To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Hereditary hemorrhagic telangiectasia (HHT) is a disease of abnormal vasculature where patients are predisposed to strokes of multiple etiologies. We assessed yearly stroke incidence among Albertans with HHT and compared with the general population. Given the tendency for stroke in HHT patients, we expected HHT patients to have higher stroke incidence, in particular at younger ages.
Population-based administrative health data on inpatient and ambulatory admissions were extracted over a 16-year period using International Classification of Diseases (ICD)-9 and ICD-10, Canada codes. We analyzed overall occurrence of strokes in Alberta by age, gender, stroke subtype, and diagnosis of HHT.
The age-standardized incidence rate of stroke in HHT was 450 per 100,000 compared with 260 per 100,000 in the general population with a rate ratio of 1.73 (95% confidence interval (CI) [1.046-2.842]). This study found a higher HHT prevalence in Alberta (1 in 3800) compared to the world average of 1 in 5000. Women were also more likely to be diagnosed with HHT, with a 3.25:1 female gender preponderance in the yearly incidence.
This study not only shows that HHT patients are at higher risk of having a stroke but also quantifies that risk using an age-adjusted metric in Alberta. This province has a higher than expected disease burden of HHT, with the majority of cases affecting women. Our study found that acute ischemic strokes and transient ischemic attacks are far more common than hemorrhage in HHT. As HHT is a rare, multi-system, chronic disease, these patients should be referred to an HHT Centre of Excellence.
This chapter reviews the current literature on the frequency and causes of multiple brain infarcts, particular clinical and/or topographical patterns that suggest specific underlying mechanisms, and etiologies. The presence of multiple lacunar infarcts is an important prognostic indicator not only for functional recovery but also for a higher rate of recurrence. Various underlying conditions associated with multifocal involvement of the cerebral vasculature and/or a high rate of recurrent strokes may be responsible for multiple brain infarcts. Acute multiple infarcts may involve both hemispheres and may suggest some specific clinical pictures, particular causes, such as large artery disease, cardioembolism, angiitis, hematological disorders, hemodynamic mechanisms, or venous infarcts. In patients with simultaneous multiple, bihemispheric, and multilevel infarcts, most causes seem to be of similar type. Simultaneous multiple and multilevel infarcts may be associated with specific neurocognitive/psychological dysfunction patterns in most of the patients, allowing diagnosis accuracy.
Anterior choroidal artery (AChA) territory infarcts represent the second most common infarct in the territory of the deep perforators of the carotid artery system. The classical pattern of clinical signs attributed to AChA territory infarction is hemiplegia, hemianesthesia, and homonymous hemianopia, often associated with neuropsychological signs. Aphasia, spatial neglect, attention disorder, executive functioning impairment, and delayed memory are reported to be less severe than when due to thalamic or cortical infarctions. The high prevalence of arterial hypertension or diabetes mellitus as an isolated risk factor of stroke in small-sized AChA infarcts suggests that small artery disease is a common etiology of AChA territory infarcts. The clinical syndromes, vascular risk factor profile, presumed etiology of stroke, and prognosis allow consideration of small and large AChA territory infarcts in the differential diagnosis of patients with brain ischemia.
The study of respiratory dysfunction following a cerebrovascular event may permit localization of the neuroanatomical lesion. In addition, some respiratory dysfunctions are related to the etiology and the prognosis of stroke. This chapter reviews current knowledge regarding these associations. Unilateral hemispheric ischemic strokes appear to affect respiratory function to a modest degree. In contrast to cerebral hemispheric involvement, brainstem strokes may induce a more typical respiratory pattern, allowing more precise correlation between structure and function. Patients with severe obstructive sleep apnea (OSA) syndrome may develop ischemic stroke more frequently, as OSA syndrome with an apnea-hypopnea index (AHI) >30 was associated with stroke in an elderly population. The adverse effects of central hyperventilation may be related to arterial vasoconstriction induced by hypocapnia, leading to decrease in cerebral blood flow but also inducing impairment in cerebral autoregulation and cerebral arterial compliance.
This chapter addresses both organizational and clinical aspects of the frontal lobes, particularly the signs, symptoms, and cerebrovascular lesion patterns. The frontal lobes comprise multiple functional entities and can be subdivided into three major divisions: primary motor, premotor, and prefrontal cortical areas. The cognitive, emotional, and behavioral domains of frontal lobe syndromes can be particularly challenging. Strokes involving the lateral primary motor and premotor cortices typically involve rostral branches (precentral and central artery) of the superior division of the middle cerebral artery (MCA). Although few studies have systematically analyzed the short and long-term outcome of patients with frontal lobe strokes, it is clear that there is a substantial role for health providers in managing and supporting the recovery. Variables influencing recovery include the location and extent of the cerebral damage, associated cognitive, motor, and emotional impairments, treatment services, and supportive care.
Dysarthria is characterized by dysfunction of the structures implicated in the control, initiation, and coordination of speech output: lips, tongue, jaw, palate, and larynx, which are innervated by the facial, glossopharyngeal, vagal, and hypoglossal nerves. Lesions that cause dysarthria occur in one of several locations along the neuraxis. This chapter presents the clinical features of dysarthria resulting from stroke and its associated neurological signs. Ischemic lesions of the upper motor neuron system may be unilateral or bilateral, cortical or subcortical. Ischemic lesions in the vertebrobasilar territory can result in both upper and lower motor neuron involvement. Ataxic dysarthria is the result of lesions occurring in the territory of the superior cerebellar and posterior inferior cerebellar arteries. Dysarthria can follow ischemic lesions of the extrapyramidal system occurring in the vascular territories of the deep penetrating branches of the anterior and middle cerebral arteries.
The arterial system supplying the midbrain is terminal for the midbrain itself, arising from the basilar artery and from the bifurcation of the basilar artery. According to magnetic resonance imaging (MRI)-based stroke registries, the midbrain was involved in 0.9% of strokes and 3% to 8% of posterior circulation infarcts. Oculomotor palsies are frequent in midbrain strokes and dominate the neurological picture. Combined upward- and downward-gaze palsy has been related to bilateral or unilateral midbrain infarcts. A lacunar infarct of the lateral midbrain affecting the pyramidal tract in the cerebral peduncle can cause pure motor stroke. Midbrain hematomas or infarcts that involve the sensory lemniscus have been reported as causes of pure sensory strokes. Bilateral, isolated small infarcts in the lateral midbrain involving the corticospinal tracts have been responsible for tetraplegia and mutism, leaving conscious patients with only gaze movements as a means to communicate.
The posterior cerebral arteries (PCAs) are the major sources of blood supply to the midbrain, thalamus, occipital lobes, inferior and medial temporal lobes, and portions of the posterior inferior parietal lobes. The PCAs originate from the terminal bifurcation of the basilar artery, encircle the midbrain, and then divide into cortical branches as they reach the dorsal surface of the midbrain. Patients with PCA stenosis may have transient ischemic attacks (TIAs) alone, or they may precede infarction. The main clinical feature distinguishing proximal PCA occlusion from the other types of PCA strokes is hemiplegia. Unilateral and bilateral PCA territory infarctions can also result from mass lesions that cause transtentorial herniation and increased intracranial pressure. The temporal and calcarine artery branches are most often involved. Patients with bilateral infarctions involving the lingual and fusiform gyri in the inferior portions of the temporal lobes often manifest a restless, hyperactive state.
The primary function of the sensory cortex is to discriminate sensation: appreciation and recognition of spatial relations, appreciation of similarity and differences of external objects, precise localization of the point touched, and identification of objects (stereognosis). Although less carefully examined than motor or speech abnormalities, somatosensory abnormality is present in at least half of stroke patients. The sensory abnormality is characterized by the presence of paresthesias and a selective loss of lemniscal sensation. Pontine tegmental strokes affecting the sensory tracts are often accompanied by sensory symptoms. Concomitant involvement of the adjacent pyramidal tract results in a sensory-motor stroke, and additional involvement of the cerebellothalamic fibers at the ventrolateral nucleus may produce a hypesthetic ataxic hemiparesis syndrome. Although motor symptoms are usually dominant in patients with subcortical strokes, small or even relatively large lesions primarily affecting the thalamocortical sensory radiation can result in pure or predominant sensory symptoms.
Severe ischemic stroke with progressive edema development is frequently life-threatening and associated with a poor prognosis due to limited expandability within the cranial cavity. This chapter describes the relevant aspects of supra- and infratentorial space-occupying strokes with particular emphasis on the role of decompressive surgery. Large ischemic infarction of the middle cerebral artery (MCA) territory can lead to a clinical syndrome called malignant MCA stroke. Cranial computed tomography (CT) is still the most widely used radiological modality to diagnose and monitor malignant MCA infarction. The only specific treatment option for this type of stroke with a solid base of evidence and major impact on the clinical course to date is decompressive surgery, that is, hemicraniectomy. Swelling of a large space-occupying cerebellar infarct appears within a few days from symptom onset and can lead to compression of the brainstem and midbrain or cause a hydrocephalus.
Memory systems are usually divided in five main categories: semantic, episodic, primary, procedural, and perceptual representation systems. Both semantic and episodic memories are forms of long-term memory with an unlimited capacity. The arterial blood supply of anatomical structures involved in memory comes from different sources. Memory impairment after stroke results from the cumulative effects of stroke and preclinical Alzheimer's disease or to unrecognized preexisting dementia. Mild memory complaints are frequent in stroke survivors. Confusion and memory loss can also result from infarction of the inferior genu of the internal capsule. This syndrome features fluctuating alertness, inattention, memory loss, apathy, abulia, psychomotor retardation, and severe memory loss. Concerning the influence of treatment modalities on memory defects, there are no differences between early and late aneurysmal surgery. Objective memory impairment is more frequent after surgical than after endovascular treatment of the ruptured aneurysm.
Pseudoxanthoma elasticum (PXE) is an inherited connective tissue disorder, characterized predominantly by skin, eye, cardiac, and vascular abnormalities. The genetic defect has been mapped to the ABCC6 gene on chromosome 16. The most characteristic and diagnostic feature of PXE is the angioid streaks found in the retina. The streaks are red-brown or gray, are usually wider than veins, and radiate from the optic disc. Abdominal angina and ischemic bowel disease occasionally develop. Hypertension is also very common in patients with PXE and often contributes to the cardiac and cerebrovascular pathology leading to strokes. Premature occlusive cervicocranial disease and aneurysmal subarachnoid hemorrhage are the two cerebrovascular problems directly attributable to PXE. It is difficult in patients with Binswanger-like abnormalities, PXE, and hypertension to know how much of the abnormalities, if any, relate directly to PXE and how much are attributable to the hypertension.
Henoch-Schönlein purpura (HSP), the most common vasculitis that affects children, is an acute, small-vessel leukocytoclastic process. HSP is a systemic vasculitis involving vascular wall deposits of predominantly immunoglobulin (Ig) A within the small vessels of the gut, skin, joints, and kidneys, and in the mesangium of the renal glomeruli. The most frequent laboratory abnormalities are high erythrocyte sedimentation rates, microscopic hematuria, proteinuria, and elevated levels of IgA. HSP is known to cause neurological complications including seizure, chorea, encephalopathy, focal neurological signs, cortical blindness, as well as cranial and peripheral neuropathies and intracerebral hemorrhage. Ischemic infarction and strokes also occur in HSP. Pulse steroids have been shown to be effective, but sometimes plasmapheresis has been used to arrest disease progressio. Patients with severe nephritis, especially with the nephritic syndrome, have often been treated with corticosteroids and cyclophosphamide, cyclosporine, or azathioprine.
This chapter explores the relationship of stroke with Susac's syndrome. In Susac's syndrome, diagnostic signs involve the retina. Fundoscopic examination shows arteriolar occlusions with narrowing of arterioles, as well as signs of other ischemic changes in the affected vascular area, such as edema and increased vascular permeability. Fluorescein angiography is often helpful in showing the vascular occlusions and leaking into the retina. Magnetic resonace imaging (MRI) is the neuroimaging study of choice and fluid-attenuated inversion recovery (FLAIR) a sensitive sequence for detecting lesions of Susac's syndrome as well as to show their heterogeneity. Small-vessel diseases are responsible for a large amount of ischemic and hemorrhagic strokes as well as encephalopathies including Susac's syndrome. Misdiagnoses include multiple sclerosis, but differential diagnosis must be done with all causes of multifocal neurologic symptoms with hearing and/or visual loss. Calcium channel blockers (nimodipine), anticoagulants, and aspirin may be useful in treatment.
The epidermal nevus syndrome refers to the association of any epidermal nevus with extracutaneous abnormalities. The most common extracutaneous abnormalities are neurologic, skeletal, and ocular, although other organs may also be involved. Widespread use of magnetic resonance imaging (MRI) has resulted in an increasing appreciation of the role of cortical malformations in patients with neurological symptoms. Strokes and vascular abnormalities have been reported in patients with the epidermal nevus syndrome. Arteriovenous malformations and leptomeningeal angiomas have been found in some patients with the epidermal nevus syndrome. Generally, the diagnosis of an epidermal nevus is not in doubt. If there are any doubts, a skin biopsy should be obtained. Treatment of the nevus with dermabrasion, diathermy, laser treatment, and cryotherapy is associated with a fairly high risk of recurrence of the nevus. Focal resection of the epidermal nevus before puberty is advised because of the increased risk of tumor development.
Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is an ophthalmologic syndrome rather than a specific entity, characterized by multiple cream-colored placoid lesions located in the posterior pole "lying at the level of the pigment epithelium and choroids". The ophthalmoscopic hallmarks of APMPPE consist of creamcolored, flat, and discrete placoid, without clear-cut marginal lesions at the level of the retinal pigment epithelium, masking the fundus view of the underlying choroids, which typically involve the macula but are never seen anterior to the equator. The fact that cardiovascular diseases (CVDs) occur in patients with APMPPE strongly supports the thesis that it represents a particular "uveo-cerebral vasculitic syndrome". Various etiologies have been found (infectious/postinfectious; vaccinations; inflammations; autoimmune diseases; vasculitis; paraneoplastic syndrome). The neurological complications of APMPPE are headache, aseptic meningitis, encephalitis, multiple sclerosis-like disease, and pseudo tumor cerebri. CVDs associated with APMPPE consist of ischemic cortical strokes and deep infarcts with striatocapsular infarctions.
This chapter contains detailed, up-to-date information about the nature, diagnosis, and treatment of Ehlers-Danlos syndromes (EDS) that cause strokes. The EDS are a group of connective tissue diseases classically characterized by fragile or hyperelastic skin, hyperextensible joints, vascular lesions, and easy bruising and excessive scarring after an injury. Numerous mutations of the COL3A1 gene on chromosome 2, including point mutations, exon skipping mutations, and multi-exon deletions, have been attributed to this disease. EDS patients develop arterial dissections. The cerebrovascular complications include intracranial aneurysms, arterial rupture, carotid-cavernous fistulae, and arterial dissections. The intracranial internal carotid artery is the most common site for an aneurysm, and rupture of the internal carotid artery within the cavernous sinus can create a direct carotid-cavernous fistula. The fragile arteries make angiography and surgery difficult, but some patients have had successful surgery or endovascular treatment.
This chapter highlights the clinical, pathophysiologic, and biochemical links between inflammatory bowel disease (IBD) and ischemic stroke. Deep venous thrombosis (DVT) and pulmonary embolism (PE) account for the overwhelming majority of thrombotic events in patients with IBD. Descriptions of IBD-associated central nervous system (CNS) vasculitis are based on angiography showing segmental narrowing in the small to medium-sized arteries. Of the many IBD-related hypercoagulable state manifestations, an estimated 10 percentage are ischemic strokes. Hyperhomocysteinemia has recently emerged as an independent risk factor for stroke; homocysteine is a sulfur-containing amino acid formed during the demethylation of the amino acid methionine. The mechanism for ischemic strokes in IBD patients is multifactorial, but likely secondary to an abnormal coagulability profile and, in rare situations, cerebral vasculitis. Better management of IBD flares, improved compliance with newer IBD medications, and quicker surgical interventions might lead to better outcomes and stroke risk reduction.
Marfan's syndrome is a connective tissue disorder responsible for an extensive and generalized malformation of organs and systems. An estimate of the risk of developing a cerebrovascular event in Marfan's syndrome is entirely elusive, both in general and for a particular patient. Severity of the vascular malformations differs from patient to patient and, in the worst cases, the chance of a disastrous event is largely related to other than neurological causes. Valvular dysfunction and disturbances of cardiac rhythm can produce embolic strokes basically no different from any other embolic stroke. Intracerebral aneurysms and aneurysmal rupture have for a long time been considered frequent complications of Marfan's syndrome. However, there are currently no prophylactic or curative medical treatments for the crucial Marfan's anomalies. Additional progress in understanding genetics and biochemical defects and in the elucidation of the ultimate mechanisms related to malformations in Marfan's syndrome are expected in the near future.
Sneddon's syndrome (SS) refers to an infrequent disorder combining skin and ischemic cerebral lesions in patients without a recognizable connective tissue or inflammatory or chronic infectious disease. As a rule, the transient ischemic attacks and strokes are multiple and recurrent in the same or different vascular territories. Both cortical and subcortical areas in the anterior and posterior circulation can be affected, but the most common lesions leading to progressive clinical disability are white matter abnormalities and lacunar infarcts. A large retrospective study on the anti-phospholipid antibody syndrome demonstrated that treatment with high-intensity warfarin (producing an international normalized ratio [INR] of >3) with or without low-dose aspirin (75 mg/day) is significantly more effective than treatment with low-intensity warfarin (producing an INR of <3) with or without treatment with low-dose aspirin or treatment with aspirin alone in preventing further thrombotic events.