Citations

Objective. To report an unusual cause of coma in an adult.Design. Case report.Setting. University teaching hospital.Patient. A previously healthy 53-year-old man initially presented with altered mental status and progressed to coma. He was found to be substantially hyperammonemic and did not improve with lactulose therapy and continuous venovenous hemodialysis.Results. Biochemical testing revealed previously undiagnosed ornithine transcarbamylase deficiency, and the patient responded to arginine, sodium phenylacetate, and sodium benzoate.Conclusion. Even in adult patients with no known history, inborn errors of metabolism must be considered in the differential diagnosis of unexplained coma. Defects of the urea cycle can present with an unprovoked hyperammonemic coma.

Objectives/HypothesisAssess the role of retropharyngeal lymph node dissection in oropharyngeal squamous cell carcinoma treated with transoral robotic surgery (TORS).Study DesignProspective case series.MethodsRetrospective analysis of 72 patients with oropharyngeal squamous carcinoma treated with transoral oropharyngectomy, neck dissection, and retropharyngeal node dissection.ResultsEight of 55 (14.5%) patients with tonsil primaries had retropharyngeal metastases in contrast to none with tongue base primaries. The presence of pathologically positive retropharyngeal nodes was associated with clinical tumor (T) (P=.002) and node (N) stage (P=.007), preoperative computed tomography (CT) (P<.001), and positron emission tomography (PET)‐CT scan (P<.001). The negative predictive value of early T (Tx,1‐2) and N stage (N0‐N2a) was 91.7% and 100%, respectively. Preoperative CT and PET‐CT both yielded a positive predictive value of 100%, while the negative predictive value of imaging was optimized to 95.3% when these modalities were combined.ConclusionsIn patients with tonsil cancer the risk of retropharyngeal metastases is negligible in the presence of clinically T1‐2, N0‐N2a disease and negative CT and PET‐CT. We estimate that 40% of patients meet these criteria and may safely forego treatment of the retropharyngeal nodes. Approximately 10% of patients will have positive imaging and we recommend retropharyngeal node dissection at the time of surgery to treat macroscopic disease. In the remaining patients at risk for retropharyngeal node involvement, adjuvant radiotherapy is generally indicated based on other adverse features, and these nodes may be incorporated into the treatment field.Level of Evidence4. Laryngoscope, 2013

ABSTRACTIntroductionThe clinical significance of striational antibodies (StrAbs) detected in the course of paraneoplastic antibody testing is unknown.MethodsWe compared all 203 striational antibody (StrAb)‐seropositive patients identified (2004–2005) during evaluation for paraneoplastic antibodies with age‐ and sex‐matched seronegative controls.ResultsThymoma and myasthenia gravis (MG) were significantly more common among cases (P<0.0001). Cancers more rarely detected after StrAb detection were adenocarcinoma in 5 patients and sarcoma in 3 patients. All patients who had a cancer identified after StrAb testing had a titer of ≥1:7680 or a coexisting muscle AChR‐binding antibody. Autoimmune disorders more commonly observed among cases (with any StrAb value) included: hypothyroidism; rheumatoid arthritis; and pernicious anemia (all P<0.05).ConclusionsStrAbs may serve as a diagnostic clue for an autoimmune diagnosis. There is a low likelihood of oncological significance in patients with StrAb titers <1:7680 without coexisting paraneoplastic Abs. Muscle Nerve, 2013

Traumatic brain injury (TBI) is a global public health epidemic. In the US alone, more than 3 million people sustain a TBI annually. It is one of the most disabling injuries as it may cause motor and sensory deficits and lead to severe cognitive, emotional, and psychosocial impairment, crippling vital areas of higher functioning. Fueled by the recognition of TBI as the “signature injury” in our wounded soldiers in Iraq and Afghanistan, and its often devastating impact on athletes playing contact sports, interest in TBI and TBI research has increased dramatically. Unfortunately, despite increased awareness of its detrimental consequences, there has been little progress in developing effective TBI interventions. Recent evidence, however, strongly indicates that nutritional intervention may provide a unique opportunity to enhance the neuronal repair process after TBI. To date, two omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have the most promising laboratory evidence for their neuro-restorative capacities in TBI. Although both animal models and human studies of brain injuries suggest they may provide benefits, there has been no clinical trial evaluating the effects of n-3 fatty acids on resilience to, or treatment, of TBI. This article reviews the known functions of n-3 fatty acids in the brain and their specific role in the cellular and biochemical pathways underlying neurotraumatic injury. We also highlight recent studies on the therapeutic impact of enhanced omega 3 intake in vivo , and how this may be a particularly promising approach to improving functional outcome in patients with TBI.

Genome‐wide association studies (GWAS) of complex traits have generated many association signals for single nucleotide polymorphisms (SNPs). To understand the underlying causal genetic variant(s), focused DNA resequencing of targeted genomic regions is commonly used, yet the current cost of resequencing limits sample sizes for resequencing studies. Information from the large GWAS can be used to guide choice of samples for resequencing, such as the SNP genotypes in the targeted genomic region. Viewing the GWAS tag‐SNPs as imperfect surrogates for the underlying causal variants, yet expecting that the tag‐SNPs are correlated with the causal variants, a reasonable approach is a two‐phase case‐control design, with the GWAS serving as the first‐phase and the resequencing study serving as the second‐phase. Using stratified sampling based on both tag‐SNP genotypes and case‐control status, we explore the gains in power of a two‐phase design relative to randomly sampling cases and controls for resequencing (i.e., ignoring tag‐SNP genotypes). Simulation results show that stratified sampling based on both tag‐SNP genotypes and case‐control status is not likely to have lower power than stratified sampling based only on case‐control status, and can sometimes have substantially greater power. The gain in power depends on the amount of linkage disequilibrium between the tag‐SNP and causal variant alleles, as well as the effect size of the causal variant. Hence, the two‐phase design provides an efficient approach to follow‐up GWAS signals with DNA resequencing.

Although comorbidity among complex diseases (e.g., drug dependence syndromes) is well documented, genetic variants contributing to the comorbidity are still largely unknown. The discovery of genetic variants and their interactions contributing to comorbidity will likely shed light on underlying pathophysiological and etiological processes, and promote effective treatments for comorbid conditions. For this reason, studies to discover genetic variants that foster the development of comorbidity represent high‐priority research projects, as manifested in the behavioral genetics studies now underway. The yield from these studies can be enhanced by adopting novel statistical approaches, with the capacity of considering multiple genetic variants and possible interactions. For this purpose, we propose a bivariate Mann‐Whitney (BMW) approach to unravel genetic variants and interactions contributing to comorbidity, as well as those unique to each comorbid condition. Through simulations, we found BMW outperformed two commonly adopted approaches in a variety of underlying disease and comorbidity models. We further applied BMW to datasets from the Study of Addiction: Genetics and Environment, investigating the contribution of 184 known nicotine dependence (ND) and alcohol dependence (AD) single nucleotide polymorphisms (SNPs) to the comorbidity of ND and AD. The analysis revealed a candidate SNP from CHRNA5, rs16969968, associated with both ND and AD, and replicated the findings in an independent dataset with a P‐value of 1.06 × 10–03.