2. Definition
Page 2 – Definition
| Definition |
| The spinal cord is a cylindrical, elongated structure of the central nervous system housed within the vertebral column. It functions as a two-way communication highway, relaying sensory input to the brain and motor output to the body, and serves as the site for spinal reflexes. |
| Element |
Description |
| Structure |
Cylindrical cord of nervous tissue segmented into cervical, thoracic, lumbar, sacral, and coccygeal levels. |
| Function |
Conducts nerve impulses; integrates reflexes; mediates sensory-motor interaction between brain and body. |
| Common Diseases |
Spinal cord injury, multiple sclerosis, transverse myelitis. |
| Diagnosis |
MRI, neurological examination, CSF analysis, electrophysiologic studies. |
| Treatment |
Corticosteroids, decompression surgery, rehabilitation, immunomodulatory therapy. |
3. Anatomy
Page 3 – Applied Anatomy and Diagnostic Approach
U-SSPCT–C Table
| Element |
Details |
| Units |
Cervical (C1–C8), Thoracic (T1–T12), Lumbar (L1–L5), Sacral (S1–S5), Coccygeal (Co1) |
| Size |
~42–45 cm long in adults; diameter ~1 cm. |
| Shape |
Cylindrical, slightly flattened anteroposteriorly. |
| Position |
Within vertebral canal of the spinal column, extending from foramen magnum to ~L1–L2. |
| Character |
White and gray matter zones; protected by meninges; vascularized; flexible yet resilient. |
| Time |
Develops from the neural tube; reaches full length in utero but lags behind vertebral column growth postnatally. |
| Connections |
|
| – Arterial supply |
Anterior spinal artery, posterior spinal arteries, radicular arteries from vertebral, intercostal, and lumbar arteries. |
| – Venous drainage |
Spinal veins drain into internal vertebral venous plexus. |
| – Lymphatic drainage |
Sparse; mainly via meninges into regional lymph nodes. |
| – Nerve supply |
Dorsal and ventral nerve roots; autonomic inputs via spinal nerves. |
| – Ducts |
Not applicable. |
Imaging Modalities
| Modality |
Primary Use |
When/Why Used |
| MRI |
Gold standard for soft tissue contrast, detects cord lesions, inflammation, tumors. |
Acute neurologic deficits, trauma, demyelinating diseases. |
| CT |
Bony detail; detects vertebral fractures, calcifications. |
Trauma assessment, surgical planning. |
| X-ray |
Limited; shows vertebral alignment or trauma. |
Initial trauma screening or scoliosis evaluation. |
| Myelography |
Contrast study of spinal canal and cord. |
Used when MRI is contraindicated or to assess CSF flow. |
| Ultrasound |
In neonates (open fontanelle), intraoperative guidance. |
Rare use except in specialized contexts. |
Laboratory Tests
| Test |
Purpose |
When/Why Used |
| CSF Analysis |
Identify infection, inflammation, demyelination. |
Suspected MS, meningitis, Guillain-Barré, transverse myelitis. |
| Autoantibodies |
Detect autoimmune conditions. |
Suspected neuromyelitis optica, lupus. |
| Vitamin B12 |
Assess deficiency causing myelopathy. |
Subacute combined degeneration evaluation. |
Other Diagnostic Tools
| Tool |
Use |
Indication |
| Electromyography (EMG) |
Measures electrical activity in muscles. |
Evaluates nerve root vs peripheral pathology. |
| Nerve Conduction Study |
Tests peripheral nerve integrity. |
Differentiates between cord and peripheral lesions. |
| Evoked Potentials |
Measures CNS sensory/motor pathways. |
Assesses demyelination or pathway disruption. |
4. Disease and Diagnosis
Page 4 – Disease and Diagnostic Integration
A. Diseases by Category (IINMTM Format)
| Category |
Example Disease(s) |
Structural/Imaging Features |
| Inflammatory / Immune |
Multiple sclerosis, neuromyelitis optica |
T2 hyperintense plaques; segmental cord swelling |
| Infection |
Spinal epidural abscess, TB myelitis |
Ring-enhancing lesions, vertebral body involvement |
| Neoplasm – Benign |
Ependymoma |
Central intramedullary enhancing lesion |
| Neoplasm – Malignant (Primary) |
Astrocytoma |
Ill-defined margins, cord expansion |
| Neoplasm – Malignant (Metastatic) |
Vertebral mets causing compression |
Cord compression, vertebral collapse |
| Mechanical |
Disc herniation, spinal stenosis |
Compression, canal narrowing on MRI/CT |
| Trauma |
Cord contusion, transection |
Hemorrhagic foci, high T2 signal, fracture |
| Metabolic |
B12 deficiency |
Posterior column signal changes, atrophy |
| Circulatory |
Anterior spinal artery infarct |
Pencil-thin T2 hyperintensity, “owl’s eyes” sign |
| Inherited |
Hereditary spastic paraparesis |
Diffuse thinning, signal abnormalities |
| Infiltrative |
Sarcoidosis, lymphoma |
Nodular or mass-like enhancement |
| Idiopathic |
Transverse myelitis |
Long segment T2 hyperintensity without mass |
| Iatrogenic |
Post-radiation myelopathy |
Focal cord atrophy, enhancement |
| Functional |
Not applicable |
— |
| Psychiatric |
Not applicable |
— |
B. Clinical Signs and Symptoms
| Symptom |
Meaning or Implication |
| Weakness/paralysis |
Damage to corticospinal tracts or motor neurons |
| Sensory loss |
Dorsal column or spinothalamic tract involvement |
| Hyperreflexia |
Upper motor neuron lesion |
| Loss of proprioception |
Dorsal column dysfunction |
| Urinary retention/incontinence |
Autonomic cord involvement |
| Pain |
May indicate compression, inflammation, trauma |
C. Imaging Modalities
| Modality |
Primary Use |
When/Why Used |
| MRI |
Visualize cord anatomy and pathology |
First-line for demyelinating, compressive, inflammatory lesions |
| CT |
Evaluate bone, trauma, calcified lesions |
Post-trauma, surgical planning |
| X-ray |
Assess alignment, vertebral integrity |
Initial trauma evaluation, scoliosis |
| Myelogram |
Contrast study of subarachnoid space |
When MRI is contraindicated |
D. Laboratory Tests
| Test |
Purpose |
When/Why Used |
| CSF analysis |
Detect infection, inflammation, MS |
In cases of acute/subacute myelopathy |
| B12, Folate |
Rule out metabolic myelopathy |
In subacute combined degeneration |
| Autoantibodies |
Identify autoimmune demyelination (e.g., NMO) |
Suspected immune-mediated cord disease |
E. Other Diagnostic Tools
| Tool |
Use |
Indication |
| Evoked potentials |
Assess sensory/motor conduction in CNS |
Demyelinating diseases |
| EMG/Nerve conduction |
Assess nerve-muscle connectivity |
Distinguish central vs peripheral cause |
| Physical exam |
Evaluate reflexes, tone, sensation, power |
Essential for localization |
F. Common Treatments
| Therapy |
Application |
Indications |
| High-dose corticosteroids |
Reduce inflammation and edema |
Acute MS exacerbation, transverse myelitis |
| Surgical decompression |
Alleviate cord compression |
Tumor, trauma, herniated disc |
| Plasma exchange (PLEX) |
Remove pathogenic antibodies |
Severe demyelination or NMO |
| Immunomodulators (e.g., IFN) |
Long-term inflammation suppression |
Multiple sclerosis |
| Physical therapy/rehabilitation |
Restore function, prevent complications |
All spinal cord injuries |
5. History and Culture
Page 5 – History, Culture, and Art
1. History of Anatomy
| Topic |
Description |
| Discovery |
The spinal cord was described by Galen in the 2nd century CE and later studied in more detail by Vesalius. Its segmental nature became clear in the Renaissance. |
2. History of Physiology
| Topic |
Description |
| Reflex Pathways |
The concept of reflex arcs was introduced in the 19th century by Charles Sherrington, laying the foundation of modern neurophysiology. |
3. History of Diagnosis
| Topic |
Description |
| Neurological Exam |
Classic clinical signs (e.g., Babinski reflex) were introduced in the 19th–20th centuries and are still central to evaluating cord dysfunction. |
4. History of Imaging
| Topic |
Description |
| MRI Introduction |
The use of MRI in the 1980s revolutionized spinal cord diagnosis, allowing direct visualization of white and gray matter pathology. |
5. History of Laboratory Testing
| Topic |
Description |
| CSF Analysis |
First performed in the early 20th century to detect meningitis, now expanded to autoimmune and inflammatory diagnoses. |
6. History of Therapy
| Topic |
Description |
| Rehabilitation |
Polio epidemics catalyzed modern neurorehabilitation; spinal cord injury units developed during World War II. |
7. Cultural Meaning
| Topic |
Description |
| Symbolism |
The spinal cord symbolizes strength, resilience, and structure. In many traditions, it is associated with the “kundalini” life force. |
8. Artistic Representations
| Topic |
Description |
| Art and Neuroscience |
Contemporary medical artists (e.g., Frank Netter) have illustrated spinal cord anatomy; sculptures and performance art explore paralysis. |
9. Notable Figures
| Name |
Contribution |
| Charles Sherrington |
Nobel laureate who discovered the spinal reflex arc. |
| Christopher Reeve |
Brought awareness to spinal cord injury and regeneration research. |
10. Quotes
| Quote |
Author |
| “A cord of nerves that brings motion and feeling… more than a rope, it is life itself.” |
(Paraphrased from early neuroanatomical writings) |
| “Some people are born with spinal cords of steel.” |
Unknown |
7. MCQ's
Page 6 – MCQs
Basic Science MCQ 1
Question:
What is the primary blood supply to the anterior two-thirds of the spinal cord?
A. Posterior spinal arteries
B. Anterior spinal artery
C. Vertebral artery
D. Radicular artery
Correct Answer Table
| Answer |
Explanation |
| B. Anterior spinal artery |
Supplies the anterior two-thirds of the cord, including the corticospinal tracts and anterior horns. |
Incorrect Options Table
| Option |
Explanation |
| A |
Posterior spinal arteries supply the posterior one-third. |
| C |
Vertebral arteries give rise to spinal arteries but do not directly supply the cord. |
| D |
Radicular arteries support but do not dominantly supply the anterior cord. |
Basic Science MCQ 2
Question:
Which part of the spinal cord contains sensory neuron cell bodies?
A. Ventral horn
B. Dorsal root ganglion
C. Lateral horn
D. Central canal
Correct Answer Table
| Answer |
Explanation |
| B. Dorsal root ganglion |
Houses the cell bodies of sensory neurons entering the spinal cord. |
Incorrect Options Table
| Option |
Explanation |
| A |
Contains motor neuron cell bodies. |
| C |
Contains autonomic neurons (thoracolumbar only). |
| D |
Contains CSF, not neuron cell bodies. |
Clinical MCQ 1
Question:
A patient presents with sudden onset flaccid paralysis and loss of pain and temperature sensation below the waist. Vibration sense is intact. What is the most likely diagnosis?
A. Brown-Séquard syndrome
B. Central cord syndrome
C. Anterior spinal artery syndrome
D. Posterior column syndrome
Correct Answer Table
| Answer |
Explanation |
| C. Anterior spinal artery syndrome |
Affects anterior two-thirds; causes motor and pain/temp loss with preserved dorsal column function. |
Incorrect Options Table
| Option |
Explanation |
| A |
Would cause ipsilateral loss and contralateral pain/temp loss. |
| B |
Affects upper limbs more than lower. |
| D |
Causes loss of vibration/proprioception, not motor or pain/temp. |
Clinical MCQ 2
Question:
A lesion affecting the dorsal columns bilaterally would result in loss of:
A. Pain and temperature
B. Light touch and vibration
C. Motor function
D. Autonomic function
Correct Answer Table
| Answer |
Explanation |
| B. Light touch and vibration |
Dorsal columns carry fine touch, vibration, and proprioception. |
Incorrect Options Table
| Option |
Explanation |
| A |
Carried by the spinothalamic tract. |
| C |
Controlled by the corticospinal tract. |
| D |
Mediated via autonomic pathways in lateral horn. |
Radiologic MCQ 1
Question:
Which modality is most sensitive for detecting spinal cord lesions?
A. CT
B. MRI
C. X-ray
D. Ultrasound
Correct Answer Table
| Answer |
Explanation |
| B. MRI |
MRI provides superior soft tissue resolution and cord detail. |
Incorrect Options Table
| Option |
Explanation |
| A |
Excellent for bone but poor for cord tissue. |
| C |
Cannot visualize cord. |
| D |
Not used for cord imaging except in neonates. |
Radiologic MCQ 2
Question:
What is the most likely MRI finding in multiple sclerosis involving the spinal cord?
A. Ring-enhancing abscess
B. Diffuse edema
C. T2 hyperintense plaque
D. Vertebral body collapse
Correct Answer Table
| Answer |
Explanation |
| C. T2 hyperintense plaque |
MS lesions appear as focal high-signal plaques on T2-weighted MRI. |
Incorrect Options Table
| Option |
Explanation |
| A |
Suggests abscess. |
| B |
Seen in trauma/infarction. |
| D |
Suggests bony metastasis or trauma. |
Radiologic MCQ 3
Question:
Which imaging finding suggests spinal cord infarction?
A. Butterfly-shaped hyperintensity on T2
B. Posterior enhancement
C. CSF blockage
D. Ring-enhancing mass
Correct Answer Table
| Answer |
Explanation |
| A. Butterfly-shaped hyperintensity on T2 |
“Owl’s eyes” or butterfly appearance is classic for anterior spinal infarction. |
Incorrect Options Table
| Option |
Explanation |
| B |
May suggest inflammation or post-surgical change. |
| C |
Suggests blockage, not infarct. |
| D |
Suggests abscess or tumor. |
8. Memory Image
Page 7 – Memory Image
| Visual Metaphor |
Description |
| Spinal Cord as a Suspension Bridge |
The spinal cord is portrayed as a flexible but tension-bearing suspension bridge, anchored by the brain and tethered via nerve roots to the body. Supporting towers represent vertebrae, while the cables symbolize white matter tracts transmitting impulses across the span of life. |
| Caption |
Interpretation |
Artistic rendering shows a suspension bridge symbolizing the spinal cord—anchored at the base of the brain, with vertical cables connecting to the periphery, echoing the role of nerve roots. Damage to one segment weakens the whole structure.
Courtesy: Ashley Davidoff MD, TheCommonVein.com (140540.neuro) |
The metaphor highlights the structural support, communication role, and segmental vulnerability of the spinal cord. It invites learners to understand injury impact and the interdependent nature of nervous transmission. |
Structure
2. Definition
3. Anatomy
4. Disease and Diagnosis
5. History and Culture
7. MCQ's
8. Memory Image
