Postmortem Brain Imaging in Alzheimer's Disease and Related Dementias: The South Texas Alzheimer's Disease Research Center Repository.

BACKGROUND: Neuroimaging bears the promise of providing new biomarkers that could refine the diagnosis of dementia. Still, obtaining the pathology data required to validate the relationship between neuroimaging markers and neurological changes is challenging. Existing data repositories are focused on a single pathology, are too small, or do not precisely match neuroimaging and pathology findings. OBJECTIVE: The new data repository introduced in this work, the South Texas Alzheimer's Disease research center repository, was designed to address these limitations. Our repository covers a broad diversity of dementias, spans a wide age range, and was specifically designed to draw exact correspondences between neuroimaging and pathology data. METHODS: Using four different MRI sequences, we are reaching a sample size that allows for validating multimodal neuroimaging biomarkers and studying comorbid conditions. Our imaging protocol was designed to capture markers of cerebrovascular disease and related lesions. Quantification of these lesions is currently underway with MRI-guided histopathological examination. RESULTS: A total of 139 postmortem brains (70 females) with mean age of 77.9 years were collected, with 71 brains fully analyzed. Of these, only 3% showed evidence of AD-only pathology and 76% had high prevalence of multiple pathologies contributing to clinical diagnosis. CONCLUSION: This repository has a significant (and increasing) sample size consisting of a wide range of neurodegenerative disorders and employs advanced imaging protocols and MRI-guided histopathological analysis to help disentangle the effects of comorbid disorders to refine diagnosis, prognosis and better understand neurodegenerative disorders.

Myasthenia Gravis Masquerading as an Idiopathic Unilateral Facial Paralysis (Bell's Palsy)-A Very Rare and Unique Clinical Find.

Myasthenia gravis (MG) is an uncommon autoimmune neuromuscular junction disorder manifesting as fluctuating weakness of skeletal muscles. To add to its repertoire of mimicking a wide range of neurological disorders, the present case report is, to the best of our knowledge, the very first to describe MG masquerading as an idiopathic unilateral facial paralysis (Bell's palsy, BP). Our case report is distinct, highlights a novel clinical occurrence, offers new insights of how different neurological disorders may overlap with each other, and reminds neurologists to have a very broad and thorough comprehension for effective diagnoses and treatment plans. Several other conditions that produce facial nerve palsy identical to BP have also been discussed.

Generalized tonic-clonic seizures with post-ictal atrial fibrillation.

Convulsive seizures are known to cause severe cardiopulmonary changes and increased autonomic activity. Limited reports describe peri-ictal cardiac arrhythmias such as atrial fibrillation (AF) with generalized tonic-clonic seizures (GTCS). We present a unique case of a healthy 23-year-old male patient with new onset prolonged AF in the setting of new onset seizures, occurring on three independent occasions. Over two years, our patient had multiple hospitalizations for seizures with an electrocardiogram (ECG) diagnosis of AF made on three different occasions, occurring during his post-ictal state (all within 30 min of seizure onset). These seizures were never captured by electroencephalography (EEG) or witnessed by the medical staff, but were reported by family and/or reviewed on video provided by them. After his first GTCS, his AF persisted and was medically cardioverted. Two additional instances of AF after witnessed GTCS have been captured. After his second unprovoked seizure, an anti-seizure drug (ASD) was prescribed. A multi-disciplinary approach may be adopted to address comorbidities associated with seizures. Aggressive evaluation and treatment should be employed for newly diagnosed and refractory seizure patients associated with arrhythmias, in our case AF. Peri-ictal arrhythmias may be considered a potential marker for increased sudden unexpected death in epilepsy (SUDEP) risk.

Evaluation of Cancer Patients With Suspected Pulmonary Embolism: Performance of the American College of Physicians Guideline.

BACKGROUND: Accurate risk stratification of pulmonary embolism (PE) can reduce unnecessary imaging. We investigated the extent to which the American College of Physicians (ACP) guideline for evaluation of patients with suspected PE could be applied to cancer patients in the emergency department of a comprehensive cancer center. MATERIALS AND METHODS: Data from cancer patients who underwent CT pulmonary angiography (CTPA) between August 1, 2015, and October 31, 2015, were collected. We assessed each patient's diagnostic workup for its adherence to the ACP guideline in terms of clinical risk stratification and age-adjusted d-dimer level and the degree to which these factors were associated with PE. RESULTS: Of the 380 patients identified, 213 (56%) underwent CTPA indicated per the ACP guideline, and 78 (21%) underwent CTPA not indicated per the guideline. Only one of the patients who underwent nonindicated CTPA had a PE. Fifty-seven patients underwent unnecessary d-dimer evaluation, and 71 patients with negative d-dimer test results underwent nonindicated CTPA. PEs were found in 6 of 108 (6%) low-risk patients, 22 of 219 (10%) intermediate-risk patients, and 13 of 53 (25%) high-risk patients. The ACP guideline had negative predictive value of 99% (95% confidence interval: 93%-100%) and sensitivity of 97% (95% confidence interval: 86%-100%) in predicting PE. CONCLUSION: The ACP guideline has good sensitivity for detecting PE in cancer patients and thus can be applied in this population. Compliance with the ACP guideline when evaluating cancer patients with suspected PE could reduce the use of unnecessary imaging and laboratory studies.

Atypical Thrombotic Thrombocytopenic Purpura Presenting as Stroke.

Here we report a case of atypical thrombotic thrombocytopenic purpura that presented as an ischemic cerebrovascular accident. A 56-year-old man with multiple cardiovascular risk factors presented with sudden left-sided weakness, slurred speech, and left facial droop. He showed mild improvement when he was treated with thrombolytic therapy according to the hospital stroke protocol. Later in the course, he developed thrombocytopenia followed by schistocytes revealed by peripheral blood smear and other lab abnormalities. Thrombotic thrombocytopenic purpura (TTP) was suspected, and he was treated with total plasma exchange that improved his condition significantly. This case shows that TTP can have unusual and atypical presentations either with the first episode or upon relapse, making diagnosis extremely difficult. Because patients may not present the expected clinical findings, it is important to be aware of variant presentations. In the early stages of the disease, platelet aggregation and thrombus formation may not be widespread, and thrombocytopenia and microangiopathic hemolytic anemia may not be clinically evident. Patients can present soon after the onset of symptoms when the typical laboratory abnormalities may not have had ample time to manifest. Although most other similar cases in the literature had a previous typical presentation of the disease before an atypical presentation, our patient's first presentation was atypical. An atypical presentation of disease in a patient with cardiovascular risk factors may therefore be extremely difficult to diagnose. We believe that TTP should be considered for any patient presenting with stroke and thrombocytopenia.