The superficial peroneal nerve subserves sensation on the entire surface of the dorsum of the foot, except in small areas. All previously reported techniques for evaluating nerve conduction along this nerve tested a proximal portion of the nerve. We report a new method for evaluating sensory nerve conduction of the four branches of the distal superficial peroneal nerve. Two branches to the second and third toes of the medial dorsal cutaneous nerve and two branches to the fourth and fifth toes of the intermediate dorsal cutaneous nerve were studied orthodromically and antidromically in 37 feet of 21 normal volunteers using surface stimulating and recording electrodes and with a distance of 10 cm between the stimulating and recording electrodes. Maximum nerve conduction velocities (NCV) ranged from 41.8 to 46.9 m/s, and mean response amplitude ranged from 6.5 to 7.6 microV with the orthodromic technique. Values for NCV were almost identical when elicited by antidromic and orthodromic techniques, but response amplitudes were higher with the antidromic technique. Mean amplitudes of the distal superficial peroneal nerve were about 50% of the proximal superficial peroneal, and the conduction velocity in the distal superficial peroneal was slower than that in the proximal superficial peroneal nerve, by 8-14 m/s. In seven cases, distal superficial peroneal neuropathy was confirmed with this technique: two with proper digital neuropathy, two with medial dorsal cutaneous neuropathy, and three with intermediate dorsal cutaneous neuropathy.

Near-nerve needle sensory nerve conduction of plantar nerves in 100 patients with distal sensory neuropathy with normal routine nerve conduction (DSN-NNC) found the definite neuropathy pattern (abnormality in more than three of six tested nerves) in 65%, axonal neuropathy in 35%, and the known cause in 37% of patients. Absent or diminished reflexes were a reliable indicator for large fiber neuropathy (LFN). This near-nerve needle plantar nerve study provides useful and unequivocal evidence of its value in identifying neuropathy in DSN-NNC by finding LFN in 65% of patients.

Myasthenia gravis (MG) is the most frequent neuromuscular transmission disorder with incidence of 2-20 patients per million. Its pathophysiology is autoimmune, with acetylcholine receptors (AChR) autoantibodies damaging the post-synaptic fold at the muscle membrane. MG often presents with isolated ocular symptoms, including diplopia and ptosis, at least at the onset. Even in patients with generalized symptoms, ocular signs occur in almost all patients in some point during the course of the disease. In up to 15% of the patients the disease remains confined to the eyes 1 . Other clinical features include bulbar symptoms (dysphagia, dysarthria), proximal limb muscles weakness and fatigue. Unusual presentations as distal limb muscles weakness can also be found in a minority of cases 2,3 . The main characteristic of the MG is the fluctuating weakness during the day, being milder during the morning and more severe at the evening. Physical activity usually worsens the weakness. The diagnostic confirmation of MG is often challenging. The tests usually performed to confirm the diagnosis of MG are the edrophonium test (Tensilon®), repetitive nerve stimulation (RNS), single fiber EMG and serum acetilcholine receptors (AchR) antibodies. The most traditional bedside diagnostic test for myasthenia gravis is the edrophonium test. It has been considered diagnostic of MG in the past, however false-positive results have been reported in other neurologic disorders like amyotrophic lateral sclerosis, botulism and brain tumor 4,5 . Furthermore, it carries a risk of serious cardiac adverse reations. Its sensitivity is about 86% in pure ocular disease 6 . Unfortunately it is not easily available in Brazil. Another bedside test that can be done is the sleep test, however this test is time consuming and probably not practical for the busy physician, since the patient has to take a nap of 15 to 20 minutes in a dark room for clinical comparison 7 . The other complementary tests have variable sensitivity and specificity. The diagnostic field of the RNS and AchR antibodies for pure ocular disease is quite low. The AChR antibodies are the most specific test for myasthenia gravis, however the sensitivity varies from 56% in pure ocular myasthenia according to Tabassi et al. 8 to 70% in Oh et al. 9 study. The repetitive nerve stimulation has even lesser sensitivity, varying from 35% in distal muscles to 45% in proximal muscles 10 . The most sensitive test for ocular myasthenia is single fiber EMG, reaching up to 80% in pure ocular cases and 95% in generalized disease 9 , however its specificity is low, the test is expensive, technically demanding and not widely available.The ice pack test is a very simple, safe and cheap procedure that can be performed by the physician at the bedside 10 . Moreover, the ice pack test does not require medications or expensive equipment and is free of adverse effects 11 . It consists of the application of an ice pack on the patient symptomatic eye for 3 to 5 minutes. The response is positive when there is improv...

Lipid lowering drugs are used worldwide to control dyslipidemias. The muscle disorder associated with them are coined cholesterol-lowering agents myopathy (CLAM) 1 . The annual incidence of rhabdomyolysis in patients taking statins is 3.4 per 100000 persons 2 . Between 1987 and 2001 there were 42 deaths +related to statin-induced rhabdomyolysis, resulting in a mortality rate of 0.15 per million of prescriptions 3 . Although myotonic potentials have been described in some drug-related myopathies, they are rarely reported in CLAM. Though there are a few experimental myotonic myopathy associated with statin in rabbits 4-6 , there was only one single report describing 5 patients with this finding in humans 7 .We report a patient with statin-related rhabdomyolysis and profuse myotonic potentials in the needle EMG with clinical and electrophysiological recovery shortly after the statin interruption. CaSeA 68 year-old Asian Brazilian woman was admitted with progressive painless weakness for one week, started on the proximal muscles of the four limbs and neck flexors with rapid progression to inability to walk and elevate the limbs. Urine was redbrown in color. Thirty days before the admission she was put on simvastatin due to hypercholesterolemia. Other medication she was taking was enalapril for mild hypertension. There was no personal or family history of myopathy. On neurological examination, abnormal findings were grade 2 (MRC) strength in the proximal lower limb muscles and grade 3 in the proximal upper limb muscles, grade 4 in the distal muscles and hypoactive deep tendon reflexes. No clinical myotonia was detected.A complete blood count, electrolytes, creatinine, glucose, TSH, and free T4 were all normals. Myoglobin was detected in the urine. CPK was 22.260 U/l on the admission day and 55.000 U/l on the third day. AST and ALT were 790 and 750 U/l, respectively. The nerve conduction studies perfomed in both arms and legs showed normal results in the median, ulnar, superficial radial, tibial, peroneal, superficial peroneal and sural nerves bilaterally. The F wave latencies were normal in the median, ulnar, fibular and tibial nerves bilaterally. The needle EMG perfomed with disposable monopolar needle in cervical paraspinal, supraspinatus, deltoid, triceps, abdutor pollicis brevis and first dorsal interosseus in the upper right limb and tibialis anterior, gastrocnemius, vastus lateralis and iliopsoas in the right lower limb showed rare positive sharp waves and fibrillations in the right supraspinatus muscle, as well as a few small amplitude and short duration (SASD) motor unit potentials (MUP) in the right iliopsoas muscle. On the other hand, the needle study showed profuse amount of myotonic potentials in deltoid, supraspinatus, iliopsoas and cervical paraspinal muscles on the right side (Fig 1).Simvastatin was stopped and vigorous hydration was started to prevent acute renal failure. She was discharged two weeks later with normal strength, renal function and CPK levels. A second needle EMG performed 30 days after...