A novel animal model of symptomatic neuroma for assessing neuropathic pain.

INTRODUCTION: Following amputation, peripheral nerves lack distal targets for regeneration, often resulting in symptomatic neuromas and debilitating neuropathic pain. Animal models can establish a practical method for symptomatic neuroma formation for better understanding of neuropathic pain pathophysiology through behavioral and histological assessments. We created a clinically translatable animal model of symptomatic neuroma to mimic neuropathic pain in patients and assess sexual differences in pain behaviors. METHODS: Twenty-two male and female rats were randomly assigned to one of two experimental groups: (1) neuroma surgery, or (2) sham surgery. For the neuroma experimental group, the tibial nerve was transected in the thigh, and the proximal segment was placed under the skin for mechanical testing at the site of neuroma. For the sham surgery, rats underwent tibial nerve isolation without transection. Behavioral testing consisted of neuroma-site pain, mechanical allodynia, cold allodynia, and thermal hyperalgesia at baseline, and then weekly over 8 weeks. RESULTS: Male and female neuroma rats demonstrated significantly higher neuroma-site pain response compared to sham groups starting at weeks 3 and 4, indicating symptomatic neuroma formation. Weekly assessment of mechanical and cold allodynia among neuroma groups showed a significant difference in pain behavior compared to sham groups (p < 0.001). Overall, males and females did not display significant differences in their pain responses. Histology revealed a characteristic neuroma bulb at week 8, including disorganized axons, fibrotic tissue, Schwann cell displacement, and immune cell infiltration. CONCLUSION: This novel animal model is a useful tool to investigate underlying mechanisms of neuroma formation and neuropathic pain.

Tibial nerve compression due to osteochondroma of the fibular head: A case report.

RATIONALE: Osteochondroma is one of the most common primary benign bone tumors. In most cases, this disease is asymptomatic. However, it may become symptomatic owing to nerve and vascular compression when it affects the knee joint. Isolated tibial nerve palsy caused by proximal fibular osteochondroma is rare. PATIENTS CONCERNS: A 60-year-old male, was treated for degenerative arthritis of the right knee, referred to the right great toe flexion limitation that occurred 3 weeks prior. DIAGNOSES: Magnetic resonance imaging revealed compression of the tibial nerve and surrounding muscles due to an osseous lesion in the fibular head. A nerve conduction test confirmed tibial neuropathy in the right lower leg. INTERVENTIONS: Exploratory surgery was performed to decompress the tibial nerve and remove the bony lesion histopathologically diagnosed as an osteochondroma. OUTCOMES: Fifty-five months postoperatively, toe flexion recovered to normal. No recurrence of osteochondroma was observed. LESSONS: As in our case, if a bony lesion is diagnosed on radiographs with neurological symptoms, early decompression surgery is necessary. Moreover, since it can be misdiagnosed as a simple bony spur, magnetic resonance imaging and tissue biopsy are also indicated.

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 sign¼ allowed establishing an adequate preoperative diagnosis, differentiating it from an extraneural lesion and facilitating the articular disconnection of the nerve branch during surgery.

Neuromucormycosis of Posterior Tibial Nerve: A Rare Presentation of Mucormycosis.

Opportunistic fungal infections are known to occur in immunocompromised patients. Mucormycosis is one of the most common opportunistic fungal infections with significant mortality rates. In this article, we present a case of an adult female, a known diabetic who presented with fever and pus discharge from the amputation site of toes in the left foot with blackening of the foot. Examination revealed gangrenous changes of the left foot with no distal pulses palpable. Computed tomography angiogram revealed no flow of blood in distal vessels of the left lower limb. Left below knee guillotine amputation was done. Intraoperative biopsy of the neurovascular bundle revealed invasive neuromucormycosis. She was started on liposomal amphotericin B. The wound started granulating after a few days with serial dressings and the patient was planned for split skin grafting.

Electrical stimulation or tacrolimus (FK506) alone enhances nerve regeneration and recovery after nerve surgery, while dual use reduces variance and combines strengths of each in promoting enhanced outcomes.

INTRODUCTION/AIMS: Repaired nerve injuries can fail to achieve functional recovery. Therapeutic options beyond surgery, such as systemic tacrolimus (FK506) and electrical stimulation (E-stim), can improve recovery. We tested whether dual administration of FK506 and E-stim enhances regeneration and recovery more than either therapeutic alone. METHODS: Rats were randomized to four groups: E-stim, FK506, FK506 + E-stim, and repair alone. All groups underwent tibial nerve transection and repair. Two sets of animals were created to measure outcomes of early nerve regeneration using nerve histology (n = 36) and functional recovery (n = 42) (21- and 42-day endpoints, respectively). Functional recovery was measured by behavioral analyses (walking track and grid walk) and, at the endpoint, muscle mass and force. RESULTS: Dual E-stim and FK506 administration produced histomorphometric measurements of nerve regeneration no different than either therapeutic alone. All treatments were superior to repair alone (FK506, P < .0001; E-stim, P < .05; FK506 + E-stim, P < .05). The E-stim and FK506 + E-stim groups had improved behavioral recovery compared with repair alone (at 6 weeks: E-stim, P < .05; FK506 + E-stim, P < .01). The FK506 group had improved recovery based on walking-track analysis (at 6 weeks: P < .001) and muscle force and mass (P < .05). The concurrent use of both therapies ensured earlier functional recovery and decreased variability in functional outcomes compared with either therapy alone, suggesting a moderate benefit. DISCUSSION: Dual administration of FK506 and E-stim showed minimal additive effects to further improve regeneration or recovery compared with either therapy alone. The data suggest the combination of FK506 and E-stim appears to combine the relative strengths of each therapeutic.

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.

Preoperative Imaging of Intraneural Ganglion Cysts: A Critical Systematic Analysis of the World Literature.

BACKGROUND: Advancements in imaging and an understanding of the pathomechanism for intraneural ganglion cyst formation have led to increased awareness and recognition of this lesion. However, the precise role of imaging has been advocated for but not formally evaluated. METHODS: We performed a systematic review of the world literature to study the frequency of imaging used to diagnose intraneural ganglion cysts at different sites and compared trends in identifying joint connections. RESULTS: We identified 941 cases of intraneural ganglion cysts, of which 673 had published imaging. Magnetic resonance imaging (MRI, n = 527) and ultrasonography (US, n = 123) were the most commonly reported. They occurred most frequently in the common peroneal nerve (n = 570), followed by the ulnar nerve at the elbow (n = 88), and the tibial nerve at the ankle (n = 58). A joint connection was identified in 375 cases (48%), with 62% of MRIs showing a joint connection, followed by 16% on US, and 6% on computed tomography (CT). MRI was statistically more likely to identify a joint connection than was US (P < 0.01). In the last decade, joint connections have been identified with increasing frequency using preoperative imaging, with up to 75% of cases reporting joint connections. CONCLUSIONS: Preoperative imaging plays an important role in establishing the diagnosis of intraneural ganglion cyst as well as treatment planning. Imaging has proved superior to the sole reliance of operative exposure to identify a joint connection, which is necessary to treat the underlying disease. Failure to identify cyst connections on imaging can result in an inability to truly address the underlying pathoanatomy at the time of definitive surgery, leading to a risk for clinical recurrence. Therefore, management should be guided by an intersection between new knowledge presented in the literature, clinical expertise, and surgeon experience.

Predictive factors of effective tibial nerve release in tarsal tunnel syndrome.

BACKGROUND: Factors that may affect surgical decompression results in tarsal tunnel syndrome are not known. METHODS: A retrospective single-center study included patients who had undergone surgical tibial nerve release. The effectiveness of decompression was evaluated according to whether the patient would or would not be willing to undergo another surgical procedure in similar preoperative circumstances. RESULTS: The patients stated for 43 feet (51%) that they would agree to a further procedure in similar circumstances. Six feet with space-occupying lesions on imaging had improved results, but neurolysis failed in 9 feet with bone-nerve contact. Neurolysis was significantly less effective when marked hindfoot valgus (p = 0.034), varus (p = 0.014), or fasciitis (p = 0.019) were present. CONCLUSIONS: If imaging reveals a compressive space-occupying lesion, surgery has a good prognosis. In feet with static hindfoot disorders or plantar fasciitis, conservative treatment must be optimized. Bone-nerve contact should systematically be sought.

A Minimally Invasive Full Endoscopic Approach to Tibial Nerve Neurolysis in Diabetic Foot Neuropathy: An Alternative to Open Procedures.

BACKGROUND: Dellon et al. have reported that chronic nerve compression of the tibial nerve inside the tarsal tunnel, caused by diabetes mellitus, can be relieved following open decompression surgery. However, the large skin incision resulting from Dellon's procedure may cause wound healing problems. The authors report the possibility of a minimally invasive full endoscopic procedure. METHODS: Operations were performed under local anesthesia without a pneumatic tourniquet. An anesthetic agent was applied at the proximal part of the flexor retinaculum of the foot, and a hypodermic needle was advanced into the tarsal tunnel. Tarsal tunnel pressure and blood circulation of the tibial nerve using indocyanine green assessment were measured preoperatively. One 1-cm portal skin incision was made at the anesthetized area and the Universal Subcutaneous Endoscope system was inserted into the tarsal tunnel. The flexor retinaculum, tibial nerve, blood vessels, and abductor hallucis muscle fascia were identified under endoscopic observation. After decompression of the tarsal tunnel, the authors measured tarsal tunnel pressure and blood circulation of the tibial nerve for analysis of the effectiveness of the endoscopic decompression during the procedure. RESULTS: Fourteen operations were compiled and analyzed. Postoperative clinical status was improved based on the preoperative modified Toronto Clinical Neuropathy Score. The mean tarsal tunnel pressure dropped to 4.5 mmHg during surgery from the initial preoperative 49.4 mmHg in resting position. Endoscopic indocyanine green assessment showed more than 30 percent improvement of the vascularity surrounding the tibial nerve. CONCLUSION: The authors' minimally invasive full endoscopic procedure is a viable alternative approach for tarsal tunnel syndrome patients with diabetic foot neuropathy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Outcome following neurectomy of the deep branch lateral plantar nerve and plantar fasciotomy for hindlimb proximal suspensory desmopathy in western performance horses: 21 cases.

OBJECTIVE: To report the outcome of horses used in western performance disciplines after deep branch lateral plantar neurectomy/fasciotomy surgery for hind limb proximal suspensory desmopathy (PSD). STUDY DESIGN: Retrospective analysis. SAMPLE POPULATION: Twenty-one client-owned horses. METHODS: Medical records were reviewed (2009-2019) for horses involved in western performance disciplines that had been treated with deep branch lateral plantar neurectomy and plantar fasciotomy for lameness due to hind limb PSD. Follow-up was obtained by reexamination and/or verbal interviews with owners >2 years postoperatively. RESULTS: Sixteen quarter horses and five paints were used for western pleasure (14/21), barrel racing (2/21), cutting (1/21), steer wrestling (1/21), working cow horse (1/21), team roping (1/21) and reining (1/21). A median duration of 8 months was required before horses were able to resume training or athletic work. Nine horses were able to return to a similar or higher level of athletic use, nine horses returned to a lower level of athletic performance, and three horses could not return to intended function. Owner satisfaction with outcome after the procedure was high (16/21), average (3/21), and low (2/21). CONCLUSION: Deep branch lateral plantar neurectomy and plantar fasciotomy allowed most horses to resume some athletic function as western performance horses. CLINICAL SIGNIFICANCE: These results provide evidence of potential outcomes when considering surgical treatment of hind limb PSD in western performance horses.

Unrecognized tibial nerve injury in total-ankle arthroplasty: Two case reports.

RATIONALE: Tibial nerve injury is a sustainable but rare complication during total-ankle arthroplasty (TAA). We outlined 2 previously unreported cases of tibial nerve injury in TAA, including the prognoses and possible causes. PATIENT CONCERNS: First, a 63-year-old woman complained of a 5-month history of persistent tingling sensation and numbness on the medial and plantar aspects of her foot after TAA. Second, a 50-year-old woman complained of a 6-month history of tingling sensation and numbness on the plantar surface of her forefoot after TAA. DIAGNOSIS: Explorations were performed on suspicion of tarsal tunnel syndrome; however, both patients exhibited complete laceration of tibial nerve with neuroma formation. INTERVENTIONS: In both patients, we excised the neuroma and performed end-to-end nerve repair. OUTCOMES: The sensory disturbance of the sole considerably improved at long-term follow-up over 8 years after the neurorrhaphy procedures. LESSONS: Tibial nerve injury is rare following TAA, and is sometimes unrecognized or misdiagnosed. If tibial nerve injury is suspected, prompt surgical exploration should be performed; great precaution must also be taken to prevent injury of the tibial nerve during TAA.

Viral vector delivery of follistatin enhances recovery of reinnervated muscle.

INTRODUCTION: Poor recovery following nerve repair is due to progressive temporal loss of muscle function. Follistatin (FS), a glycoprotein with anabolic properties, may enhance muscle recovery following reinnervation. METHODS: Seventy-two male Sprague-Dawley rats underwent temporary (3 or 6 month) denervation or sham denervation. After reinnervation, rats were administered adeno-associated viral vectors expressing FS deoxyribonucleic acid (isoform FS-317) injected into the target muscle or sham treatment. Final assessment included muscle function testing, muscle histomorphology, nerve histomorphology, and FS protein quantification. RESULTS: FS improved muscle mass and type IIB muscle fiber size, and increased G-ratios and mean axon diameter in the 6-month temporary denervation group (P < .05). Elevated FS protein levels were detected in treated muscle (P < .05). FS increased satellite cell counts following temporary denervation and repair (P < .05). DISCUSSION: FS treatment had anabolic, neurotrophic, and satellite cell stimulatory effects when administered following prolonged (6-month) temporary denervation and repair.

[A meta-analysis of the effect of occupational exposure to 1-bromopropane on workers' nerve conduction velocity].

Objective: To analysis the occupational exposure to 1-bromopropane on the worker's nerve conduc-tion velocity. Methods: To PubMed, Wanfang, VIP, Chinese Journal Full-text Database (CNKI) and other databases as a data source, searched and screened database to October 2017 on occupational exposure to 1-bromopropane workers on the role of nerve conduction in the paper. According to inclusion and exclusion criteria, we screened literatures, extracted data and evaluated the quality of the included studies, using RevMan5.3 software to test the heterogeneity of the results and us-ing the corresponding mathematical model for data combination analysis. Results: A total of 5 articles were included in the literature. The results showed that the tibial nerve MCV of workers in the 1-bromopropane exposure group was slower than that in the control group (SMD=-0.47,95%CI=-0.70~-0.24) , the difference was statistically significant (Z=4.06, P<0.01). The tibial nerve DL of the exposure group was more prolonged than that of the control group (SMD=0.35,95%CI=0.00~0.69) , with a statistically significant difference (Z=1.99, P=0.05). The sural nerve SCV of the exposure group was slower than that of the control group (SMD=-0.47, 95%CI=-0.78~-0.15), with a statistically significant difference (Z=2.88,P<0.01). Conclusion: Occupational exposure to 1-bromopropane may have an effect on the worker's nerve conduction ve-locity.It's necessary to do broader and deeper neurotoxicity studies about 1-bromopropane.

Tarsal tunnel syndrome caused by an uncommon ossicle of the talus: A case report.

RATIONALE: Tarsal tunnel syndrome (TTS) is a compressive neuropathy of the posterior tibial nerve or one of its branches within the tarsal tunnel that is often caused by a variety of space-occupying lesions, such as ganglia, lipomas, varicosities, neural tumors, trauma, or systemic disease. The os sustentaculi is a small accessory bone, bridged to the posterior aspect of the sustentaculum tali by fibrocartilage. To the best of our knowledge, this is a rare case of successful treatment of TTS caused by the os sustantaculi. PATIENT CONCERNS: A 37-year-old male presented with insidious onset of right ankle and foot pain for 1 year. He also complained of a tingling sensation and paresthesia from the plantar and medial aspect of the forefoot to the middle foot area along the main distribution of the medial plantar nerve. The symptoms were mild at rest, but increased upon prolonged walking. He had an ankle sprain history during a football game 2 years previously and recurrent ankle sprains had occurred more frequently in this ankle since that trauma. DIAGNOSES: Plain standing anteroposterior and lateral view radiographic findings of the right ankle reveled an accessory ossicle located posterosuperomedial to the sustentaculum tali. A computed tomography scan showed that the ossicle articulated between the talus and calcaneus. A magnetic resonance image revealed mild bone marrow edema in the ossicle and medial displacement of the tarsal structures. INTERVENTIONS: Surgery was performed under general anesthesia. The ossicle was delineated from its surrounding structures and was removed. Tension on the nerve was released. OUTCOMES: The patient's pain and hypoesthesia were immediately relieved, and the tingling sensation disappeared 6 months after surgery. The patient had no complications or recurrence of symptoms at the 1-year follow-up.

Transthyretin amyloid polyneuropathies mimicking a demyelinating polyneuropathy.

OBJECTIVE: To clearly define transthyretin familial amyloid polyneuropathies (TTR-FAPs) fulfilling definite clinical and electrophysiologic European Federation of Neurological Societies/Peripheral Nerve Society criteria for chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: From a cohort of 194 patients with FAP, 13 of 84 patients (15%) of French ancestry had late-onset demyelinating TTR-FAP. We compared clinical presentation and electrophysiology to a cohort with CIDP and POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes) syndrome. We assessed nerve histology and the correlation between motor/sensory amplitudes/velocities. Predictors of demyelinating TTR-FAP were identified from clinical and electrophysiologic data. RESULTS: Pain, dysautonomia, small fiber sensory loss above the wrists, upper limb weakness, and absence of ataxia were predictors of demyelinating TTR-FAP (p < 0.01). The most frequent demyelinating features were prolonged distal motor latency of the median nerve and reduced sensory conduction velocity of the median and ulnar nerves. Motor axonal loss was severe and frequent in the median, ulnar, and tibial nerves (p < 0.05) in demyelinating FAP. Ulnar nerve motor amplitude <5.4 mV and sural nerve amplitude <3.95 µV were distinguishing characteristics of demyelinating TTR-FAP. Nerve biopsy showed severe axonal loss and occasional segmental demyelination-remyelination. CONCLUSION: Misleading features of TTR-FAP fulfilling criteria for CIDP are not uncommon in sporadic late-onset TTR-FAP, which highlights the limits of European Federation of Neurological Societies/Peripheral Nerve Society criteria. Specific clinical aspects and marked electrophysiologic axonal loss are red flag symptoms that should alert to this diagnosis and prompt TTR gene sequencing.

Tarsal Tunnel Syndrome Caused by a Schwannoma of the Posterior Tibial Nerve.

Schwannoma is the most common tumor of the peripheral nerve sheath. However, there have been few reports on schwannoma of the posterior tibial nerve causing tarsal tunnel syndrome. We report on a 60-year-old man with tarsal tunnel syndrome caused by a schwannoma of the posterior tibial nerve, which was first diagnosed as a ganglion cyst. After enucleation of this tumor, the patient was asymptomatic and had no related sequelae except for minor numbness in the plantar aspects of his digits. Although schwannoma of the posterior tibial nerve is rare, it should be considered even if a ganglion is clinically suspected.

Posterior Tibial Nerve Lymphoma Presenting as Tarsal Tunnel Syndrome: A Case Report.

We report a case of isolated posterior tibial B-cell lymphoma of the posterior tibial nerve presenting as tarsal tunnel syndrome. This diagnosis was considered because of the clinical presentation and electrophysiologic abnormalities. It was further confirmed by the magnetic resonance imaging findings of the ankle and tissue pathologic findings. Whole body positron emission tomography confirmed this to be a localized lymphoma involving the peripheral nerve. The patient underwent chemotherapy with complete tumor resolution. She had had no relapse after 8 months of follow-up. Isolated peripheral nerve lymphomas are very rare, and involvement of the posterior tibial nerve has not been previously reported. Furthermore, the present case report highlights the importance of the clinical examination in the diagnosis of tarsal tunnel syndrome before performing surgical decompression.

Antiallodynic Effects of Endomorphin-1 and Endomorphin-2 in the Spared Nerve Injury Model of Neuropathic Pain in Mice.

BACKGROUND: The spared nerve injury (SNI) model is a new animal model that can mimic several characteristics of clinical neuropathic pain. Opioids are recommended as treatment of neuropathic pain. Therefore, the present study was conducted to investigate the antinociceptive effects of endomorphin-1 (EM-1) and endomorphin-2 (EM-2) given centrally and peripherally in the SNI model of neuropathic pain in mice. METHODS: The SNI model was made in mice by sparing the sural nerve intact, when the other 2 of 3 terminal branches of the sciatic nerve (common peroneal and tibial nerves) were tightly ligated and cut. Von Frey monofilaments were used to measure the SNI-induced mechanical allodynia-like behavior. The antiallodynic effects of EM-1 and EM-2 were determined after central and peripheral administration in the SNI model of neuropathic pain. Also, the specific opioid receptor antagonists were used to determine the opioid mechanisms of EMs involved in neuropathic pain. Values were expressed as the mean ± standard deviation. RESULTS: Our results showed that the SNI mice developed prolonged mechanical allodynia-like behavior in ipsilateral paw after surgery, with the withdrawal threshold value being 0.061 ± 0.02 g after 14 days. EM-1 and EM-2 produced significant antiallodynic effects in ipsilateral paw after intracerebroventricular (i.c.v.) administration, more effective than that of morphine. The peak withdrawal thresholds of 10 nmol EM-1 and EM-2 determined at 5 minutes after injection were 0.92 ± 0.36 and 0.87 ± 0.33 g, respectively, higher than that of morphine (0.46 ± 0.20 g). Moreover, both EMs (10 nmol, i.c.v.) exerted significant antiallodynic effects in the contralateral paw, whereas no significant antinociceptive activity was seen after i.c.v. administration of morphine with equimolar dose. It was noteworthy that EM-1 and EM-2 produced antinociception through distinct µ1- and µ2-opioid receptor subtypes, and the EM-2-induced antiallodynia contained an additional component that was mediated by the release of endogenous dynorphin A, acting on κ-opioid receptor. In addition, the antiallodynic activities of peripheral administration of EM-1, EM-2, and morphine were also investigated. Intraplantar, but not subcutaneous administration of EM-1 and EM-2 also exhibited potent antinociception, establishing the peripheral and local effects. Both µ1- and µ2-opioid receptor subtypes, but not the δ- or κ-opioid receptors were involved in the peripheral antiallodynia of EMs. CONCLUSIONS: The present investigation demonstrated that both EM-1 and EM-2 given centrally and peripherally produced potent antiallodynic activities in SNI mice, and differential opioid mechanisms were involved.

Cystic degeneration of the tibial nerve: magnetic resonance neurography and sonography appearances of an intraneural ganglion cyst.

Extra- and intraneural ganglion cysts have been described in the literature. The tibial nerve ganglion is uncommon and its occurrence without intra-articular extension is atypical. The pathogenesis of cystic degeneration localized to connective and perineural tissue secondary to chronic mechanical irritation or idiopathic mucoid degeneration is hypothesized. Since the above pathology is extremely rare and the magnetic resonance imaging examination detects the defining characteristics of the intrinsic alterations of the tibial nerve, the authors illustrate such a case of tibial intaneural ganglion cyst with its magnetic resonance neurography and sonography appearances.

Schwannoma and neurofibroma of the posterior tibial nerve presenting as tarsal tunnel syndrome: review of the literature with two case reports.

We present two case reports of peripheral nerve tumors (schwannoma and neurofibroma) that presented as tarsal tunnel syndrome for many years. There has never been a report of multiple neurofibroma of the posterior tibial nerve presenting as a tarsal tunnel syndrome. Both patients were treated surgically with good outcomes.