Purpose: To report a case of transient cortical blindness following cervical transforaminal epidural injection.Case summary: A 58-year-old diabetic and hypertensive male was referred to the ophthalmology department with sudden-onset bilateral visual disturbances after cervical transforaminal epidural injection for neck pain. During the procedure, an intravascular contrast medium was injected into the left vertebral artery. Immediately after the injection, the patient complained of bilateral visual disturbances, mild headache, and dizziness. Twelve hours after the procedure, his visual acuity was reduced to hand motion perception in both eyes. Anterior segment and fundus examinations were unremarkable. Pupillary light reflexes and extraocular muscle movements were normal. Brain magnetic resonance imaging, magnetic resonance angiography, and fluorescein angiography showed no significant findings. There were no other neurological abnormalities. The patient was treated conservatively with intravenous dexamethasone and nimodipine based on a provisional diagnosis of transient cortical blindness. The symptoms gradually improved 2 days after the procedure; visual acuity recovered to 20/20 by the third day. Conclusions Although contrast-induced transient cortical blindness is rare, it should be considered in patients with bilateral visual loss after transforaminal epidural injection. It is a benign and reversible condition but requires a prompt diagnosis.

Background: and PurposeMonoclonal antibodies (mAbs) targeting calcitonin-gene-related peptide (CGRP) or its receptor (anti-CGRP-R) have been widely administered to patients with migraine who show inadequate responses to preventive medications. Among patients in whom a particular anti-CGRP-R mAb is ineffective, switching between different anti-CGRP-R mAbs can be the next option. Few studies have investigated treatment outcomes for antibody switching, especially between mAbs with the same target of the CGRP ligand. We aimed to determine the treatment outcome after switching between two anti-CGRP mAbs (galcanezumab to fremanezumab). Methods: We identified migraine patients in a prospective headache clinic registry who received galcanezumab for ≥3 months and were switched to fremanezumab for a further ≥3 months at a single university hospital. We defined a treatment response as a ≥50% reduction in the number of days with a moderate or severe headache at the third month of treatment relative to baseline. The treatment response after switching to fremanezumab was compared with the initial treatment response to galcanezumab. Results: Among 21 patients identified in the registry, 7 (33.3%) were initial responders to galcanezumab. After switching to fremanezumab, 7 (33.3%) showed a treatment response. The treatment response rate was 28.6% in the initial responders and 71.4% in the nonresponders to galcanezumab (p>0.999). Conclusions Switching between anti-CGRP mAbs (galcanezumab to fremanezumab) yielded a treatment outcome comparable to that reported previously when switching from an anti-CGRP-R mAb (erenumab) to an anti-CGRP mAb (galcanezumab or fremanezumab). The treatment response to fremanezumab seems to be independent of the prior treatment response to galcanezumab. Our findings suggest that switching to another anti-CGRP mAb can be considered when a particular anti-CGRP mAb is ineffective or intolerable.

Background: The median-to-ulnar comparison test (MUCT), and increasingly, ultrasonography (US) are considered as complementary to and more sensitive than median nerve conduction study (NCS) in diagnosing carpal tunnel syndrome (CTS). Methods: In consecutive patients with hand paresthesia compatible with CTS but with normal median NCS, we additionally performed the MUCT and analyzed whether it yielded better diagnostic sensitivity. Results: In total, 163 hands of clinically diagnosed CTS patients were examined with routine NCS. The MUCT and US were performed in 81 hands and 31 hands, respectively. While median NCS was diagnostic in 85 (52.1%) hands, MUCT failed to demonstrate superior sensitivity over median NCS in the other hands and US revealed related abnormalities better than both routine NCS (p=0.006) and MUCT (p=0.002). Conclusions The MUCT offered no additional diagnostic benefit. On the other hand, sonographic examination had higher sensitivity for the diagnosis of CTS when applying several diagnostic criteria. Thus, US could be the screening test for diagnosing CTS prior to NCS with higher sensitivity than MUCT. However, further studies are needed to define the appropriate diagnostic criteria for US.

Background: The median-to-ulnar comparison test (MUCT), and increasingly, ultrasonography (US) are considered as complementary to and more sensitive than median nerve conduction study (NCS) in diagnosing carpal tunnel syndrome (CTS). Methods: In consecutive patients with hand paresthesia compatible with CTS but with normal median NCS, we additionally performed the MUCT and analyzed whether it yielded better diagnostic sensitivity. Results: In total, 163 hands of clinically diagnosed CTS patients were examined with routine NCS. The MUCT and US were performed in 81 hands and 31 hands, respectively. While median NCS was diagnostic in 85 (52.1%) hands, MUCT failed to demonstrate superior sensitivity over median NCS in the other hands and US revealed related abnormalities better than both routine NCS (p=0.006) and MUCT (p=0.002). Conclusions The MUCT offered no additional diagnostic benefit. On the other hand, sonographic examination had higher sensitivity for the diagnosis of CTS when applying several diagnostic criteria. Thus, US could be the screening test for diagnosing CTS prior to NCS with higher sensitivity than MUCT. However, further studies are needed to define the appropriate diagnostic criteria for US.

Background: Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is an under-recognized cause of heart failure (HF) with clinical phenotypes that vary across regions and genotypes.We sought to characterize the clinical characteristics of ATTR-CM in Asia. Methods: Data from a nationwide cohort of patients with ATTR-CM from six major tertiary centres in South Korea were analysed between 2010 and 2021. All patients underwent clinical evaluation, biochemical laboratory tests, echocardiography, and transthyretin (TTR) genotyping at the time of diagnosis. The study population comprised 105 Asian ATTR-CM patients (mean age: 69 years; male: 65.7%, wild-type ATTR-CM: 41.9%). Results: Among our cohort, 18% of the patients had a mean left ventricular (LV) wall thickness < 12 mm. The diagnosis of ATTR-CM increased notably during the study period (8 [7.6%] during 2010–2013 vs. 22 [21.0%] during 2014–2017 vs. 75 [71.4%] during 2018–2021).Although the duration between symptom onset and diagnosis did not differ, the proportion of patients with HF presenting mild symptoms increased during the study period (25% NYHA class I/II between 2010–2013 to 77% between 2018–2021). In contrast to other international registry data, male predominance was less prominent in wild-type ATTR-CM (68.2%). The distribution of TTR variants was also different from Western countries and from Japan.Asp38Ala was the most common mutation. Conclusion A nationwide cohort of ATTR-CM exhibited less male predominance, a proportion of patients without increased LV wall thickness, and distinct characteristics of genetic mutations, compared to cohorts in other parts of the world. Our results highlight the ethnic variation in ATTR-CM and may contribute to improving the screening process for ATTR-CM in the Asian population.