[Overlap syndrome of systemic lupus erythematosus and dermatomyositis presented a large demyelinating subcortical lesion mimicking brain tumor and high level of CSF antineuronal and serum anti-ribosomal P antibodies].

We reported a 50-year-old man with an overlap syndrome of dermatomyositis and SLE, whose magnetic resonance image of the brain showed a rapidly increasing large tumor-like focal lesion unequally enhanced by Gd-DTPA in the left frontal lobe. Its pathological finding by the brain biopsy was fibrinoid necrosis, inflammatory cell aggregation around blood vessels and many myelin-laden macrophages with central necrosis. Although many cases of blood vessel injury are reported in CNS lupus, in this case the brain lesion partly took reversible course and neural symptoms such as paresis were slight and the lesion well responded to steroid. Moreover we considered that the measurement of serum anti-ribosomal P and CSF antineuronal antibodies are useful to diagnose cases as CNS lupus.

[A case with myositis as a manifestation of chronic graft-versus-host-disease (GVHD) with severe muscle swelling developed after aggressive muscular exercise].

We report a 21-year-old-man, with myositis as a manifestation of chronic graft-versus-host-disease (GVHD). He was diagnosed as having acute myelogenous leukemia at the age of 18 years, and had bone marrow transplantation (BMT) two years after the onset of the disease. Cutaneous manifestation of acute GVHD appeared on the twelfth day following BMT, which responded to prednisolone. Thereafter, GVHD has been well-controlled except for mild liver dysfunction which was thought to be a sign of chronic GVHD. Eleven months after BMT, he enjoyed snowboarding for two days from morning till night. Two days later, he experienced muscle swelling with pain and fever, which gradually worsened for which he was admitted to our hospital. Neurological examination revealed severe proximal and distal muscle swelling with fever and tenderness in all extremities. Mild, symmetrical, proximal weakness was observed in all four limbs. Severity of muscle swelling and its generalized nature restricted the movements of shoulder-, elbow- and ankle-joints and he was unable to walk. Laboratory investigations revealed creatine kinase (CK) of 7,860 IU/L, C-reactive protein (CRP) of 21.5 mg/dL and raised biliary enzymes. MRI generated high intensity signals from the swollen muscles. Muscle biopsy examination of involved areas showed severe interstitial edema and mononuclear cells infiltration. Macrophages were scattered through out the perimysium and endomysium. On the other hand, T cells and B cells were localized to the endomysium. Although a lot of CD8 positive T cells were seen adjacent to non-necrotic fibers, none of them was obviously invading the non-necrotic fibers. Perifascicular atrophy was not seen. Symptoms gradually worsened over two weeks or so when prednisolone was started to which he responded rapidly. While tapering steroids, the symptoms relapsed on resuming aggressive exercise. Resumption of the treatment regime promptly controlled the symptoms. The cause of myositis as a manifestation of chronic GVHD is unclear. T-cell or B-cell dysfunction, collagen-vascular-like processes, viral infection and direct damage by radiation or chemotherapy have been supposed to involve in the disease process. Our case suggests that aggressive muscular exercise could play as a initiator of myositis as a manifestation of chronic GVHD.

[A case of chronic inflammatory demyelinating polyneuropathy presenting with acute pain and SIADH followed by weakness of all four limbs 2 month after the first symptoms].

We report a 73-year-old man who presented symptoms of low back pain and SIADH followed by weakness of all four limbs and sensory disturbance of the lower legs 2 month after the first symptoms. He was referred to our department because of the evolution of weakness. Neurological examination on admission revealed weakness of the arms and legs, areflexia, and hypoesthesia of the lower legs. The straight leg raising test induced prominent radiating pain bilaterally. The level of sodium was 114 mEq/l, the plasma osmolality was 239 mOsm/kg, and the level of plasma antidiuretic hormone was 3.45 pg/ml. Other blood chemical values were unremarkable. The urine osmolality was 527 mOsm/kg. T1-weighted MR image with gadolinium showed thickening and enhancement of the nerve root. Nerve conduction study revealed compromised conduction with demyelinating features, and somatosensory evoked potential study could not show any potentials. He was diagnosed as having CIDP complicating with SIADH. An association between SIADH and AIDP has been much reported previously. To our knowledge, however, there has been no report of SIADH complicating with CIDP.