Types of Strokes That Affect Balance
Strokes affecting the cerebellum, brainstem cerebellar tracts, and cerebellar peduncles are most likely to significantly impact balance due to their role in coordinating muscle activity and maintaining postural stability. 1
Cerebellar and Brainstem Strokes
Ataxia, a key disorder affecting balance, is present in 68-86% of patients with brainstem stroke 1. These strokes disrupt the neural pathways critical for coordinated movement, resulting in:
- Delayed movement initiation
- Timing errors in movement sequences
- Abnormal limb trajectories
- Dysmetria (inability to properly measure distance in muscular acts)
Pathophysiology of Balance Disruption
The cerebellum integrates sensory inputs from visual, vestibular, and somatosensory systems to control both anticipatory and reactive motor responses to postural disturbances 2. When stroke damages this integration system:
- Postural control becomes impaired
- Balance reactions are delayed or uncoordinated
- Risk of falls increases significantly
Right Frontal-Left Cerebellar Circuit
Damage to the right frontal-left cerebellar circuit is particularly problematic for balance 2. This circuit:
- Creates internal models predicting sensory consequences of movements
- Ensures precise timing of motor sequences needed for complex movements
- Maintains appropriate postural adjustments during movement
Other Stroke Locations Affecting Balance
While cerebellar/brainstem strokes have the most direct impact on balance, other stroke locations can also contribute to balance problems:
- Basal ganglia strokes: Disrupt motor control and automatic postural adjustments 3
- Internal capsule lesions: Affect motor pathways necessary for coordinated movement 3
- Insular cortex damage: May impair integration of sensory information needed for balance 3
Clinical Manifestations
Patients with stroke-related balance impairments typically present with:
- Decreased postural stability during quiet standing
- Delayed and less coordinated responses to balance perturbations
- Asymmetrical weight bearing (favoring the non-affected side)
- Increased risk of falls (up to 50% in community-dwelling stroke survivors) 1
Assessment and Management
Assessment
Balance assessment should be part of routine clinical practice for all stroke patients 1. Key evaluations include:
- Standardized balance tests that challenge different aspects of postural control
- Assessment of balance confidence and fear of falling
- Evaluation of fall risk factors
Management
Balance training programs should be implemented for all stroke patients with poor balance, low balance confidence, or fall risk 1. Effective approaches include:
- Balance-specific activities (e.g., practice responding to challenges in standing)
- General activities (strengthening exercises, gait activities)
- Progressive difficulty in training activities
- Assistive devices or orthotics when appropriate
For patients with cerebellar ataxia, postural training and task-oriented therapy may improve motor performance 1. Case studies indicate that intensive task-oriented therapy can improve motor performance and use of ataxic limbs in stroke-related ataxia.
Special Considerations
- Water-based programs have not shown benefit for balance training 1
- Improving balance alone may not be sufficient for preventing falls, as falls often have multiple contributing causes
- Patients with ataxia without concurrent hemiparesis generally have better prognosis for functional recovery 1
Balance impairments after stroke can significantly impact quality of life and increase mortality risk through falls and related injuries. Early identification and targeted rehabilitation of balance deficits, particularly in patients with cerebellar or brainstem strokes, is essential for improving outcomes and reducing fall-related morbidity.