Neuromuscular Diseases A Practical Guideline - part 6

237 Sural nerve Genetic testing NCV/EMG Laboratory Imaging Biopsy + + used The sural nerve is formed from two branches: the medial cutaneous nerve of the calf (tibial nerve) and the lateral cutaneous nerve of the calf (common peroneal nerve). In general, the sural nerve contains only sensory fibers. It runs along the middle of the calf region, lateral to the Achilles tendon and lateral malleolus. The nerve innervates the lateral ankle and lateral aspect of the sole, to the base of the 5th toe. The sural nerve gives rise to the lateral calcaneal nerves posterior and proximal to the tip of the lateral malleolus. At the proximal fifth metatarsal tuberosity the nerve divides into a lateral branch (the dorsolateral cutaneous nerve of the fifth toe) and a medial branch, providing sensation to the dorsome-dial fifth toe and dorsolateral fourth toe. Numbness, pain, and paresthesias at the lateral side of the foot. Symptoms after excision: Dysesthesias occur in 40–50% of cases. Neuroma formation may also occur. Postoperative scarring may result in dysesthesias. There is no difference in outcome between whole nerve biopsy or fascicular biopsy. Tinel’s sign may indicate the site of the lesion. Baker’s Cyst Arthroscopy, operation for varicose veins Calf muscle biopsies Elastic socks Footwear Tight lacing Acute or chronic ankle sprain Avulsion fracture of base of 5th metatarsal bone Adhesion after soft tissue injury Fractured sesamoid bone in peroneus longus tendon Ganglion Idiopathic neuroma Osteochondroma Sitting with crossed ankles Shoes Anatomy Symptoms Signs Pathogenesis Popliteal fossa Calf Ankle This is trial version www.adultpdf.com 238 Surgery: Ankle fractures, talus, calcaneus, base of fifth metatarsal, Achilles tendon rupture Diagnosis Differential diagnosis Therapy Prognosis References Laboratory (include genetics), electrophysiology, imaging, biopsy, sensory NCV Diagnosis of neuroma: Tinel‘s sign, pain and paresthesias below distal fibula or along the lateral or dorsolateral border of the foot. Asymmetric neuropathy Herpes zoster (rare) S1 irritation Padding of shoewear, steroids, excision and transposition of the nerve stump Depends upon the etiology Dawson DM, Hallet M, Wilbourn AJ (1999) Entrapment neuropathies of the foot and ankle. In: Dawson DM, Hallet M, Wilbourn AJ (eds) Entrapment neuropathies. Lippincott Raven, Philadelphia, pp 297–334 Gabriel CM, Howard R, Kinsella N, et al (2000) Prospective study of the usefulness of sural nerve biopsy. J Neurol Neurosurg Psychiatry 69: 442–446 Killian JM, Foreman PJ (2001) Clinical utility of dorsal sural nerve conduction studies. Muscle Nerve 24: 817–820 Pollock M, Nukada N, Taylor P, et al (1983) Comparison between fascicular and whole nerve biopsy. Ann Neurol 13: 65–68 Staal A, van Gijn J, Spaans F (1999) The sural nerve. In: Staal A, van Gijn J, Spaans F (eds) Mononeuropathies. Saunders, London, pp 143–144 This is trial version www.adultpdf.com 239 Mononeuropathy: interdigital neuroma and neuritis Genetic testing NCV/EMG Laboratory Imaging Biopsy + + Terminal branch of tibial nerve at the head of III and IV metatarsal bone, and toes. Pain in the forefoot, localized to the second and third interdigital space. Numbness and paresthesias of adjacent toes may be present. Aggravated by shoes (e.g., high heels). Worsened by standing and walking. Sometimes sensory loss at opposing side of affected toes. Pain may be provoked by compression of metatarsal 3,4 or 3,5. Interdigital tenderness. Pain might be elicited by adduction of metatarsals and metatarsal compression. Pain and paresthesias of adjacent toes may be present. Forefoot pain and numbness may also occur. Mechanical irritation of the nerve may cause neuroma and neuritis. Lateral pressure from adjacent metatarsal heads result in neuritis and neuroma formation. NCV (SNAP reduction) – difficult to assess. Ultrasound MRI Local injection: lidocaine Studies: Electrophysiology, imaging Freiberg’s infarction Metatarsophalangeal pathology (instability, synovitis) Metatarsal stress fracture Plantar keratosis Avoidance of high heeled shoes Anti-inflammatory drugs and pain therapy Steroid or local anesthetic agent injection Surgery Anatomy Symptoms Clinical syndrome Causes Diagnosis Differential diagnosis Therapy This is trial version www.adultpdf.com 240 References Dawson DM (1999) Interdigital (Morton’s) neuroma and neuritis. In: Dawson DM, Hallet M, Wilbourn AJ (eds) Entrapment neuropathies. Little Brown and Company, Philadelphia, pp 328–331 Kaminsky S, Griffin L, Milsap J, et al (1997) Is ultrasonography a reliable way to confirm the diagnosis of Morton’s neuroma? Orthopedics 20: 37–39 Lassmann G, Lassmann H, Stockinger L (1976) Morton’s metatarsalgia: light and electron microscopic observations and their relations to entrapment neuropathies. Virchows Arch 370: 307–321 Levitsky KA, Alman BA, Jessevar DS, et al (1993) Digital nerves of the foot: anatomic variations and implications regarding the pathogenesis of interdigital neuroma. Foot Ankle 14: 208–214 Oh S, Kim HS, Ahmad BK (1984) Electrophysiological diagnosis of interdigital neuropathy of the foot. Muscle Nerve 7: 218–225 Zanetti M, Lederman T, Zollinger H, et al (1997) Efficacy of MR imaging in patients suspected of having Morton’s neuroma. Am J Neuroradiol 168: 529–532 This is trial version www.adultpdf.com 241 Nerves of the foot ... - tailieumienphi.vn