What is a right frontoparietal subacute infarct?

Right Frontoparietal Subacute Infarct: Definition and Clinical Significance

A right frontoparietal subacute infarct is a stroke affecting the frontal and parietal lobes of the right cerebral hemisphere that is in the subacute phase (typically 24 hours to 2 weeks after onset), most commonly occurring in the middle cerebral artery (MCA) territory. 1

Temporal Classification

• Subacute phase refers to the period from when thrombolytic therapy is no longer indicated (beyond the acute window) up to approximately two weeks after stroke onset 2
• During this phase, infarcted tissue begins to enhance on imaging, which can sometimes mimic other pathologies like brain metastases 1
• The subacute infarct can be distinguished from tumor by its wedge-like (non-nodular) shape involving white matter and often overlying cortex, with enhancement that regresses over time rather than increases 1

Anatomical Territory and Vascular Distribution

• The frontoparietal region is most commonly affected by MCA territory infarction, representing approximately 20% of strokes in this distribution 1
• The right MCA supplies the lateral motor and sensory cortex, which contains representation for the contralateral (left) face and upper extremity 3
• This location is distinct from other common stroke territories: middle cerebral artery territory (40%), multifocal (10.8%), and thalamus (4.6%) 1

Expected Clinical Deficits

Left-sided motor and sensory symptoms are the hallmark presentation:

• Contralateral hemiparesis affecting the left face and arm more prominently than the leg 3
• Left hemisensory loss following a similar distribution (face and arm > leg) 4
• Left homonymous hemianopsia if the optic radiations are involved 4

Neuropsychological deficits specific to right hemisphere lesions:

• Left-sided neglect is common with right frontoparietal lesions 4
• Multitasking disorder can occur from disruption of the right frontoparietal attentional axis, which governs the ability to hold several tasks in working memory simultaneously 5
• Attention and working memory impairments may persist even after motor recovery 6
• Visual-spatial processing deficits, as these functions are predominantly right hemisphere-mediated 4

Imaging Characteristics

On CT imaging:

• Loss of gray-white differentiation in the cortical ribbon may be detected within 6 hours in up to 82% of MCA territory ischemia 3
• Hyperdense MCA sign may indicate thrombus or embolus 3
• Sulcal effacement in the affected region 3

On MRI:

• Subacute infarcts begin to enhance following the acute phase, typically showing wedge-like enhancement patterns 1
• DWI abnormalities may be present but can be less prominent in venous infarction compared to arterial infarction 1
• The enhancement pattern regresses over time, distinguishing it from tumor progression 1

Clinical Pitfalls and Important Considerations

Hemorrhagic transformation risk:

• Early infarct signs involving more than one-third of the MCA territory are associated with increased risk of hemorrhagic transformation following thrombolytic therapy 3
• In the context of infective endocarditis, recent studies suggest hemorrhagic conversion rates of <10%, much lower than older series reported 1

Functional prognosis:

• Patients with MCA territory involvement have less complete neurological recovery (50%) compared to non-MCA territories (83%) 1
• Chronic multitasking deficits may persist even when standard neuropsychological tests appear normal, significantly impacting daily functioning 5
• Attention and academic skill impairments may persist long-term despite apparent motor recovery 6

Subacute management priorities:

• All patients should be admitted for cardiac and neurologic monitoring 2
• Aspirin should be initiated within 24 hours unless contraindicated 2
• Evaluation for aspiration risk and swallowing assessment is essential 2
• Prevention of complications including venous thromboembolism, pressure sores, infection, and delirium 2