Extended lumbar drainage in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis of diagnostic test accuracy.

BACKGROUND: When appropriately selected, a high proportion of patients with suspected idiopathic normal pressure hydrocephalus (iNPH) will respond to cerebrospinal fluid diversion with a shunt. Extended lumbar drainage (ELD) is regarded as the most accurate test for this condition, however, varying estimates of its accuracy are found in the current literature. Here, we review the literature in order to provide summary estimates of sensitivity, specificity, positive- and negative predictive value for this test through meta-analysis of suitably rigorous studies. METHODS: Studies involving a population of NPH patients with predominantly idiopathic aetiology (>80%) in which the intention of the study was to shunt patients regardless of the outcome of ELD were included in the review. Various literature databases were searched to identify diagnostic test accuracy studies addressing ELD in the diagnosis of iNPH. Those studies passing screening and eligibility were assessed using the QUADAS-2 tool and data extracted for bivariate random effects meta-analysis. RESULTS: Four small studies were identified. They showed disparate results concerning diagnostic test accuracy. The summary estimates for sensitivity and specificity were 94% (CI 41-100%) and 85% (CI 33-100%), respectively. The summary estimates of positive and negative predictive value were both 90% (CIs 65-100% and 48-100%, respectively). CONCLUSION: Large, rigorous studies addressing the diagnostic accuracy of ELD are lacking, and little robust evidence exists to support the use of ELD in diagnostic algorithms for iNPH. Therefore, a large cohort study, or ideally an RCT, is needed to determine best practice in selecting patients for shunt surgery.

Dupuytren's contracture: emerging insight into a Viking disease.

Dupuytren's disease is a fibroproliferative condition of the palm, with a predilection for men, which has affected Northern Europeans since the Viking conquests. Although strongly heritable, clear evidence exists for environmental factors that modify the underlying genetic risk, such as diabetes, heavy drinking, and smoking. Evidence also exists for epilepsy (probably due to treatment with certain anti-epileptic drugs), and Human Immunodeficiency Virus infection. Recent large studies have shown no relationship with manual labour or vibrating tools. Two theories have emerged regarding the pathogenic mechanism: the first attributes the aberrant healing process that characterises Dupuytren's to free radicals, generated as a result of microangiopathy, whereas the second cites a genetic tendency toward apoptosis-resistant myofibroblasts. Despite only one study demonstrating linkage, emerging data from genome-wide association studies highlight a series of single nucleotide polymorphisms near members of the Wnt signalling pathway, and transcriptional profiling studies have consistently identified certain components of the extracellular matrix.

Not always asthma: clinical and legal consequences of delayed diagnosis of laryngotracheal stenosis.

Laryngotracheal stenosis (LTS) is a rare condition that occurs most commonly as a result of instrumentation of the airway but may also occur as a result of inflammatory conditions or idiopathically. Here, we present the case of a patient who developed LTS as a complication of granulomatosis with polyangiitis (GPA), which was misdiagnosed as asthma for 6 years. After an admission with respiratory symptoms that worsened to the extent that she required intubation, a previously well 14-year-old girl was diagnosed with GPA. Following immunosuppressive therapy, she made a good recovery and was discharged after 22 days. Over subsequent years, she developed dyspnoea and "wheeze" and a diagnosis of asthma was made. When she became pregnant, she was admitted to hospital with worsening respiratory symptoms, whereupon her "wheeze" was correctly identified as "stridor," and subsequent investigations revealed a significant subglottic stenosis. The delay in diagnosis precluded the use of minimally invasive therapies, with the result that intermittent laser resection and open laryngotracheal reconstructive surgery were the only available treatment options. There were numerous points at which the correct diagnosis might have been made, either by proper interpretation of flow-volume loops or by calculation of the Empey or Expiratory Disproportion Indices from spirometry data.