As with ischemic strokes, lacunar infarcts usually present with sudden onset neurological deficits. However, a subset of lacunar infarctions may present in a stepwise pattern and are known to worsen even during admission. Lacunar infarcts are common in the deep brain nuclei, including the thalamus, basal ganglia, pons, and white matter of the internal capsule. Lacunar infarcts can be asymptomatic and are noted on imaging as incidental findings. Silent lacunar infracts are more common than symptomatic lacunar infarcts.[20]

Clinical presentation depends on the area of brain involvement. Lacunar infarcts in the centrum semiovale may present without symptoms and can be found incidentally on brain imaging for some other cause. However, certain lacunar infarcts, like in the posterior limb of the internal capsule or the pons, can present with severe hemiplegia. Often, cortical findings, such as neglect, visual disturbances, aphasia, and behavioral changes are absent in clinical presentation of lacunar stroke as they occur in subcortical areas of the brain.

Lacunar strokes seldom affect memory, language, and judgment. There are about 20 different types of lacunar syndromes described in the literature. The most common lacunar syndromes are as described below:

1. Pure motor hemiparesis-: It involves the posterior limb of the internal capsule, corona radiata. This type presents with contralateral hemiparesis of face, arm, and leg. Mild dysarthria may be present with the absence of sensory symptoms. These are the most common lacunar syndromes. They account for 45% of cases of lacunar strokes. Cortical signs like aphasia, cognitive deficit, or visual symptoms are always absent. Pure motor stroke can present as a combination of weakness in the arm, leg, or face on one side or any of these parts alone.
2. Ataxic hemiparesis: It comprises of 10-18% of cases. It involves the internal capsule, pons, or corona radiata. It causes hemiparesis of the contralateral face and leg and ataxia of the contralateral limb. Ataxia is the prominent feature of this stroke.
3. Pure sensory stroke: It involves the thalamus or corona radiata; it presents with the absent or abnormal sensation of contralateral of face, arm, and leg. It accounts for 7% of cases of lacunar strokes. The sensations affected are pain, temperature, touch, pressure, vision, hearing, and taste. A common form of thalamic lacunar stroke is known as Dejerine Roussy syndrome.[21]
4. Dysarthria-clumsy hand syndrome involves the pons or internal capsule, presents with dysarthria, problem pronouncing words due to voice box muscle weakness, including tongue, larynx, and other facial muscle weakness. Contralateral clumsiness of the upper extremity is present with preserved motor strength. Apparent difficulty with subtle fine movements such as writing or tying a shoelace may be present.
5. A sensory-motor stroke involves the thalamus, internal capsule, or putamen-capsule-caudate, and presents clinically with a combination of ipsilateral sensory and motor loss. Sensory-motor lacunar strokes are the second most common type of lacunar strokes. They account for 20% of cases.[22][23][24]

Most penetrating branches arise from the middle cerebral artery; the intracranial non-stenotic atheroma in the large vessel may cause a lacunar stroke by blocking the penetrating branch artery at its takeoff point.[25]

Neurological fluctuation and deterioration is a common feature of subcortical strokes. More than 40% with subcortical infarct deteriorate neurologically within the first week of onset of stroke symptoms. One-third of the deteriorated patients reverse spontaneously. The rest of them suffer a physical disability.[26] Lacunar strokes are also a common cause of vascular dementia and mild cognitive impairment, often overlooked in clinical practice. Multiple silent lacunar strokes are documented on brain MRI, with patients presenting with mild cognitive impairment and early dementia.[27]

Sudden onset neurological deficit requires emergent neuroimaging. An initial non-contrast head CT scan is preferred in an acute setting as it is readily available, quick, and useful to rule out life-threatening conditions such as intracerebral bleed or herniation as well as to clear the patient for possible intervention.

CT scan seldom identifies lacunar ischemic insult within the first 24 hours due to its small size. If seen, lacunar strokes are ill-defined hypodensities on CT scan, unless there is a hemorrhagic component to the acute stroke. A hyperdensity of a large artery on non-contrast head CT indicates the presence of thrombus inside the arterial lumen or vessel calcification. Early infarct signs on non-contrast CT include loss of gray-white differentiation and focal hypoattenuation of brain parenchyma. These details are difficult to read in small subcortical strokes. Chronic lesions may appear as hypodense foci.

CT angiogram of the head and neck can also be done. This can show a filling defect that is consistent with a thrombus blocking a specified vessel. It may also show arterial narrowing, and extensive vessel disease, like in the carotid arteries, which may be a source of an embolus or the middle cerebral artery features consistent with an atheroma. Neurovascular imaging modality is essential to determine the presence of large artery occlusion as it helps determine the need for catheter guided thrombolysis.

MRI is a superior imaging modality in acute and subacute settings in the detection of lacunar infarction. In the acute stage, the MRI diffusion-weighted image (DWI) has the most diagnostic accuracy. MRI-DWI helps to differentiate between acute and chronic infarction.[28] In an acute setting, on T1-weighted images, lacunes appear as focal areas of decreased signal intensity and as focal areas of hyperintensity on T2-weighted images. Chronic lesions are isointense to CSF on all sequences.

In cases where a neck angiogram is not done, carotid ultrasound helps diagnose an atherosclerotic narrowing of the extracranial carotid artery. The risk of stroke is higher in patients with severe carotid artery stenosis (CAS). The U.S. Preventive Services Task Force considers 70%-99% carotid stenosis to be clinically significant. Carotid artery intervention is recommended in clinically significant lesions.

Extensive embolic workup, including echocardiography and vascular imaging evaluation, is very low yield in cases of lacunar strokes.[29] However, this may be necessary in some cases, like in young patients with no obvious medical issues.

Other immediate tests to be performed include blood glucose levels, electrocardiogram, complete blood count including platelets, troponin, prothrombin time, and international normalized ratio (INR), activated partial thromboplastin time, and a complete metabolic panel and lipid panel. These tests are helpful in the assessment of underlying stroke risk factors.

Treatment principles for acute lacunar stroke are very similar to any acute ischemic stroke. The initial goal of acute stage treatment is ensuring medical stability and determining candidacy for thrombolysis. Tissue plasminogen activator (TPA) improves outcomes for patients with ischemic stroke if administered within 4.5 hours of symptom onset. Once intracerebral bleed is ruled out, intravenous thrombolysis is an important step in the treatment. An acute lacunar infarct is efficiently treated with TPA.[30][31]

If symptom onset duration is more than 4.5 hours and there is suspicion for intracranial arterial occlusion in the anterior circulation, CTA/MRA is useful for selecting candidates for mechanical thrombectomy between 6 to 24 hours from last known well.

Management of patient who presents with acute lacunar infarct out of TPA window consistent with a non-cardioembolic stroke includes dual antiplatelet therapy (DAPT) with aspirin and clopidogrel within 24 hours of symptom onset and continued for 21 days. DAPT in the acute phase is effective in lowering recurrent ischemic stroke for 90 days from symptom onset. In patients who received TPA, antiplatelet therapy should be delayed for 24 hours.

Management of hypertension includes allowing for permissive hypertension unless the blood pressure is markedly elevated (i.e., more than 220/120 mmHg), in this case, lower blood pressure by 15% during the first 24 hours, hold any outpatient antihypertensive medications at admission for the early 24 hours, unless other comorbid conditions require the immediate lowering of blood pressure. In patients where TPA is given or who undergo thrombectomy, lowering the blood pressure below 185/110 mmHg is ideal.

Blood sugar management is done to maintain euglycemia with recommended blood glucose levels at 60–180 mg/dL. Both hypoglycemia and hyperglycemia should be monitored and corrected. The recommended HbA1c goal is 6.5 to 7.

Correct volume status by giving isotonic saline as stroke patients tend to be volume depleted. Keep oxygen saturation above 90%. Continue statin therapy with goal LDL less than 70 mg/dl. Assess swallowing function before advancing diet. VTE prophylaxis and early mobilization efforts are an essential part of the treatment plan.[32]

Stroke Prevention 

Primary and secondary prevention of stroke remains an essential part of the treatment plan. Primary prevention includes the prevention of the first episode of stroke, and secondary prevention includes prevention of recurrence.

Primary stroke prevention measures include risk factor management that provides for, use of antihypertensive medications, diabetes control, cholesterol-lowering agents, smoking cessation, dietary intervention, weight loss, and exercise.

Secondary prevention includes antithrombotic agents like aspirin, clopidogrel, extended-release dipyridamole, ticlopidine, and management of underlying risk factors. Antiplatelet agents reduce the risk of recurrence in patients with lacunar strokes.[33] Blood pressure control, diabetes control, lipid management, smoking cessation, weight loss, and regular exercise included in secondary prevention strategies. Blood pressure reduction at a target of systolic blood pressure less than 130 mmHg is beneficial.[34]

Double antiplatelet therapy (clopidogrel and aspirin) for secondary prevention has not shown a further reduction in the risk of recurrence in lacunar stroke.[35] Secondary prevention of stroke is an essential strategy; it can prevent as much as 80% of all recurrent strokes.[36]

Oral anticoagulants are not considered for small cerebral vessel disease-related stroke prevention, including recurrent lacunar infarcts, as they disproportionately increase intracranial cerebral hemorrhage risk.[37]

Physical therapy and rehabilitation is an essential step for managing patients who suffer lacunar strokes that cause physical disability. These patients require rehabilitation. The goal of rehabilitation is to optimize functional recovery after a stroke and level of independence and maintain quality of life.

Differential diagnosis of lacunar infarcts include the following:

• Large vessel ischemic stroke in the middle cerebral artery territory: it is clinically differentiated from lacunar strokes by the presence of cortical signs, including altered mental status, aphasia, hemineglect, etc.
• Intracranial hemorrhages: hemorrhage can be easily seen on neuroimaging modalities like CT scan of the brain.
• Seizures: seizures are caused by excess neuronal activity and can be differentiated clinically by its tonic-clonic activity, postictal state after having seizures.
• Complicated migraine: symptoms are usually accompanied by headache and aura. A typical aura may involve visual disturbances, sensory symptoms, motor weakness, or speech disturbances.
• Brain tumors: are distinguished by their characteristic appearance on MRI.
• Multiple sclerosis (MS): can cause paroxysmal attacks of ataxia and dysarthria. MRI helps distinguish the presence of plaques due to MS from a stroke. Further cerebral vasoreactivity measured by transcranial Doppler (TCD) sonography can be used for differentiating ischemic and demyelinating lesions. The presence of oligoclonal bands on lumbar puncture is characteristic of multiple sclerosis.

Earlier studies suggested that lacunar stroke has a better prognosis compared to other strokes. It has a high survival rate, a low recurrence rate, and a relatively good functional recovery. In general, lacunar infarcts have a relatively favorable prognosis.[38]

However, recent studies showed that in the earlier stages of the disease, the prognosis of lacunar stroke appears to be benign. Still, long term prognosis with lacunar stroke constitutes an increased risk of death, mainly from cardiovascular causes. The risk of recurrence of stroke is similar to any other type of stroke. Patients with recurrent small vessel disease are at increased risk of developing cognitive decline and dementia.[39][13]

Lacunar strokes are thought to be the leading cause of vascular dementia and cognitive impairment.[13] Accumulated lacunar infarcts can lead to other disease-related complications due to physical disability, including, but not limited to, aspiration pneumonia, deep vein thrombosis, pulmonary embolism, urinary tract infection, depression, and decubitus ulcers.

Most patients with lacunar infarctions have significant improvement of neurologic deficits. Physical therapy, speech therapy, occupational therapy, and rehabilitation services remain essential after hospital care to regain maximum strength and functional level after stroke.

Patients need to be aware of risk factors that raise the risk of stroke. Compliance with antithrombotic agents to prevent the recurrence of stroke is essential. Patients are advised to maintain a healthy diet, exercise regularly, avoid smoking, and avoid excess alcohol use. Together, these habits reduce the risk of having strokes in general. If patients have high blood pressure, lipid disorder, or diabetes, regular follow-up with their primary care provider is essential to keep these risk factors optimally controlled.

The timeline of recovery from lacunar stroke is different for everyone. Home safety is essential. Fall-risk due to physical disability is common. Depression is common in people who have experienced a stroke and should be addressed if present. Cognitive impairment due to multiple subcortical strokes can progress to vascular dementia and should be monitored.

Patients with lacunar infarctions must be managed and seen by a neurologist and physical, occupational, and social therapists to get comprehensive care. Physical deficits like ataxia and motor hemiparesis are managed with physical therapy, while muscle relaxants like baclofen and tizanidine can be used for spasticity. The role of pharmacists remains crucial in patients receiving multiple medications to keep a drug interaction check. Rehabilitation therapy must be continued to maximize the patient’s neurologic function to bring close to his/her baseline before the infarction.

Long term care coordination is the responsibility of the primary care provider. Emphasis on the management of stroke risk factors includes intense antihypertensive therapy, lipid management, and strict control of blood sugars after the lacunar ischemic event.