Introduction Ossification of the posterior longitudinal ligament (OPLL) is a slowly progressive disorder that can result in spinal stenosis and myelopathy. Myelopathy in patients with OPLL is related to both static and dynamic factors. The most common anatomic location is…
Introduction Hypertrophic olivary degeneration (HOD) is the result of an insult to the dentato-rubro-olivary pathway ( Fig. 22.1 ), otherwise known as the Guillain-Mollaret triangle (GMT). After an insult (infarct, hemorrhage, trauma, tumor, surgery) that disrupts the GMT, hypertrophic degeneration…
Introduction The empty sella turcica was first described in 1949 as a condition where the sella turcica is only partially filled by the pituitary gland, which appears flattened against the sellar floor ( Fig. 19.1 ). Autopsy studies confirm the…
Introduction Idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure (ICP) without apparent inciting etiology. Pseudotumor cerebri (PTC) is also a commonly accepted term describing the same disorder. Many authors advocate limiting the definition of IIH to a…
Introduction Intracranial hypotension is a clinical manifestation of low cerebrospinal fluid (CSF) volume or pressure caused by a dural CSF leak. It is usually precipitated by dural injury from an iatrogenic event such as a lumbar puncture, recent surgery, overshunting,…
Introduction Autoimmune encephalitis refers to a recently recognized group of immune-mediated disorders that involve the central nervous system (CNS). These conditions, which overlap in their clinical manifestations and imaging findings, are ultimately tied to specific antibodies ( Fig. 11.1 ).…
Introduction Herpes simplex encephalitis (HSE) is the most common cause of fatal sporadic encephalitis worldwide. In adults and older children, most cases of HSE are caused by the herpes simplex virus 1 (HSV-1) virus. Patients initially present with nonspecific neurologic…
Introduction Central pontine myelinolysis (CPM) was originally described by . He first detailed the entity in a group of malnourished and alcoholic patients. Further studies and advancement in medicine have shown that CPM most commonly results from the rapid correction…
Introduction The accurate age determination of a subdural hemorrhage is one of the most common and basic assessments in the setting of head trauma. On computed tomography (CT), the classic descriptions of blood products within the subdural space relate to…
Introduction Magnetic resonance imaging (MRI) can differentiate between acute, subacute, and chronic hemorrhage because of its sensitivity and specificity to hemoglobin degradation products. Therefore the imaging interpreter is, with proper knowledge, able to estimate the age of a brain parenchymal…