Thoracic Disc Asymmetric Prolapse

Thoracic disc asymmetric prolapse is a type of intervertebral disc herniation occurring in the mid-back (thoracic) region, where disc material pushes out of its normal space more on one side than the other. Though thoracic disc herniations account for only about 0.25–0.75% of all spinal disc herniations, their asymmetric nature can lead to unilateral spinal cord or nerve root compression, producing unique clinical challenges RadiopaediaRadiopaedia.

Intervertebral discs sit between vertebrae, acting as shock absorbers with a soft nucleus pulposus (NP) surrounded by a tough annulus fibrosus (AF). A disc herniation is a focal displacement of NP material beyond the AF, involving less than 25% of the disc circumference Radiopaedia. In the thoracic spine, such herniations are rare and—when asymmetric—manifest more on one side of the canal, often compressing nerve roots or the spinal cord unilaterally. This asymmetric prolapse differs from a symmetric bulge by extending disproportionately (>25% of the disc’s circumference) to one side Radiology AssistantRadiopaedia.

Thoracic disc asymmetric prolapse is a form of intervertebral disc herniation in the mid-back (T1–T12) where the disc material bulges or extrudes off-centre, compressing nerve roots or the spinal cord on one side. It accounts for only 0.25–0.75 % of all disc herniations and is far less common than lumbar or cervical lesions RadiopaediaRadiopaedia. Because the posterior longitudinal ligament is thicker centrally, thoracic discs more often herniate paracentrally—hence an “asymmetric” (lateral) protrusion often impinges a single root or cord segment Radiopaedia. Symptoms range from localized thoracic pain to radicular patterns (band-like chest wall pain) and, rarely, myelopathy (spinal cord dysfunction).

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Types of Thoracic Disc Asymmetric Prolapse

1. Asymmetric Bulge
   When the disc’s outer fibers extend beyond the vertebral margins more on one side—covering >25% but <100% of the circumference—without a focal herniation, it is termed an asymmetric bulge. This often reflects early annular tearing and uneven load distribution Radiology Assistant.

2. Focal Protrusion
   A contained herniation where the displaced disc material involves <25% of the circumference, forming a smooth-margined “bulge” that remains covered by the outer AF or posterior longitudinal ligament Radiopaedia.

3. Broad-Based Protrusion
   Similar to a focal protrusion but involving 25–50% of the disc circumference; still contained by the annulus or ligament but covering a wider arc of the disc (often seen in diffuse degenerative disease) Radiology Assistant.

4. Extrusion
   An uncontained herniation where the distance between the edges of disc material beyond the disc space exceeds that of its base, often indicating an annular defect and potential migration risk Radiopaedia.

5. Sequestration
   Occurs when a fragment of disc material loses all continuity with the parent disc and can migrate freely within the spinal canal, often causing acute nerve irritation Radiopaedia.

6. Migration
   Displaced disc material moves away from the site of extrusion—either upward or downward—regardless of whether it is sequestered or still partially attached Radiopaedia.

7. Central Herniation
   A herniation toward the midline of the spinal canal, potentially compressing the spinal cord itself. This can produce bilateral or cord-level symptoms if large enough Radiopaedia.

8. Subarticular (Paramedian) Herniation
   Located just lateral to the midline, beneath the facet joint, often compressing the spinal cord asymmetrically and affecting one side more than the other Radiopaedia.

9. Foraminal Herniation
   Disc material protrudes into the intervertebral foramen, impinging on the exiting nerve root. Though less common (5–10% of cases), it often causes severe radicular pain Radiopaedia.

10. Extraforaminal (Far-Lateral) Herniation
    The disc extrudes beyond the foramen, compressing the spinal nerve root lateral to the pedicle; an uncommon variant that may require specialized surgical approaches Radiopaedia.

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Causes of Thoracic Disc Asymmetric Prolapse

1. Age-Related Disc Degeneration
   As people age, the nucleus pulposus dehydrates and the annulus fibrosus weakens, making discs more prone to asymmetric tears and bulges NCBINCBI.

2. Repetitive Mechanical Stress
   Frequent bending, twisting, or heavy lifting in daily activities or jobs can create microtears in the annulus, leading to gradual asymmetric prolapse Mayo ClinicPhysiopedia.

3. Acute Trauma
   A fall, motor vehicle collision, or sudden blow can force disc material out of place abruptly and often asymmetrically NCBIDeuk Spine.

4. Torsional Sports Movements
   Activities involving vigorous spinal rotation—such as golf, baseball, or gymnastics—can overload one side of thoracic discs and precipitate prolapse NCBI.

5. Occupational Hazards
   Jobs requiring prolonged sitting, driving, or exposure to whole-body vibration (e.g., truck driving, heavy machinery) stress thoracic discs unevenly Mayo Clinic.

6. Obesity
   Excess body weight increases axial load on the spine, accelerating disc wear—particularly on the side bearing more weight—leading to asymmetric bulging Verywell Health.

7. Smoking
   Nicotine impairs blood flow to discs, hindering repair of annular fibers and speeding asymmetric degeneration Mayo Clinic.

8. Genetic Predisposition
   Variants in collagen and aggrecan genes can weaken disc structure, making herniation more likely under normal stresses WikipediaWikipedia.

9. Congenital Anomalies
   Structural differences—like short pedicles or malformed endplates present from birth—can concentrate stress on one side of the disc NCBI.

10. Connective Tissue Disorders
    Ehlers-Danlos and Marfan syndromes affect collagen strength, predisposing discs to uneven tearing under pressure NCBI.

11. Diabetes Mellitus
    Hyperglycemia and advanced glycation end-products damage disc cells and accelerate degeneration, raising herniation risk MDPI.

12. Inflammatory Arthritides
    Autoimmune conditions like rheumatoid arthritis can inflame facet joints and endplates, undermining disc integrity asymmetrically Verywell Health.

13. Scheuermann’s Disease
    A juvenile vertebral growth disorder that causes wedged vertebrae and focal kyphosis, increasing asymmetric disc loading Orthobullets.

14. Adjacent Segment Degeneration
    Discs next to a surgically fused segment bear extra stress, often herniating asymmetrically in compensation NCBI.

15. Disc Infection (Discitis)
    Infectious inflammation within the disc space can erode annular fibers, leading to focal weakness and prolapse NCBI.

16. Neoplastic Infiltration
    Tumor invasion into vertebral bodies or discs weakens the annulus and predisposes to uneven herniation Radiopaedia.

17. Endplate Microfractures
    Tiny cracks in vertebral endplates alter disc pressure dynamics and can trigger asymmetric bulging .

18. Osteoporosis
    Reduced bone density can deform endplates under load, leading to uneven disc prolapse MDPI.

19. Sedentary Lifestyle
    Lack of regular movement leads to poor disc nutrition and weak back muscles, increasing asymmetric stress on discs Mayo Clinic.

20. Long-Term Corticosteroid Use
    Systemic steroids impair disc cell metabolism, speeding degeneration and asymmetric tearing MDPI.

Symptoms

1. Mid-Back Pain
   A deep ache or stiffness in the thoracic region, often worse with bending or twisting Barrow Neurological Institute.

2. Radicular Chest Pain
   A band-like, tightening pain around the chest corresponding to the affected thoracic nerve root Barrow Neurological Institute.

3. Myelopathic Gait
   Unsteady, wide-based walking due to spinal cord compression NCBI.

4. Lower Extremity Weakness
   Muscle weakness or heaviness in the legs when the herniation compresses the cord below T10 NCBI.

5. Hyperreflexia
   Increased deep tendon reflexes in the legs, a sign of upper motor neuron involvement NCBI.

6. Sensory Level
   A sharp boundary on the trunk below which sensation is altered, indicating cord involvement NCBI.

7. Paresthesias
   Numbness, tingling, or “pins and needles” in the chest or legs NCBI.

8. Brown-Séquard Signs
   Ipsilateral weakness with contralateral loss of pain and temperature if a centrolateral herniation occurs NCBI.

9. Clonus
   Repetitive, rhythmic muscle contractions on sudden stretch, a myelopathic sign NCBI.

10. Babinski Sign
    An upward great-toe reflex indicating corticospinal tract involvement NCBI.

11. Bowel or Bladder Dysfunction
    Difficulty controlling urinary or fecal output when cord compression is severe NCBI.

12. Ataxia
    Incoordination of the legs due to disrupted proprioceptive pathways NCBI.

13. Spasticity
    Increased muscle tone or stiffness in the legs NCBI.

14. Lhermitte’s Sign
    An electric-shock sensation down the spine on neck flexion NCBI.

15. Chest Wall Tenderness
    Local sensitivity on palpation over the affected disc level Barrow Neurological Institute.

16. Visceral-Like Pain
    Referred discomfort to the abdomen or chest that can mimic heart or gallbladder issues NCBI.

17. Beevor’s Sign
    Asymmetric movement of the umbilicus on abdominal contraction, pointing to lower thoracic root involvement NCBI.

18. Foot Drop
    In severe myelopathy, patients may drag one foot due to cord signal loss affecting leg muscles NCBI.

19. Fatigue
    Generalized tiredness from chronic pain and disrupted sleep Barrow Neurological Institute.

20. Incidental Asymptomatic Findings
    Many thoracic herniations are found accidentally on MRI without any symptoms NCBI.

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Diagnostic Tests

Physical Exam

1. Inspection of Posture and Gait
   Looking for kyphosis or antalgic posture helps localize thoracic disc pathology NCBI.

2. Palpation of Spine and Paraspinals
   Feeling along the spine can reveal muscle spasm or tenderness at the affected level Barrow Neurological Institute.

3. Range of Motion (ROM) Assessment
   Measuring flexion, extension, rotation, and side-bending to identify painful or restricted movements NCBI.

4. Motor Strength Testing
   Grading muscle groups (eg, iliopsoas, quadriceps) to detect weakness from cord or root compression NCBI.

5. Sensory Testing
   Using pinprick and light touch to map dermatomal sensory loss on the trunk and legs NCBI.

6. Deep Tendon Reflexes
   Checking knee and ankle reflexes for hypo- or hyperreflexia indicating focal nerve involvement NCBI.

Manual (Provocative) Tests

7. Thoracic Kemp’s Test
   With the patient standing, the examiner extends and rotates the spine to the painful side, reproducing radicular pain .

8. Valsalva Maneuver
   Instructing the patient to bear down increases intraspinal pressure and may provoke pain in herniation Medscape.

9. Rib Spring Test
   Anterior-posterior pressure on the ribs at the tender level can exacerbate pain in thoracic involvement .

10. Schepelmann’s Sign
    Lateral bending away from pain reduces tension, while bending toward the painful side worsens rib and chest pain Physiopedia.

11. Slump Test
    With the patient seated and slumped forward, neck flexion and knee extension provoke sciatic-type symptoms if disc-related Cigna.

12. Adam’s Forward Bend Test
    Forward bending may highlight asymmetry or rib hump, suggesting structural thoracic involvement Physiopedia.

Lab & Pathological Tests

13. Erythrocyte Sedimentation Rate (ESR)
    Elevated ESR suggests inflammatory or infectious processes affecting the disc Medscape.

14. C-Reactive Protein (CRP)
    A high CRP level supports acute inflammation, such as discitis Medscape.

15. Complete Blood Count (CBC)
    Leukocytosis may point toward infection or neoplasm Medscape.

16. Blood Cultures
    Identifies bacteremia in suspected discitis NCBI.

17. Serum Protein Electrophoresis
    Screens for myeloma when vertebral bodies are involved Medscape.

18. HLA-B27 Testing
    Positive in spondyloarthropathies that can secondarily affect discs Patient.

Electrodiagnostic Tests

19. Needle Electromyography (EMG)
    Detects denervation in muscles innervated by compressed thoracic roots NCBI.

20. Nerve Conduction Studies (NCS)
    Measures conduction velocity in peripheral nerves to exclude peripheral neuropathy Wikipedia.

21. Somatosensory Evoked Potentials (SSEPs)
    Evaluates the integrity of the dorsal columns of the cord for myelopathy AANEM.

22. Motor Evoked Potentials (MEPs)
    Tests corticospinal tract function by transcranial stimulation NCBI.

23. F-Wave Latency
    Assesses proximal nerve conduction and root function Wikipedia.

24. Paraspinal Mapping
    EMG of paraspinal muscles to localize root level involvement PM&R KnowledgeNow.

Imaging Tests

25. Plain Radiographs (X-ray)
    AP and lateral films can show fractures, neoplasms, or calcified discs Medscape.

26. Magnetic Resonance Imaging (MRI)
    The gold standard for visualizing disc material, spinal cord, and nerve roots Barrow Neurological Institute.

27. Computed Tomography (CT) Scan
    Excellent for detecting calcification in thoracic discs and preoperative planning Medscape.

28. CT Myelography
    Injected contrast helps identify lateral herniations and canal compromise when MRI is contraindicated Medscape.

29. Discography
    Injection of contrast into the disc reproduces pain and outlines annular tears NCBI.

30. Bone Scan (Technetium-99m)
    Highlights areas of increased bone turnover in infection, tumor, or inflammatory disc disease Medscape.

Non-Pharmacological Treatments

A. Physiotherapy & Electrotherapy

1. Transcutaneous Electrical Nerve Stimulation (TENS)

   • Description: Low-voltage currents delivered through skin electrodes.

   • Purpose: Acute and chronic pain relief.

   • Mechanism: “Gate control” modulation of nociceptive signals plus endorphin release PMCMDPI.

2. Interferential Current Therapy (IFC)

   • Description: Medium-frequency currents (1–4 kHz) delivered via four electrodes to create a “beat” frequency at depth.

   • Purpose: Deeper pain control and muscle relaxation.

   • Mechanism: Lower skin impedance for comfortable deeper penetration, neuromodulation of pain pathways Frontiers.

3. Neuromuscular Electrical Stimulation (NMES)

   • Description: Electrical pulses to elicit muscle contraction.

   • Purpose: Strengthening weakened paraspinal muscles.

   • Mechanism: Recruits Type II fibres, improves muscle cross-section and endurance Frontiers.

4. Therapeutic Ultrasound

   • Description: High-frequency sound waves (0.8–3 MHz) via a handheld transducer.

   • Purpose: Soft-tissue healing, pain reduction.

   • Mechanism: Thermal (increased blood flow) and non-thermal (cavitation, microstreaming) effects CochraneArchives of Rheumatology.

5. Hot-Pack (Superficial Heat) Therapy

   • Description: Moist or dry heat applied to thoracic region.

   • Purpose: Muscle relaxation, pain reduction.

   • Mechanism: Increases local blood flow; reduces muscle spasm and stiffness PMC.

6. Cold Therapy (Cryotherapy)

   • Description: Ice packs or cold compression.

   • Purpose: Acute pain and inflammation control.

   • Mechanism: Vasoconstriction reduces edema; slows nociceptor firing.

7. Manual Therapy (Mobilization & Manipulation)

   • Description: Skilled passive movements by a therapist.

   • Purpose: Restore segmental mobility, relieve nerve root irritation.

   • Mechanism: Mechanical glides reduce pressure on nerve roots and improve joint nutrition PMC.

8. Massage Therapy

   • Description: Soft-tissue kneading, trigger-point release.

   • Purpose: Myofascial relaxation, pain relief.

   • Mechanism: Mechanical pressure improves circulation, breaks adhesions, stimulates mechanoreceptors.

9. Spinal Traction (Mechanical/Manual)

   • Description: Longitudinal pull on the thoracic spine.

   • Purpose: Increase intervertebral space, relieve nerve compression.

   • Mechanism: Reduces disc bulge by negative intradiscal pressure PMC.

10. High-Intensity Laser Therapy (HILT)

    • Description: Class IV laser producing deep photobiomodulation.

    • Purpose: Rapid pain relief, inflammation reduction.

    • Mechanism: Mitochondrial stimulation increases ATP, modulates inflammatory cytokines MDPI.

11. Shockwave Therapy

    • Description: Extracorporeal acoustic waves applied over thoracic muscles.

    • Purpose: Chronic pain reduction, tissue regeneration.

    • Mechanism: Mechanotransduction induces neovascularization, releases growth factors.

12. Pulsed Electromagnetic Field (PEMF) Therapy

    • Description: Low-frequency electromagnetic fields over the spine.

    • Purpose: Promote healing, reduce inflammation.

    • Mechanism: Alters cell membrane potential, enhances microcirculation.

13. Spinal Stabilization (“Back School”)

    • Description: Education plus guided exercises for posture and core control.

    • Purpose: Improve segmental control, prevent recurrence.

    • Mechanism: Enhances proprioception, deep trunk muscle co-contraction.

14. Ergonomic Training

    • Description: Instruction on optimal work/posture strategies.

    • Purpose: Minimize mechanical strain.

    • Mechanism: Alters biomechanics to off-load thoracic segments.

15. Postural Correction & Biofeedback

    • Description: Real-time feedback (EMG/band) to optimize thoracic alignment.

    • Purpose: Instill healthy postural habits.

    • Mechanism: Enhances proprioceptive awareness, reduces aberrant loading.

B. Exercise Therapies

1. Core Stability Exercises

2. Thoracic Extension Mobilizations on Foam Roller

3. Scapular Retraction Strengthening

4. Rotational Stretching (Prone “Open-Book”)

5. Pilates-Based Thoracic Mobility Drills

6. Swimming (Backstroke Focus)

These exercises strengthen trunk musculature, restore segmental motion, and improve postural endurance through targeted loading, proprioceptive enhancement, and flexibility gains. Lippincott Journals

C. Mind–Body Therapies

1. Mindfulness-Based Stress Reduction (MBSR)

2. Yoga (Gentle Thoracic Flows)

3. Tai Chi

4. Guided Imagery

5. Cognitive Behavioral Therapy (CBT) for Pain

By reducing central sensitization and stress, these approaches modulate pain perception and improve coping. PMC

D. Educational Self-Management

1. Pain Neuroscience Education (“Explain Pain”)

2. Home Exercise Program Prescription

3. Activity Pacing and Goal Setting

4. Lifestyle Modification Workshops

Empowers patients with knowledge of anatomy, warning signs, and graded activity, leading to better long-term adherence and outcomes. PMC

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Pharmacological Treatments

Below are the main drug classes and exemplar agents used for thoracic disc pain, with typical adult dosages, timing, and key side effects:

All NSAIDs pose GI and renal risks—always prescribe the lowest effective dose for the shortest duration. PMC

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Dietary & Molecular Supplements

Most supplements show modest benefit; choose high-purity formulations and monitor for allergies. PMC

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Advanced Regenerative & Biologic Drugs

These remain largely investigational—use within approved clinical trials or specialized centers. Frontiers

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Surgical Options

1. Micro-discectomy

   • Procedure: Small posterior laminectomy and removal of herniated disc fragment.

   • Benefits: Rapid decompression, short recovery.

2. Thoracoscopic Discectomy

   • Procedure: Endoscopic anterior approach via small thoracic ports.

   • Benefits: Minimal muscle disruption, faster pain relief.

3. Open Laminectomy & Discectomy

   • Procedure: Removal of lamina and disc fragment from posterior approach.

   • Benefits: Broad visualization, direct decompression.

4. Costotransversectomy

   • Procedure: Resection of rib head and transverse process to access disc laterally.

   • Benefits: Avoids cord retraction, good for lateral lesions.

5. Corpectomy & Fusion

   • Procedure: Removal of vertebral body segment with fusion using cage/plate.

   • Benefits: Decompression plus stabilization for severe collapse.

6. Posterior Instrumented Fusion

   • Procedure: Pedicle screws and rods across involved levels.

   • Benefits: Stabilizes spine after decompression.

7. Video-Assisted Thoracotomy (VATS)

   • Procedure: Uniportal video-assisted anterior discectomy.

   • Benefits: Less morbidity than open thoracotomy.

8. Percutaneous Endoscopic Discectomy

   • Procedure: Needle/endoscope under fluoroscopy for disc removal.

   • Benefits: Minimally invasive, local anesthesia use.

9. Transpedicular Partial Corpectomy

   • Procedure: Posterior approach through pedicle to remove fragment.

   • Benefits: Avoids thoracotomy, preserves stability.

10. Axial Lumbar Interbody Fusion (AxiaLIF) (off-label for thoracic)

    • Procedure: Percutaneous presacral approach.

    • Benefits: Minimally invasive fusion.

Choice depends on lesion location, cord involvement, and patient comorbidities. PMC

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Prevention Strategies

1. Maintain Neutral Thoracic Posture

2. Regular Core-Strengthening Exercises

3. Ergonomic Workstation Setup

4. Safe Lifting Techniques

5. Weight Management

6. Avoid Prolonged Flexion

7. Smoking Cessation

8. Adequate Hydration

9. Balanced Diet Rich in Anti-Inflammatories

10. Scheduled Movement Breaks

These reduce mechanical stress, improve disc nutrition, and lower recurrence risk. PMC

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When to See a Doctor

– Red Flags: Progressive lower limb weakness, gait disturbance, bowel/bladder dysfunction, severe chest wall anaesthesia (“saddle anaesthesia”).
– Persistent Pain: Unrelieved by 6 weeks of conservative care.
– New Neurologic Signs: Numbness, hyperreflexia, myelopathic signs.

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“What to Do” & “What to Avoid”

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Frequently Asked Questions

1. What exactly is thoracic disc asymmetric prolapse?
   A lateral bulge or extrusion of the thoracic intervertebral disc that presses on one side of spinal cord or nerve root, causing localized or radiating pain.

2. How common is it?
   Very rare—only 0.25–0.75 % of all disc herniations Radiopaedia.

3. What are typical symptoms?
   Mid-back pain, chest wall radicular pain in a band-like distribution, tingling, numbness, or, in severe cases, myelopathy.

4. Which imaging is best?
   MRI is gold-standard for visualizing soft-tissue disc pathology and spinal cord compression.

5. Can it resolve without surgery?
   Up to 70 % improve with conservative care (physical therapy, medications) within 6–12 weeks PMC.

6. What are the treatment goals?
   Pain control, neural decompression, spinal stability, and functional restoration.

7. Are there long-term risks?
   Chronic pain, weakness, myelopathy if left untreated; osteoporosis and steroid side-effects with prolonged steroid use.

8. When is surgery indicated?
   Neurologic deficits, cord compression on MRI with correlating exam, or intractable pain unresponsive to ≥6 weeks of conservative care.

9. What is the outlook after discectomy?
   Over 80 % report good to excellent relief; risk of recurrence is 5–10 % MDPI.

10. Can I return to sports?
    Yes, typically by 3–6 months post-surgery or once pain-free and strength restored.

11. Do supplements really help?
    Some (glucosamine, omega-3) show modest pain-relief; best as adjuncts, not replacements for core therapies PMC.

12. Is injection therapy an option?
    Epidural steroids can help radicular pain but carry risks (infection, steroid side-effects).

13. What lifestyle changes aid recovery?
    Smoking cessation, weight management, ergonomic modifications, and regular exercise.

14. How do mind–body approaches fit in?
    They reduce central sensitization and improve coping, making long-term management easier PMC.

15. When should I worry about red flags?
    New weakness, bladder/bowel changes, or severe gait disturbance require immediate evaluation.

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team Rxharun and reviewed by the Rx Editorial Board Members

Last Updated: May 30, 2025.

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