From the Guidelines
The workup for unilateral lower extremity weakness should begin with a thorough history and physical examination, followed by a resting Ankle-Brachial Index (ABI) as the initial diagnostic test to confirm suspected Peripheral Artery Disease (PAD) 1. The physical exam should assess muscle strength, tone, reflexes, sensation, coordination, and gait to localize the lesion.
- A detailed history focusing on onset, progression, associated symptoms, and risk factors is crucial.
- Initial testing with a resting ABI is a simple, noninvasive test that measures systolic blood pressures at the arms and ankles to establish the diagnosis and institute guideline-directed medical therapy (GDMT) 1.
- Depending on the clinical presentation and resting ABI values, additional physiological testing studies may be indicated, including exercise treadmill ABI testing, measurement of the toe-brachial index (TBI), and additional perfusion assessment measures 1.
- Studies for anatomic imaging assessment, such as duplex ultrasound, computed tomography angiography (CTA), or magnetic resonance angiography (MRA), are generally reserved for highly symptomatic patients in whom revascularization is being considered 1.
- It is essential to consider alternative causes of leg weakness, such as neurological or musculoskeletal conditions, and to guide the diagnostic approach based on clinical findings to prompt identification of the underlying cause and appropriate treatment 1.
From the Research
Unilateral Lower Extremity Weakness Workup
The workup for unilateral lower extremity weakness involves a thorough evaluation to determine the underlying cause.
- The evaluation begins with a detailed history and physical examination to clarify the complaint of weakness and determine the pattern of weakness 2.
- Diagnostic testing, such as imaging studies, may be necessary to rule out certain conditions, such as spinal epidural hematoma or lumbar spinal stenosis 3.
- In some cases, the patient may present with acute-onset pain in the unilateral limb with or without motor weakness, and clinicians should consider the possibility of ischemic monomelic neuropathy (IMN) 3.
- A symptoms and signs approach to the patient with neuromuscular weakness is essential, highlighting key aspects of the clinical history and examination 2.
- The patient's age at symptom onset, any identified inciting factors, tempo of symptom progression, pattern of weakness, and associated symptoms and signs are all important diagnostic clues in the evaluation of a patient presenting with muscle weakness 2.
- Central cord syndrome, characterized by disproportionately greater upper-extremity motor impairment than lower-extremity motor impairment, bladder dysfunction, and variable degree of sensory loss below the level of the injury, can also present as unilateral weakness 4.