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Although CSI and GS are established prediction metrics in meteorological literature,3-6, 8, 10-12 few texts have translated them into medical literature.9, 13 We provide here the first translation of CSI and GS into epilepsy literature. We suggest CSI may be an appropriate measure to complement Sens, Spec, PPV and NPV, particularly as it allows combined interpretation of PPV and Sens whilst also avoiding the inflation of NPV and Spec when there are many TNs. GS may be a better metric when there are fewer TN and more CH. Based on the current findings, we suggest a CSI of ≥0.8 would be a reasonable threshold score for achieving diagnostic accuracy. Optimal diagnostic thresholds for GS remain to be elucidated.

Free-Cog is a recently described, hybrid screening instrument incorporating tests of cognitive and executive function. In this study, Free-Cog was reformulated as separate tests of cognitive function and executive function to examine whether this might improve screening accuracy for cognitive impairment (dementia and mild cognitive impairment) compared to the standard, unitary Free-Cog. The two separate tests, designated “Free-Cog-Cog” and “Free-Cog-Exec,” were either combined using the Boolean logical “AND” and “OR” operators (serial and parallel combination) or used to construct a stepwise decision tree. Serial combination improved specificity and positive predictive value whereas parallel combination improved sensitivity, findings typically observed when applying these operators. Stepwise application identified groups with high and low probability of cognitive impairment but failed to adequately differentiate those in the intermediate uncertain diagnosis group. Although the dataset used was relatively small, the findings of this study suggest little benefit for reformulations of Free-Cog compared to the standard, unitary instrument.

Many metrics exist for the evaluation of binary classifiers, all with their particular advantages and shortcomings. Recently, an “Efficiency Index” (EI) for the evaluation of classifiers has been proposed, based on the consistency (or matching) and contradiction (or mismatching) of outcomes. This metric and its confidence intervals are easy to calculate from the base data in a 2 × 2 contingency table, and their values can be qualitatively and semi-quantitatively categorised. For medical tests, in which context the Efficiency Index was originally proposed, it facilitates the communication of risk (of the correct diagnosis versus misdiagnosis) to both clinicians and patients. Variants of the Efficiency Index (balanced, unbiased) which take into account disease prevalence and test cut-offs have also been described. The objectives of the current paper were firstly to extend the EI construct to other formulations (balanced level, quality), and secondly to explore the utility of the EI and all four of its variants when applied to the dataset of a large prospective test accuracy study of a cognitive screening instrument. This showed that the balanced level, quality, and unbiased formulations of the EI are more stringent measures.

Epileptic seizures are increasingly recognized as part of the clinical phenotype of patients with Alzheimer’s disease (AD). However, the evidence base on which to make treatment decisions for such patients is slim, there being no clear recommendation based on systematic review of the few existing studies of anti-seizure drugs in AD patients. Here the authors examine the potential implications for the treatment of seizures in AD of the results of the recently published SANAD II pragmatic study, which examined the effectiveness of levetiracetam, zonisamide, or lamotrigine in newly diagnosed focal epilepsy, and of valproate and levetiracetam in generalized and unclassifiable epilepsy.

Aim: To examine three different accuracy metrics for evaluation of cognitive screening instruments: overall correct classification accuracy (Acc), the sum of true positives and negatives divided by the total number tested; balanced accuracy (balanced Acc), half of the sum of sensitivity and specificity; and unbiased accuracy (unbiased Acc), removing biasing effects of random associations between test results and disease prevalence. Materials & methods: Data from a prospective test accuracy study of Mini-Addenbrooke’s Cognitive Examination were used to calculate and plot the Acc measures. Results: Each Acc metric resulted in a similar pattern of results across the range of Mini-Addenbrooke’s Cognitive Examination cut-offs for diagnosis of both dementia and mild cognitive impairment. Acc and balanced Acc gave more optimistic outcomes (closer to possible maximum value of 1) than unbiased Acc. Conclusion: Unbiased Acc may have advantages over Acc and balanced Acc by removing biasing effects of random associations between test result and disease prevalence.

An “efficiency index” (EI) for the evaluation of binary classifiers was recently characterised, where EI is the ratio of classifier accuracy to inaccuracy. The purpose of this study was to further develop EI by substituting balanced accuracy and unbiased accuracy in place of accuracy, and their respective complements in place of inaccuracy, to construct balanced EI and unbiased EI measures. Additional investigations, using the dataset of a prospective pragmatic test accuracy study of a cognitive screening instrument, explored use of the log method to calculate confidence intervals for the various EI formulations; the dependence of EI formulations on prevalence; and comparison of EI formulations with analogous formulations based on the Identification Index (II), a previously described metric which is also based on accuracy and inaccuracy, where II is accuracy minus inaccuracy. EI formulations are shown to have advantages over II formulations, in particular their boundary values (0 and ∞) mean that negative values never occur, unlike the case for II, and the inflection point of 1 demarcates likelihood of correct versus incorrect classification.

This chapter considers the differential diagnosis of TGA. Key considerations include cerebrovascular disease (TIA, stroke), epilepsy (transient epileptic amnesia, TEA), and psychological causes, as well as a variety of other causes of transient amnesia (migraine, drugs, hypoglycaemia, head injury). On clinical grounds alone, it is often possible to distinguish TGA from other causes of transient amnesia.

This chapter begins with a consideration of the typical clinical features of an attack of TGA. Although relatively stereotyped, nevertheless different authors have used the “TGA” terminology to describe different events characterised by transient amnesia. Following the description of possible boundaries for what might be included or excluded from the TGA label, diagnostic criteria were developed by Hodges and Warlow in 1990 for definite or pure TGA. Whether variants of TGA exist is still uncertain; if so, they are much rarer, gauged by the frequency of published reports.

First published over 400 years ago, this new edition of Robert Burton's The Anatomy of Melancholy still has the capacity to engage and edify readers in ways which may impact on their clinical practice.

INTRODUCTION: The UK uses the 2-week-wait (2WW) pathway for rapid access to cancer services. It is unclear whether this is effective for brain cancer. METHODS: We retrospectively analysed all 2WW referrals for brain cancer between 2009 and 2016 in a district general neurology department. We compared clinical presentations to national guidelines and diagnoses of brain cancer. RESULTS: Of the 153 cases analysed, four brain cancers were identified: two glioblastomas and two metastases. Headaches were the most common referral. The end diagnosis was mostly migraine. The highest positive predictive value was for behavioural/personality change (5.3%) and sub-acute neurological deficit (3.2%). There was no significant association between any symptom(s) and brain cancer. CONCLUSION: The 2WW pathway is not effective in the diagnosis of brain cancer. Resources are better directed towards clinical research and treatment trials. Headache remains the most common reason for referral although it is not yet a reliable indicator of brain cancer.