Opsoclonus in Uremia With Resolution After Hemodialysis.

ABSTRACT: A 78-year-old man was evaluated for altered mentation in the setting of significant uremia. On examination, he was found to be encephalopathic with generalized myoclonus and spontaneous opsoclonus. He had no known risk factors for the development of opsoclonus and upon undergoing hemodialysis, experienced near resolution of his eye movement abnormalities, thus highlighting a possible link between the uremic state and opsoclonus.

Management of Elevated Intracranial Pressure: a Review.

PURPOSE OF REVIEW: Principles of intracranial pressure (ICP) management continue to be an essential part of the neurointensivist's skillset as appropriate treatment decisions can prevent secondary injury to the central nervous system. This review of the literature aims to: discuss commonly encountered pathologies associated with increased ICP, summarize diagnostic approaches used in evaluating ICP, and present evidence-based treatment paradigms that drive clinical care in intensive care units. RECENT FINDINGS: Recent topics of discussion include invasive and non-invasive modalities of diagnosis and monitoring, recent developments in hypothermia, hyperosmolar therapy, pharmacological interventions, and surgical therapies. The authors also present an example of an algorithm used within our system of hospitals for managing patients with elevated ICP. Recent advances have shown the mortality benefits in appropriately recognizing and treating increased ICP. Multiple modalities of treatment have been explored, and evidence has shown benefit in some. Further work continues to provide clarity in the appropriate management of intracranial hypertension.

Hemodynamic impingement and the initiation of intracranial side-wall aneurysms.

Objective The natural history intracranial aneurysms (IA) remains poorly understood despite significant morbidity and mortality associated with IA rupture. Hemodynamic impingement resulting in elevations in wall shear stress and wall shear stress gradient (WSSG) has been shown to induce aneurysmal remodeling at arterial bifurcations. We investigate the hemodynamic environment specific to side-wall pre-aneurysmal vasculature. We hypothesize that fluid impingement and secondary flow patterns play a role in side-wall aneurysm initiation. Methods Eight side-wall internal carotid artery aneurysms from the Aneurisk repository were identified. Pre-aneurysmal vasculature was algorithmically reconstructed. Blood flow was simulated with computational fluid dynamic simulations. An indicator of isolated fluid impingement energy was developed by insetting the vessel surface and calculating the impinging component of the fluid dynamic pressure. Results Isolated fluid impingement was found to be elevated in the area of aneurysm initiation in 8/8 cases. The underlying fluid flow for each area of initiation was found to harbor secondary flow patterns known as Dean's vortices, the result of changes in momentum imparted by bends in the internal carotid artery (ICA). Conclusion Isolated fluid impingement and secondary flow patterns may play a major role in the initiation of side-wall aneurysm initiation. We are unable to determine if this role is through direct or indirect mechanisms but hypothesize that elevations in isolated fluid impingement mark areas of cerebral vasculature that are at risk for aneurysm initiation. Thus, this indicator provides vascular locations to focus future study of side-wall aneurysm initiation.

Influence of Relative Residence Time on Side-Wall Aneurysm Inception.

BACKGROUND: Relative residence time (RRT) is a marker of disturbed blood flow, marked by low magnitude and high oscillatory wall shear stress (WSS). The relation between solute residence time in proximity to the vascular endothelium and the atherosclerotic process is well appreciated in the literature. OBJECTIVE: To assess the influence of RRT on side-wall aneurysm inception to better understand the role of atherosclerosis in aneurysm formation. METHODS: Fourteen side-wall internal carotid artery aneurysms from the Aneurisk repository which met criteria for parent vessel reconstruction were reconstructed with Vascular Modeling Toolkit. Computational fluid dynamics analysis was carried out in Fluent. RRT was calculated in MATLAB (The MathWorks Inc, Natick, Massachusetts). We analyzed the results for correlations, defined as presence or absence of local elevations in RRT in specific regions of vasculature. RESULTS: RRT was concluded to be negatively correlated with aneurysm inception in this study of side-wall internal carotid artery aneurysms, with 12/14 cases yielding the absence of local RRT elevations within or in close proximity of the removed ostium. Subsequent analysis of WSS showed that 11 of 14 aneurysms were formed in an atheroprotective environment, with only 1 of 14 formed in an atherogenic environment. Two models were found to be of indeterminate environment. CONCLUSION: Atherogenesis and atherosclerosis have long been thought to be a major inciting factor responsible for the formation of aneurysms in the cerebral vasculature. We propose that inception of side-wall aneurysms occurs in hemodynamic environments that promote an atheroprotective endothelial phenotype and that the atheroprotective phenotype is therefore aneurysmogenic.

Spontaneous Bilateral Carotid-Cavernous Fistulas Secondary to Cavernous Sinus Thrombosis.

Bilateral carotid cavernous fistulas are rare entities that can cause debilitating symptoms and can lead to more severe consequences if left untreated. Therefore, the recognition and adequate treatment of these pathologies is very important. We present 2 cases of bilateral carotid cavernous fistulas that arose as a result of cavernous sinus thrombosis. We review the literature and discuss the pathophysiology, symptomatology, management, and treatment of bilateral carotid cavernous fistulas. Within our own cases, treatment of the patients was varied. The patient in case 1 was successfully treated with endovascular therapy after a failed trial of anticoagulation. The patient in case 2 demonstrated resolution of bilateral carotid cavernous fistulas after anticoagulation therapy. Case 2 highlights the fact that certain cases of bilateral carotid cavernous fistulas due to cavernous sinus thrombosis may benefit from extensive anticoagulation therapy. If anticoagulation therapy is unsuccessful, endovascular therapy may prove beneficial in resolving the fistulous shunt.

Delayed Occipital Artery Pseudoaneurysm Following Blunt Force Trauma.

BACKGROUND: Occipital artery pseudoaneurysms are extremely rare pathologies that manifest after traumatic injury; only 11 cases have been reported in the literature. Because of their low incidence and vague symptoms, the initial diagnosis can be difficult. However, for correctly diagnosed occipital artery pseudoaneurysms, many successful treatment modalities exist. METHODS: We review the pathology of occipital pseudoaneurysms, elucidate the reasons for their rarity, discuss effective diagnostic measures, and discuss the currently available treatment options. We also present a case of a 16-year-old boy who sustained blunt force trauma in May 2014 and presented 6 months later with a painful, pulsatile mass in the occipital region. RESULTS: The patient underwent surgical resection to alleviate the pain and the potential risk of hemorrhage. He experienced complete resolution of pain and associated symptoms. CONCLUSIONS: Our case highlights the fact that occipital swelling, a significant initial sign of pseudoaneurysm development, can be delayed. Therefore, occipital artery pseudoaneurysms cannot be ruled out of the differential diagnosis based on time course alone. Surgical resection is a quick and effective method for relief of severe pain resulting from occipital artery pseudoaneurysms. Although they are rare entities, occipital artery pseudoaneurysms must be considered in the differential diagnosis of cases of pulsatile mass lesions in the posterior scalp.

Cerebrospinal fluid otorrhea and pseudomonal meningitis in a child with Mondini dysplasia: case report.

PURPOSE: Mondini dysplasia is a rare congenital inner ear malformation that presents with abnormal cochlear development with accompanied vestibular dilation and vestibular aqueduct enlargement. This dysfunctional anatomy provides the potential for sensorineural hearing deficits, cerebrospinal fluid leaks, and severe cases of recurrent meningitis. METHODS: We present the case of a child with Mondini dysplasia who presented with unilateral hearing loss and cerebrospinal fluid (CSF) otorrhea that was surgically repaired through a combined middle fossa/transmeatal middle ear approach to alleviate any recurrence of infection and cerebrospinal fluid otorrhea. RESULTS: Postoperatively, the patient remained neurologically stable without any further CSF leakage. CSF cultures revealed a Pseudomonas aeruginosa infection, a rare occurrence within the context of Mondini dysplasia. Retrograde bacterial spread from the external ear canal into the CSF space has been theorized as the possible pathogenesis of the resulting meningitis. The patient was successfully treated with intravenous antibiotics without any neurologic complications. CONCLUSIONS: Although Mondini dysplasia is a rare malformation, the life-threatening sequelae of meningitis that can result from the dysfunctional anatomy makes it a condition that requires elevated clinical vigilance, especially when considering children with hearing loss associated with recurrent meningitis, otorrhea, or rhinorrhea.