What are the symptoms of a lacunar infarct (cerebral small vessel disease) in the right thalamus?

From the Guidelines

Symptoms from a lacunar infarction in the right thalamus typically include contralateral sensory deficits, particularly numbness or altered sensation on the left side of the body. According to the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack by the American Heart Association/American Stroke Association 1, lacunar stroke is defined as a lacunar syndrome with normal computed tomography (CT)/magnetic resonance imaging (MRI) or subcortical stroke measuring <1.5 cm in diameter on CT or MRI. Patients may experience a pure sensory stroke with decreased sensation to touch, temperature, pain, and vibration on the left face, arm, trunk, and leg. Some patients develop thalamic pain syndrome (also called central post-stroke pain), characterized by severe, burning pain in the affected areas that can be debilitating and difficult to treat. Other possible symptoms include:

• Mild left-sided weakness
• Ataxia (lack of coordination)
• Subtle cognitive changes such as decreased attention or memory problems
• Thalamic hand posture with the affected hand held in a flexed position. The symptoms occur because the thalamus serves as a critical relay center for sensory information traveling to the cerebral cortex, and damage disrupts these pathways. The specific symptoms depend on which thalamic nuclei are affected by the infarction, with posterior nuclei involvement more likely to cause sensory deficits and anterior nuclei damage potentially affecting cognitive function.

From the Research

Symptoms of Lacunar Infarction in the Right Thalamus

• Lacunar infarcts or small subcortical infarcts result from occlusion of a single penetrating artery and account for one quarter of cerebral infarctions 2
• Patients with a lacunar infarct usually present with a classical lacunar syndrome (pure motor hemiparesis, pure sensory syndrome, sensorimotor stroke, ataxic hemiparesis or dysarthria-clumsy hand) and, less frequently, an atypical lacunar syndrome 2
• The symptoms of lacunar infarction in the right thalamus may include sensory disturbances, such as numbness or tingling, and motor weakness or paralysis 2
• Lacunar infarcts show a paradoxical clinical course with a favorable prognosis in the short term, characterized by a low early mortality and reduced functional disability on hospital discharge, but with an increased risk of death, stroke recurrence and dementia in the mid- and long term 2

Risk Factors and Prevention

• Hypertension and diabetes mellitus are major risk factors for lacunar stroke 2
• Antiplatelet drugs, careful blood pressure control, the use of statins and modification of lifestyle risk factors are key elements in secondary prevention after lacunar stroke 2, 3
• Aspirin has been shown to reduce the risk of recurrent stroke in patients with lacunar stroke 4
• However, the addition of clopidogrel to aspirin did not significantly reduce the risk of recurrent stroke and did significantly increase the risk of bleeding and death 5

Prognosis and Treatment

• Lacunar stroke is a heterogeneous disease with various mechanisms, including most commonly lipohyalinosis and less commonly atheromatous disease and cardioembolism 6
• A better understanding of pathomechanisms of neurological deterioration may lead to investigating the utility of novel treatment strategies and optimisation of short-term antithrombotic treatment strategies to reduce the risk of neurological deterioration and prevent long-term disability in patients with lacunar stroke 6
• The prognosis after lacunar infarcts is not benign; the risk of recurrent stroke is no lower than for other ischaemic stroke subtypes, and there is an increased risk for cognitive decline, dementia and death in the long term 3