Impact of endolymphatic hydrops on the function of the horizontal canal during caloric stimulation in Ménière's disease.

PURPOSE: When a dizzy patient with episodic vertigo has an abnormal caloric and a normal video head impulse test (vHIT), this caloric-vHIT dissociation provides vital information for a diagnosis of Ménière's disease (MD). Endolymphatic hydrops (EH), a histological marker of MD, is hypothesized to be involved in the caloric-vHIT dissociation in MD through hydropic duct distension of the horizontal semicircular canal (SC). This study was designed to determine the impact of EH on the function of horizontal SC during caloric stimulation. METHODS: Caloric test and vHIT were used to evaluate the function of horizontal SC every six months, annual magnetic resonance imaging (MRI) was used to evaluate the degree of EH size in the vestibule, and monthly vertigo and hearing evaluation was done for 12 months. EH shrinkage was defined as the size change of vestibular EH from significant to none. RESULTS: Among 133 MD patients evaluated for eligibility, 67 patients with caloric-vHIT dissociation entered the study. Fifteen participants had EH shrinkage (G-I), while 52 participants had no remarkable EH change (G-II). Average values (IQR) of the maximum slow phase velocity in G-I and G-II were 29.6 (13.0-34.0) and 25.9 (17.3-31.3), respectively, at baseline, 26.1 (9.0-38.0) and 23.6 (18.0-28.3) at 12 months. Two-factor repeated-measures ANOVA showed no significant differences between the groups (P = 0.486). The values of vestibulo-ocular reflex gain of the horizontal SC in G-I and G-II remained above 0.8 during the study period. CONCLUSIONS: EH detected by MRI shows limited correlation with caloric stimulation results.

A Case Report of Pembrolizumab-Induced Allergic Hepatitis.

The immune checkpoint inhibitor pembrolizumab is now considered a first-line treatment for recurrent or metastatic head and neck squamous cell cancer. Pembrolizumab is less toxic than conventional chemotherapy but may result in immune-related adverse events. We report a case in which liver injury occurred just two days after the administration of pembrolizumab plus chemotherapy. A 48-year-old woman achieved a complete response after chemoradiotherapy for cT2N3bM0 squamous cell carcinoma of the oropharynx with multiple lymph node metastases. However, the tumor recurred one year later, and she was started on pembrolizumab plus chemotherapy. On day 3, her alanine aminotransferase and aspartate transaminase concentrations markedly increased. She was initially diagnosed with drug-induced liver injury and all medications were withdrawn. Her liver function recovered within two weeks without intervention. The lymphocyte transformation test was only positive for pembrolizumab. Clinicians should consider pembrolizumab-induced allergic hepatitis as a possible cause of liver injury after excluding liver metastasis and immune-related adverse events.