Background : Hereditary transthyretin (ATTRv) amyloidosis, a disorder accompanied by axonal polyneuropathy, is often misdiagnosed as chronic inflammatory demyelinating polyneuropathy (CIDP). Prolongation of distally evoked compound muscle action potential duration (DCMAPD), an electrophysiological parameter of heterogeneous conduction delay at the distal part of the motor nerve suggesting demyelinating neuropathies, is included in an index of diagnostic criteria for CIDP. However, DCMAPDs are strongly influenced by low-frequency filtering (LFF) settings, which differ across hospitals worldwide.
Aim : To analyze DCMAPD in patients with ATTRv amyloidosis with polyneuropathy (ATTRv-PN).
Methods : DCMAPs of the median, ulnar, tibial, and peroneal nerves were recorded under LFF settings of 2, 10, and 20 Hz in 50 patients with ATTRv-PN. The changes of DCMAPD accompanied with the changes of LFF settings were analyzed. The appropriateness of the cut-off values of the DCMAPD in the latest criteria for CIDP, which defined under various LFF settings, was also validated in ATTRv-PN patients.
Results : The DCMAPD was shorter with increasing LFF settings. Less than 10％ of patients with ATTRv-PN demonstrated prolonged DCMAPD of the ulnar, tibial, and peroneal nerves. In contrast, ten patients demonstrated prolonged DCMAPD in the median nerve under LFF settings of 2, 10, and/or 20 Hz. Nine of the ten cases were complicated with carpal tunnel syndrome (CTS).
Conclusion : Prolongation of DCMAPDs in the ulnar, tibial, and peroneal nerves is rare in ATTRv-PN patients. DCMAPD analysis of the median nerve in patients with ATTRv-PN requires caution, because they frequently develop CTS and those with CTS may demonstrate prolonged DCMAPD.

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Background : Psychotic symptoms leading to self-harm and harm to others are a critical concern in treatment. This study aimed to investigate the characteristics and treatment methods of difficult-to-treat patients under the Medical Treatment and Supervision Act (MTSA) and long-term involuntary inpatients under the Mental Health and Welfare Act and assess the impact of the MTSA on psychiatric treatment.
Methods : Data were collected from 233 inpatients (179 men and 44 women) under the MTSA and 65 inpatients (58 men and 7 women) who were involuntarily hospitalized for >18 months due to the risk of self-harm or harm to others under the Mental Health and Welfare Act. We compared basic demographics and pharmacotherapy between the 102 inpatients under the MTSA and 53 inpatients under the Mental Health and Welfare Acts with psychotic disorders.
Results : Difficult-to-treat cases under the MTSA included 82 grievous bodily harm cases (35％), 80 murder cases (34％), 48 arson cases (21％), and cases of other offenses. Psychotic disorders were the most frequent primary diagnosis (85％), and comorbid psychiatric disorders were present in 68 cases (25.8％). In contrast, long-term hospitalizations under the Mental Health and Welfare Act were predominantly due to schizophrenia (80％). Comparative analysis of pharmacotherapy revealed higher usage of clozapine in the MTSA group and antipsychotic and anti-parkinsonian medications in the Mental Health and Welfare Act group.
Conclusion : These findings suggest that the MTSA encourages a reduction in the use of multiple antipsychotics and the adoption of clozapine in treatment regimens.

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Rheumatoid meningitis (RM) is a rare central nervous system disorder in patients with rheumatoid arthritis. A 72-year-old man with a history of rheumatoid arthritis developed sensorineural hearing loss on the left side 3 months ago ; he subsequently exhibited neurological symptoms, including dizziness, nausea, and impaired consciousness. He was diagnosed with RM after excluding malignancies and infections via systemic assessments, which included imaging and cerebrospinal fluid examinations. He was treated with corticosteroids, which improved his neurological symptoms despite the remaining hearing impairment. To the best of our knowledge, only four cases of sensorineural hearing loss in RM, including our patient, have been reported. Furthermore, this report demonstrates hearing impairment as a crucial symptom in RM diagnosis.

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