BRACHIAL PLEXUS, CERVICAL RADICULOPATHIES, AND PERIPHERAL NEUROPATHIES DrRamonReyesMD

BRACHIAL PLEXUS, CERVICAL RADICULOPATHIES, AND PERIPHERAL NEUROPATHIES

The Major Differential Diagnosis Most Cervical Spine Infographics Ignore

International Scientific Update 2026

DrRamonReyesMD ⚕️
EMS Solutions International

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INTRODUCTION

One of the greatest limitations of cervical spine infographics is the assumption that every arm symptom originates from a cervical nerve root.

Clinical reality is far more complex.

Patients presenting with:

• Neck pain.
• Shoulder pain.
• Hand numbness.
• Weakness.
• Loss of dexterity.
• Paresthesias.

may actually have:

• Cervical radiculopathy.
• Brachial plexopathy.
• Peripheral neuropathy.
• Double Crush Syndrome.
• Cervical myelopathy.
• Central neurological disease.

Assuming that every numb finger is caused by a cervical disc herniation is a common diagnostic mistake.

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THE BRACHIAL PLEXUS

The Great Forgotten Structure

The brachial plexus is the neural highway connecting the cervical spinal cord to the upper limb.

It originates from:

C5

C6

C7

C8

T1

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PLEXUS ORGANIZATION

Roots

↓

Trunks

↓

Divisions

↓

Cords

↓

Terminal Nerves

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UPPER TRUNK

Formed by:

C5 + C6

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Clinical Presentation

May mimic:

• C5 radiculopathy.
• C6 radiculopathy.

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Common Deficits

• Deltoid weakness.
• Biceps weakness.
• Impaired shoulder abduction.
• Weak external rotation.

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Differential Diagnosis

Is this:

C5 Radiculopathy?

or

Upper Trunk Plexopathy?

Electrodiagnostic testing is often decisive.

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ERB-DUCHENNE PALSY

Classic upper trunk lesion.

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Characteristic Posture

"Waiter's Tip"

• Arm adducted.
• Internally rotated shoulder.
• Extended elbow.
• Pronated forearm.

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MIDDLE TRUNK

Formed by:

C7

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Clinical Presentation

May mimic:

C7 Radiculopathy

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LOWER TRUNK

Formed by:

C8 + T1

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Clinical Importance

Frequently confused with:

C8 Radiculopathy

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Findings

• Hand weakness.
• Grip weakness.
• Interosseous wasting.
• Loss of fine motor skills.

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KLUMPKE PALSY

Classic lower trunk injury.

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Findings

• Claw hand.
• Intrinsic muscle weakness.
• Thenar atrophy.
• Hypothenar atrophy.

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PARSONAGE-TURNER SYNDROME

Neuralgic Amyotrophy

One of the most underdiagnosed neurological disorders.

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Typical Presentation

Sudden severe shoulder pain.

Followed by:

• Weakness.
• Atrophy.
• Functional impairment.

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Common Diagnostic Error

Diagnosing:

Cervical Disc Herniation

when the true diagnosis is:

Inflammatory Brachial Plexopathy

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C6 RADICULOPATHY VS CARPAL TUNNEL SYNDROME

A common clinical dilemma.

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C6 Radiculopathy

Usually associated with:

• Neck pain.
• Scapular pain.
• Arm pain.

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Carpal Tunnel Syndrome

Typically:

• No neck pain.
• Worse at night.
• Median nerve distribution.
• Positive Phalen test.
• Positive Tinel sign.

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C8 RADICULOPATHY VS ULNAR NEUROPATHY

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C8 Radiculopathy

May cause:

• Neck pain.
• Radiating symptoms.
• Finger flexor weakness.

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Ulnar Neuropathy

Typically causes:

• Localized symptoms.
• Worsening with elbow flexion.
• Positive Tinel at the cubital tunnel.

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DOUBLE CRUSH SYNDROME

One of the most important concepts in modern neurology.

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Definition

Proximal compression

Distal compression

↓

Disproportionately severe symptoms

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Classic Example

C6 Foraminal Stenosis

Carpal Tunnel Syndrome

↓

Symptoms far worse than expected from either lesion alone.

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KEY MESSAGE

The correct question is not:

Which vertebra causes this symptom?

The correct question is:

Is this a root, plexus, peripheral nerve, or spinal cord disorder?

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CONCLUSION

A rigorous neurological examination must always distinguish between:

• Radiculopathy.
• Plexopathy.
• Peripheral neuropathy.
• Myelopathy.

Failure to differentiate these entities remains one of the leading causes of diagnostic error in cervical spine medicine.

DrRamonReyesMD ⚕️
EMS Solutions International
International Scientific Update 2026

SCIENTIFIC FOUNDATION AND EVIDENCE BASE

This work is based on the current scientific evidence and recommendations published by the leading international organizations, scientific societies, and research groups dedicated to spinal disorders, neurosurgery, neurology, cervical radiculopathy, and degenerative cervical myelopathy (DCM), including AO Spine, RECODE-DCM, the WFNS Spine Committee, the American Association of Neurological Surgeons (AANS), the Congress of Neurological Surgeons (CNS), the North American Spine Society (NASS), the American Academy of Neurology (AAN), Global Spine Journal, Spine, European Spine Journal, Journal of Neurosurgery: Spine, The Lancet Neurology, and Nature Reviews Neurology. The terminology and concepts surrounding Degenerative Cervical Myelopathy (DCM) are now internationally standardized through the AO Spine RECODE-DCM initiative.

The information presented integrates contemporary knowledge regarding:

• Cervical neuroanatomy.
• Dermatomes.
• Myotomes.
• Deep tendon reflexes.
• Cervical radiculopathies.
• Brachial plexopathies.
• Peripheral neuropathies.
• Degenerative cervical myelopathy.
• Cervical biomechanics.
• Spinal cord compression syndromes.
• Cervical trauma.
• MRI–clinical correlation.
• Electromyography (EMG) and nerve conduction studies.
• Evidence-based diagnostic algorithms.

Modern cervical spine assessment cannot be reduced to simplistic charts assigning a single symptom to a specific vertebra. Current evidence demonstrates that diagnosis requires integration of clinical history, neurological examination, imaging findings, electrophysiological studies, and functional assessment.

Cervical clinical syndromes are probabilistic rather than deterministic. MRI abnormalities do not necessarily explain symptoms, and many radiographic findings may represent age-related changes without clinical significance. Conversely, patients with relatively modest imaging abnormalities may experience substantial neurological dysfunction.

Particular attention must be given to the early recognition of Degenerative Cervical Myelopathy (DCM), now recognized as the leading cause of chronic spinal cord dysfunction in adults worldwide. Early symptoms may include subtle hand clumsiness, gait disturbances, impaired dexterity, balance abnormalities, and upper motor neuron signs. Delayed diagnosis remains a major international challenge and is associated with greater long-term disability.

The interpretation of cervical MRI requires careful clinicoradiological correlation. Findings such as foraminal stenosis, spinal cord compression, T2 hyperintensity, T1 hypointensity, and myelomalacia must always be interpreted within the context of the patient's neurological examination and overall clinical presentation.

Similarly, electrophysiological testing remains an important adjunct for differentiating:

• Cervical radiculopathy.
• Brachial plexopathy.
• Peripheral nerve entrapment.
• Double Crush Syndrome.
• Motor neuron disorders.

The modern approach to cervical spine medicine emphasizes localization of neurological dysfunction rather than reliance on isolated imaging findings.

A meticulous neurological examination remains the most valuable diagnostic tool in cervical spine medicine. The clinician's task is not merely to identify anatomical abnormalities but to determine whether those abnormalities are clinically meaningful and whether the spinal cord, nerve roots, brachial plexus, or peripheral nerves are involved.

The concepts presented throughout this work are aligned with the most recent international recommendations available through 2026 and reflect the educational standards used by specialists in:

• Neurology.
• Neurosurgery.
• Orthopaedic Spine Surgery.
• Physical Medicine and Rehabilitation.
• Pain Medicine.
• Emergency Medicine.
• Trauma Surgery.
• Tactical and Operational Medicine.

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RECOMMENDED INSTITUTIONAL REFERENCES

AO Spine
https://www.aofoundation.org/spine

AO Spine RECODE-DCM
https://www.aofoundation.org/spine/research/recode-dcm

American Association of Neurological Surgeons (AANS)
https://www.aans.org

Congress of Neurological Surgeons (CNS)
https://www.cns.org

North American Spine Society (NASS)
https://www.spine.org

American Academy of Neurology (AAN)
https://www.aan.com

WFNS Spine Committee
https://wfns-spine.org

Global Spine Journal
https://journals.sagepub.com/home/gsj

European Spine Journal
https://link.springer.com/journal/586

Spine
https://journals.lww.com/spinejournal

Journal of Neurosurgery: Spine
https://thejns.org/spine

The Lancet Neurology
https://www.thelancet.com/journals/laneur

Nature Reviews Neurology
https://www.nature.com/nrneurol

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SELECTED KEY REFERENCES

Fehlings MG, Evaniew N, Ter Wengel PV, et al.
AO Spine Clinical Practice Recommendations for Diagnosis and Management of Degenerative Cervical Myelopathy: Evidence Based Decision Making.
Global Spine Journal, 2025.
DOI: https://doi.org/10.1177/21925682251331050

Fehlings MG, Tetreault LA, Riew KD, et al.
A Clinical Practice Guideline for the Management of Patients With Degenerative Cervical Myelopathy.
Global Spine Journal, 2017.
DOI: https://doi.org/10.1177/2192568217703088

Nouri A, Tetreault L, Singh A, et al.
Degenerative Cervical Myelopathy: Epidemiology, Genetics and Pathogenesis.
Spine, 2015.
DOI: https://doi.org/10.1097/BRS.0000000000000913

Badhiwala JH, Ahuja CS, Akbar MA, et al.
Degenerative Cervical Myelopathy: Update and Future Directions.
Nature Reviews Neurology, 2020.
DOI: https://doi.org/10.1038/s41582-019-0303-0

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International Scientific Update 2026
Evidence-Based Review
EMS Solutions International