Neuroimaging in Acute Stroke

Predictors of computed tomography imaging in patients presenting with sudden hearing loss

Objective

Sudden sensorineural hearing loss (SSNHL) is a rare presentation requiring timely diagnosis and treatment. Despite recommendations against obtaining computed tomography (CT) imaging of the head in clinical practice guidelines, this investigation is often completed in patients with sudden hearing loss. The aim of this study was to determine the proportion of patients undergoing CT imaging of the head for SSNHL at our center and identify predictive factors for the use of CT imaging.

Methods

Retrospective chart review of adult patients referred for SSNHL to two academic otology/neurotology practices between January 2018 and May 2021. Patient demographics, comorbid medical conditions, associated symptoms, location of initial presentation, audiologic results, and completed imaging studies were collected. Statistical analysis was performed with SPSS software.

Results

Ninety-eight patients with audiologically confirmed SSNHL were included. Twenty-two patients (22.4%) underwent CT imaging as an investigation for SSNHL. The presence of vertigo (odds ratio 6.90; 95% confidence interval 2.43, 19.56) and presentation to the emergency room (odds ratio 8.71; 95% confidence interval 3.02, 25.16) were significantly associated with undergoing CT imaging. These two variables were statistically significant independent predictors of CT imaging on multivariate regression analysis (p = .01, p = .001, respectively).

Conclusion

A significant proportion of patients with SSNHL undergo low-yield CT imaging of the head, particularly patients presenting to the emergency room with vertigo. These results highlight an opportunity for focused education and quality improvement initiatives.Level of evidence: 4.

Diagnostic Contribution of Magnetic Resonance Imaging and Computerized Tomography in Patients with Unidentified Vertigo and Normal Neurologic Examination in Emergency Medicine

Background

Vertigo and dizziness are common symptoms in patients presenting to emergency medicine (ED) clinics. Vertigo may be caused by peripheral or central origin. Routine imaging is not indicated; however, neuroimaging is increasing, and published studies have revealed a small number of positive findings on imaging modalities.

Aims

The aim of this study was to investigate whether neurological imaging was necessary in patients classified as "unidentified vertigo," who were admitted to the emergency department with vertiginous complaints and not revealing typical peripheral vertigo findings and any neurological deficits.

Materials and Methods

All patients with "dizzy symptoms" were included in the study. For patients who met the definition of "unidentified vertigo," experimental neurological imaging studies were done. Head computerized tomography (CT), magnetic resonance imaging (MRI) with gradient-echo sequences (GRE), and diffusion weighted images (DWI) were used for imaging. Patients who underwent neuroimaging in the ED were followed up for 6 months in Neurology and ENT clinics.

Results

A total of 351 patients were included in the study. Experimental imaging was performed on 100 patients. CT detected a significant pathology associated with the vertigo complaint in only one patient. MRI results were similar to the CT results. MRI-GRE sequences showed some additional pathologies in 14 patients and 4 of them were thought to be related to vertiginous symptoms. None of the patients classified as "non-central causes of vertigo" in the neuroimaging group developed TIA or CVD during 6 months of follow-up.

Conclusion

Head CT can be adequate to exclude life-threatening central pathology in "undifferentiated vertigo patients" and the addition of MRI did not add any diagnostic accuracy in ED management. Using the physical examination findings effectively to make a specific diagnosis may reduce misdiagnosis and improve resource utilization.

Neurologic Emergencies in the Elderly

Neurologic diseases are a major cause of death and disability in elderly patients. Due to the physiologic changes and increased comorbidities that occur as people age, neurologic diseases are more common in geriatric patients and a major cause of death and disability in this population. This article discusses the elderly patient presenting to the emergency department with acute ischemic stroke, transient ischemic attack, intracerebral hemorrhage, subarachnoid hemorrhage, chronic subdural hematoma, traumatic brain injury, seizures, and central nervous system infections. This article reviews the subtle presentations, difficult workups, and complicated treatment decisions as they pertain to our older patients."

Towards automatic MRI volumetry for treatment selection in acute ischemic stroke patients

In many tertiary clinical care centers, decision-making and treatment selection for acute ischemic stroke is based on magnetic resonance imaging (MRI). The "mismatch" concept aims to segregate the infarct core from potentially salvageable hypo-perfused tissue, the so-called penumbra that is determined from a combination of different MRI modalities. Recent studies have challenged the current concept of tissue at risk stratification targeted to identify the best treatment options for every individual patient. Here, we propose a novel, more elaborate image analysis approach that is based on supervised classification methods to automatically segment and predict the extent of the tissue compartments of interest (healthy, infarct, penumbra regions). The output of the algorithm is a label image including quantitative volumetric information about each tissue compartment. The approach has been evaluated on an image dataset of 10 stroke patients and it compared favorably to currently available tools.

Factors Associated with Cognitive Decline in Transient Ischemic Attack Patients

Chronic cerebrovascular disease and large ischemic stroke are both associated with cognitive impairment. Much less is known about the acute cognitive sequelae of transient ischemic attack (TIA). Although often overlooked, there is increasing evidence that cognitive impairment does occur following TIA. In some patients, cognitive changes persist after resolution of focal neurological deficits, but the temporal profile of these symptoms is unknown. In addition, clinical and imaging correlates of cognitive impairment after TIA have not been systematically studied. This under-studied and recognized problem has significant implications for TIA patient management. In this review, we summarize the evidence currently available and identify future research priorities.

Imaging the facial nerve: a contemporary review

Imaging plays a critical role in the evaluation of a number of facial nerve disorders. The facial nerve has a complex anatomical course; thus, a thorough understanding of the course of the facial nerve is essential to localize the sites of pathology. Facial nerve dysfunction can occur from a variety of causes, which can often be identified on imaging. Computed tomography and magnetic resonance imaging are helpful for identifying bony facial canal and soft tissue abnormalities, respectively. Ultrasound of the facial nerve has been used to predict functional outcomes in patients with Bell's palsy. More recently, diffusion tensor tractography has appeared as a new modality which allows three-dimensional display of facial nerve fibers.