Diagnostic Workup for Paraplegia
The diagnostic workup for paraplegia must begin with immediate determination of the spinal cord injury level and completeness using the American Spinal Injury Association (ASIA) Impairment Scale, followed by comprehensive vascular assessment including bilateral arm blood pressures, lower extremity pulse examination, and ankle-brachial index measurement. 1
Immediate Neurological Assessment
ASIA Impairment Scale Evaluation
Perform standardized motor and sensory function testing using the ASIA scale to establish the level and completeness of spinal cord injury. 1 This assessment is the foundation for determining prognosis and treatment planning.
Document lower extremity motor strength using an objective scale: 0 (no movement), 1 (flicker of movement), 2 (able to bend knee to move leg), 3 (unable to perform straight leg raise against gravity but better leg movement), 4 (normal movement with expected ambulation). 2 A score of 3 warrants immediate neurological consultation.
Assess for "late conversion" from complete to incomplete injury, which occurs in approximately 4% of patients more than 4 months after injury. 3
Critical Vascular Examination
Measure blood pressure in both arms to identify subclavian artery stenosis, with differences >15-20 mmHg considered abnormal and requiring further evaluation. 2, 1 This is essential because patients with paraplegia have increased risk of peripheral vascular disease.
Palpate all four lower extremity pulses bilaterally (femoral, popliteal, dorsalis pedis, posterior tibial) and grade as 0 (absent), 1 (diminished), 2 (normal), or 3 (bounding). 2, 1, 4
Auscultate for femoral bruits and inspect legs for elevation pallor, dependent rubor, cool temperature, and prolonged venous filling time (>20 seconds). 2, 4
Hemodynamic Testing
Ankle-Brachial Index (ABI)
- Calculate ABI for both legs by dividing the higher of dorsalis pedis or posterior tibial pressure by the higher arm pressure. 2 Interpret results as:
Special Considerations for Diabetes and Renal Failure
In patients with diabetes or renal failure, measure toe pressure or toe-brachial index (TBI) if resting ABI is normal or >1.30, as arterial calcification causes falsely elevated ABI readings. 2, 4 TBI <0.70-0.75 confirms peripheral artery disease despite normal ABI. 4
Never attribute poor perfusion to "microangiopathy" without excluding macrovascular disease, as peripheral artery disease is typically the actual cause. 4
Skin and Pressure Point Assessment
Comprehensive Skin Examination
Thoroughly examine all pressure points, especially the sacrum, ischial tuberosities, and trochanters, for signs of pressure injuries or osteomyelitis. 1 This is critical as paraplegic patients are at extremely high risk for pressure ulcers.
Assess skin temperature and color changes in extremities and lower torso, which may indicate embolization or ischemia. 2
Wound Classification
- In patients with chronic lower-limb wounds (≥2 weeks duration), apply the Wound, Ischaemia, and foot Infection (WIfI) classification system to estimate amputation risk. 2, 1 This is essential even without hemodynamic parameters of critical limb perfusion.
Imaging Studies
Initial Imaging Protocol
Obtain duplex ultrasound as the first-line imaging method to confirm peripheral artery disease lesions and screen for vascular pathology. 2, 1
Perform brain MRI with FLAIR sequences (coronal and sagittal views) to identify cerebral contusions in the bilateral precentral gyri, which can cause paraplegia and may be misdiagnosed as spinal injury. 5 This is particularly important in trauma cases where the mechanism is unclear.
Consider CTA or MRA as adjuvant imaging in symptomatic patients with aorto-iliac or multisegmental/complex disease. 2, 1
Spinal Imaging
- Obtain MRI of the spinal cord to rule out compressive lesions, epidural hematoma, or other structural causes requiring emergent surgical intervention. 6, 7 Early decompression within 24 hours of symptom onset is critical for neurological recovery.
Laboratory Studies
- Obtain complete blood count, renal function, electrolytes, and inflammatory markers (C-reactive protein, erythrocyte sedimentation rate). 1
Functional Assessment
Mobility Testing
Use the "Get Up and Go Test" to assess mobility and balance in patients with incomplete paraplegia who retain ambulatory function. 1
Document quality of life using validated tools such as VasculQoL-6. 1
Perform serial motor assessments by asking patients to hold extended, straight legs off the bed for at least 5 seconds, with repeated evaluations in the first hours and days after presentation. 2
Prognosis Indicators
Motor Recovery Patterns
Patients with initial neurologic level at or below T9 have 38% chance of regaining some lower extremity motor function, primarily in hip flexors and knee extensors. 3
Patients with 1-month lower extremity motor score >10 points and hip flexion or knee extension strength ≥2/5 can achieve community ambulation with reciprocal gait pattern using crutches and orthoses at 1 year. 8
Motor recovery is independent of neurologic level of injury, with most recovery occurring in the first 6 months before plateauing. 8
Critical Pitfalls to Avoid
Never assume peripheral artery disease is absent based solely on palpable pulses; confirm with objective ABI testing if clinical suspicion exists. 1, 4
Do not fail to distinguish between paraplegia and paraparesis, as this affects prognosis and treatment planning. 1
Avoid underestimating psychological factors including depression, which significantly impacts rehabilitation outcomes and quality of life. 1
Do not delay surgical decompression in cases of spinal epidural hematoma or compressive lesions, as prompt intervention within 24 hours is essential for neurological recovery. 7