1/4. Reversible F-wave hyperexcitability associated with antibodies to potassium channels in Isaacs' syndrome.We report a case of Isaacs' syndrome showing F-wave hyperexcitability which was reversible after either epidural block or plasmapheresis. A 14-year-old girl with progressive muscle cramp and myokymia in the legs showed high amplitude, long duration, polyphasic F-waves after either tibial nerve or peroneal nerve stimulation. Potassium current of PC-12 cell membrane was suppressed by her serum, IgM of which strongly reacted with proteins of approximately 50 kDa of the lysates of a PC-12 cell line. After an epidural nerve block with 1 per cent lidocaine 10 ml, the myokymia temporally improved, during which time the hyperexcitable F-waves became normalized. We treated her with double filtration plasmapheresis, which resulted in remarkable improvement of myokymia; simultaneously, the abnormal F-waves showed a decrease in amplitude, duration, and in the number of phases. We concluded that there was hyperexcitability of the proximal site of motor fibers in our patient, and possible immune mechanisms gave rise to the myokymia and unusual F-wave features.- - - - - - - - - - ranking = 1keywords = muscle cramp, cramp (Clic here for more details about this article) |
2/4. Successful immunoglobulin treatment in a patient with neuromyotonia.Neuromyotonia is characterized by spontaneous and continuous muscle fibre activity leading to muscle cramps, pseudomyotonia, myokymia and weakness. Electromyographic recordings show typical findings. An auto-immune mechanism has been suggested in at least a subset of patients. Various therapies have been tried with different outcome. A patient with neuromyotonia responding well to high-dose immunoglobulin treatment is presented.- - - - - - - - - - ranking = 1keywords = muscle cramp, cramp (Clic here for more details about this article) |
3/4. Isaacs' syndrome (autoimmune neuromyotonia) in a patient with systemic lupus erythematosus.patients with systemic lupus erythematosus (SLE) often produce autoantibodies against a large number of antigens. A case of SLE is presented in which muscle twitching and muscle cramps were associated with an autoantibody directed against the voltage-gated potassium channel of peripheral nerves (Isaacs' syndrome).- - - - - - - - - - ranking = 1keywords = muscle cramp, cramp (Clic here for more details about this article) |
4/4. Finger flexion resembling focal dystonia in Isaacs' syndrome.We describe a patient with a 5-month history of gradually progressive painless flexion of the left ring finger associated with cramps in both thighs. She has severe chronic obstructive pulmonary disease and was on salbutamol. serum anti-voltage-gated potassium channel antibodies was positive. electromyography showed generalized neuromyotonia and myokymic discharges. The cramps were partially relieved by phenytoin. We would like to highlight that finger flexion resembling dystonia can be a presenting sign of Isaacs' syndrome.- - - - - - - - - - ranking = 0.3581164750829keywords = cramp (Clic here for more details about this article) |