Imaging of Atypical and Complicated Posterior Reversible Encephalopathy Syndrome.

Posterior reversible encephalopathy syndrome (PRES) is a condition clinically characterized by headache, altered mental status, seizures, and visual loss and may be associated with systemic hypertension, preeclampsia/eclampsia, chemotherapy, immunosuppressive therapies in the setting of organ transplantation, and uremic encephalopathy. While brain imaging in patients with PRES typically reveals symmetric vasogenic edema within the parietal and occipital lobes, PRES may present with atypical imaging findings such as central brainstem and deep gray involvement without subcortical edema, and even spinal cord involvement. Additionally, PRES may be complicated in some cases by the presence of cytotoxic edema and hemorrhage. This review will serve to summarize the pathophysiologic theories and controversies underlying PRES, imaging features encountered in atypical and complicated PRES, and the implications these findings may have on patient prognosis.

Intracranial Hemorrhage Imaging.

Intracranial hemorrhage is a medical event frequently encountered in the clinical practice of radiology that has significant potential for patient morbidity and mortality. The expedient and accurate identification of intracranial hemorrhage as well as elucidation of the underlying cause can assist in optimizing the care of these patients. In this review, we attempt to familiarize the reader with the imaging appearance of multiple types of intracranial hemorrhage, both intra-axial and extra-axial and utilizing both computed tomography and magnetic resonance imaging, as well as to provide a framework for assessment of the underlying cause of the hemorrhage.

Endovascular therapy using flow diversion for giant internal carotid artery pseudoaneurysm arising in the setting of an invasive pituitary macroadenoma.

This report illustrates the unusual occurrence of a pseudoaneurysm arising in the setting of a skull base mass and describes the first reported use of endovascular flow diversion therapy in such a setting. A 63-year-old man with occasional headaches during the preceding month presented with the acute onset of severe left retroorbital headache and oculomotor nerve palsy. Computed tomography (CT) and CT angiogram revealed a destructive skull base mass with an associated giant probable pseudoaneurysm of the cavernous segment of the left internal carotid artery. The patient underwent endoscopic transsphenoidal biopsy with a subsequent diagnosis of prolactinoma. Endovascular therapy utilizing two Pipeline™ flow diversion embolization devices was performed with subsequent resolution of the patient's headache and improvement in his cranial nerve deficits/cavernous sinus syndrome.

Intracranial germinoma.

Pineal region tumors make up less than 1% of all intracranial neoplasms, with the majority being of germ cell origin. We describe the diagnostic evaluation and treatment of a patient presenting with neurological deficits who was found to have a germinoma of the pineal gland.

Basilar artery thrombosis in the setting of antiphospholipid syndrome.

Antiphospholipid syndrome is an autoimmune disorder characterized by arterial or venous thrombosis, recurrent first-trimester pregnancy loss, and multiple additional clinical manifestations. We describe a man with severe atherosclerotic basilar artery stenosis and superimposed in situ thrombus who was found to have antiphospholipid syndrome.

Spinal cord ependymoma presenting with neurological deficits in the setting of trauma.

Ependymomas represent 4% of all primary central nervous system neoplasms in adults, with 30% occurring in the spinal cord. We describe a young man with neurological deficits following a motor vehicle accident who was found to have an intramedullary cervicothoracic ependymoma.

Ganglioglioma and migraine headache.

Mixed neuronal/glial neoplasms represent a minority of intracranial neoplasms, typically associated with a more favorable prognosis than the more common higher-grade glial neoplasms. We describe a young man with headache, confusion, and slurred speech who was found to have a ganglioglioma.

Adrenomegaly and septic adrenal hemorrhage (Waterhouse-Friderichsen syndrome) in the setting of congenital adrenal hyperplasia.

Congenital adrenal hyperplasia refers to a spectrum of autosomal recessive inherited disorders of steroidogenesis most commonly identified on newborn screenings. We describe a young woman who presented with abdominal pain and on subsequent imaging was found to have features of congenital adrenal hyperplasia. Imaging findings, treatment, and potential complications are discussed.

Fourth ventricular subependymoma presenting as worsening headache.

Subependymomas are rare, slow-growing benign neoplasms. Although most are asymptomatic, they can present with symptoms related to increased intracranial pressure and hydrocephalus. We describe a 47-year-old man with worsening headaches who was found to have a subependymoma, with a focus on the imaging findings, differential diagnoses, pathology, and treatment.