Walsh & Hoyt: Neovascularisation

In eyes with persistent hypoperfusion, further evidence of panocular ischemia becomes evident, including neovascularization of the iris (rubeosis iridis), retina, optic disc, and anterior chamber angle

Walsh & Hoyt: Seizures

Most seizures occur at the onset of intracerebral hemorrhage or within the first 24 hours (819,820). Anticonvulsants can usually be discontinued after the first month in patients who have had no further seizures. Patients who have a seizure more than two weeks after the onset of an intracerebral hemorrhage are at higher risk for further seizures and may require long-term prophylactic treatment with anticonvulsants (820)

Walsh & Hoyt: Pathophysiology

Intracerebral hemorrhages commonly occur in the cerebral lobes, basal ganglia, thalamus, brain stem (predominantly the pons), and cerebellum. Extension into the ventricles occurs in association with deep, large hematomas. Edematous parenchyma, often discolored by degradation products of hemoglobin, is visible adjacent to the clot. Histologic sections are characterized by the presence of edema, neuronal damage, macrophages, and neutrophils in the region surrounding the hematoma. The hemorrhage spreads between planes of white-matter cleavage with minimal destruction, leaving nests of intact neural tissue within and surrounding the hematoma. This pattern of spread accounts for the presence of viable and salvageable neural tissue in the immediate vicinity of the hematoma

Walsh & Hoyt: Pathology

Neurons are more vulnerable to oxygen deprivation than are oligodendroglia and astrocytes, whereas microglia and blood vessels are least vulnerable. After an episode of hypoxia, therefore, structural damage may be limited to neurons (selective neuronal necrosis), or it may include glia and blood vessels. In addition, neurons of the phylogenetically older portions of the CNS are more resistant than neurons of the newer portions (selective vulnerability). The gray matter of the spinal cord and most of the brainstem thus may remainun damaged despite almost total destruction of the cerebral cortex. Infarction

Walsh & Hoyt: Ocular Symptoms

A variety of transient visual symptoms and signs may develop in patients with disease in the carotid arterial system

Walsh & Hoyt: Computed Tomography Angiography

CTA also reliably evaluates the arteries of the head and neck

Walsh & Hoyt: Dissection of the Cervical Arteries

Cervicocerebral arterial dissections occur when blood extrudes into the wall of an artery supplying the brain

Walsh & Hoyt: Diagnosis

Although the rapid onset of abnormalities and a decreased level of consciousness suggest the diagnosis of intracerebral hemorrhage, distinguishing definitively between cerebral infarction and intracerebral hemorrhage requires imaging of the brain

Walsh & Hoyt: Subarachnoid Hemorrhage

Table 40.7

Walsh & Hoyt: Diagnosis

The diagnosis of ""stroke"" is based on clinical definitions and can be difficult, especially in the setting of TIA. There are few data about in-hospital diagnostic accuracy of stroke. In 1999, Allder et alreported an 8.6% rate of clinical misdiagnosis in a study of 70 patients who were thought to have carotid distribution ischemia and were imaged at a mean of 11.4 hours post-onset. Of some interest to those involved in triaging patients for acute treatments, data have been reported for the pre-hospital diagnosis of hyperacute cerebrovascular disease by paramedical personnel using a variety of protocols with positive predictive values of about 70%80%. With the development of new drugs used within the first few hours after a stroke, accurate diagnosis by paramedical personal and non-neurologists such as emergency room physicians has become essential