LAUSR

lateralis, tibialis anterior, and gastrocnemius muscles, similar to a previous report [2]. It revealed persistent and involuntary contractions in the hypodermal muscles of the trapezius (left), deltoid (right and left), tibialis anterior (right), and gastrocnemius (right) (Video 1). Regarding malignancy survey, the levels of carcinoembryonic antigen, soluble cytokeratin 19 fragment, and progastrin-releasing peptide in the peripheral blood were elevated to 8.0 ng/mL (normal <5.0), 6.2 ng/mL (normal <3.5), and 159 pg/mL (normal <80.9), respectively. Chest computed tomography (CT) revealed a tumor in the right lung (Fig. 1b). We assessed the antibodies related to paraneoplastic syndrome, using a commercially available immunoblot assay, EUROLineScan (Euroimmun, Luebeck, Germany). The intensity of the antigen band of anti-titin antibodies was borderline + [0, negative; (+), borderline; +, ++, and +++, representing three degrees of positive test]. The IgG anti-voltage-gated potassium channels complex antibody level was 19 pM (normal <72.0 pM). Following surgical removal of the tumor, the pathological diagnosis was also LCNEC, at the disease stage of T2aN1M0, stage IIA. Three months post-surgery, the symptoms of muscle cramps and pain were improved. The patient was prescribed pregabalin at 100 mg/day and remained under good condition regarding his neurological symptoms. Eight months post-surgery, he received radiological therapy (gamma knife) owing to brain metastasis. Chest CT revealed no tumor relapses. He claimed that invisible muscle cramps continuously remained on the bilateral deltoid, trapezius, pectoralis major, and gastrocnemius. Pregabalin was needed continuously to ameliorate his muscle pain. Needle EMG indicated continuous neuromyotonic discharge on the first dorsal interossei on the right side. Muscle ultrasonography revealed muscle cramps in the deltoid (right and left) and trapezius (left) (Video 1), not observed in the tibialis anterior and gastrocnemius. To the Editor,