Shear wave elastography of tibial nerve in patients with diabetic peripheral neuropathy-A cross-sectional study.

OBJECTIVE: To explore the role of shear wave elastography of the tibial nerve as a potential ultrasonographic method for the diagnosis of tibial neuropathy in patients with type 2 diabetes. MATERIALS AND METHODS: This cross-sectional study included 50 subjects each in case (patients with diabetic tibial neuropathy diagnosed on the basis of clinical features and nerve conduction study) and control groups (non-diabetic non-neuropathic healthy volunteers). The exclusion criteria included the presence of type 1 diabetes, a known history of neuropathy from other causes except for type 2 diabetes, or a history of leg or ankle fracture. Cross-sectional area and shear wave velocity values of the tibial nerve were measured in both groups. Demographic details and body mass index were obtained in both groups and additionally, the duration of type 2 diabetes and HbA1c values in the case group were also noted. Wilcoxon Mann-Whitney U test was used to compare these variables in study groups. ROC curve analysis provided additional findings. RESULTS: Tibial nerve stiffness was significantly higher in the case group (p-value < 0.001). The study groups did not significantly differ in the Cross-sectional area of the tibial nerve (p-value 0.57). The case group exhibited a higher frequency of loss of the fascicular pattern of the tibial nerve (40% vs 18%, p-value 0.027). Duration of diabetes mellitus and HbA1c values did not significantly affect Shear wave velocity values in the case group. At the cut-off value of Shear wave velocity of 3.13 m/s, sensitivity and specificity to diagnose diabetic peripheral neuropathy were 94% and 88% respectively. CONCLUSION: Increased nerve stiffness is seen in patients with diabetic peripheral neuropathy. Shear wave elastography might prove as a novel noninvasive technology for screening/early diagnosis of diabetic peripheral neuropathy.

Diagnostic Approach to Lower Limb Entrapment Neuropathies: A Narrative Literature Review.

Entrapment neuropathies of the lower limb are a misunderstood and underdiagnosed group of disorders, characterized by pain and dysesthesia, muscular weakness, and specific provoking movements on physical examination. The most frequent of these syndromes encountered in clinical practice are fibular nerve entrapment, proximal tibial neuropathy, sural nerve neuropathy, deep gluteal syndrome or sciatic nerve entrapment, and lateral femoral cutaneous nerve entrapment, also known as meralgia paresthetica. These are commonly mistaken for lumbar plexopathies, radiculopathies, and musculotendinous diseases, which appear even more frequently and have overlapping clinical presentations. A comprehensive anamnesis, physical examination, and electrodiagnostic studies should help clarify the diagnosis. If the diagnosis is still unclear or a secondary cause of entrapment is suspected, magnetic resonance neurography, MRI, or ultrasonography should be conducted to clarify the etiology, rule out other diseases, and confirm the diagnosis. The aim of this narrative review was to help clinicians gain familiarity with this disease, with an increase in diagnostic confidence, leading to early diagnosis of nerve damage and prevention of muscle atrophy. We reviewed the epidemiology, anatomy, pathophysiology, etiology, clinical presentation, and EDX technique and interpretation of the entrapment neuropathies of the lower limb, using articles published from 1970 to 2022 included in the Pubmed, MEDLINE, Cochrane Library, Google Scholar, EMBASE, Web of Science, and Scopus databases.

The portrait of a stranger: the hypereosinophilic syndrome with cardiac involvement.

INTRODUCTION: Hypereosinophilic syndrome is a rare clinical condition, and cardiac involvement confers a poor prognosis. Hypereosinophilic myocarditis is a medical emergency and targeted treatment should be started promptly even before a definitive diagnosis could be made. CASE PRESENTATION: A 27-year-old female patient is hospitalized for exertional dyspnea, chest pain, and fatigue for the past 2 weeks. She also describes left leg paresthesias. Clinical examination was in normal limits. ECG showed sinus tachycardia, QS pattern in V1-V4, and diffuse flattened T waves. Laboratory tests revealed increased inflammatory markers, hypereosinophilia, elevated cardiac enzymes, high NT-proBNP. Echocardiography revealed LV dysfunction (EF 31%), while cardiac MRI showed diffuse delayed enhancement with predominant subendocardial disposition. The electromyogram was suggestive of left tibial nerve neuropathy. We interpreted the case as eosinophilic myocarditis with an urgent requirement of therapy and initiated high-dose glucocorticoid therapy and the GDMT 4-pillar heart failure treatment. We excluded common infectious, myeloproliferative syndromes, and frequent associated autoimmune diseases. With prednisone, the eosinophil count rapidly normalized and we gradually tapered the dose by 5 mg per week, however continuing with heart failure therapy. At monthly follow-up visits, there was a significant clinical improvement, with normalization of the eosinophilic count, and a near-normalization of myocardial function. The only symptom that persisted was paresthesias linked to left tibial neuropathy. CONCLUSION: The surprisingly rapid and favorable course of the disease offers a high index of suspicion for a toxic or a reactive transitory etiology, however still unidentified. In our case, the cause of eosinophilia remained unknown, although we managed to narrow down the possible etiologies. A surprisingly good clinical response was obtained with non-specific treatment targeting mainly hyperosinophilic myocarditis.

Vascular entrapment neuropathy of the tibial nerve within the gastrocnemius muscle.

BACKGROUND: Vascular compression is an extremely rare cause of mononeuropathy and compression of selective tibial nerve branches is an additionally a rare finding and makes diagnosis difficult. CASE DESCRIPTION: Here within, we describe the case of a 41-year-old male who presented with isolated mononeuropathy of the medial gastrocnemius (MG) branch of the tibial nerve presented as persistent fasciculations and atrophy. After electromyography and clinical evaluation, surgical exploration was recommended. A vascular bundle was found to be compressing the MG branch of the tibial nerve and thus was ligated to decompress the nerve. Postoperatively, all fasciculations improved and muscle atrophied improved. CONCLUSION: Vascular compression resulting in mononeuropathy of the peripheral nerves is a rare clinical entity. Clinicians should include these etiologies on their differential when considering surgical exploration of mononeuropathies.

Can the axial cross-sectional area of the tibial nerve be used to diagnose tarsal tunnel syndrome? An ultrasonography study.

INTRODUCTION: The axial cross-sectional area (CSA) of the tibial nerve can be measured with ultrasonography. In patients who have posteromedial tarsal tunnel syndrome (TTS), there is little information on the nerve's CSA even though this information could be useful for determining whether the nerve is damaged. This led us to carry out a case-control study in which the tibial nerve's axial CSA was measured in healthy patients and in patients with TTS. HYPOTHESIS: The tibial nerve's axial CSA can be used as a diagnostic criterion for TTS. METHODS: Twenty-three patients (27 feet) (11 men, 12 women, mean age=54±14 years), who had clinical and electroneuromyography signs of TTS, were compared to 21 healthy adults (8 men, 13 women, mean age 39±10 years). An ultrasonography examination was carried out to look for a source of nerve compression, then the axial CSA of the tibial nerve was measured 10cm above the tarsal tunnel (lCSA) and inside the tunnel itself (ttCSA). The difference between the two measurements was then calculated: ΔCSA=ttCSA-lCSA. The data were analysed using correlation tests and non-parametric tests, a multivariate linear regression and ROC tests. RESULTS: A compressive cause was found by ultrasonography in 13 patients. The mean values of ttCSA and ΔCSA were 20.1±8.8 mm2 [6-42] vs. 10.3±2.3 mm2 [8-14] (p=0.0001) and 9.8±6.7 mm2 [0-29] vs. -0.2±1.8 mm2 [-3-4] (p<0.0001) in the patients and the controls, respectively. The differences in ΔCSA remained significant in the multivariate analysis after adjusting for age and weight. The best threshold for ttCSA in the TTS group was 15 mm2 with 74% sensitivity and 100% specificity. The best threshold for ΔCSA was 5mm2 with 81% sensitivity and 100% specificity. DISCUSSION: The difference in the measured axial CSA of the tibial nerve by ultrasonography between the posteromedial tarsal tunnel and 10cm above the tunnel is a key data point for the diagnosis of tarsal tunnel syndrome with and without compressive etiology. LEVEL OF EVIDENCE: III, diagnostic case-control study.

Tarsal tunnel syndrome: a still challenge condition / Síndrome do túnel do tarso: uma condição ainda desafiadora

Tarsal tunnel syndrome is a rare, under diagnosed and often confused neuropathy with other clinical entities. There is a lack of population studies on this disease. Herein, we performed a non-systematic review of articles between January 1992 and February 2018. Although with a less complex anatomy comparing to the carpal tunnel, the tarsal tunnel is source of pain and some other conditions. Treatment involves conservative measures such as analgesics and physical therapy rehabilitation or surgical procedures in case of conservative treatment failure. Randomized control studies are lack and mandatory for uncover the best modality of treatment for this condition.

A Síndrome do túnel do tarso é uma rara e subdiagnosticada neuropatia geralmente confundida com outras entidades clínicas. Há falta de estudos populacionais sobre a doença. Assim sendo, realizamos uma revisão da literatura de artigos entre Janeiro de 1992 e fevereiro de 2018. Apesar de possuir uma anatomia de menor complexidade comparada ao túnel do carpo, o túnel do tarso é origem de dor e algumas outras condições. O tratamento envolve medidas conservadoras como analgésicos e terapia de reabilitação ou procedimentos cirúrgicos, em caso de falha do tratamento conservador. Estudos randomizados são escassos e necessários para descoberta da melhor modalidade de tratamento desta condição.

Posterior Tibial Neuropathy Secondary to Pseudoaneurysm of the Proximal Segment of the Anterior Tibial Artery with Delayed Onset.

Anterior tibial artery is a nonvital artery which is one of the three arteries of the leg. This artery has a short proximal l segment in the popliteal region and a long segment in the anterior compartment of the leg designated as distal segment. With consideration of the deep location of the proximal segment in the popliteal fossa, it is less susceptible to trauma and subsequent formation of an aneurysm. On the contrary, the superficial long distal segment is more susceptible to trauma with high chance of pseudoaneurysm formation at the site of unrecognized injury. In this article, a 38-year-old military man being manifested about a decade after a trivial missile fragment injury with progressive posterior tibial neuropathy is presented. A giant pseudoaneurysm arising from the proximal segment of the anterior tibial artery was confirmed with angiography and the exact size of this pathology was documented with contrasted computed tomographic scan. The aneurysmal sac removal was accomplished after ligation of the corresponding artery proximal and distal to the sac followed by tibial nerve neurolysis which result in full recovery. In careful review we found that neither pseudoaneurysm arising from the proximal tibial artery nor posterior tibial neuropathy due to the compressive effect of the aneurysmal sac of this segment has been reported previously. Our primary purpose for reporting this case is not to describe the rarity of pseudoaneurysm formation at proximal segment of this artery but rather to describe delayed-onset posterior tibial vascular compressive neuropathy due to such an aneurysm. Eventually due to the potential sequel of a pseudoaneurysm, it is important for the surgeons to have high index of suspicion to prevent a missed or delayed diagnosis.

Neurovascular Compression Caused by Popliteus Muscle Enlargement Without Discrete Trauma.

Popliteal entrapment syndrome caused by isolated popliteus muscle enlargement is very rare, although its occurrence has been reported after discrete trauma. However, popliteal artery stenosis with combined peroneal and proximal tibial neuropathy caused by popliteus muscle enlargement without preceding trauma has not been reported. A 57-year-old man presented with a tingling sensation and pain in his left calf. He had no previous history of an injury. The symptoms were similar to those of lumbosacral radiculopathy. Calf pain became worse despite treatment, and the inability to flex his toes progressed. Computed tomography angiography and magnetic resonance imaging of the lower extremity showed popliteal artery stenosis caused by popliteus muscle enlargement and surrounding edema. An electrodiagnostic study confirmed combined peroneal and proximal tibial neuropathy at the popliteal fossa. Urgent surgical decompression was performed because of the progressive neurologic deficit and increasing neuropathic pain. The calf pain disappeared immediately after surgery, and he was discharged after the neurologic functions improved.

Neurovascular Compression Caused by Popliteus Muscle Enlargement Without Discrete Trauma

Popliteal entrapment syndrome caused by isolated popliteus muscle enlargement is very rare, although its occurrence has been reported after discrete trauma. However, popliteal artery stenosis with combined peroneal and proximal tibial neuropathy caused by popliteus muscle enlargement without preceding trauma has not been reported. A 57-year-old man presented with a tingling sensation and pain in his left calf. He had no previous history of an injury. The symptoms were similar to those of lumbosacral radiculopathy. Calf pain became worse despite treatment, and the inability to flex his toes progressed. Computed tomography angiography and magnetic resonance imaging of the lower extremity showed popliteal artery stenosis caused by popliteus muscle enlargement and surrounding edema. An electrodiagnostic study confirmed combined peroneal and proximal tibial neuropathy at the popliteal fossa. Urgent surgical decompression was performed because of the progressive neurologic deficit and increasing neuropathic pain. The calf pain disappeared immediately after surgery, and he was discharged after the neurologic functions improved.

Neurovascular Compression Caused by Popliteus Muscle Enlargement Without Discrete Trauma

Popliteal entrapment syndrome caused by isolated popliteus muscle enlargement is very rare, although its occurrence has been reported after discrete trauma. However, popliteal artery stenosis with combined peroneal and proximal tibial neuropathy caused by popliteus muscle enlargement without preceding trauma has not been reported. A 57-year-old man presented with a tingling sensation and pain in his left calf. He had no previous history of an injury. The symptoms were similar to those of lumbosacral radiculopathy. Calf pain became worse despite treatment, and the inability to flex his toes progressed. Computed tomography angiography and magnetic resonance imaging of the lower extremity showed popliteal artery stenosis caused by popliteus muscle enlargement and surrounding edema. An electrodiagnostic study confirmed combined peroneal and proximal tibial neuropathy at the popliteal fossa. Urgent surgical decompression was performed because of the progressive neurologic deficit and increasing neuropathic pain. The calf pain disappeared immediately after surgery, and he was discharged after the neurologic functions improved.

Popliteus muscle hemorrhage as a rare cause of a proximal tibial neuropathy.

Proximal tibial neuropathy is an uncommon focal mononeuropathy that is most often caused by trauma, ischemia, or neoplastic infiltration or compression of the tibial nerve. We report a patient who presented with a tibial neuropathy following a leg injury, which initially mimicked a lumbosacral radiculopathy but which was the result of a proximal tibial neuropathy. Electrophysiologic studies confirmed a proximal tibial neuropathy and MRI revealed a popliteus muscle hemorrhage with mass effect on the tibial nerve. Following conservative management the patient had little recovery of function after 15 months.

Compressive neuropathy of the posterior tibial nerve at the lower calf caused by a ruptured intramuscular baker cyst.

Baker cyst is an enlargement of the gastrocnemius-semimembranosus bursa. Neuropathy can occur due to either direct compression from the cyst itself or indirectly after cyst rupture. We report a unique case of a 49-year-old man with left sole pain and paresthesia who was diagnosed with posterior tibial neuropathy at the lower calf area, which was found to be caused by a ruptured Baker cyst. The patient's symptoms resembled those of lumbosacral radiculopathy and tarsal tunnel syndrome. Posterior tibial neuropathy from direct pressure of ruptured Baker cyst at the calf level has not been previously reported. Ruptured Baker cyst with resultant compression of the posterior tibial nerve at the lower leg should be included in the differential diagnosis of patients who complain of calf and sole pain. Electrodiagnostic examination and imaging studies such as ultrasonography or magnetic resonance imaging should be considered in the differential diagnosis of isolated paresthesia of the lower leg.

Compression and entrapment neuropathies.

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

Compressive Neuropathy of the Posterior Tibial Nerve at the Lower Calf Caused by a Ruptured Intramuscular Baker Cyst

Baker cyst is an enlargement of the gastrocnemius-semimembranosus bursa. Neuropathy can occur due to either direct compression from the cyst itself or indirectly after cyst rupture. We report a unique case of a 49-year-old man with left sole pain and paresthesia who was diagnosed with posterior tibial neuropathy at the lower calf area, which was found to be caused by a ruptured Baker cyst. The patient's symptoms resembled those of lumbosacral radiculopathy and tarsal tunnel syndrome. Posterior tibial neuropathy from direct pressure of ruptured Baker cyst at the calf level has not been previously reported. Ruptured Baker cyst with resultant compression of the posterior tibial nerve at the lower leg should be included in the differential diagnosis of patients who complain of calf and sole pain. Electrodiagnostic examination and imaging studies such as ultrasonography or magnetic resonance imaging should be considered in the differential diagnosis of isolated paresthesia of the lower leg.

Compressive Tibial Neuropathy Induced by Myxoid Liposarcoma in the Popliteal Fossa

Tibial nerve compression occurs most often at the ankle. A proximal tibial nerve entrapment at the popliteal fossais rare because of the deep location of the nerve. We report a case of tibial neuropathy caused by a myxoid liposarcoma at the popliteal fossa, which was diagnosed by electrophysiologic studies, magnetic resonance imaging and an open excisional biopsy. This case illustrates that tumors should be considered when patients present with an entrapment neuropathy of the proximal tibial nerve.

Posterior tibial neuropathy by a Baker's cyst

Baker's cysts are rare cause of peripheral nerve entrapment and only a few cases of tibial nerve entrapment resulting from the popliteal cyst in the calf muscle have been reported in the literature. We present a case of rheumatoid arthritis complicated by a Baker's cyst with a tibial nerve entrapment. It is important to diagnose a Baker's cyst early and to differentiate it from thrombophlebitis, a popliteal aneurysm, tumor or muscle tear to effect optimal therapy and to obviate a potential neuropathy. Prompt recognition of these cases may save the patients unnecessary procedures and delay in treatment.