What are the typical symptoms of a right-sided lacunar infarct?

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From the Guidelines

Typical symptoms of a right-sided lacunar infarct include contralateral (left-sided) pure motor hemiparesis, pure sensory syndrome, ataxic hemiparesis, or dysarthria-clumsy hand syndrome, depending on the specific location of the small vessel occlusion. Patients commonly experience weakness and/or numbness on the left side of the body, particularly affecting the face, arm, and leg, without significant cognitive or visual field deficits. Unlike larger cortical strokes, lacunar infarcts typically do not cause neglect, aphasia, or visual field cuts. These small, deep infarcts (usually less than 15mm in diameter) result from occlusion of penetrating arteries that supply deep brain structures such as the internal capsule, basal ganglia, thalamus, or pons.

Key Symptoms

  • Contralateral (left-sided) pure motor hemiparesis
  • Pure sensory syndrome
  • Ataxic hemiparesis
  • Dysarthria-clumsy hand syndrome

Important Considerations

  • Lacunar infarcts are associated with diabetes or hypertension and are not usually caused by atherosclerosis 1
  • Determining the most probable ischemic stroke subtype may provide useful prognostic information and help decide whether to study a stroke patient for the presence of unrecognized CHD 1
  • Patients with small-vessel disease appear to be at lower risk of cardiac-related death compared to those with other ischemic stroke subtypes 1

From the Research

Typical Symptoms of Right-Sided Lacunar Infarct

The symptoms of a right-sided lacunar infarct can vary, but they typically include:

  • Pure motor hemiparesis: weakness or paralysis of the face, arm, and leg on the left side of the body 2
  • Pure sensory syndrome: numbness or tingling sensations on the left side of the body 2
  • Sensorimotor stroke: a combination of motor and sensory symptoms on the left side of the body 2
  • Ataxic hemiparesis: weakness or paralysis of the left side of the body, accompanied by a loss of coordination and balance 2, 3
  • Dysarthria-clumsy hand: difficulty speaking and clumsiness in the left hand 2

Clinical Syndromes

Lacunar infarcts can also cause other clinical syndromes, including:

  • Pure motor stroke: weakness or paralysis of the face, arm, and leg on the left side of the body 4
  • Pure sensory stroke: numbness or tingling sensations on the left side of the body 4
  • Dysarthria with motor disability of one hand: difficulty speaking and weakness or clumsiness in the left hand 4

Diagnosis and Prognosis

Diagnosis of lacunar infarct is typically made with MRI, and the prognosis is generally good 4. However, patients with lacunar infarct are at increased risk of death, stroke recurrence, and dementia in the mid- and long term 2, 5. Risk-factor modification, including control of hypertension, diabetes, and hyperlipidemia, is important for preventing further strokes 2, 5, 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Lacunar stroke.

Expert review of neurotherapeutics, 2009

Research

Lacunar infarct.

Clinical and experimental hypertension (New York, N.Y. : 1993), 2006

Research

Long-term prognosis after lacunar infarction.

The Lancet. Neurology, 2003

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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