Application of the Bayesian network theory in clinical trial data: Severity shift in spasticity numeric rating scale in patients with multiple sclerosis.

BACKGROUND: Data digitization expands data collection opportunities, representing both a chance to understand interrelationships between variables and a challenge to identify the most appropriate clinical factors. Applications of causal inference techniques to clinical trial data is becoming very attractive, especially with the intent to provide insights into the relationships between baseline characteristics and outcomes. Graphical representations of model structures and conditional probabilities can be powerful tools to illustrate relationships in a high-dimensional data setting. METHODS: We review and apply Bayesian network theory to a clinical case study, presenting an analytical approach to investigating and visualizing causal relationships. We propose the use of the adherence score to compare data networks' patterns based on different variables' discretization. Data from adult patients with spasticity related to multiple sclerosis (MSS) from two randomized placebo-controlled clinical trials of nabiximols were used as analysis sets. The training and validation sets included 106 (53 treated, 53 placebo) and 155 (76 treated, 79 placebo) participants, respectively. The primary objective was to create a network and estimate the causal dependencies between participants' characteristics, changes in MSS severity as reflected by shifts in the patient-reported numeric rating scale (NRS), and changes in symptoms, functional abilities, and quality of life factors. RESULTS: A causal network was identified between the key factors of assigned treatment, end of study spasticity NRS, and mental health/vitality subscales of the 36-Item Short Form Health Survey questionnaire (4 nodes and 3 edges; adherence score = 93%). In patients with mild spasticity, the impact of nabiximols on mental health or vitality subscales resulted in a probability ratio of 1.63. The decomposed mediation effect of spasticity NRS was observed through a mediation analysis between treatment and mental health (99.4%) or vitality (93.7%) subscales. CONCLUSIONS: The use of innovative methods such as causal networks is highly encouraged to identify dependent relationships among key factors in clinical trial data and drive insights for additional research.

Acute Elemental Mercury Poisoning Masquerading as Fever and Rash.

This is a case series of 3 children from a single family who developed symptomatic elemental mercury poisoning requiring hospitalization and chelation. The mercury exposure primarily occurred in the home but the mercury was also tracked to one of their schools requiring environmental cleanup at both the home and school. The clinical assessment and management, as well as public health investigation and response, are discussed. There are many lessons learned in this difficult, often delayed, diagnosis. Early recognition of this environmental toxic exposure is essential. Communication between the clinicians and public health officials played a critical role. Public education prevented panic. Proper environmental sampling, and assessment and management of those exposed, were a few of the many challenges faced in this complicated case series.

Acute Methylenedioxypyrovalerone Toxicity.

The objective of this study was to characterize the acute clinical effects, laboratory findings, complications, and disposition of patients presenting to the hospital after abusing synthetic cathinone. We conducted a retrospective multicenter case series of patients with synthetic cathinone abuse by searching for the terms bath salts, MDPV, methylenedioxypyrovalerone, mephedrone, methcathinone, methylone, methedrone, and cathinone within the "agent" field of a national clinical toxicology database (ToxIC). The medical records of these patients were obtained and abstracted by investigators at each study site. Patients with confirmatory testing that identified a synthetic cathinone in either blood or urine were included in the series. Patients who had either an undetectable synthetic cathinone test or no confirmatory testing were excluded. A data abstraction sheet was used to obtain information on each patient. We entered data into an Excel spreadsheet and calculated descriptive statistics. We identified 23 patients with confirmed synthetic cathinone exposure--all were positive for methylenedioxyprovalerone (MDPV). Eighty-three percent were male and 74 % had recreational intent. The most common reported clinical effects were tachycardia (74 %), agitation (65 %), and sympathomimetic syndrome (65 %). Acidosis was the most common laboratory abnormality (43 %). Seventy-eight percent of patients were treated with benzodiazepines and 30 % were intubated. Ninety-six percent of patients were hospitalized and 87 % were admitted to the ICU. The majority (61 %) of patients was discharged home but 30 % required inpatient psychiatric care. There was one death in our series. The majority of patients presenting to the hospital after abusing MDPV have severe sympathomimetic findings requiring hospitalization. A number of these patients require inpatient psychiatric care after their acute presentation.

Cardiotoxicity associated with the synthetic cannabinoid, K9, with laboratory confirmation.

Synthetic cannabinoids have been popular recreational drugs of abuse for their psychoactive properties. Five of the many synthetic cannabinoids have been recently banned in the United States because of their unknown and potentially harmful adverse effects. Little is known about these substances. They are thought to have natural cannabinoid-like effects but have different chemical structures. Adverse effects related to synthetic cannabinoids are not well known. We provide clinical effects and patient outcome following K9 use. In addition, we briefly review synthetic cannabinoids. We present a 17-year-old adolescent boy with chest pain, tachycardia, and then bradycardia associated with smoking K9. Two synthetic cannabinoids, JWH-018 and JWH-073, were confirmed on laboratory analysis. In addition to the limited current data, we demonstrate harmful adverse effects related to toxicity of 2 synthetic cannabinoids. Further studies are needed.

Intravenous fat emulsion therapy for intentional sustained-release verapamil overdose.

We report the first case of sustained-release verapamil toxicity treated with Intralipid fat emulsion (IFE). Toxicity was confirmed by elevated serial serum verapamil and metabolite, norverapamil, levels. Most previously reported cases of IFE therapy involve local anaesthetic toxicity and cardiac arrest. Our patient was in shock despite standard therapy. No adverse events were noted and the patient fully recovered.

Late-onset seizures associated with quetiapine poisoning.

INTRODUCTION: Quetiapine, a second-generation antipsychotic, acts at multiple brain neurotransmitter receptors and has the potential for serious complications. Although seizures have been described in the literature, delayed seizure onset has not been reported. We report the first case of delayed seizures after a significant quetiapine overdose. CASE REPORT: A 27-year-old female presented to the emergency department following an overdose of approximately 30 g of quetiapine. Twenty-four hours after arrival, the patient had 2 seizures. The patient was then intubated and remained in the ICU for four days. EEG was negative for epileptiform activity. The serum quetiapine levels (MedTox, St. Paul, MN) were 8.67 mg/L on hospital day one and 3.28 mg/L on hospital day three. DISCUSSION: Quetiapine poisoning, with serum levels, associated with seizures has been reported in one prior case. Our case report represents late-onset seizures with serum levels above therapeutic range (>1 mg/L). The serum concentrations of quetiapine in this case were consistent with those in postmortem case reports.