Question 1: Spinal Ependymoma
Stem:
A 45-year-old man presents with a 6-month history of progressive lower limb weakness and back pain. An MRI of the thoracic spine reveals a 3 cm, well-defined, centrally located intramedullary mass at the T10 level, which is expanding the spinal cord. The lesion is avidly enhancing and has associated T2-hypointense “caps” at its superior and inferior poles.
Question:
What is the most likely diagnosis?
(A) Spinal Astrocytoma
(B) Spinal Ependymoma
(C) Schwannoma
(D) Transverse Myelitis
(E) Haemangioblastoma
Correct Answer: (B) Spinal Ependymoma.
Explanation:
- Why (B) is correct: This is the classic presentation. Ependymomas are the most common intramedullary tumour in adults. They are typically central (arising from the ependymal-lined central canal), well-defined, and associated with haemorrhage, which leads to the pathognomonic “haemosiderin cap” sign (the T2-hypointense “caps”).
- Why (A) is wrong: Astrocytomas are the most common intramedullary tumour in children. They are typically eccentric, infiltrative, ill-defined, and do not have a haemosiderin cap.
- Why (C) is wrong: A schwannoma is an intradural-extramedullary tumour (outside the cord) and would displace the cord, not expand it from within.
- Why (D) is wrong: Transverse myelitis is an inflammatory process that causes diffuse, ill-defined cord signal and swelling, not a discrete, haemorrhagic mass.
- Why (E) is wrong: A haemangioblastoma is also an intramedullary tumour but is less common. It presents as a small, enhancing nodule with a large associated syrinx (fluid cavity) and prominent flow voids.
Key Points: Spinal Ependymoma 🧠
- Most common intramedullary tumour in adults.
- Location: Classically central within the cord. Thoracic spine is a common site.
- Imaging: Well-defined, enhancing, expansile mass.
- Key Sign: “Haemosiderin Cap Sign” (T2-dark signal at the poles) from chronic haemorrhage.
- A Myxopapillary Ependymoma is a specific variant found in the conus medullaris and filum terminale.
Question 2: Spinal Schwannoma
Stem:
A 50-year-old woman presents with right-sided T8 radicular pain. An MRI of the thoracic spine shows a 2.5 cm, avidly enhancing, ovoid mass in the intradural-extramedullary compartment. The mass is seen extending through and causing smooth, scalloped widening of the T8-T9 neural foramen.
Question:
What is the most likely diagnosis?
(A) Spinal Meningioma
(B) Spinal Schwannoma
(C) Ependymoma
(D) Extradural Metastasis
(E) Epidural Abscess
Correct Answer: (B) Spinal Schwannoma.
Explanation:
- Why (B) is correct: A schwannoma (or neurofibroma) is the most common intradural-extramedullary (ID-EM) tumour. Arising from the nerve sheath, its pathognomonic feature is its tendency to grow through the neural foramen, causing smooth, bony widening. This creates the classic “dumbbell” shape.
- Why (A) is wrong: A meningioma is the second most common ID-EM tumour. It has a broad dural base (“dural tail”) and typically does not widen the foramen. It is also more likely to calcify.
- Why (C) is wrong: An ependymoma is intramedullary (inside the cord).
- Why (D) is wrong: A metastasis is extradural and would cause destructive, irregular bony erosion, not smooth widening.
- Why (E) is wrong: An epidural abscess is a fluid collection with rim enhancement and is not a discrete solid mass in this compartment.
Key Points: Spinal Schwannoma
- Most common intradural-extramedullary tumour.
- Pathology: Benign nerve sheath tumour.
- Imaging: Avidly enhancing mass.
- Key Sign: “Dumbbell” shape with smooth widening of the neural foramen.
- Association: Multiple schwannomas (and meningiomas) are seen in Neurofibromatosis Type 2 (NF-2).
Question 3: Spinal Epidural Abscess
Stem:
A 60-year-old diabetic man with a history of intravenous drug use presents with a 3-day history of high fever, severe focal back pain, and new-onset bilateral leg weakness. An urgent MRI reveals a long-segment, rim-enhancing fluid collection within the dorsal epidural space, which is severely compressing the thecal sac.
Question:
What is the most likely diagnosis?
(A) Transverse Myelitis
(B) Spinal Dural AV Fistula
(C) Spinal Epidural Abscess
(D) Extradural Metastasis
(E) Spondylodiscitis
Correct Answer: (C) Spinal Epidural Abscess.
Explanation:
- Why (C) is correct: The clinical triad of fever, back pain, and neurological deficit is classic for a spinal epidural abscess (SEA). The risk factors (diabetes, IVDU) are also classic. The MRI finding of a rim-enhancing fluid collection in the epidural space (most commonly dorsal) causing mass effect on the cord confirms the diagnosis. This is a neurosurgical emergency.
- Why (A) is wrong: Transverse myelitis is an intramedullary inflammatory process, not an epidural collection.
- Why (B) is wrong: An SDAVF is a vascular issue causing cord oedema and flow voids, not an abscess.
- Why (D) is wrong: A metastasis is a solid enhancing mass, not a fluid collection.
- Why (E) is wrong: Spondylodiscitis (infection of the disc/endplates) is often the source of an SEA, but the primary finding causing the cord compression here is the abscess itself.
Key Points: Spinal Epidural Abscess FOR
- A neurosurgical emergency!
- Clinical Triad: Fever, back pain, neurological deficit.
- Risk Factors: Diabetes, IVDU, recent spinal procedure, sepsis.
- Imaging: Rim-enhancing fluid collection in the epidural space (classically dorsal) causing cord compression. Often associated with discitis/osteomyelitis.
Question 4: Spinal Dural AV Fistula (SDAVF)
Stem:
A 65-year-old man presents with a 1-year history of progressive, bilateral lower limb weakness, gait difficulty, and sensory disturbances. An MRI of the spine shows T2 high signal within the conus medullaris and lower thoracic cord, with prominent, serpiginous flow voids seen on the dorsal surface of the cord.
Question:
This combination of congestive myelopathy and dorsal flow voids is classic for:
(A) Spinal Dural Arteriovenous Fistula (SDAVF)
(B) Anterior Spinal Artery Infarct
(C) Guillain-Barré Syndrome
(D) Ependymoma
(E) Transverse Myelitis
Correct Answer: (A) Spinal Dural Arteriovenous Fistula (SDAVF).
Explanation:
- Why (A) is correct: This is the classic presentation. An SDAVF is an abnormal connection that shunts arterial blood into low-pressure spinal veins. This causes venous congestion and hypertension (congestive myelopathy), which appears as T2 high signal (oedema) in the cord, typically starting at the conus. The engorged, arterialised draining veins are visible as dorsal flow voids.
- Why (B) is wrong: An infarct is acute, has an “owl’s eye” appearance, and lacks flow voids.
- Why (C) is wrong: Guillain-Barré is a clinical diagnosis; it classically shows enhancement of the cauda equina nerve roots, not cord oedema with flow voids.
- Why (D) is wrong: An ependymoma is a focal, solid intramedullary mass.
- Why (E) is wrong: Transverse myelitis also causes T2 cord signal, but it is typically more swollen and lacks the prominent flow voids.
Key Points: Spinal Dural AV Fistula (SDAVF)
- Most common spinal vascular malformation.
- Pathology: Shunt from a dural artery to a medullary vein -> venous congestion.
- Clinical: Progressive myelopathy (weakness/sensory loss) in an older man.
- Imaging:
- T2 high signal (oedema) in the cord, often starting at the conus medullaris.
- Serpiginous T2 flow voids on the dorsal surface of the cord.
- Note: A treatable cause of myelopathy.
Question 5: Multiple Sclerosis (MS) Plaque
Stem:
A 32-year-old woman presents with a 3-day history of paraesthesia in her left hand and leg. A C-spine MRI reveals a well-defined, ovoid, T2-bright lesion in the posterior aspect of the cervical cord at C3. The lesion is less than one vertebral body in length. A brain MRI confirms multiple periventricular white matter lesions.
Question:
This spinal cord finding is most characteristic of:
(A) Transverse Myelitis
(B) Multiple Sclerosis (MS) Plaque
(C) Neuromyelitis Optica (NMO)
(D) Astrocytoma
(E) Syringomyelia
Correct Answer: (B) Multiple Sclerosis (MS) Plaque.
Explanation:
- Why (B) is correct: Spinal plaques in MS have a classic appearance: they are focal, ovoid, T2-bright lesions that are short segment (< 2 vertebral bodies) and characteristically located in the posterior or peripheral white matter tracts of the cervical cord. The concurrent brain lesions confirm the diagnosis.
- Why (A) is wrong: Transverse myelitis is typically long-segment (> 3 vertebral bodies) and central, affecting both grey and white matter.
- Why (C) is wrong: NMO (Devic’s disease) is the main differential but is also a long-segment myelitis, typically > 3 bodies (LETM).
- Why (D) is wrong: An astrocytoma is a tumour that would expand the cord (mass effect).
- Why (E) is wrong: A syringomyelia is a cystic (fluid-filled) cavity, not a solid plaque.
Key Points: MS Spine Plaques
- Location: Cervical cord is most common.
- Distribution: Posterior and peripheral (dorsal/lateral columns).
- Size: Short segment (< 2 vertebral bodies).
- Appearance: Ovoid, “flame-shaped” T2-bright lesions.
Question 6: Extradural Metastasis (Cord Compression)
Stem:
A 68-year-old man with a known history of lung cancer presents to the ED with acute paraplegia and a T8 sensory level. An urgent MRI shows a destructive lesion in the T8 vertebral body and posterior elements. This is associated with a large extradural soft-tissue mass that is circumferentially encasing and severely compressing the thecal sac and spinal cord.
Question:
This is a neurosurgical emergency. Which of the following is the most likely diagnosis?
(A) Malignant Spinal Cord Compression
(B) Spinal Epidural Abscess
(C) Spondylodiscitis
(D) Spinal Meningioma
(E) Transverse Myelitis
Correct Answer: (A) Malignant Spinal Cord Compression.
Explanation:
- Why (A) is correct: The patient has a known primary (lung cancer) and new, acute neurological symptoms. The MRI confirms a solid, extradural (epidural) mass arising from a destructive bone lesion, which is causing severe cord compression. This is the classic picture of malignant spinal cord compression.
- Why (B) is wrong: An epidural abscess is a fluid-filled, rim-enhancing collection and is associated with fever/sepsis, not typically a destructive bone lesion.
- Why (C) is wrong: Discitis involves the disc space and endplates, not a focal destructive bone mass.
- Why (D) is wrong: A meningioma is intradural-extramedullary (inside the dura, outside the cord) and does not arise from the bone.
- Why (E) is wrong: Transverse myelitis is an intramedullary signal change (inflammation), not an extrinsic compressive mass.
Key Points: Malignant Cord Compression
- Most common cause: Extradural metastases from lung, breast, prostate, or renal cancer.
- Location: Thoracic spine is most common.
- Imaging: Look for a destructive vertebral body lesion (e.g., missing pedicle – “winking owl” sign) with an associated epidural soft-tissue mass that compresses the cord.
- Note: A neurosurgical/oncological emergency.
Question 7: Anterior Spinal Artery Infarct
Stem:
A 70-year-old man undergoes an emergency open repair of a thoracoabdominal aortic aneurysm. Post-operatively, he awakens with flaccid paraplegia and a loss of pain and temperature sensation in his lower limbs, but preservation of vibration and proprioception. An urgent spinal MRI is performed.
Question:
What is the most likely finding on the axial T2-weighted images?
(A) A large, dorsal, rim-enhancing epidural collection.
(B) Bilateral, symmetric, high-signal in the anterior horns of the grey matter, resembling “snake eyes” or “owl’s eyes”.
**(C)
** A short-segment, T2-bright plaque in the posterior cord.
(D) Diffuse, T2-bright signal in the conus with dorsal flow voids.
(E) A centrally located, haemorrhagic intramedullary mass.
Correct Answer: (B) Bilateral, symmetric, high-signal in the anterior horns of the grey matter, resembling “snake eyes” or “owl’s eyes”.
Explanation:
- Why (B) is correct: This is the classic presentation of an anterior spinal artery infarct, a known complication of aortic surgery. The clinical picture is anterior cord syndrome (loss of motor, pain, and temp; preserved dorsal columns). The anterior spinal artery supplies the anterior 2/3 of the cord. On T2 MRI, the ischaemia manifests as bilateral, symmetric T2 high signal in the anterior horns (grey matter), which looks like “snake eyes” or “owl’s eyes” on axial cuts.
- Why (A) is wrong: This is an epidural abscess.
- Why (C) is wrong: This is an MS plaque.
- Why (D) is wrong: This is a spinal dural AV fistula.
- Why (E) is wrong: This is an ependymoma.
Key Points: Anterior Spinal Artery Infarct
- Clinical: Anterior Cord Syndrome (loss of motor, pain, temp; preserved dorsal columns – proprioception/vibration).
- Cause: Often a “watershed” infarct, or a complication of aortic surgery (disruption of the artery of Adamkiewicz).
- Imaging:
- Axial T2: “Owl’s Eye” / “Snake Eye” Sign (bilateral T2-bright anterior horns).
- DWI: Restricted diffusion (key for acute phase).
Question 8: Syringomyelia (Syrinx)
Stem:
A 28-year-old woman presents with a 1-year history of a “cape-like” sensory loss (loss of pain and temperature, but preserved touch) across her shoulders and arms, and new-onset scoliosis. An MRI of her spine is performed.
Question:
What is the most likely finding on the MRI?
(A) A central, fluid-filled, T2-bright cavity within the cervical and upper thoracic spinal cord.
(B) An ill-defined, eccentric, T2-bright intramedullary tumour.
**(C)
** Multiple, short-segment, T2-bright plaques in the posterior cord.
(D) A rim-enhancing fluid collection in the dorsal epidural space.
(E) Bilateral “owl’s eye” T2 signal in the anterior horns.
Correct Answer: (A) A central, fluid-filled, T2-bright cavity within the cervical and upper thoracic spinal cord.
Explanation:
- Why (A) is correct: The clinical picture of “cape-like” sensory loss is classic for a central cord syndrome, which is most commonly caused by a syringomyelia (or syrinx). This is a fluid-filled (CSF) cavity within the spinal cord that disrupts the decussating spinothalamic (pain/temp) fibres.
- Why (B) is wrong: This describes an astrocytoma, which can cause a syrinx, but the primary finding for the symptoms is the syrinx itself.
- Why (C) is wrong: This is multiple sclerosis.
- Why (D) is wrong: This is an epidural abscess.
- Why (E) is wrong: This is an anterior spinal artery infarct.
Key Points: Syringomyelia (Syrinx)
- Definition: A fluid-filled (CSF) cavity within the spinal cord.
- Clinical: “Dissociated sensory loss” (loss of pain/temp, preserved proprioception/touch) in a “cape-like” distribution.
- Imaging: A central, fluid-isointense (T1-dark, T2-bright) cystic cavity.
- Most Common Cause: Chiari I malformation (tonsillar descent > 5mm below foramen magnum). Always check the foramen magnum.
Question 9: Tethered Cord Syndrome
Stem:
A 25-year-old woman presents with a new-onset foot drop, lower back pain, and urinary incontinence. She has a small, fatty lump (lipoma) in her lower back, which has been present since birth. An MRI of the lumbar spine is performed.
Question:
What is the most likely primary finding on the MRI?
(A) The conus medullaris is terminating at the L4 level.
(B) The conus medullaris is terminating at the T12 level.
(C) A large, destructive, lytic lesion at L4.
(D) An intradural-extramedullary schwannoma at L3.
(E) A large disc extrusion at L5/S1.
Correct Answer: (A) The conus medullaris is terminating at the L4 level.
Explanation:
- Why (A) is correct: This is the definition of a tethered spinal cord. In an adult, the conus medullaris (the tip of the cord) should terminate at or above the L1-L2 disc space. A conus terminating at L4 is low-lying and indicates tethering. This is often associated with cutaneous stigmata (lipoma, hairy patch) and spinal dysraphism.
- Why (B) is wrong: Termination at T12 is normal.
- Why (C) & (D) are wrong: These are tumours, which are less likely than a tethered cord given the congenital lipoma.
- Why (E) is wrong: A disc extrusion can cause these symptoms but is not associated with a congenital lipoma.
Key Points: Tethered Cord Syndrome
- Definition: A low-lying conus medullaris, which should normally terminate at or above L1/L2 in an adult.
- Clinical: Back/leg pain, weakness, foot deformities, urinary/bowel dysfunction.
- Associations: Spinal Dysraphism (spina bifida, lipomyelomeningocele), thickened filum terminale (> 2 mm), cutaneous stigmata (hairy patch, lipoma, dermal sinus).
Question 10: Diastematomyelia
Stem:
A 10-year-old girl is referred for a new-onset scoliosis and a patch of hair (hypertrichosis) over her lumbar spine. An MRI of the spine reveals that the spinal cord is sagittally split into two hemicords. A bony spur is seen arising from the posterior aspect of the L2 vertebral body and passing through this cleft.
Question:
What is the most likely diagnosis?
(A) Diastematomyelia
(B) Syringomyelia
(C) Spinal Ependymoma
(D) Tethered Cord
(E) Dermal Sinus
Correct Answer: (A) Diastematomyelia.
Explanation:
- Why (A) is correct: Diastematomyelia is the specific term for a split spinal cord. It is a form of spinal dysraphism. The presence of a bony or fibrous spur separating the two hemicords (each with its own dural sac) is characteristic of Type 1 diastematomyelia. It is commonly associated with scoliosis and cutaneous stigmata.
- Why (B) is wrong: A syrinx is a cyst within the cord, not a split of the cord.
- Why (C) is wrong: This is a solid tumour within the cord.
- Why (D) is wrong: A tethered cord (low-lying conus) is often associated with diastematomyelia, but the primary finding described is the split itself.
- Why (E) is wrong: A dermal sinus is a tract from the skin, which can lead to a dermoid cyst, but it is not a split cord.
Key Points: Diastematomyelia (Split Cord)
- Definition: A sagittal cleft dividing the spinal cord into two hemicords.
- Type 1: Two hemicords, each with its own dural sac, separated by a bony or fibrous spur.
- Type 2: Two hemicords within a single dural sac.
- Associations: Scoliosis, cutaneous stigmata (hairy patch, lipoma), tethered cord.
Question 11: Degenerative Cord Oedema
Stem:
A 72-year-old man presents with a 1-year history of progressive gait imbalance, loss of fine motor skills in his hands, and “electric shock” sensations down his spine on neck flexion (Lhermitte’s sign). An MRI of the cervical spine shows severe, multilevel spondylosis and spinal canal stenosis, worst at C4/C5. At this level, there is a focal, ill-defined area of T2 high signal within the compressed spinal cord.
Question:
This T2 signal change represents:
(A) Myelomalacia (cord oedema/gliosis)
(B) An acute MS plaque
(C) An intramedullary astrocytoma
(D) An anterior spinal artery infarct
(E) A syrinx
Correct Answer: (A) Myelomalacia (cord oedema/gliosis).
Explanation:
- Why (A) is correct: The clinical picture is classic for cervical myelopathy (cord dysfunction). The T2 high signal at the site of maximum stenosis is a direct sign of cord injury from the chronic compression. This signal represents oedema (if acute) or gliosis/myelomalacia (if chronic). It is a key prognostic finding.
- Why (B) is wrong: An MS plaque is a demyelinating lesion, not one caused by mechanical compression. It would be unlikely to occur exactly at the level of maximum spondylosis.
- Why (C) is wrong: An astrocytoma is a primary tumour that expands the cord, not a signal change caused by external compression.
- Why (D) is wrong: An infarct is an acute vascular event and would not be the result of chronic, progressive spondylosis.
- Why (E) is wrong: A syrinx is a well-defined cystic cavity, not an ill-defined T2 signal.
Key Points: Cervical Spondylotic Myelopathy
- Cause: Chronic spinal cord compression from degenerative changes (disc-osteophyte bars, facet hypertrophy).
- Clinical: Gait disturbance, loss of hand dexterity, Lhermitte’s sign.
- MRI:
- Primary: Spinal canal stenosis with cord compression.
- Secondary: T2 high signal within the cord at the compression level. This indicates oedema or myelomalacia and is a poor prognostic sign.
Question 12: Neuromyelitis Optica (NMO)
Stem:
A 38-year-old woman presents with acute blindness in her right eye (optic neuritis) and a new-onset paraplegia. An MRI of the spine reveals a longitudinally extensive transverse myelitis (LETM), with a T2-bright lesion that is centrally located, swollen, and spans five vertebral body segments in the thoracic cord.
Question:
This combination of optic neuritis and LETM is highly specific for:
(A) Neuromyelitis Optica (NMO)
(B) Multiple Sclerosis (MS)
(C) Spinal Dural AV Fistula
(D) Sarcoidosis
(E) Spinal Cord Infarct
Correct Answer: (A) Neuromyelitis Optica (NMO).
Explanation:
- Why (A) is correct: NMO (or Devic’s disease) is the classic differential for MS. It is defined by the combination of optic neuritis and LETM (Longitudinally Extensive Transverse Myelitis), which is a cord lesion spanning > 3 vertebral bodies. It is associated with the Aquaporin-4 (AQP4) antibody.
- Why (B) is wrong: MS plaques are classically short-segment (< 2 bodies) and peripherally located. A long-segment lesion makes MS highly unlikely.
- Why (C) is wrong: An SDAVF causes congestive myelopathy with dorsal flow voids, not an inflammatory LETM.
- Why (D) is wrong: Neurosarcoidosis can also cause LETM, but the combination with optic neuritis is the classic presentation of NMO.
- Why (E) is wrong: An infarct is a vascular event and does not typically present with optic neuritis.
Key Points: NMO vs. MS
- NMO (Devic’s Disease):
- Antibody: Aquaporin-4 (AQP4).
- Spine Lesion: LETM (Longitudinally Extensive, > 3 segments), central, swollen.
- Optic Neuritis: Often bilateral and severe.
- Multiple Sclerosis (MS):
- Antibody: None.
- Spine Lesion: Short segment (< 2 segments), posterior/peripheral, cervical.
- Optic Neuritis: Often unilateral.
Question 13: Guillain-Barré Syndrome (GBS)
Stem:
A 30-year-old man presents with rapidly ascending, symmetric paralysis and areflexia, which began 10 days after a gastrointestinal infection. A contrast-enhanced MRI of the lumbar spine is performed.
Question:
What is the most classic (though not always present) imaging finding for GBS?
(A) Diffuse, smooth enhancement of the cauda equina nerve roots.
(B) A centrally located intramedullary mass.
**(C)
** A long-segment T2-bright lesion in the conus.
(D) An extradural, rim-enhancing fluid collection.
(E) A completely normal MRI.
Correct Answer: (A) Diffuse, smooth enhancement of the cauda equina nerve roots.
Explanation:
- Why (A) is correct: GBS is an acute inflammatory demyelinating polyneuropathy. The clinical diagnosis is paramount (ascending paralysis, areflexia). When imaging is performed, the most characteristic finding is abnormal, avid enhancement of the intrathecal nerve roots of the cauda equina (and sometimes the cranial nerves). The enhancement of the anterior roots is often more prominent, correlating with the motor symptoms.
- Why (B) is wrong: This is an ependymoma.
- Why (C) is wrong: This is myelitis (inflammation of the cord itself), which is not typical for GBS.
- Why (D) is wrong: This is an epidural abscess.
- Why (E) is wrong: A normal MRI is also a very common finding in GBS, as the inflammation is often at a microscopic level. However, (A) is the classic positive finding.
Key Points: Guillain-Barré Syndrome (GBS)
- Clinical: Acute, ascending, symmetric paralysis with areflexia. Often post-infectious.
- Pathology: Autoimmune attack on peripheral nerve myelin.
- Imaging:
- MRI is often normal.
- Classic Positive Finding: Avid, smooth enhancement of the cauda equina nerve roots (especially anterior roots).
Question 14: Central Cord Syndrome (Clinical)
Stem:
A 78-year-old man with known severe cervical spondylosis falls forward, striking his chin. He presents to the ED with weakness in all four limbs. On examination, his motor power in his upper limbs is 2/5, while in his lower limbs it is 4/5. Sensory loss is variable.
Question:
This clinical presentation is pathognomonic for:
(A) Central Cord Syndrome
(B) Anterior Cord Syndrome
(C) Brown-Séquard Syndrome
(D) Posterior Cord Syndrome
(E) Complete Cord Transection
Correct Answer: (A) Central Cord Syndrome.
Explanation:
- Why (A) is correct: This is the definition of Central Cord Syndrome. It is the most common incomplete cord syndrome, classically caused by a hyperextension injury in an older person with spondylosis. This “pinches” the cord, causing haemorrhage/oedema in the central portion. Since the corticospinal tract fibres for the arms are located more medially (centrally) than the fibres for the legs, the result is motor weakness that is worse in the upper limbs than the lower limbs.
- Why (B) is wrong: Anterior cord syndrome involves loss of all motor, pain, and temp below the lesion.
- Why (C) is wrong: Brown-Séquard is a hemicord syndrome (ipsilateral motor loss, contralateral pain/temp loss).
- Why (D) is wrong: Posterior cord syndrome is rare and involves loss of proprioception/vibration only.
- Why (E) is wrong: Complete transection would involve 0/5 power in both upper and lower limbs (depending on level).
Key Points: Central Cord Syndrome
- Mechanism: Hyperextension injury in a patient with pre-existing cervical spondylosis.
- Clinical: Motor weakness worse in the upper limbs than the lower limbs.
- Pathology: Central cord haemorrhage/oedema, affecting the medially-located arm fibres of the corticospinal tract.
Question 15: Traumatic Cord Haematoma (Haematomyelia)
Stem:
A 20-year-old man is involved in a severe flexion-distraction (Chance) fracture of the thoracic spine. A sagittal MRI of the spine shows T2 signal change within the cord.
Question:
On the T1-weighted images, what finding would be most specific for an acute traumatic haemorrhage within the cord?
(A) A focal area of high signal (T1-bright) within the cord.
(B) A focal area of low signal (T1-dark) within the cord.
(C) A fluid-filled syrinx.
(D) Dorsal serpiginous flow voids.
(E) A normal T1-weighted signal.
Correct Answer: (A) A focal area of high signal (T1-bright) within the cord.
Explanation:
- Why (A) is correct: Haematomyelia is a collection of blood within the spinal cord. In the acute-to-subacute phase (after 24-72 hours), methaemoglobin forms, which is paramagnetic and appears bright on T1-weighted images. This is a key differentiator from simple oedema, which is T1-dark.
- Why (B) is wrong: Low T1 signal would indicate oedema (T2-bright), a syrinx (T2-bright), or a chronic infarct.
- Why (C) is wrong: A syrinx is a chronic (or subacute) collection of CSF, not acute blood.
- Why (D) is wrong: These are signs of a dural AV fistula.
- Why (E) is wrong: Given the severe trauma and T2 signal, a normal T1 signal would be less likely than either oedema or haemorrhage. T1-bright is specific for blood.
Key Points: Traumatic Cord Injury
- Cord Oedema/Contusion: T2-bright, T1-dark. Most common finding.
- Haematomyelia (Intramedullary Haemorrhage):
- T1-bright (due to subacute methaemoglobin).
- T2-variable (often bright with a dark rim).
- A poor prognostic sign.
- Transection: Complete disruption of the cord.
