Understanding the pathophysiology of idiopathic intracranial hypertension (IIH): a review of recent developments.

Idiopathic intracranial hypertension (IIH) is a condition of significant morbidity and rising prevalence. It typically affects young people living with obesity, mostly women of reproductive age, and can present with headaches, visual abnormalities, tinnitus and cognitive dysfunction. Raised intracranial pressure without a secondary identified cause remains a key diagnostic feature of this condition, however, the underlying pathophysiological mechanisms that drive this increase are poorly understood. Previous theories have focused on cerebrospinal fluid (CSF) hypersecretion or impaired reabsorption, however, the recent characterisation of the glymphatic system in many other neurological conditions necessitates a re-evaluation of these hypotheses. Further, the impact of metabolic dysfunction and hormonal dysregulation in this population group must also be considered. Given the emerging evidence, it is likely that IIH is triggered by the interaction of multiple aetiological factors that ultimately results in the disruption of CSF dynamics. This review aims to provide a comprehensive update on the current theories regarding the pathogenesis of IIH.

Development and validation of a peripheral cell ratio and lactate score for differentiating status epilepticus from prolonged psychogenic nonepileptic seizures.

OBJECTIVE: Differentiating status epilepticus (SE) from prolonged psychogenic nonepileptic seizures (pPNES) can be difficult clinically. We aimed to define the utility of peripheral cell counts, cell ratios, and lactate levels in distinguishing SE from pPNES. METHODS: Retrospective two-center study investigating the sensitivity and specificity of acute (≤12 h of event offset) peripheral cell counts, cell ratios (neutrophil-lymphocyte ratio, neutrophil-monocyte ratio, monocyte-lymphocyte ratio, platelet-lymphocyte ratio, systemic immune-inflammatory index [SII], systemic inflammatory response index [SIRI]), and lactate levels in differentiating SE from pPNES. Patients were identified from two tertiary hospitals, with one forming the development cohort and the other the validation cohort. Using generalized additive models to generate biomarker vs time curves, optimal blood collection times were defined for set parameters. Three diagnostic scores combining neutrophil count, SII, or SIRI with lactate levels were developed and validated in separate cohorts. RESULTS: For the development cohort, 1262 seizure-like events were reviewed and 79 SE and 44 pPNES events were included. For the validation cohort, 241 events were reviewed and 20 SE and 11 pPNES events were included. Individually, the biomarkers generally had low sensitivity and reasonable specificity for differentiating SE from pPNES, with the neutrophil count, SIRI, and SII performing best with sensitivities of 0.65-0.84, specificities of 0.64-0.89, and ROC AUCs of 0.78-0.79. Lactate levels peaked at 60 min, while cell counts and ratios peaked after 240 min. Combining early peaking lactate levels and later peaking neutrophil count, SIRI or SII resulted in three scores that improved predictive potential with sensitivities of between 0.75 and 0.79, specificities between 0.93 and 1.00, and ROC AUCs of 0.89-0.91. SIGNIFICANCE: Lactate levels peak early post-SE, whereas cell counts and ratios do so later. The differing post-event time profiles of lactate levels vs neutrophil count, SIRI, and SII allow incorporation into three separate scores which can assist in differentiating SE from pPNES.

Ambiguous medical abbreviation study: challenges and opportunities.

BACKGROUND: Healthcare workers often abbreviate for convenience, but ambiguous abbreviations may cause miscommunication, which jeopardises patient care. Robust large-scale research to quantify abbreviation frequency and ambiguity in medical documents is lacking. AIMS: To calculate the frequency of abbreviations used in discharge summaries, the proportion of these abbreviations that are ambiguous and the potential utility of auto-expansion software. METHODS: We designed a software programme to extract all instances of abbreviations from every General Medical Unit discharge summary from the Royal Melbourne Hospital in 2015. We manually expanded abbreviations using published inventories and clinical experience, logging multiple expansions for any abbreviation if identified. Abbreviations were classified based on well defined criteria as standardised and likely to be well understood, or ambiguous. Outcome measures included the range and frequency of standardised and ambiguous abbreviations, and the feasibility of electronic auto-expansion software based on these measures. RESULTS: Of the 1 551 537 words analysed from 2336 documents, 137 997 (8.9%) were abbreviations with 1741 distinct abbreviations identified. Most abbreviations (88.7%) had a single expansion. The most common abbreviation was PO (per os/orally), followed by BD (bis in die/twice daily) and 68.1% of abbreviations were standardised, largely pertaining to pathology/chemicals. This meant, however, that a large proportion (31.9%) of abbreviations (2.8% of all words) were ambiguous. The most common ambiguous abbreviation was Pt (patient/physiotherapy), followed by LFT (liver function test/lung function test). CONCLUSIONS: Close to one-third of abbreviations used in general medical discharge summaries were ambiguous. Electronic auto-expansion of ambiguous abbreviations is likely to reduce miscommunication and improve patient safety.