Clinical Evaluation of Posterior Canal Benign Paroxysmal Positional Vertigo

Background: Benign paroxysmal positional vertigo (BPPV) is a mechanical peripheral vestibular disorder which may involve any of the three semicircular canals but principally the posterior. In as much as the literature has described theories to explain the mechanism of BPPV and also contains scholarly works that elucidate BPPV; its management remains an enigma to most clinicians. To this end; this work was aimed at outlining an evidence-based best practice for most common form of BPPV. Materials and Methods: A systematic review of the literature was conducted between 1948 and June 2011 in PubMed; Embase; Ovid; and Cochrane database through the online Library of the University of Cape Town. Seventy-nine worthy articles that addressed the study were selected on consensus of the two authors. Conclusion: There is consensus for the use of canalith repositioning procedures as the best form of treatment for posterior canal canalolithiasis. However; successful treatment is dependent on accurate identification of the implicated canal and the form of lithiasis. Furthermore; clinicians should note that there is no place for pharmacological treatment of BPPV; unless it is to facilitate repositioning

The Sensitivity and Specificity of Lassa Virus IgM by ELISA as Screening Tool at Early Phase of Lassa Fever Infection

"Background: Early diagnosis; prompt treatment; and disease containment are vital measures in the management of Lassa fever (LF); a lethal and contagious arenaviral hemorrhagic disease prevalent in West Africa. Lassa Virus (LAV)-specific Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) test; the gold standard for diagnosis; is unavailable in most centers. Serologic detection of LAV IgM is a more accessible tool and this work was to investigate its adequacy as an early marker for LF. Patients and Methods: A prospective case-control study conducted July 2007-March 2011 in a tertiary referral health center in Nigeria. Blood samples for test and control were evaluated for Lassa specific antigens and IgM using RT-PCR (primers S36+ and LVS 339) and indirect ELISA (Lassa Nucleo-protein (NP)-Antigen) respectively. RT-PCR outcome was used as standard to test for the sensitivity and specificity of IgM. Results: Of the 37 confirmed cases of LF infection by RT-PCR; 21 (57) were IgM positive. Amongst the 35 confirmed negative cases (control group); eight were IgM positive. The diagnostic sensitivity and specificity of the IgM assay were 57 and 77 respectively. The negative and positive predictive values of the IgM serological assay were 63 and 72 ; respectively; while the efficiency of the test was 67. Conclusion: The specificity and sensitivity of IgM as a screening tool for early detection of LF appear weak and; hence; the need for a reliable LF ""rapid screening kit"" since RT-PCR is unavailable in most centers. In the interim; ""high clinical index of suspicion;"" irrespective of IgM status; requires urgent referral to confirmatory centers."