Updated: Jul 16, 2008
The lacunar hypothesis proposes that (1) symptomatic lacunes present with distinctive lacunar syndromes and (2) a lacune is due to occlusion of a single deep penetrating artery generated by a specific vascular pathology. This concept is controversial because different definitions of lacunes have been used. Lacunes may be confused with other empty spaces, such as enlarged perivascular (Virchow-Robbins) spaces, in which the specific small-vessel pathology occasionally is absent. Originally, lacunes were defined pathologically, but lacunes now are diagnosed on clinical and radiological grounds. This problem is compounded by the present inability to image a single penetrating artery.1
Lacunes may be defined as small subcortical infarcts (<15 mm in diameter) in the territory of the deep penetrating arteries; lacunes may present with specific lacunar syndromes or may be asymptomatic. Unfortunately, the 5 classical lacunar syndromes and the radiologic appearances are not specific for lacunes (see History). Lacunes occur most frequently in the basal ganglia and in the internal capsule, thalamus, corona radiata, and pons.
Much of our current knowledge of lacunar strokes is due to Fisher's prior cadaveric dissection of post-mortem stroke patients. He found that most symptomatic lacunar strokes are due to the occlusion of penetrating arteries of 200-800 μ m in diameter, whereas those with smaller-diameter penetrating artery infarcts tended to be asymptomatic.
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Lacunes are caused by occlusion of a single penetrating artery. The deep penetrating arteries are small, nonbranching end arteries (usually smaller than 500 μ m in diameter), which arise directly from much larger arteries (eg, the middle cerebral artery, anterior choroidal artery, anterior cerebral artery, posterior cerebral artery, posterior communicating artery, cerebellar arteries, basilar artery). Their small size and proximal position predispose them to the development of microatheroma and lipohyalinosis.2
Initially, lipohyalinosis was thought to be the predominant small-vessel pathology of lacunes; however, microatheroma now is thought to be the most common mechanism of arterial occlusion (or stenosis). Occasionally, atheroma in the parent artery blocks the orifice of the penetrating artery (luminal atheroma), or atheroma involves the origin of the penetrating artery (junctional atheroma).
A hemodynamic (hypoperfusion) mechanism is suggested when there is a stenosis (and not occlusion) of the penetrating artery. When no evidence of small-vessel disease is found on histologic examination, an embolic cause is assumed, either artery-to-artery embolism or cardioembolism. In one series, 25% of patients with clinical, radiologically defined lacunes had a potential cardiac cause for their strokes.
In the United States and other Western nations, lacunes account for 15-25% of all ischemic strokes. In 2 community - based studies in the United States, the annual incidence rates of lacunar strokes were 13.4 and 19.5 cases per 100,000 population.
Two European community-based studies found higher annual incidence rates (31.7 and 53 cases per 100,000 population). This difference in incidence rates between the US and European studies may be due in part to different definitions used in the studies.
Some studies have found higher frequencies of lacunar strokes in African Americans, Mexican Americans, and Hong Kong Chinese.6
Some studies have indicated that there is a higher incidence of lacunar strokes in men.
The incidence of lacunar strokes increases with age. The mean age of first lacunar stroke is approximately 65 years.
Lacune-related symptoms may occur suddenly or may evolve in either a fluctuating (eg, the capsular warning syndrome) or a progressive manner.Each of the 5 classical lacunar syndromes has a symptom complex that is relatively specific to it. Occasionally, cortical infarcts and intracranial hemorrhages can mimic a lacunar syndrome.7 Cortical symptoms (eg, aphasia, neglect) and visual field defects are absent.
Physical examination findings differ in each of the lacunar syndromes, as follows:
The cause of lacunar infarction is occlusion of a single small penetrating artery. This occlusion may be due to microatheroma and lipohyalinosis, which are associated with hypertension, smoking, and diabetes, or may result from microembolism from the heart or carotid arteries.5,9
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Hypoglycemia
Middle Cerebral Artery Stroke
Migraine Headache
Other stroke subtypes (large artery disease, cardioembolic, hemorrhagic)
Seizure (Todd paresis)
Space-occupying lesion (abscess, tumor)
Lacunes are not examined histologically except at necropsy. Histologically, lacunes are no different from other brain infarcts. Cells undergoing necrosis initially are pyknotic, but their plasma and nuclear membranes then break down. Polymorphonuclear cells appear, followed by macrophages, and the necrotic tissue is removed by phagocytosis. A cavity surrounded by a zone of gliosis is the end result. Careful examination may reveal the underlying small-vessel pathology.
Microatheroma causing occlusion or stenosis of a deep penetrating artery is the most common small-vessel pathology, usually involving the artery in the first half of its course. Histologically, microatheroma is identical to large-vessel atheroma with subintimal deposition of lipids and proliferation of fibroblasts, smooth muscle cells, and lipid-laden macrophages.
Lipohyalinosis is seen in the smaller penetrating arteries (<200 μ m in diameter) and occurs almost exclusively in patients with hypertension. It has features of atheroma formation and fibrinoid necrosis, with lipid and eosinophilic fibrinoid deposition in the media.
After the initial assessment of a patient who has suffered a lacunar stroke, a physical therapy program should provide passive exercises, with the major joints of the paretic limb being put through a full range of motion (ROM). As soon as patients are stable and can tolerate more active therapy, encourage them to sit up (initially in bed and later in a chair), to stand, and to transfer safely; then, they can commence ambulating with assistance and aids, as required. The physical therapist can provide splints and braces to support joints and limbs, to treat and prevent complications (eg, shoulder-hand syndrome, spasticity), and to assist the patient in walking.
When the patient who has had a lacunar stroke becomes stable, assess his/her ability to perform activities of daily living (ADLs), such as dressing and undressing, bathing, personal grooming, toileting, preparing meals, and eating. The occupational therapist can advise on equipment that may allow the patient to be more independent. If the patient is returning home, an assessment of the residence identifies potential problems and necessary modifications (eg, handrails, moving a bed to a ground level room), thereby providing confidence to the patient and family.
A speech-language therapist can assist with speech-language problems and swallowing disorders in patients who have had a lacunar stroke. Early assessment of a patient with swallowing problems may prevent dehydration and malnutrition from inadequate intake, as well as prevent aspiration and pneumonia. In addition to the bedside assessment, cinefluoroscopy with barium swallow may be required. Treatment may require a change in food consistency, a change in positioning or compensatory swallowing technique, or placement of a feeding tube. Patients with lacunes may be dysarthric (but not dysphasic), requiring treatment to improve functional communication.
Following stroke, recreational therapy improves a patient's independence, self-confidence, and ability to function, through participation in individual and group recreational activities that the patient previously enjoyed, as well as through participation in new ones. The recreational therapist must assess the medical condition and physical capabilities of the patient, in addition to that individual's interests and hobbies. Then, the therapist must help the patient to set realistic goals and to make any modifications needed to achieve them. Recreational therapy not only allows the stroke patient to practice motor skills but also allows him/her to remain socially active. Recreational therapy includes leisure activities, such as going for a walk, fishing, and gardening, as well as involvement in family and community activities, such as playing cards or going to a restaurant or to church.
The prevention of deep venous thrombosis (DVT), aspiration pneumonia, urinary tract infection, and decubitus ulcers are important considerations for any patient following stroke.
Surgery (eg, gastrostomy/jejunostomy) rarely is required as a result of a lacunar stroke, but patients with severe dysphagia may require long-term tube feeding.
A social worker should be consulted to assess personal and family resources, to inform the patient and family of available government resources, to facilitate discharge planning, and to coordinate community services.
Some patients with spasticity or joint contractures following a lacunar stroke may benefit from the injection of botulinum toxin or neurolytic agents.
The medications used in the management of lacunes are not specific to this stroke subtype.
These agents are used to improve stroke outcome. The National Institute of Neurological Disorders and Stroke (NINDS) study on recombinant tissue-type plasminogen activator (rt-PA) showed an 11-13% absolute increase in the number of ischemic stroke patients with a favorable outcome at 3 months with tissue plasminogen activator (t-PA).13,14
T-PA used in management of acute myocardial infarction (AMI), acute ischemic stroke, and pulmonary embolism (PE). No other IV-administered fibrinolytic has been shown to have clinical efficacy. A post hoc analysis showed that all stroke subtypes benefit from t-PA treatment.
0.9 mg/kg (not to exceed 90 mg), 10% given as bolus IV and remainder infused over 1 h IV
Not established
Drugs that alter platelet function (aspirin, ticlopidine, and clopidogrel) and anticoagulants may increase risk of bleeding with alteplase therapy; AHA guidelines recommend withholding antiplatelet agents and anticoagulants for 24 h after alteplase administration because of risk of intracerebral hemorrhage (ICH)
American Heart Association (AHA) guidelines:
1) Beyond 3 h of stroke onset (or when last well)
2) CT scan evidence of recent major infarction
3) Concomitant anticoagulation (with prolonged aPTT or PT greater than 15 s or INR greater than 1.7)
4) Platelet count <100,000/μ L
Documented hypersensitivity; another stroke or major head injury in last 3 mo; major surgery in last 14 d; pretreatment systolic BP >185 mm Hg or diastolic BP >110 mm Hg; rapidly improving signs; mild deficit; prior intracerebral hemorrhage; blood glucose <50 mg/dL or >400 mg/dL; seizure at onset of stroke; gastrointestinal or urinary bleeding in last 21 d; recent myocardial infarction
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Monitor for bleeding, especially at arterial puncture sites, with coadministration of vitamin K antagonists; control and monitor blood pressure frequently during and following alteplase administration (when managing acute ischemic stroke); do not use >0.9 mg/kg to manage acute ischemic stroke; doses >0.9 mg/kg may cause ICH
These agents for secondary stroke prevention, if commenced within 48 hours of stroke onset, confer a small survival benefit.
Alternatives to aspirin include ticlopidine and clopidogrel. These drugs and a combination of aspirin and dipyridamole may be marginally superior to aspirin alone.
30-1300 mg/d PO; in US, usual dose is 325 mg PO qd
Not established
Effects may decrease with antacids and urinary alkalinizers; corticosteroids decrease salicylate serum levels; additive hypoprothrombinemic effects and increased bleeding time may occur with coadministration of anticoagulants; may antagonize uricosuric effects of probenecid and increase toxicity of phenytoin and valproic acid; doses greater than 2 g/d may potentiate glucose-lowering effect of sulfonylurea drugs
Documented hypersensitivity; liver damage, hypoprothrombinemia, vitamin K deficiency, bleeding disorders, asthma; due to association of aspirin with Reye syndrome, do not use in children (age <16 y) with flu
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Caution in past history of peptic ulcer disease; bleeding disorder, thrombocytopenia, renal disease, severe hepatic disease, asthmatic patient with nasal polyps; may cause transient decrease in renal function and aggravate chronic kidney disease; avoid use in patients with severe anemia or with a history of blood coagulation defects or in patients who are taking anticoagulants
Selectively inhibits adenosine diphosphate (ADP) binding to platelet receptor and subsequent ADP-mediated activation of glycoprotein (GP) IIb/IIIa complex, thereby inhibiting platelet aggregation. Indicated for reduction of atherothrombotic events following recent stroke.
75 mg PO qd
Not established
Coadministration with naproxen associated with increased occult GI blood loss; clopidogrel prolongs bleeding time; safety of coadministration with warfarin not established
Documented hypersensitivity; active pathological bleeding, such as peptic ulcer, or intracranial hemorrhage
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Caution in patients at increased risk of bleeding from trauma, surgery, or other pathological conditions; caution in patients with lesions with propensity to bleed (such as ulcers)
These agents are employed for prophylaxis of DVT and pulmonary embolism.
Can be used in conjunction with compression stockings or pneumatic stockings. Augments activity of antithrombin III and prevents conversion of fibrinogen to fibrin. Does not lyse actively but can inhibit further thrombogenesis. Prevents reaccumulation of clot after spontaneous fibrinolysis.
5000 U SC bid
Not established
Digoxin, nicotine, tetracycline, and antihistamines may decrease effects; NSAIDs, aspirin, dextran, dipyridamole, and hydroxychloroquine may increase toxicity
Documented hypersensitivity, subacute bacterial endocarditis, active bleeding, and history of heparin-induced thrombocytopenia
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
In neonates, preservative-free heparin is recommended to avoid possible toxicity (gasping syndrome) by benzyl alcohol, which is used as preservative; caution in severe hypotension and shock
These agents are used for secondary stroke prevention.15
The Heart Outcomes Prevention Evaluation (HOPE) study showed the benefit of ramipril in patients with vascular disease and in patients with diabetes who have vascular risk factors. It is not known whether this is a class effect.
Initial dose: 2.5 mg PO qd; titrate up to 10 mg PO qd
Not established
Ramipril may increase digoxin, lithium, and allopurinol levels; probenecid may increase ramipril levels; coadministration with diuretics or NSAIDs increase hypotensive effects
Documented hypersensitivity; history of angioedema
D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Renal impairment, severe congestive heart failure, hypertensive patient with renal artery stenosis, and aortic stenosis
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Nitkunan A, Barrick TR, Charlton RA, et al. Multimodal MRI in cerebral small vessel disease. Its relationship with cognition and sensitivity to change over time. Stroke. Apr 24 2008;[Medline].
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Adams HP Jr, Brott TG, Furlan AJ, et al. Guidelines for thrombolytic therapy for acute stroke: a supplement to the guidelines for the management of patients with acute ischemic stroke. A statement for healthcare professionals from a Special Writing Group of the Stroke Council, American Heart Association. Circulation. Sep 1 1996;94(5):1167-74. [Medline]. [Full Text].
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lacunar stroke, lacunar infarct, lacunar infarction, lacune, ischemic stroke, small-vessel disease, hemiparesis, ataxic hemiparesis, dysarthria, clumsy hand, motor stroke, sensory stroke, sensorimotor stroke, hypertension, diabetes mellitus, embolism, cardioembolism, artery-to-artery embolism
Adam B Agranoff, MD, Physiatrist and Partner, Chelsea Back Care, Chelsea Community Hospital
Adam B Agranoff, MD is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation and North American Spine Society
Disclosure: Nothing to disclose.
Edward H Wong, MB, BCh, Stroke Fellow, Department of Clinical Neurological Sciences, London Health Sciences Centre, University of Western Ontario
Edward H Wong, MB, BCh is a member of the following medical societies: American Academy of Neurology and American Heart Association
Disclosure: Nothing to disclose.
Robert J Kaplan, MD, Associate Professor, Department of Physical Medicine and Rehabilitation, University of Kansas School of Medicine and Medical Center
Robert J Kaplan, MD is a member of the following medical societies: American Academy of Physical Medicine and Rehabilitation, American Association of Neuromuscular and Electrodiagnostic Medicine, Association of Academic Physiatrists, International Spine Intervention Society, and Physiatric Association of Spine, Sports and Occupational Rehabilitation
Disclosure: Nothing to disclose.
Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.
Richard Salcido, MD, Chairman, Erdman Professor of Rehabilitation, Department of Physical Medicine and Rehabilitation, University of Pennsylvania School of Medicine
Richard Salcido, MD is a member of the following medical societies: American Academy of Pain Medicine, American Academy of Physical Medicine and Rehabilitation, American College of Physician Executives, American Medical Association, and American Paraplegia Society
Disclosure: Nothing to disclose.
Kelly L Allen, MD, Consulting Staff, Department of Physical Medicine and Rehabilitation, Lourdes Regional Rehabilitation Center, Our Lady of Lourdes Medical Center
Disclosure: Nothing to disclose.
Denise I Campagnolo, MD, MS, Director of Multiple Sclerosis Clinical Research and Staff Physiatrist, Barrow Neurology Clinics, St. Joseph's Hospital and Medical Center; Investigator for Barrow Neurology Clinics; Director, NARCOMS Project for Consortium of MS Centers, Phoenix
Denise I Campagnolo, MD, MS is a member of the following medical societies: Alpha Omega Alpha, American Association of Neuromuscular and Electrodiagnostic Medicine, American Paraplegia Society, Association of Academic Physiatrists, and Consortium of Multiple Sclerosis Centers
Disclosure: Teva Neuroscience Honoraria Speaking and teaching; Serono-Pfizer Honoraria Speaking and teaching
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