[A comparative analysis of the clinical symptoms of benign paroxysmal positional vertigo between older and young and middle-aged patients]

Objective: To compare the differences in clinical symptoms and the time required for diagnosis of benign paroxysmal positional vertigo (BPPV) between older patients and young and middle-aged patients in the structured inquiry of dizziness history. Methods: The medical records of 6 807 patients diagnosed with BPPV from the Vertigo Database of Vertigo Clinical Diagnosis, Treatment, and Research Center of Beijing Tiantan Hospital, Capital Medical University, between January 2019 and October 2021 were retrospectively analyzed. The data included basic demographic information, clinical symptoms in a structured medical history questionnaire, and the time interval from the appearance of BPPV symptoms to diagnosis consultation. The patients were divided into the young and middle-aged group (<65 years old) and the older group (≥65 years old). The differences in clinical symptoms and consultation time were compared between these two groups. Categorical variables were represented by numbers (%), and compared using Chi-squared tests or Fisher's exact probability test for analysis; whereas, continuous variables conforming to normal distribution were represented by mean±standard deviation. Both data groups were compared and analyzed by Student's t-test. Results: The mean age of the older group was 65-92 (71±5) years, while the mean age of the middle-aged group was 18-64 (49±12) years. The incidence of vertigo (42.5% vs. 49.1%, χ²=23.69, P<0.001); vertigo triggered by changes in position of the head or body (52.4% vs. 58.7%, χ²=22.31, P<0.001); and autonomic symptoms (10.1% vs. 12.4%, χ²=7.09, P=0.008) were lower, but hearing loss (11.8% vs. 7.8%, χ²=27.36, P<0.001) and sleep disorders (18.5% vs. 15.2%, χ²=11.13, P=0.001) were higher in the older group than in the young and middle-aged group. The time from the appearance of dizziness to diagnosis was commonly longer in the older patient group than the other group (55.0% vs. 38.5%, χ²=55.95, P<0.001). Conclusions: Older patients with BPPV have more atypical symptoms and complex concomitant symptoms than young and middle-aged patients. For older patients with dizziness, positional testing is needed to confirm the possibility of BPPV even if the clinical symptoms are atypical.

Monitoring of filarial antigens in jirds and patients after treatment

We developed a sandwich ELISA with monoclonal antibodies to monitor filarial antigens in animals and patients after infection and treatment. Levels of antimicrofilarial antibodies and parasite antigens were measured periodically in 40 B. malayi infected jirds. In all animals L3 HC11 antigen was detected earlier than Mf ES34 antigen, while antimicrofilarial antibodies appeared much more slowly. These serologic changes precede the onset of patent infections. After 3 courses of treatment with DEC and M170, the levels of parasite antigen in sera and of Mf in peritoneal cavities were monitored in 23 infected jirds. In 8 jirds Mf became negative, no adult worms were found in 7 jirds and a single degenerating female worm was present in 1 jird. ES34 and HC11 were undetectable in 8/8 and 6/8 necropsy sera. Mf persisted in 11 animals, 9 jirds were necropsied, 8 contained adult worms. Detectable levels of ES34 or HC11 antigen were present in 7/9 and 8/9 from these animals. In sham-treatment, few changes were noted in control animals. Thus, parasitological findings at necropsy are correlated with the results of antigen detection assay. We analyzed serial serum samples from 32 bancroftian microfilaremia collected 1-42 months after DEC therapy. Mf resolved rapidly in all treated individuals. ES34 disappeared faster than HC11, 3 months after treatment. Levels of ES34 and HC11 antigens remained detectable or rising after treatment in 8 and 10 individuals. Four patients' Mf recurred 20-42 months after treatment. These findings show that the remaining or a rise in serum levels of antigen after therapy predicts recurrent microfilaremia in patients and additional treatment is needed.

Parasite antigenemia in untreated and treated lymphatic filarial infections

To evaluate the merit of antigen detection assays as a tool to monitor the efficacy of chemotherapy for lymphatic filariasis, we serially measured antigen levels in sera from jirds infected with Brugia malayi and from humans with bancroftian filariasis. Antigenemia was detected in all animals with parasitologically proven infection and was present in jirds with prepatent or occult filariasis. Antigen levels correlated with worm burdens, and progressively declined in drug-cured animals. Treatment with diethylcarbamazine (DEC) triggered a transient increase in serum levels of filarial antigens bearing the epitope recognized by the monoclonal antibody HC 11. All patients with bancroftian filariasis became amicrofilaremic within one week after DEC treatment. Antigenemia levels slowly declined over a period of several months in all but one treated individual. Forty-two months after treatment, progressively rising antigen levels are present in 10 patients. Six of these remain amicrofilaremic; in the other 4, elevated antigenemia levels preceded or were detected at the same time as recurrent parasitemia. Periodic monitoring of antigenemia levels after treatment of patients with lymphatic filariasis can be used to identify individuals who are likely to develop recurrent microfilaremia before the parasites become detectable in blood samples, thereby allowing timely retreatment.