Mental nerve neuropathy (MNN) or “numb chin syndrome” is a rare neurologic symptom most often associated with malignancy. Patients typically develop paresthesia or numbness localized to the chin and lower lip and will often seek care at their local emergency department. Pain and expansion of the lower jaw may also be present. We report a case of MNN associated with a metastatic lesion in the mandible. The purpose of this article is to highlight the importance of recognizing MNN, a potentially life-threatening symptom of metastatic carcinoma, and enable clinicians to properly diagnose MNN, which may mimic other conditions that affect the mandible.

Informed consent to participation in research is an important protector of potential subjects’ rights and autonomy. Ethical research involving critically ill people is challenging because their medical condition often makes obtaining informed consent impossible. This is especially true in the prehospital setting, where additional barriers to obtaining informed consent exist. A recently published Canadian policy (Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans) specifies circumstances under which an exception to the requirement for informed consent may be granted so that vulnerable individuals are not denied the potential benefits of participating in research. This article reviews the rationale for the Tri-Council Policy Statement and illustrates some problems with its application in the context of a Canadian prehospital study on continuous positive airway pressure. A new risk analysis model and a national research ethics board are discussed as possible ways to facilitate interpretation and application of the current exception of informed consent policy.

A 28-year-old male with atraumatic abdominal pain and transient hypotension was assessed using bedside emergency department (ED) ultrasonography and contrast enhanced helical computed tomography (CT). Both tests revealed free intraperitoneal fluid, but neither detected a splenic defect. The patient subsequently underwent splenectomy for a ruptured spleen. His serology for typical viral causes was negative. This article discusses spontaneous splenic rupture, the role of imaging in diagnosis, and the limitations of ED ultrasound and contrast enhanced helical CT.

We report a case of a 53-year-old man whose first manifestation of coronary artery disease was an acute isolated posterior myocardial infarction (IPMI). Acute IPMI is relatively uncommon and predominantly due to occlusion of the left circumflex coronary artery. IPMI is challenging to diagnose due to the absence of ST segment elevation on a standard 12-lead electrocardiogram (ECG) even in the setting of total coronary artery occlusion and transmural (Q-wave) infarct. We discuss the diagnostic implications of the absence of tall R waves in leads V1 and V2 on this patient’s ECG. The utility of posterior leads (V7 through V9) is demonstrated. The controversy surrounding the use of thrombolytic therapy or primary angioplasty in the setting of acute IPMI without ST segment elevation on a standard 12-lead ECG is reviewed.

In the emergency department (ED), the typical manifestation of impaired glucose homeostasis seen in patients with severe bacterial infections is hyperglycemia. Severe hypoglycemia is generally not a presenting feature of sepsis in children in the emergency setting, and thus may lead to delayed diagnosis and management. We present a case of a 14-year-old boy who attended the ED with constitutional symptoms and severe hypoglycemia as the initial presentation of overwhelming meningococcal sepsis and discuss the impairment of glucose homeostasis in patients with sepsis.

Reviews of the medical literature have always been an important resource for physicians. Increasingly, qualitative and quantitative systematic reviews (SRs) have replaced the traditional “narrative review” as a means of capturing and summarizing current evidence on a topic or, when possible, answering a specific clinical question. This paper is Part II of a 2-part series designed to provide emergency physicians with the background necessary to locate, critically evaluate and interpret SRs. The paper expands on the critical appraisal principles discussed in Part I by focusing on quality assessment, data synthesis and interpretation of results. To illustrate key points and facilitate readability, examples from the emergency medicine literature have been included and technical details have been kept to a minimum. The references, however, are comprehensive and provide a resource for readers seeking further information.

Hypokalemic periodic paralysis is a rare and dramatic complication of hyperthyroidism. This series summarizes the clinical and metabolic features of 10 patients who presented to the Western and Sunshine hospitals in Melbourne, Australia, between 1997 and 2002 with thyrotoxic periodic paralysis (TPP). TPP classically presents with proximal lower-limb weakness in the setting of a low potassium level and biochemical evidence of thyrotoxicosis: low thyroid-stimulating hormone levels along with elevated free thyroxine (FT4) or free triiodothyronine (FT3). The challenge for emergency physicians is to recognize the association with thyroid disease, since features of hyperthyroidism may not be apparent on history and examination. Acute treatment with potassium supplements and long-term management is aimed at achieving an euthyroid state. Thyrotoxic periodic paralysis is more common in Asian populations; however, increasing immigration from Asia will lead to higher TPP prevalence in Western countries.