A 71-year-old woman with normal renal function one month prior to presentation was diagnosed with shingles on her right thigh and received valacyclovir (VACV 3,000 mg/day). She was subsequently admitted to the hospital for evaluation of renal dysfunction and impaired consciousness. Acyclovir (ACV) neurotoxicity was suspected, and VACV was discontinued with initiation of continuous renal replacement therapy. Her symptoms resolved. Blood tests revealed a blood ACV level of 57.5 μg/mL. The patient was diagnosed with ACV neurotoxicity based on her clinical course. Clinicians should be mindful that renal dysfunction and ACV neurotoxicity may occur even in patients with normal renal function before treatment. Among all reported cases of ACV neurotoxicity in patients with normal renal function before VACV administration, 9 of 10 patients were aged > 65 years. Thus, these studies support our findings that elderly patients warrant special attention. ACV neurotoxicity symptoms are nonspecific but may improve with early diagnosis and drug discontinuation. The incidence of shingles is increasing in recent years, and the number of VACV prescriptions in primary care is expected to increase. Primary care physicians should be familiar with ACV neurotoxicity to ensure the prompt diagnosis of this condition.

Ankle exercises are useful for preventing deep vein thrombosis, as they increase venous blood flow velocity. The cause for the increased venous blood flow velocity during ankle exercises may be the skeletal-muscle pump, but the mechanism is not clearly understood. The purpose of this study was to investigate the effects of the dorsiflexion angle and gastrocnemius muscle contraction on venous blood flow velocity during ankle exercises and to investigate the mechanism of the increase in venous blood flow velocity. The blood flow velocity in the popliteal vein, ankle joint angle, and surface electromyographic activity of the gastrocnemius muscle were measured at rest and during ankle exercises in the prone position in young healthy volunteers. The significant increase in venous blood flow velocity was observed during dorsiflexion phase, max dorsiflexion and during planter flexion phase. The peak venous blood flow velocity was different in each subject and classified into four types. The correlations of venous blood velocity to ankle joint angle and with the surface electromyographic activity of the gastrocnemius muscle were not statistically significant. These findings suggest that venous blood flow velocity increases not only during plantar flexion and dorsiflexion.