What are the signs and symptoms of a right parietal lobe stroke?

Signs of Right Parietal Lobe Stroke

The primary signs of a right parietal lobe stroke include left-sided neglect, abnormal visual-spatial ability, left-sided weakness, left-sided sensory loss, and left-sided paresthesia. 1

Primary Neurological Manifestations

• Left-sided weakness (hemiparesis) - Contralateral motor deficits affecting the left side of the body 1, 2
• Left-sided sensory loss or paresthesia - Reduced sensation or abnormal sensations on the left side 1
• Left-sided neglect - Failure to attend to stimuli in the left visual field, particularly when competing stimuli are present in the right visual field 2, 3
• Abnormal visual-spatial ability - Difficulty with spatial orientation, navigation, and perception 1
• Right homonymous hemianopsia - Visual loss involving the right visual field 1

Cognitive and Perceptual Manifestations

• Constructional apraxia - Difficulty drawing or constructing objects, which correlates more strongly with unilateral spatial neglect on drawing than with hemianopia 2
• Unilateral spatial neglect on drawing (USND) - Inability to attend to the left side when drawing objects 2
• Dressing apraxia - Difficulty putting on clothes correctly, particularly attending to the left side 2
• Anosognosia - Lack of awareness of one's deficits, which correlates with the severity of hemiplegia 2
• Impaired detection of contralateral somatosensory stimuli - Reduced ability to detect tactile stimuli on the left side 4

Complex Perceptual Deficits

• Bilateral deficit for high-level motion perception - Despite unilateral lesion, patients may show impaired perception of apparent motion in both visual fields 5
• Extinction - Failure to perceive stimuli on the left when simultaneous stimuli are presented on both sides 3
• Motor impersistence - Inability to maintain a motor action, which correlates with the severity of hemiplegia 2

Rare Manifestations

• Gerstmann's syndrome - In cases of reversed cerebral dominance, right parietal stroke can lead to left-right disorientation, finger agnosia, dyscalculia, and dysgraphia 6

Imaging Findings

• Focal parenchymal changes - Brain parenchymal changes in the parietal lobe can be visualized on MRI better than CT 1
• Hemorrhagic transformation - May present as petechial or confluent hemorrhage in the right parietal region 1
• Diffusion-weighted imaging abnormalities - Consistent with acute infarction, though findings may be reduced compared to arterial infarction 1

Clinical Pearls and Pitfalls

• Left neglect, motor impersistence, and anosognosia tend to occur primarily with large strokes involving the right parietal lobe and structures beyond 2
• Small deep lesions can occasionally produce behavioral abnormalities comparable to those of larger superficial cortical lesions 2
• The severity of neglect has been linked to poor rehabilitation outcomes in patients suffering from acute stroke 4
• Visual extinction may be relieved by reducing the hyperactivity of the undamaged left hemisphere, suggesting inter-hemispheric inhibition plays a role in symptom manifestation 3

Diagnostic Considerations

• Symptoms may not become apparent in the first several hours or even days post-injury 1
• Patients with right parietal stroke may have altered level of consciousness in 19% of cases 1
• The presence of specific symptoms may be related to the length of recovery timeframe and risk of persistent symptoms 1

Understanding these signs is crucial for early recognition and intervention in right parietal lobe stroke, which can significantly impact morbidity, mortality, and quality of life outcomes.