tibial CMAP and the sural SNAP for both controls and patients. Multivariate linear regression analyses showed that the predicted tibial CMAP can be calculated using the following equations: for male subjects without PN, tibial CMAP = 20.7 - 0.21 × age; for female subjects without PN, tibial CMAP = 23.3 - 0.21 × age and for patients with mild PN, tibial CMAP = 2.7 + sural SNAP. This study demonstrates the high correlation between the tibial CMAP and the sural SNAP in subjects without PN and patients with mild axonal peripheral neuropathy, and provides mathematical equations for the calculation of the predicted tibial CMAP for such individuals.

A prospective observational cohort study of posterior tibial nerve stimulation in patients with multiple sclerosis: design and methods

BACKGROUND

Posterior tibial nerve stimulation (PTNS) is a promising treatment for lower urinary tract symptoms (LUTS) in patients with MS. However, long term data focusing on PTNS impact on health-related quality of life (HRQOL), bowel and bladder symptoms are lacking. This paper describes a study protocol that examines the extended efficacy of PTNS on MS related bladder and bowel symptoms and resulting HRQOL.

METHODS/DESIGN

This is a single-centered, prospective, longitudinal, observational cohort study of patients with MS who suffer from LUTS and are refractory to two prior treatment modalities. Participants who have elected to pursue PTNS therapy for LUTS will be eligible. The primary outcome is the median number of urinary frequency and incontinence episodes on a 3-day voiding diary at 3, 12 and 24 months compared to baseline. Secondary outcome measures will include change in total AUA-SS, M-ISI, NBSS, SF-12, SSS and BCS scores from baseline The Expanded Disability Status Scale and magnetic resonance imaging will be evaluated at baseline and annually throughout the study.

DISCUSSION

This research protocol aims to expand on the existing literature regarding outcomes of PTNS in MS. Specifically, it will provide long term follow-up data on bladder, bowel, sexual and HRQOL outcomes. The completion of this study will provide longitudinal efficacy data of the impact of PTNS in MS patients.

TRIAL REGISTRATION

NCT04063852.

Effect of ankle dorsiflexion on displacement and strain in the tibial nerve and biceps femoris muscle at the posterior knee during the straight leg raise: Investigation of specificity of nerve movement

BACKGROUND

A structural differentiation maneuver has been proposed to differentiate between muscle and nerve involvement during the straight leg raise test. However, to date, the mechanical specificity of this maneuver for the tibial nerve at the posterior knee has not been tested. The aim of this study was to investigate the specificity of ankle dorsiflexion as a differentiation maneuver between the tibial nerve and the biceps femoris muscle at the posterior knee during the straight leg raise in cadavers.

METHODS

A cross-sectional study was carried out. In fresh frozen cadavers, with microstrain devices and Vernier calipers, strain and excursion in the tibial nerve and distal biceps femoris muscle were measured during ankle dorsiflexion at 0°, 30°, 60° and 90° of hip flexion of the straight leg raise.

FINDINGS

Ankle dorsiflexion resulted in significant distal excursion and increased strain in the tibial nerve (p < 0.05) whilst the muscle was not affected by the dorsiflexion (p > 0.05) at all hip flexion angles.

INTERPRETATION

Ankle dorsiflexion was mechanically specific between the tibial nerve and biceps femoris during the straight leg raise. This study adds to evidence that, in certain circumstances, dorsiflexion may be used in differentiation of nerve and muscle disorders in the posterior knee.

Obturator to tibial nerve transfer via saphenous nerve graft for treatment of sacral plexus root avulsions: A cadaveric study

INTRODUCTION

In cases of sacral nerve avulsion injuries, proximal nerve stumps are not available because of its protected position in pelvis, and results of nerve repair or graft are unsatisfactory. Nerve transfer can reduce the regeneration time and improve the results of recovery.

HYPOTHESIS

The obturator nerve transfer to the tibial nerve via saphenous nerve graft is possible and feasible.

MATERIALS AND METHODS

Ten male adult cadaveric lower limbs dissected to identify the location of the anterior branch of obturator nerve, the saphenous nerve and the medial gastrocnemius branch. The saphenous nerve was cut from its origin and transferred to the anterior branch of obturator nerve. As well, it was cut distally and transferred to the medial gastrocnemius branch. After nerve coaptation, surface area and fascicle count were determined by histological methods.

RESULTS

In all limbs, the proximal and distal stumps of saphenous nerve were reached the anterior branch of obturator and the medial gastrocnemius branch, respectively without tension. The mean of fascicle number in the anterior branch of obturator nerve, proximal and distal stump of the saphenous nerve and stump of medial gastrocnemius nerve branch were 2.90±0.99, 4.50±2.70, 4.00±2.26 and 4.30±1.25, respectively.

DISCUSSION

This study showed that it is possible to transfer the obturator nerve to the medial gastrocnemius branch via saphenous nerve bridge; and their histological parameters are match in a good manner. Therefore, this technique is suggested for patients with sacral nerve avulsion injuries.

LEVEL OF EVIDENCE

IV, case series of cadaveric study.

Different electrode positioning for transcutaneous electrical nerve stimulation in the treatment of urgency in women: a study protocol for a randomized controlled clinical trial

BACKGROUND

Urgency is a complaint of sudden, compelling desire to pass urine, which is difficult to defer, caused by involuntary contraction of the detrusor muscle during the bladder-filling stage. To enable detrusor inhibition, electrotherapy resources such as transcutaneous tibial nerve stimulation (TTNS) and parasacral transcutaneous electrical stimulation (PTES) have been used. The objective this study is to publish the study protocol that aims to investigate whether urgency decreases after treatment with both of the techniques.

METHODS

This randomized controlled clinical trial will include 99 women, aged more than 18 years old, with urgency (score ≥ 8 in the Overactive Bladder-Validated 8-Question Awareness Tool [OAB-V8]). Women will be randomly allocated into three groups: TTNS, PTES, and placebo. The following questionnaires will be applied: the Anamnesis Record, the Incontinence Questionnaire Overactive Bladder, the King's Health Questionnaire, the 24-Hour Voiding Diary, and the OAB-V8, at four different time points: at baseline prior to the first session, at the 6th session, the 12th session and at follow-up. The current used for the transcutaneous electrical stimulation will be a symmetrical balanced biphasic pulsed current, for 12 sessions, twice a week, for 20 minutes. Qualitative variables will be displayed as frequency and percentage, quantitative variables as mean and standard deviation. Comparison of urgency severity among groups will be performed with a repeated measures ANOVA, considering the effect of the three groups and the four evaluations, and interactions among them.

DISCUSSION

The present study aims to contribute evidence for a more in-depth discussion on electrode positioning for electrostimulation used in urgency treatment. It should be emphasized that, based on the possibility of confirming the hypothesis that urgency will decrease in a similar way after both treatments (TTNS and PTES), the PTES will be used as an option for positioning the electrodes alternatively to the tibial nerve region in special populations, such as amputees or people with severe lower limb sensory impairment.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials (ReBEC) ID: RBR-9rf33n, date of registration: 17 May 2018.

Results of ultrasound-guided release of tarsal tunnel syndrome: a review of 81 cases with a minimum follow-up of 18 months

Background

This study aims to analyse the clinical results of ultrasound-guided surgery for the decompression of the tibial nerve, including its distal medial and lateral branches, to treat tarsal tunnel syndrome. These structures are the complete flexor retinaculum and the deep fascia of the abductor hallucis muscle, including individualised release of the medial and lateral plantar nerve tunnels.

Method

This is a retrospective review of 81 patients (36 men and 45 women) with an average age of 41 years old (32–62) and an average clinical course of 31 months (8–96) compatible with idiopathic tarsal tunnel syndrome, who underwent ultrasound-guided decompression of the proximal and distal tarsal tunnel between February 2015 and November 2017 (both months included), with a minimum follow-up of 18 months.

Results

Based on the Takakura et al. scale for the 81 patients, 76.54% obtained excellent results, 13.58% good results, and 9.87% poor results.

The patients with the longest course of symptoms displayed the worst results.

Conclusion

Although 9% of patients did not improve, ultrasound-guided tarsal tunnel release might be a viable alternative to conventional open approaches.

[Percutaneous posterior tibial nerve electrostimulation in urge urinary incontinence and faecal incontinence]

OBJECTIVE

The main aim of this study was to assess the efficacy of percutaneous posterior tibial nerve electrostimulation (P-PTNS) in urge urinary incontinence (UUI) and faecal incontinence (FI) refractory to first-line treatment. A secondary aim was to identify predictors of treatment response. To do this, we performed a 2-year analytical, longitudinal and prospective study in patients with UUI and FI treated with P-PTNS.

MATERIAL AND METHODS

We included patients with UUI and FI who were treated with P-PTNS and who completed the bladder/faecal incontinence diary and severity and quality of life questionnaires. We excluded patients with neurogenic UUI and those who abandoned treatment or did not complete the questionnaires. We assessed demographic and clinical variables (micturition/defecation habits pre- and postreatment), severity scales before and after treatment (ICIQ-SF, Sandvick and Wexner), subjective improvement and quality of life (IQOL and FIQL pre- and postreatment). The statistical analysis was conducted using SPSS v19.

RESULTS

The sample consisted of 21 patients divided into 2 groups: -UUI group, 9 patients. After P-PTNS, there was a statistically significant improvement in diurnal (p=.018) and nocturnal (p=.016) urinary frequency, urgencies/day (p=.018), urine leakage/day (p=.027), ICIQ-SF and Sandvick (p=.018), and IQOL (p=.012). This improvement was related to exercise (p=.039) and prolapse (p=.05). -Group FI, 12 patients. After P-PTNS, there was a statistically significant improvement in defecation frequency (p=.027), incontinence (p=.012), Wexner scale (p=.007), and FIQL in its 4 dimensions (lifestyle, behaviour, embarrassment p=.005; and depression p=.008). This improvement was related to age (p=.048), time since onset (p=.044) and prolapse (p=.026).

CONCLUSIONS

The P-PTNS is effective in UUI and FI refractory to conventional treatment. Treatment response is affected by several factors.

Extrinsic compression neuropathy of the tibial nerve secondary to accessory soleus muscle in a young teenager

Compression neuropathy of the tibial nerve or one of its terminal branches (tarsal tunnel syndrome) is relatively uncommon. Accessory musculature on the posteromedial aspect of the ankle is a rare extrinsic cause of compression. Therefore, it should be considered in patients with prolonged manifestations of tibial nerve compression. A detailed history and physical examination, together with proper radiological evaluation, allow for accurate diagnosis. In this case report, a 13-year old female teenager on history, physical examination, and imaging studies was diagnosed as compression neuropathy of the tibial nerve secondary to accessory soleus muscle. After surgical excision of the accessory soleus muscle with no tarsal tunnel release, the patient presented with complete resolution of her manifestations continued free of symptoms for one and half year postoperatively. The accessory soleus muscle is a potential extrinsic cause for tibial nerve compression neuropathy.

LEVEL OF CLINICAL EVIDENCE

5.

A study protocol on nerve mobilization induced diffusion tensor imaging values in posterior tibial nerve in healthy controls and in patients with diabetic neuropathy-multigroup pretest posttest design

Background

Diabetic neuropathy is the commonest chronic disabling complication of diabetes which may lead to amputation and compromising patient’s quality of life. It is characterized by pain, sensation loss associated with neural edema. Diffusion tensor imaging parameter i.e. fraction anisotropy determines the free water proton diffusion in the healthy nerve. Since the diabetes leads to altered mechanosensitivity of the posterior tibial nerve thereby, might interferes with the water molecules movement. Therefore the present clinical trial will provide the evidence of improving the diffusion tensor imaging in the diabetic neuropathy directly by targeting the nerve through nerve mobilization treatment.

Methods

Participants with Type II Diabetes Mellitus induced peripheral neuropathy will be selected randomly on the basis of eligibility criteria and informed consent will be taken. Participants will be recruited into three groups. Group A (experimental group A) will receive neural mobilization technique, Group B (experimental group B) will receive conventional therapy and Group C (control group) will receive sham treatment for 3 weeks. MRI technique, Visual analogue scale and neuropathy specific quality of life questionnaire will be used as assessment tools. Assessment will be taken at baseline and post intervention.

Conclusion

this clinical trial will provide the evidence of efficacy of nerve mobilization in determining the diffusion tensor imaging (DTI) changes in the posterior tibial nerve in patients with diabetic neuropathy. This trial will also be the first one in itself to look at the treatment induced DTI changes in the peripheral nerve.

Trial Registration

Clinical Trial Registry of India (CTRI/2019/06/019552).