The MRI appearance of myloglossus.

PURPOSE: This case report describes the MRI appearance and significance of the myloglossus muscle, a variant extrinsic tongue muscle. METHODS: The myloglossus muscle was incidentally discovered on imaging performed for head and neck cancer evaluation. RESULTS: The myloglossus is best visualized on non-fat saturated T2 MRI and has signal characteristics that match those of muscle. It originates at the angle of the mandible and inserts into the tongue between the styloglossus and hyoglossus. CONCLUSION: Accurate identification and delineation of the extrinsic muscles of the tongue, including the myloglossus, is essential for proper staging and treatment of head and neck cancers. This case report attempts to fill a void in depicting the MRI appearance of myloglossus muscle.

CT Imaging Computed Tomography/Computed Tomography Angiography/Perfusion in Acute Ischemic Stroke and Vasospasm.

Computed tomography (CT), CT angiography (CTA), and CT perfusion (CTP) play crucial roles in the comprehensive evaluation and management of acute ischemic stroke, aneurysmal subarachnoid hemorrhage (SAH), and vasospasm. CTP provides functional data about cerebral blood flow, allowing radiologists, neurointerventionalists, and stroke neurologists to more accurately delineate the volume of core infarct and ischemic penumbra allowing for patient-specific treatment decisions to be made. CTA and CTP are used in tandem to evaluate for vasospasm associated with aneurysmal SAH and can help provide an insight into the physiologic impact of angiographic vasospasm, better triaging patients for medical and interventional treatment.

The interplay among a dental procedure, infective endocarditis, and an acute ischemic stroke.

BACKGROUND: This case report highlights the rare association among a dental procedure, infective endocarditis, and an acute ischemic stroke. CASE DESCRIPTION: A 54-year-old woman who experienced an acute ischemic stroke 5 weeks after a tooth extraction is described. The initial symptoms of this patient included mild to moderate word-finding difficulty and right facial droop. Computed tomographic angiography revealed a left M1 segment middle cerebral artery occlusion (thrombolysis in cerebral infarction scale, 0) with reconstitution of the distal middle cerebral branches through arterial collaterals. After initial administration of tissue plasminogen activator, endovascular thrombectomy was successfully performed with thrombolysis in cerebral infarction scale 3 (complete) recanalization. After the procedure, the patient showed improvement in language and neurologic deficits. Imaging showed multifocal, bilateral, cortical, and deep brain hemorrhages. Blood cultures grew Streptococcus mitis, ultimately leading to the diagnosis of endocarditis. Echocardiographic imaging revealed moderate to severe aortic insufficiency, a mitral valve vegetation, and mild mitral valve regurgitation. After evaluation by the cardiothoracic surgery team, the patient was discharged with intravenous antibiotics and short-term outpatient follow-up with the cardiothoracic surgery team. PRACTICAL IMPLICATIONS: Dental procedures, although generally safe, can introduce oral bacteria into the bloodstream, leading to bacterial seeding of cardiac valves and subsequent infective endocarditis. Recognizing infective endocarditis subsequent to a dental procedure, including a tooth extraction, as a potential cause of an acute ischemic stroke is vital so that prompt treatment can be initiated.

MR Imaging-based Biomarker Development in Hemorrhagic Stroke Patients Including Brain Iron Quantification, Diffusion Tensor Imaging, and Phenomenon of Ultra-early Erythrolysis.

This review article discusses the role of MR imaging-based biomarkers in understanding and managing hemorrhagic strokes, focusing on intracerebral hemorrhage (ICH) and aneurysmal subarachnoid hemorrhage. ICH is a severe type of stroke with high mortality and morbidity rates, primarily caused by the rupture of small blood vessels in the brain, resulting in hematoma formation. MR imaging-based biomarkers, including brain iron quantification, ultra-early erythrolysis detection, and diffusion tensor imaging, offer valuable insights for hemorrhagic stroke management. These biomarkers could improve early diagnosis, risk stratification, treatment monitoring, and patient outcomes in the future, revolutionizing our approach to hemorrhagic strokes.

Newer Updates in Pediatric Vascular Diseases.

Pediatric neurovascular pathology directly involves or is in close proximity to the central nervous system (CNS). These vascular pathologies can occur in isolation or in association with broader syndromes. While some vascular pathologies are unique to the pediatric population, the full spectrum of adult neurovascular lesions can also affect children however, may present differently both clinically and on diagnostic imaging. Non-invasive (Ultrasound, CT, MRI) imaging plays a critical role in the diagnosis, treatment planning, and follow-up of vascular lesions involving the CNS. The modality can be chosen based on the age of the child, urgency of diagnosis, and local availability. Each modality has sensitivities and specificities which vary based on the location and imaging findings of a specific neurovascular pathology. In addition to non-invasive options, digital subtraction angiography (DSA) may be used as both a diagnostic and therapeutic imaging method for pediatric vascular lesions of the central nervous system. The diagnosis and management of pediatric cerebrovascular disease requires the close collaboration between pediatricians and pediatric specialists including neuroradiologists, neurologists, neurosurgeons, cardiologists, neurointerventionalists, and anesthesiologists among others. A detailed understanding of imaging findings, natural history, and treatment options is essential to guide and monitor imaging and treatment. The goal of this review is to provide the reader with an overview on pediatric neurovascular pathologies, provide examples of pathognomonic imaging findings, and present a brief review of endovascular treatment options, if applicable.

Successful retrieval of ethylene vinyl alcohol (EVOH) from the left middle cerebral artery during preoperative embolization of a juvenile nasopharyngeal angiofibroma (JNA).

Preoperative embolization of a juvenile nasopharyngeal angiofibroma (JNA) using ethyl vinyl alcohol (EVOH) is an effective adjunctive treatment prior to surgical resection. While liquid embolic agents are safe to use, we present a unique case involving the migration of EVOH into the left middle cerebral artery (MCA) through an external carotid artery-internal carotid artery (ECA-ICA) collateral during preoperative embolization using a dual-lumen balloon catheter. A 16-year-old male presented with left-sided nasal congestion, new nasal intonation in voice, and epistaxis. CT imaging showed a hypervascular mass centered within the left posterior nasal cavity and nasopharynx with expansion of the ipsilateral sphenopalatine foramen. A JNA was diagnosed, and preoperative embolization was performed prior to surgical resection. During the embolization procedure, EVOH migrated into the intracranial circulation through a hypertrophied ECA-ICA collateral. Angiography confirmed embolic material at the left MCA bifurcation. The embolic material was successfully removed using a balloon guide catheter and stentriever. This case is presented to highlight potential complications and rescue techniques used in the setting of non-target embolization occurring during JNA embolization.

Stronger prediction of motor recovery and outcome post-stroke by cortico-spinal tract integrity than functional connectivity.

OBJECTIVES: To examine longitudinal changes in structural and functional connectivity post-stroke in patients with motor impairment, and define their importance for recovery and outcome at 12 months. METHODS: First-time stroke patients (N = 31) were studied at 1-2 weeks, 3 months, and 12 months post-injury with a validated motor battery and resting-state fMRI to measure inter-hemispheric functional connectivity (FC). Fractional anisotropy (FA) of the cortico-spinal tract (CST) was derived from diffusion tensor imaging as a measure of white matter organization. ANOVAs were used to test for changes in FC, FA, and motor performance scores over time, and regression analysis related motor outcome to clinical and neuroimaging variables. RESULTS: FA of the ipsilesional CST improved significantly from 3 to 12 months and was strongly correlated with motor performance. FA improved even in the absence of direct damage to the CST. Inter-hemispheric FC also improved over time, but did not correlate with motor performance at 12 months. Clinical variables (early motor score, education level, and age) predicted 80.4% of the variation of motor outcome, and FA increased the predictability to 84.6%. FC did not contribute to the prediction of motor outcome. CONCLUSIONS: Stroke causes changes to the CST microstructure that can account for behavioral variability even in the absence of demonstrable lesion. Ipsilesional CST undergoes remodeling post-stroke, even past the three-month window when most of the motor recovery happens. FA of the CST, but not inter-hemispheric FC, can improve to the prediction of motor outcome based on early motor scores.

Essential role for Co-chaperone Fkbp52 but not Fkbp51 in androgen receptor-mediated signaling and physiology.

Fkbp52 and Fkbp51 are tetratricopeptide repeat proteins found in steroid receptor complexes, and Fkbp51 is an androgen receptor (AR) target gene. Although in vitro studies suggest that Fkbp52 and Fkbp51 regulate hormone binding and/or subcellular trafficking of receptors, the roles of Fkbp52 and Fkbp51 in vivo have not been extensively investigated. Here, we evaluate their physiological roles in Fkbp52-deficient and Fkbp51-deficient mice. Fkbp52-deficient males developed defects in select reproductive organs (e.g. penile hypospadias and prostate dysgenesis but normal testis), pointing to a role for Fkbp52 in AR-mediated signaling and function. Surprisingly, ablation of Fkbp52 did not affect AR hormone binding or nuclear translocation in vivo and in vitro. Molecular studies in mouse embryonic fibroblast cells uncovered that Fkbp52 is critical to AR transcriptional activity. Interestingly, Fkbp51 expression was down-regulated in Fkbp52-deficient males but only in affected tissues, providing further evidence of tissue-specific loss of AR activity and suggesting that Fkbp51 is an AR target gene essential to penile and prostate development. However, Fkbp51-deficient mice were normal, showing no defects in AR-mediated reproductive function. Our work demonstrates that Fkbp52 but not Fkbp51 is essential to AR-mediated signaling and provides evidence for an unprecedented Fkbp52 function, direct control of steroid receptor transcriptional activity.