Schwannoma is an encapsulated nerve sheath tumor that is distinct from neurofibromatosis. It is defined as the occurrence of multiple schwannomas without any bilateral vestibular schwannomas. A 46-year-old man with multiple schwannomas involving peripheral nerves of the ipsilateral lower extremity presented with neurologic symptoms. Electrodiagnostic studies revealed multiple mononeuropathies involving the left sciatic, common peroneal, tibial, femoral and superior gluteal nerves. Histologic findings confirmed the diagnosis of schwannoma. We reported this rare case of segmental schwannomatosis that presented with neurologic symptoms including motor weakness, which was confirmed as multiple mononeuropathies by electrodiagnostic studies.
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Bisphosphonates are potent inhibitors of bone resorption and considered as a gold standard and are generally recommended as first-line therapy in patients with osteoporosis. Though bisphosphonates are shown to significantly reduce the risk of vertebral, non-vertebral and hip fractures, recent reports suggest a possible correlation between long-term bisphosphonate therapy and the occurrence of insufficiency fractures owing to prolonged bone turnover suppression. We report a patient with non-traumatic stress fractures of bilateral femoral shafts related to long-term bisphosphonate therapy indicating the need for a critical evaluation of patients with long-term bisphosphonate therapy.
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To perform nerve conduction studies of the four branches of the superficial peroneal nerves to determine normal values and anatomic variations in Koreans.
Antidromic sensory nerve conduction studies of the four distal branches were performed on 70 healthy subjects (100 feet). We applied electrical stimulation at the midpoint of medial and lateral malleoli for the medial dorsal cutaneous nerve (MDCN), and at the lateral 1/4 point between the medial and lateral malleoli for the 2 branches of the intermediate dorsal cutaneous nerve (IDCN).
Reference values (mean±SD) of the onset/ peak latency (ms)/ sensory action potential amplitude (µV) for the two branches of the MDCN and for the first branch of the IDCN were 2.2±0.3/2.9±0.3/9.2±3.1, 2.2±0.3/2.8±0.3/9.1±3.0 and 2.3±0.4/2.9±0.3/8.5±2.8, respectively. For the second IDCN branch, the reference values were 2.3±0.4/3.0±0.4/7.1±2.6 but anomalous sural innervation was also found. Three types of IDCN innervations to the fourth interdigital web space were detected. In type I, the fourth interdigital webspace was innervated solely by the IDCN, whereas in type II, it was innervated by both the IDCN and distal sural nerve. In type III, it was solely innervated by the distal sural nerve.
The results of this study show the reference values of the distal sensory branches of the superficial peroneal nerve, and provide information on the variant innervations to the fourth interdigital web space.
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