Yasuhisa Baba

P1 and P2 components of human visual evoked potentials are modulated by depth perception of 3-dimensional images

OBJECTIVE To determine the cerebral activity correlated with depth perception of 3-dimensional (3D) images, by recording of human visual evoked potentials (VEPs). METHODS Two figures consisting of smaller and larger squares were presented alternately. VEPs were recorded in two conditions. In condition I, we used two figures which yielded flat 2-dimensional images. In condition II, we used two figures which yielded 3D images, which were concave and convex, respectively. RESULTS P1, P2, and N1/P2 amplitude were significantly greater in condition II than in condition I. The P1/N1 amplitude tended to be greater in condition II than in condition I. P1 and N1 were predominantly distributed over the right temporo-parieto-occipital regions. P2 and N2 were distributed over bilateral parieto-occipital regions. CONCLUSIONS The difference in P1 amplitude between two conditions can be explained by the difference between conditions, one of which yielded depth perception while the other did not, since previous studies showed that P1 and N1 are modulated by perception of images in depth. The role of P2 and the mechanism responsible for the increase in P2 amplitude during condition II remain unknown. SIGNIFICANCE We recorded VEPs and identified electrophysiological correlates of depth perception with 3D images produced by concave/convex figures.

Idiopathic thrombocytopenic purpura and myasthenia gravis after fludarabine treatment for chronic lymphocytic leukemia

We report a patient with chronic lymphocytic leukemia (CLL) who developed idiopathic thrombocytopenic purpura (ITP) and myasthenia gravis (MG) after fludarabine therapy. ITP developed after 6 cycles of fludarabine treatment, and MG occurred 2 months after the onset of ITP. MG was successfully treated with immunosuppressive therapy and plasma exchange, while rituximab was effective for CLL and ITP. Fludarabine seemed to have an important role in the onset of ITP and MG in this case.

Paraneoplastic neurological syndrome in a patient with gastric cancer.

Paraneoplastic neurological syndromes (PNSs) are a heterogeneous group of neurological disorders caused by immunemediated mechanisms. The incidence of PNS is much less than 1% for solid tumors, except for small-cell lung cancer and thymoma. We report a rare case of gastric cancer that presented with primary clinical findings of PNS. The patient was a 63-year-old woman who was admitted for worsening neuropathy. Laboratory and neurological tests excluded a nutritional deficit, diabetes mellitus, and connective tissue disease as causes of her neuropathy. Computed tomography (CT) of the abdomen, positron emission tomography (PET)-CT, and endoscopy of the stomach revealed gastric cancer with lymph node swelling. Distal gastrectomy was performed and pathological and immunohistochemical examinations indicated endocrine cell carcinoma. The gastrectomy stopped the exacerbation of her symptoms and recurrence was not observed, but the neurological disorders were irreversible. This case suggests that early diagnosis of the primary tumor is required to improve the outcome in patients with PNS.

Atypical drug-induced hypersensitivity syndrome with human herpesvirus 6 reactivation due to calcium blockers.

Dear Editor, Drug-induced hypersensitivity syndrome (DIHS), characterized by serious adverse systemic reactions in addition to skin rash, is frequently associated with human herpesvirus 6 (HHV-6) reactivation. The main DIHS symptoms include generalized exanthematous eruption, occasionally accompanied by small pustules, facial edema, high fever, systemic lymphadenopathy, leukocytosis, eosinophilia, atypical lymphocytosis and liver dysfunction. This syndrome develops within 2–6 weeks after taking the causal drugs, persisting for 2 weeks to several months after drug discontinuation and recurrence is often noted. Major causal drugs of DIHS include anticonvulsant, allopurinol, sulfasalazine, dapsone, minocycline and mexiletine chloride. However, DIHS can be induced by drugs other than the major causal drugs. We herein report a case of atypical DIHS with HHV-6 reactivation that developed approximately 19 months after taking calcium blockers. A 78-year-old Japanese man developed amyotrophic lateral sclerosis (ALS) in 2008. In 2009, the patient was administrated steroid pulse therapy and i.v. immunoglobulin (IVIG), followed by treatment with 35 mg/day prednisolone (PSL)that was gradually reduced to 1 mg/day. Since 2008, the patient had also been receiving azelnidipine and verapamil hydrochloride for hypertension. Nineteen months later, he developed an itchy maculopapular rash on the buttocks that rapidly spread to the whole body. Seven days after the onset, he was admitted to our hospital with a generalized maculopapular rash with facial edema (Fig. 1) and high fever. Physical examination revealed redness of the pharynx and lymphadenopathy. His medication was discontinued except PSL. Laboratory tests on admission showed leukocytosis (11.20 9 10/L) with eosinophilia (11.8%) and atypical lymphocytes (1.0%), slight liver dysfunction (aspartate aminotransferase, 38 IU/L; alanine aminotransferase, 38 IU/L), and low immunoglobulin (Ig)G level (813 mg/dL; normal, 870–1,700). The CD4/CD8 ratio was 1.36. The biopsy specimen from the patient’s left upper arm revealed marked hyperkeratosis and spongiosis; edema in the dermis; and lymphocytic infiltration with some eosinophils in the upper dermis and around the subepidermal vessels(Fig. 2). The patient’s condition improved gradually with 20 mg/day PSL treatment that was reduced to 1 mg/day until the 20th hospital day. Specific IgG titers for HHV-6 had increased from 20 (on admission) to 2560 (on day 20). Real-time polymerase chain reaction revealed that the HHV-6 DNA copy number in the peripheral white blood cells (WBC) and serum had significantly increased: WBC, 2300 copies/10 cells on day 3 and 20 copies/10 cells on day 20; and serum, 110 copies/mL on day 3 and 100 copies/mL on day 20. No other herpesvirus reactivation was observed. Lymphocyte stimulation tests performed on day 8 showed a positive result only for azelnidipine (stimulation index, 232%), and all other medications were resumed without any adverse effects. Two months after calcium blockers were discontinued, a maculopapular rash with high fever reappeared, and the HHV6 DNA level in the peripheral WBC (200 copies/10 cells) increased. Efficacy of IVIG treatment for DIHS is still controversial. However, because complication of a bacterial infectious disease was not excluded because of an increase of C-reactive protein (5.14 mg/dL),a 3-day IVIG treatment (5 g/day) was started. After the treatment, the patient recovered gradually without any antibiotic treatment. Our patient showed all characteristics of DIHS, with slight liver dysfunction. We suspected azelnidipine and/or verapamil hydrochloride as the causative drugs, although the lymphocyte stimulation test was positive only for azelnidipine. These drugs have not been reported as the causative drugs of DIHS or drug eruptions resembling DIHS. The cause of HHV-6 reactivation and DIHS development in our case remains unknown. Anticonvulsants, the major DIHS causal drugs, sometimes induce hypogammaglobulinemia, even in the absence of DIHS symptoms. The IgG level was relatively low in our case. This might indicate that the patient’s immunological function may have been impaired due to long-term corticosteroid administration or other causes, leading to HHV-6 reactivation during the adverse drug reaction. (a) (b)

P1-1 Statistical analysis of VEPs to transient full-field pattern-reversal stimulation in 167 normal adults

Objective: To study the effect of age, gender, head size on patternreversal VEP. Method: Studies were conducted on 167 healthy adult volunteers (96 women, 71 men). The entire stimulating field subtended an angle of 16 degrees; each individual square of the checkerboard subtended 15, 30, or 60 minutes of arc measured to the eye. The subject was seated on a chair 127 cm from TV screen. Screen luminance was 25 luxes; background luminance was 15 luxes. VEPs were obtained by a stimulation frequency of a pattern reversal every 1 sec. Each evoked potential was the result of the summation of 60 responses. Midoccipital electrode was placed 5 cm above the inion, and was referred to a midfrontal reference electrode 12 cm above the nasion. We measured each peak latency of P50, N75, P100, and N145, and peak-to-peak amplitude of P50-N75, N75-P100, and P100-N145. Three way ANOVA was used to evaluate the effects of age, gender, head size on pattern-reversal VEP latency and amplitudes. Result: The age influenced each peaks latency. The checksize influenced each peak latency and amplitude (P50-N75, N75-P100). The smaller the checksize was, the larger both the latency and amplitude were. The gender each peak latency and each peak-to-peak amplitude. Latency was shorter and amplitude was larger in women than in men. The head size did not influence VEPs. Conclusion: Pattern VEP latencies are influenced by age, gender, and checksize. Pattern VEP amplitudes are influenced by gender and checksize. are influenced by gender and checksize.

57. A case of serotonin syndrome assessed by repeated EEG recordings

A case of 35-year-old Japanese woman with depression and diabetic nephropathy was reported. She had been receiving hemodialysis (HD) twice a week for one year. She took 100 mg-amitriptyline, 8 mg-perospirone, 400 mg-carbamazepine, 30 mg-baclofen and several benzodiazepines every day. 10 mg-paroxetine was added for her depressive symptoms, three weeks later she felt appetite-loss, insomnia and fatigue, and at last she got the somnolent state. On admission, she showed much sweating, mydriasis and consciousness disturbance (GCS: E2V1M1). Except mild hyperglycemia and renal dysfunction, laboratory data and brain MRI findings were normal. Accordingly she was diagnosed as serotonin syndrome. Although the drug administration was discontinued and HD was performed, her consciousness state was not improved. She was then treated with hemodialysis-filtration (HDF), which made her awake with myoclonic limb jerk. EEGs were recorded (1) on admission, (2) in the worst consciousness state, (3) immediately after HDF and (4) during the recovery state. These findings were (1) frontal dominant deltaactivity, (2) generalized deltaand theta-activity with triphasic waves, (3) frontal dominant theta-activity with generalized sharp waves, (4) normal alpha-activity, respectively. The symptoms were prolonged because of her condition (e.g., renal failure and polypharmacy). Consequently the time course of serotonin syndrome could be assessed by repeated EEG recordings.