Review Question - QID 219457

Differentiation between vascular and neurogenic claudication is a critical step in managing patients with activity-related lower extremity pain. Trunk flexion generally improves symptoms in neurogenic claudication and this can be a key finding obtained from a thorough history during the initial evaluation.

There can be significant overlap in symptoms between neurogenic and vascular claudication. Both can cause lower extremity pain worsened with activity. In neurogenic claudication, this is often secondary to the exacerbation of a limited cross-sectional area available for the neural elements within the spinal canal, which improves with postural changes that increase the available space, such as trunk flexion. With vascular claudication, symptoms are provoked by an imbalance between muscular oxygen supply and demand, which can be relieved by rest to lessen the demand, regardless of spinal posture.

Tomkins-Lane et al. conducted an international Delphi study to reach expert consensus on the diagnosis of lumbar spinal stenosis (LSS) causing neurogenic claudication. They found that the aspects of the patient history and examination most agreed upon to reach a clinical diagnosis of LSS included “flex forward to relieve symptoms”, “feel relief when using a shopping cart or bicycle”, and “normal and symmetric foot pulses”. The authors concluded that with the six most agreed-upon responses, clinicians are 80% certain of a diagnosis.

Haig et al. performed a blinded, controlled trial that sought to evaluate the reliability of an initial clinical evaluation to differentiate between neurogenic and vascular claudication. A blinded neurosurgeon and vascular surgeon evaluated patients from three groups: asymptomatic volunteers, patients offered surgical intervention for spinal stenosis, and patients with peripheral vascular symptoms and a positive ankle-brachial index (ABI). They found strong agreement between the combined clinical evaluations and the recruitment diagnoses, and strong comparative agreement between the neurosurgical and vascular clinical perspectives. They concluded that the history portion of the evaluation was more reliable in reaching an accurate diagnosis compared to the physical examination, which showed poor reproducibility.

Incorrect Answers:
Answer 1: Relief of pain when standing stationary is more consistent with vascular claudication.
Answer 2: Symptoms provoked when riding a stationary bicycle suggest a vascular etiology of the patient’s lower extremity pain. In neurogenic claudication, riding a stationary bicycle with the trunk flexed would be expected to lessen symptoms compared to upright walking.
Answer 4: Asymmetric distal pulses are concerning for a vascular etiology causing the patient’s symptoms.
Answer 5: Postural changes that increase the space available for the neural elements within the spinal canal are expected to improve symptoms caused by neurogenic claudication. Failure of postural changes to relieve symptoms is concerning for a vascular etiology causing the patient’s symptoms.