Cost-effectiveness analysis of CTA and LP for evaluation of suspected SAH after negative non-contrast CT

Charting the Next Road Map for CSF Biomarkers in Alzheimer's Disease and Related Dementias

Clinical prediction of underlying pathologic substrates in people with Alzheimer's disease (AD) dementia or related dementia syndromes (ADRD) has limited accuracy. Etiologic biomarkers - including cerebrospinal fluid (CSF) levels of AD proteins and cerebral amyloid PET imaging - have greatly modernized disease-modifying clinical trials in AD, but their integration into medical practice has been slow. Beyond core CSF AD biomarkers (including beta-amyloid 1-42, total tau, and tau phosphorylated at threonine 181), novel biomarkers have been interrogated in single- and multi-centered studies with uneven rigor. Here, we review early expectations for ideal AD/ADRD biomarkers, assess these goals' future applicability, and propose study designs and performance thresholds for meeting these ideals with a focus on CSF biomarkers. We further propose three new characteristics: equity (oversampling of diverse populations in the design and testing of biomarkers), access (reasonable availability to 80% of people at risk for disease, along with pre- and post-biomarker processes), and reliability (thorough evaluation of pre-analytical and analytical factors influencing measurements and performance). Finally, we urge biomarker scientists to balance the desire and evidence for a biomarker to reflect its namesake function, indulge data- as well as theory-driven associations, re-visit the subset of rigorously measured CSF biomarkers in large datasets (such as Alzheimer's disease neuroimaging initiative), and resist the temptation to favor ease over fail-safe in the development phase. This shift from discovery to application, and from suspended disbelief to cogent ingenuity, should allow the AD/ADRD biomarker field to live up to its billing during the next phase of neurodegenerative disease research.

Malpractice Litigation Related to Diagnosis and Treatment of Intracranial Aneurysms

BACKGROUND AND PURPOSE

Approaches to management of intracranial aneurysms are inconsistent, in part due to apprehension relating to potential malpractice claims. The purpose of this article was to review the causes of action underlying medical malpractice lawsuits related to the diagnosis and management of intracranial aneurysms and to identify the factors associated and their outcomes.

MATERIALS AND METHODS

We consulted 2 large legal databases in the United States to search for cases in which there were jury awards and settlements related to the diagnosis and management of patients with intracranial aneurysms in the United States. Files were screened to include only those cases in which the cause of action involved negligence in the diagnosis and management of a patient with an intracranial aneurysm.

RESULTS

Between 2000 and 2020, two hundred eighty-seven published case summaries were identified, of which 133 were eligible for inclusion in the analysis. Radiologists constituted 16% of 159 physicians sued in these lawsuits. Failure to diagnose was the most common medical malpractice claim referenced (100/133 cases), with the most common subgroups being "failure to include cerebral aneurysm as a differential and thus perform adequate work-up" (30 cases), and "failure to correctly interpret aneurysm evidence on CT or MR imaging" (16 cases). Only 6 of these 16 cases were adjudicated at trial, with 2 decided in favor of the plaintiff (awarded $4,000,000 and $43,000,000, respectively).

CONCLUSIONS

Incorrect interpretation of imaging is relatively infrequent as a cause of malpractice litigation compared with failure to diagnose aneurysms in the clinical setting by neurosurgeons, emergency physicians, and primary care providers.

Overview of cerebrospinal fluid cytology

Cerebrospinal fluid (CSF) cytology, i.e., the cytologic evaluation of its cellular composition, forms an integral part of the neurologist's armamentarium. Total and differential cell counts provide important first information across a spectrum of pathologic conditions involving the central nervous system and its coverings. CSF samples require immediate processing, ideally within 1 hour from collection. Upon centrifugation cytology is commonly assessed on May-Grunwald-Giemsa stains. Several additional stains are available for the identification of infectious agents such as bacteria or fungi, or the further specification of neoplastic cells by immunocytochemistry. The evaluation warrants familiarity with cytologic characteristics of cells across normal and diseased states. In normal CSF, lymphocytes and monocytes are encountered. A predominance of neutrophil granulocytes suggests bacterial meningitis and prompts search for intracellular bacteria. In contrast, in viral and chronic infections lymphocytes and monocytes prevail. Upon activation lymphocytes typically enlarge and eventually differentiate into plasma cells. Similarly, monocytes differentiate into macrophages that clear cellular debris. Macrophages that contain fragments of erythrocytes or hemoglobin degradation products are referred to as erythro- or siderophages, both of which indicate prior subarachnoid hemorrhage. Likewise, the detection of tumor cells is specific for neoplastic meningitis, although false-negative CSF cytologies are frequent. In summary, detailed morphologic workup of CSF samples provides valuable diagnostic information and is mandated in all cases with elevated cell count, computed tomography-negative suspected subarachnoid hemorrhage, and neoplastic meningitis. In all cases it needs to be interpreted in the clinical context and complements other clinical and laboratory findings.