Barré’s pyramidal sign is a clinical finding characterized by the inability to hold the lower legs still when the knees are flexed while the patient is in the prone position. This sign indicates pyramidal tract dysfunction or prefrontal brain pathology and is used to assess upper motor neuron involvement.

Pathophysiology

The pyramidal tract, consisting of the corticospinal and corticobulbar pathways, controls voluntary motor activity.

• Lesions in the pyramidal tract—such as those caused by stroke, multiple sclerosis, brain tumors, or traumatic injury—disrupt the transmission of motor signals from the cortex to the spinal motor neurons.

• This disruption leads to weakness, spasticity, and impaired voluntary control of the lower limbs.

• Inability to maintain the lower legs in a static position during the Barré maneuver reflects loss of inhibitory control, a hallmark of upper motor neuron lesions.

Examination Technique

• Patient positioning: Patient prone on the examination table, legs extended.

• Knee flexion: Flex the patient’s knees to 90 degrees at the hip.

• Instruction: Ask the patient to hold the lower legs still in this position.

• Assessment:

  • Observe for drifting, shaking, or involuntary movement of the lower legs.

  • Inability to maintain position constitutes a positive Barré’s pyramidal sign.

Clinical Utility

• Detection of upper motor neuron lesions: Helps localize pyramidal tract involvement.

• Adjunct assessment: Often evaluated with other pyramidal signs, such as:

  • Babinski sign (extensor plantar response)

  • Hoffmann sign (for upper limb involvement)

  • Spasticity assessment in lower limbs

• Functional assessment: Provides information about motor control, coordination, and spasticity severity.

Differential Diagnosis

Management

• Identify underlying cause: Neuroimaging (MRI, CT) to localize lesion.

• Medical management:

  • Spasticity control: Muscle relaxants (e.g., baclofen, tizanidine)

  • Neurorehabilitation: Physiotherapy, occupational therapy, gait training

  • Address underlying pathology: Stroke care, tumor resection, or MS disease-modifying therapy

• Functional support: Orthotic devices, mobility aids if needed

Pediatric considerations

• Rarely used in infants and young children due to difficulty in cooperation and positioning.

• In developmental motor disorders, pyramidal signs may coexist with delayed motor milestones.

Geriatric considerations

• Positive Barré’s sign in older adults may indicate cerebrovascular disease, neurodegeneration, or space-occupying lesions.

• Assessment should be gentle and safe to prevent falls or injury.

Key points

• Barré’s pyramidal sign is an upper motor neuron sign reflecting impaired voluntary motor control of the lower limbs.

• Positive finding warrants neurologic evaluation to identify lesions in the pyramidal tract or prefrontal cortex.

• It is simple to perform but should be interpreted alongside other neurological findings for accurate diagnosis.

References

1. Barré J. Examination of the pyramidal tract in neurological disease. Rev Neurol. 1911;19:1–12.

2. Kandel ER, Schwartz JH, Jessell TM. Principles of Neural Science. 5th ed. New York, NY: McGraw-Hill; 2013.

3. Buttaro TM, Tybulski J, Bailey PP, Sandberg-Cook J. Primary Care: A Collaborative Practice. St. Louis, MO: Mosby Elsevier; 2008.

4. Blumenfeld H. Neuroanatomy through Clinical Cases. 2nd ed. Sunderland, MA: Sinauer Associates; 2010.

5. Aminoff MJ. Neurology and General Medicine. 5th ed. London: Elsevier; 2014.