Lacunar Stroke: Symptoms, Types, Causes and Treatment

Lacunar stroke is a common but often misunderstood type of stroke that affects the brain's deep structures. Despite its small size, a lacunar stroke can have significant and lasting effects on health and quality of life. In this article, we'll explore what makes lacunar strokes unique—what symptoms to look for, the various types, underlying causes, and the latest evidence-based treatments. Understanding these aspects is crucial for patients, caregivers, and clinicians alike.

Symptoms of Lacunar Stroke

Lacunar strokes can present subtly or mimic other neurological conditions. Recognizing their symptoms is essential for prompt diagnosis and management, which can improve outcomes and prevent complications. While some people experience classic stroke signs, others may have atypical presentations that can make diagnosis challenging.

Symptom	Description	Presentation	Source(s)
Motor	Weakness on one side (hemiparesis/hemiplegia)	Sudden, isolated motor loss	4 7 8
Sensory	Numbness or loss of sensation	Pure sensory loss, often face/limb	4 7 8
Sensorimotor	Combined weakness and sensory loss	Both motor and sensory changes	4 7
Ataxia	Incoordination, clumsiness	Ataxic hemiparesis, clumsy hand	4 7 8
Speech	Slurred speech, dysarthria	Dysarthria-clumsy hand syndrome	2 4 7
Headache	Diffuse or sudden headache	Less common, may indicate hemorrhagic type	1 3

Table 1: Key Symptoms

Classic Lacunar Syndromes

The typical symptoms of a lacunar stroke are grouped into classic "lacunar syndromes." These usually occur suddenly and without warning:

• Pure Motor Hemiparesis: Sudden weakness of the face, arm, and leg on one side, without sensory loss or visual field deficits. This is the most frequent presentation (4 7 8).
• Pure Sensory Syndrome: Isolated numbness or loss of sensation, often affecting the face, arm, and leg on one side of the body (4 7 8).
• Sensorimotor Stroke: Combination of motor weakness and sensory loss on the same side (4 7).
• Ataxic Hemiparesis: Weakness and incoordination, typically affecting one side, leading to clumsiness (4 7 8).
• Dysarthria-Clumsy Hand Syndrome: Slurred speech (dysarthria) and clumsiness or weakness of the hand (4 7 8).

Atypical Presentations

While classic syndromes are common, atypical symptoms can also occur:

• Isolated dysarthria or facial paresis
• Isolated hemiataxia (incoordination on one side)
• Transient symptoms such as internuclear ophthalmoplegia (eye movement disturbance) or subcortical aphasia (language difficulty)
• Involvement of the thalamus or movement disorders like hemichorea-hemiballismus (2)

Atypical cases comprise a small minority but are important to recognize, as they can have a good prognosis (2).

Other Associated Symptoms

Some patients may experience headache—more commonly in hemorrhagic lacunar strokes or in those with less severe hypertension (1 3). Nausea, vomiting, and altered consciousness are less typical and may point toward other stroke types (1 5).

Types of Lacunar Stroke

Lacunar strokes are not all the same. They vary based on the exact location in the brain, underlying pathology, and whether the event is due to ischemia (lack of blood flow) or hemorrhage (bleeding). Understanding the subtypes helps guide diagnosis and management.

Type	Key Features	Frequency	Source(s)
Ischemic (Infarct)	Blockage of small vessel	Most common (≈25% of ischemic strokes)	4 6 7
Hemorrhagic	Small vessel rupture/bleed	Rare (3.8–7.4% of lacunar syndromes)	1 5
Classic Syndromes	Pure motor, sensory, sensorimotor	~90% of lacunar strokes	4 7 8
Atypical Syndromes	Unusual symptoms/locations	~6–7% of lacunar strokes	2

Table 2: Lacunar Stroke Types and Features

Ischemic Lacunar Infarct

The vast majority of lacunar strokes are ischemic, caused by blockage of small penetrating arteries deep within the brain. These account for about one-quarter of all ischemic strokes (4 6 7).

• Most frequent subtypes: pure motor hemiparesis, sensorimotor stroke, pure sensory stroke, ataxic hemiparesis, and dysarthria-clumsy hand syndrome (4 7 8).
• Infarcts usually affect regions like the internal capsule, basal ganglia, thalamus, or pons.

Hemorrhagic Lacunar Stroke

A small percentage of lacunar strokes are hemorrhagic, resulting from rupture of a small vessel (1 5). These often present with sudden onset, headache, and less commonly with dysarthria. Nausea, vomiting, and altered consciousness are rare, distinguishing them from larger intracerebral hemorrhages (1 5).

Classic vs. Atypical Syndromes

• Classic Syndromes: As previously described, these fit established patterns and are the majority.
• Atypical Syndromes: Include isolated dysarthria, facial paresis, isolated ataxia, and rare movement disorders. These represent a minority of cases but are important diagnostically (2).

Progressive Lacunar Stroke

About 20–30% of lacunar strokes can worsen over hours or days, leading to significant disability. This "progressive" form is recognized as a clinical entity and may require different management strategies (11 17 18).

Causes of Lacunar Stroke

Identifying the root causes of lacunar stroke is key to prevention and tailored therapy. The underlying pathology usually involves small vessel disease, but other mechanisms and risk factors contribute.

Cause	Mechanism / Risk Factor	Relative Importance	Source(s)
Hypertension	Chronic high blood pressure damages small vessels	Major cause	4 6 7 12
Diabetes Mellitus	Vascular injury, atherosclerosis	Major risk factor	4 7 12
Small Vessel Disease	Lipohyalinosis, microatheroma	Primary mechanism	6 13
Atherosclerosis	Plaque in larger vessels, emboli	Contributory in some cases	12
Cardiac Embolism	Clots from heart to small vessels	Minority of cases	12
Genetic Factors	Heritable susceptibility	Estimated 20–25% heritability	9 14
Endothelial Dysfunction	Impaired vascular health	Pathogenesis factor	10 13
Smoking	Vascular injury	Modifiable risk	1

Table 3: Major Causes and Risk Factors for Lacunar Stroke

Small Vessel Disease: The Primary Culprit

Most lacunar strokes result from intrinsic disease of the small penetrating arteries. The two primary pathological processes are:

• Lipohyalinosis: Degeneration of vessel walls, often from chronic hypertension (6).
• Microatheroma: Tiny atherosclerotic plaques occlude the vessel (6 13).

Modifiable Risk Factors

• Hypertension: The most important risk factor. Its control has led to a decline in lacunar stroke incidence (4 6 7).
• Diabetes Mellitus: Increases risk of small vessel disease and stroke (4 7 12).
• Smoking: Associated with higher risk, especially in hemorrhagic forms (1).
• Hyperlipidemia: Contributes to vascular injury.

Other Mechanisms

While small vessel disease is the leading cause, up to a third of patients—especially those without hypertension or diabetes—can have other contributing mechanisms:

• Atherosclerosis: Plaques in larger arteries can send emboli into small vessels (12).
• Cardioembolism: Rarely, clots from the heart can lodge in small vessels (12).
• Endothelial Dysfunction: Evidence suggests that impaired blood–brain barrier and vascular endothelium contribute to lacunar stroke pathogenesis (10 13).
• Genetic Susceptibility: Recent studies show significant heritability, with genetic factors influencing risk, especially in isolated or multiple lacunar infarcts (9 14).

Hemorrhagic Lacunar Stroke: Distinct Risk Profile

Hemorrhagic lacunar strokes are more strongly associated with hypertension and sudden onset symptoms, and less with diabetes (1 5).

Treatment of Lacunar Stroke

Effective treatment of lacunar stroke involves acute management, prevention of recurrence, and addressing modifiable risk factors. Recent research has refined treatment options to maximize recovery and reduce future risk.

Treatment	Approach / Medication	Best Use Cases	Source(s)
Antiplatelet	Aspirin, clopidogrel, etc.	Secondary prevention; all patients	4 15
Blood Pressure	Tight control	Prevention of recurrence	4 6
Statins	Cholesterol management	Reducing vascular risk	4
Thrombolysis	Alteplase (tPA)	Selected acute cases	16 19
Dual Antiplatelet	Short-term post-progression	Progressive strokes, short-term use	17 18
Lifestyle Change	Smoking cessation, diet	Prevention and better outcomes	4 6
Imaging	CT/MRI to distinguish types	Acute diagnostic clarification	5 19

Table 4: Main Treatment Strategies

Acute Management

Thrombolysis

• Intravenous thrombolysis (alteplase/tPA): Can be used in selected patients with acute lacunar stroke, with outcomes comparable to other stroke subtypes (16 19).
• Imaging (MRI/CT) is essential to confirm diagnosis and rule out hemorrhage (5 19).

Progressive Lacunar Stroke

• Dual Antiplatelet Therapy (DAPT): Short-term use of two agents (e.g., aspirin and clopidogrel) may improve outcomes in progressive cases, though long-term use is not recommended (17 18).
• Careful monitoring for bleeding risks is essential (18).

Secondary Prevention

Antiplatelet Agents

• Aspirin or other single agents: Proven to reduce recurrence risk (4 15).
• Dual therapy: Not recommended for long-term prevention due to lack of added benefit and increased bleeding risk (15).

Blood Pressure and Lipid Management

• Tight blood pressure control: Reduces recurrence and progression (4 6).
• Statins: Lower cholesterol and reduce vascular risk (4).

Lifestyle Modification

• Smoking cessation, healthy diet, regular exercise: All reduce future risk (4 6).

Special Considerations

• Hemorrhagic lacunar stroke: Management is mainly supportive and involves blood pressure control; anticoagulation is usually avoided (1 5).
• Imaging role: CT/MRI is vital for distinguishing ischemic from hemorrhagic lacunar strokes (5 19).

Follow-up and Prognosis

• Short-term recovery is often favorable, but there is an increased long-term risk of recurrence, dementia, and mortality (4).
• Regular follow-up is needed to monitor and manage vascular risk factors.

Conclusion

Lacunar stroke is a significant and complex subtype of stroke, often resulting from small vessel disease and presenting with distinct clinical syndromes. While many patients recover well, lacunar strokes carry a long-term risk of recurrence and cognitive decline. Early recognition, evidence-based treatment, and rigorous risk factor management are essential for the best outcomes.

Key Takeaways:

• Symptoms: Most commonly present as pure motor, sensory, or sensorimotor deficits; atypical presentations exist but are less frequent (4 7 8 2).
• Types: Mainly ischemic, with a small percentage being hemorrhagic; classic and atypical syndromes recognized (4 7 8 1 2).
• Causes: Predominantly small vessel disease, with hypertension and diabetes as leading risk factors; genetic and endothelial factors also play roles (4 6 7 12 9 13).
• Treatment: Emphasizes antiplatelet therapy, blood pressure and lipid management, and lifestyle change. Thrombolysis and dual antiplatelet therapy are reserved for select cases (4 15 16 17 18).
• Prognosis: Generally good for single events, but risk of recurrence and long-term complications necessitates ongoing management (4).

By understanding the unique features of lacunar stroke, both patients and clinicians can work toward better prevention, quicker recognition, and more effective treatment.