Lecture notes for spinal cord injuries and diseases

1. SPINAL CORD INJURIES AND
DISEASES
By
CHIKOMELE JONATHAN R
MD5 2017/18
+255757714388
TANZANIA

2. SCI
• Spinal cord injury (SCI) is an insult to the spinal cord resulting in a
change, either temporary or permanent, in its normal motor, sensory,
or autonomic function
• Patients with spinal cord injury usually have permanent and often
devastating neurologic deficits and disability
• Insult to spinal cord resulting in a change, in the normal motor,
sensory or autonomic function. This change is either temporary or
permanent.

3. Mechanisms:
i) Direct trauma
ii) Compression by bone fragments / haematoma / disc
material
iii) Ischemia from damage / impingement on the spinal
arteries

4. Cont..
South African Statistics (GSH Acute Spinal Cord Injury Unit 2007)
• MVA 56%
• Falls 16%
• Gunshot Injuries 11%
• Blunt Assault 6%
• Diving Accidents 5%
• Stab Wounds 4%
• Sport Injuries 3%

5. Other causes:
• Vascular disorders
• Tumours
• Infectious conditions
• Spondylosis
• Iatrogenic
• Vertebral fractures secondary to osteoporosis
• Development disorders

6. ANATOMY OF THE SPINAL CORD
• Extends from medulla oblongata – L1
• Lower part tapered to form conus medullaris
• Typical adult spinal cord ranges between 42 and 45 centimeters (cm)
about (16 to 18 inches) in length.
• In cross section it is roughly cylindrical and slightly flattened both
posteriorly and anteriorly

7. The spinal cord is shorter than the vertebral canal that houses
it.
Conus medullaris:tapered inferior end of the spinal cord,it
marks the official “end” of the spinal cord proper.
Cauda equine:Inferior to conus medularis,it is the nerve roots
(groups of axons) that project inferiorly from the spinal cord.
Filum terminale:Within the cauda equine,it is a thin strand of
pia mater.It helps anchor the conus medullaris to the coccyx.

9. Internal Anatomy

10. Dorsal root(posterior) – sensory fibres
Ventral root (anterior) – motor fibres
Dorsal and ventral roots join at intervertebral
foramen to form the spinal nerve

11. Physiology and function
THE GRAY MATTER
• Grey matter – sensory and motor nerve cell
• The gray matter may be subdivided into the following
components:
anterior horns
lateral horns
posterior horns
the gray commission

13. THE WHITE MATTER
• The white matter of the spinal cord is external to the gray
matter. Composed of;
-ascending and descending tracts
-Posterior funiculus:
-Lateral funiculus.
-Anterior funiculus

14. White Matter
• 1. columns
a. anterior
b. posterior
c. lateral
• 2. tracts
a. ascending
b. descending
Posterior columns
Anterior columns
Lateral columns
Lateral columns

15. Tracts of the Spinal Cord

16. Organization of
Sensory or Ascending
Pathways

17. Tracts :
1) Posterior column:
• Fine touch
• Light pressure
• Proprioception

18. 2) Lateral corticospinal tract :
• Skilled voluntary movement
3) Lateral spinothalamic tract :
• Pain & temperature sensation

19. • Posterior column and lateral corticospinal tract crosses
over at medulla oblongata
• Spinothalamic tract crosses in the spinal cord and
ascends on the opposite side
NB to understand this as it helps to understand the
clinical features of injury patterns and the
neurological deficit

20. Motor or Descending Tracts of the Spinal
Cord
Name Location Function
Lateral
Corticospinal
Lateral
Column
Muscles of the limbs,
hands, and feet
Anterior
Corticospinal
Anterior
Column
Muscles of the axial
skeleton
Corticobulbar Cerebral
Peduncle
Skeletal muscles of the
head and neck via cranial
nerves
Rubrospinal Lateral
Column
Skeletal muscles of the
limbs, hands, and feet
Tectospinal Anterior
Column
Skeletal muscles of the
head and eyes in response
to visual stimuli

21. Motor or Descending Tracts of the Spinal
Cord
Name Location Function
Vestibulospinal Anterior
column
Muscle for maintaining
balance in response to head
movements
Lateral
reticulospinal
Anterior
column
Facilitates flexor reflexes
Inhibits extensor reflexes
Medial
reticulospinal
Anterior
column
Facilitates extensor reflexes
Inhibits Flexor reflexes

22. ANATOMY CONT…..
DERMATOMES:
• A specific segment of skin supplied by a
single spinal nerve.
• All spinal nerves innervate a segment of skin
and are associated with a dermatome except
for C1
• Dermatome map:sensory segments: skin of
the body associated with a spinal nerve

23. MAP

24. General Effects
• Paralysis
• Dysfunction of bowels and bladder
• Male infertility
• Inability to regulate blood pressure
• Inability to sweat below level of injury
• Chronic pain

25. Cont..

26. Upper vs Lower Motor Neuron
• Upper motor neuron lesion
– Motor cortex internal capsule brainstem
spinal cord
• Lower motor neuron lesion
– Anterior horn cell nerve root plexus
peripheral nerve neuromuscular junction
muscle
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28. Upper & Lower Motor Neurons Lesions

30. 30
Principal Features of UMNL & LMNL
UMNL:
(1) No muscle wasting, except
from disuse ( disuse
atrophy)
(3) Spasticity ( hypertonia ) ,
called
“ clasp-knife spasticity ”
(4) Clonus present
(5) Brisk ( exaggerated )
tendon jerks
(6) Extensor plantar reflex ,
Babinski sign ( dorsiflexion
of the big toe and fanning
out of the other toes )
(7) Absent abdominal reflexes
(8) No fasciculations
(9) No fibrillation potential in
EMG
LMNL:
(1) Marked muscle wasting
(atrophy )
(3) Flacidity (Hypotonia ) ,
hence given the name “
flaccid paralysis ”
(4) No clonus
(5) Diminished or absent
tendon reflexes
(6) Absent plantar reflex
(normally it is flexor ) .
(7) Absent abdominal reflexes
(8) Fasciculations may occur .
(9) Fibrillation potentials
present .

31. Terminologiest
Monoplegia: paralysis of a single limb such as Lesion in Corona Radiate .
Hemiplegia : total paralysis of the arm, leg, and trunk on the same side of the body
Quadriplegia: paralysis of both arms and legs.
(Lesion of all limbs )
Paraplegia: paralysis of lower half of the body with involvement of both legs. (Lesion in both lower limbs)

33. Spinal shock
• With severe and acute transverse lesions, the limbs
initially may be flaccid rather than spastic
• Lasts for several days, rarely for weeks
• May overlooked for a lower motor neuron lesion
• Should not be mistaken for extensive damage to the
anterior horn cells over many segments of the cord or for
an acute polyneuropathy
25 May 2015 Spinal Cord Diseases 33

34. Spinal Shock vs Neurogenic Shock
Spinal Shock :
• Transient reflex depression of cord function below level of injury
• Initially hypertension due to release of catecholamines
• Followed by hypotension
• Flaccid paralysis
• Bowel and bladder involved
• Sometimes priaprism develops
• Symptoms last several hours to days

35. • Loss of vasomotor tone – pooling of blood
• Loss of cardiac sympathetic tone – bradycardia
• Blood pressure will not be restored by fluid infusion alone
• Massive fluid administration may lead to overload and pulmonary
edema
• Vasopressors may be indicated
• Atropine used to treat bradycardia

36. Neurogenic shock:
• Triad of i) hypotension
ii) bradycardia
iii) hypothermia
• More commonly in injuries above T6
• Secondary to disruption of sympathetic outflow from T1 –
L2

37. Features of transverse damage: Cervical cord
lesions
• Upper cervical cord
– Quadriplegia
– Weakness of the diaphragm
• C4-C5
– Quadriplegia
– Lhermitte's sign: an electric shock-like sensation down the neck, back, or extremities that
occurs with bending of the neck
• C5-C6
– Loss of power and reflexes in the biceps
• C7
– Weakness affects finger and wrist extensors and triceps
• C8
– Finger and wrist flexion are impaired
Horner’s syndrome (miosis, ptosis, and facial hypohidrosis) may accompany a cervical
cord lesion at any level
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38. Thoracic cord lesions
• Localized by the sensory level on the trunk and by the site
of midline back
– Useful markers: nipples (T4), umbilicus (T10)
• Leg weakness and disturbances of bladder and bowel
function accompany the paralysis
• Lesions at T9-T10 paralyze the lower, and not the upper,
abdominal muscles
– Resulting in upward movement of the umbilicus when the
abdominal wall contracts (Beevor’s sign)
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39. Lumbar cord lesions
• L2-L4
– Paralyze flexion and adduction of the thigh
– Weaken leg extension at the knee
– Abolish the patellar reflex
• L5-S1
– Paralyze movements of the foot and ankle
– Flexion at the knee
– Extension of the thigh
– Abolish the ankle jerks (S1)
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40. Special patterns of Spinal Cord Disease
• Brown-Sequard Hemicord Syndrome
• Central Cord Syndrome
• Anterior Spinal Artery syndrome
• Sacral cord/conus medullaris
• Cauda equina syndrome
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41. Brown-Sequard Hemicord Syndrome
• This consists of:
– Ipsilateral weakness (corticospinal tract) and loss of joint
position and vibratory sense (posterior column)
– Contralateral loss of pain and temperature sense
(spinothalamic tract) one or two levels below the lesion
• Segmental signs, such as radicular pain, muscle
atrophy, or loss of a deep tendon reflex, are unilateral
• Partial forms are more common than the fully
developed syndrome.
25 May 2015 Spinal Cord Diseases 41

42. Central Cord Syndrome
• Results from selective damage to the gray matter nerve cells
and crossing spinothalamic tracts surrounding the central canal
• In the cervical cord:
– Arm weakness out of proportion to leg weakness
– A “dissociated” sensory loss over the shoulders, lower neck, and upper
trunk (cape distribution)
– Light touch, joint position, and vibration sense in these regions
preserved
• Main causes:
– Spinal trauma
– Syringomyelia
– Intrinsic cord tumors
25 May 2015 Spinal Cord Diseases 42

43. Anterior Spinal Artery Syndrome
• Infarction of the cord is generally the result of occlusion or
diminished flow in this artery
• The result is extensive bilateral tissue destruction that
spares the posterior columns
• All spinal cord functions—motor, sensory, and
autonomic—are lost below the level of the lesion
– With the striking exception of retained vibration and position
sensation.
25 May 2015 Spinal Cord Diseases 43

44. Sacral cord/conus medullaris
• The conus medullaris is the tapered caudal termination of
the spinal cord comprising the lower sacral and single
coccygeal segments
• The distinctive conus syndrome consists:
– Bilateral saddle anesthesia (S3-S5)
– Prominent bladder and bowel dysfunction (urinary retention
and incontinence with lax anal tone)
– Impotence
– The bulbocavernosus (S2-S4) and anal (S4-S5) reflexes are absent
– Muscle strength is largely preserved
25 May 2015 Spinal Cord Diseases 44

45. Cauda equina syndrome
• Lesions of the cauda equina characterized by:
– Low back and radicular pain
– Asymmetric leg weakness and sensory loss
– Variable areflexia in the lower extremities
– Relative sparing of bowel and bladder function
• Mass lesions in the lower spinal canal often produce a
mixed clinical picture with elements of both cauda equina
and conus medullaris syndromes
25 May 2015 Spinal Cord Diseases 45

46. 25 May 2015 Spinal Cord Diseases 46
Conus lesion Cauda lesion
Onset Sudden bilateral Gradual unilateral
Spontaneous pain Negative, bilateral Positive, severe, radicular,
unilateral
Sensory deficit Saddle, bilateral Saddle, unilateral
Motor loss Symmetric, fasciculations Asymmetric, atrophy, no
fasciculations
Deep tendon reflex Increased Decreased
Bowel, bladder Early Late
Sexual function Impaired Less impaired

47. Non-compressive myelopathies
Vascular
• Arteriovenous malformation
• Antiphospholipid syndrome and other
hypercoagulable states
Inflammatory
• Multiple sclerosis
• Neuromyelitis optica (Devic’s Disease)
• Transverse myelitis
• Sarcoidosis
• Sjögren-related myelopathy
• Systemic lupus erythematosus Vasculitis
Infectious
• Viral: VZV, HSV-1 and -2, CMV, HIV, HTLV-
I, enteroviruses, flaviviruses
• Bacterial and mycobacterial: Borrelia,
Listeria, syphilis
• Mycoplasma pneumoniae
• Parasitic: schistosomiasis, toxoplasmosis
Developmental
• Syringomyelia
• Meningomyelocele
• Tethered cord syndrome
Metabolic
• Vitamin B12 deficiency (subacute
combined degeneration)
• Copper deficiency
25 May 2015 Spinal Cord Diseases 47

48. Compressive myelopathies
• Epidural, intradural meningioma, or intramedullary
metastasis neoplasm;
• Epidural abscess
• Epidural hemorrhage
• Cervical spondylosis
• Herniated disk
• Posttraumatic compression by fractured or displaced
vertebra or hemorrhage
25 May 2015 Spinal Cord Diseases 48

49. Other infectious myelitis (2)
• Bacterial
– Mycoplasma (acute and post infectious), Listeria monocytogenes
– TB
• Via secondary cord compression from verterbral osteomyelitis, aka Pott’s
disease
• Also via compressive tuberculomas
– Lyme disease
• Cases have been described in which clinical and MRI features resembling
acute transverse myelitis have been attributed to Lyme disease
• CSF in these cases typically demonstrates a lymphocytic pleocytosis and
elevated protein
25 May 2015 Spinal Cord Diseases 49

50. Tuberculous spondylitis
(Pott’s Disease)
• Pathogenesis related to:
– Reactivation of hematogenous foci or
– Spread from adjacent paravertebral lymph nodes
• Accounts for 40% of cases of skeletal TB
• Often involves two or more adjacent vertebral bodies
• Common sites:
– Upper thoracic spine (in children)
– Lower thoracic and upper lumbar vertebrae (in adults)
25 May 2015 Spinal Cord Diseases 50

51. Pott’s Disease cont.
• With advanced disease:
– Collapse of vertebral bodies results in kyphosis (gibbus)
– A paravertebral “cold” abscess may also form
• A catastrophic complication:
– Paraplegia due to compression of the spinal cord
• Paraparesis due to a large abscess is a medical
emergency and requires rapid drainage
• Treated with antituberculous drugs
25 May 2015 Spinal Cord Diseases 51

52. Tabes dorsalis (Locomotor Ataxia)
• Form of tertiary neurosyphilis in which the nerves of the
dorsal (or posterior) columns degenerate
– Loss of sense of position (proprioception), vibration, and
discriminative touch
– Latency period of 3-20 years
• Cardinal signs of tabes are:
– Loss of reflexes in the legs
– Impaired position and vibratory sense
– Romberg's sign
25 May 2015 Spinal Cord Diseases 52

53. Tabes dorsalis (2)
Other features include:
• Bilateral Argyll Robertson pupils
• Fleeting and repetitive lancinating pains, primarily in the legs
• Paresthesias
• Visceral crisis (Bladder disturbances, and acute abdominal pain with
vomiting
• Personality changes, dementia, deafness, visual
• Skeletal musculature is hypotonic due to destruction of the sensory
limb of the spindle reflex
• Ataxia of the legs and (tabetic) gait due to loss of position sense
occurs in half of patients
25 May 2015 Spinal Cord Diseases 53

54. Tabes dorsalis (3)
• VDRL & RPR (nontreponemal tests) may be nonreactive
in late neurosyphilis
– If suspicion suspicion for neurosyphilis, serum FTA-ABS or
TPPA (treponemal tests) are preferred
• Treatment:
– Penicillin G 3 to 4 million units IV every four hours or 24 million
units continuous IV infusion for 10 to 14 days
25 May 2015 Spinal Cord Diseases 54

55. B12 Deficiency (subacute combined
degeneration of spinal cord)
• Damage to peripheral nerves caused by demyelination and
irreversible nerve cell death
• Symptoms include:
– Paresthesias in the hands and feet
– Loss of vibration and position sensation
– Progressive spastic and ataxic weakness
– Loss of reflexes due to an associated peripheral neuropathy in a
patient who also has Babinski signs, is an important diagnostic clue
– Optic atrophy and irritability or other mental changes may be
prominent in advanced cases
25 May 2015 Spinal Cord Diseases 55

56. B12 Deficiency…cont.
• This myelopathy tends to be diffuse rather than focal; signs are
generally symmetric and reflect predominant involvement of the
posterior and lateral tracts, including Romberg's sign
• Usually established by the presence of decreased Vit B12 level
• In the cases of low-normal B12, the presence of elevated
methylmalonic acid and homocysteine levels may be useful
• Treatment:
– 1mg Cbl IM once daily for 1 week, followed by 1 mg IM every week for
four weeks
– If the underlying disorder persists, 1mg every month for the remainder of
the patient's life
25 May 2015 Spinal Cord Diseases 56

57. Evaluation
• MRI of spinal cord with and without contrast (exclude
compressive causes)
• CSF studies: Cell count, protein, glucose, IgG
index/synthesis rate, oligoclonal bands, VDRL; Gram’s
stain, acid-fast bacilli, and India ink stains; PCR for VZV,
HSV-2, HSV-1, EBV, CMV, HHV-6, enteroviruses, HIV;
antibody for HTLV-I, Borrelia burgdorferi, Mycoplasma
pneumoniae, and Chlamydia pneumoniae; viral, bacterial,
mycobacterial, and fungal cultures
25 May 2015 Spinal Cord Diseases 57

58. Evaluation cont.
• Blood studies for infection: HIV; IgG and IgM
enterovirus antibody; IgM mumps, measles, rubella, group
B arbovirus, Brucella melitensis, Chlamydia psittaci,
Bartonella henselae, schistosomal antibody; cultures for
B. melitensis.
– Also consider nasal/pharyngeal/ anal cultures for enteroviruses;
stool for Schistosoma ova.
25 May 2015 Spinal Cord Diseases 58

59. Evaluation cont.
• Immune-mediated disorders: ESR; ANA;rheumatoid
factor;complement levels; antiphospholipid and
anticardiolipin antibodies; antimicrosomal and
antithyroglobulin antibodies.
25 May 2015 Spinal Cord Diseases 59

60. Evaluation cont.
• Sarcoidosis: Serum angiotensin-converting enzyme;
serum Ca; 24-hour urine Ca; chest x-ray; chest CT; total
body gallium scan; lymph node biopsy.
• Demyelinating disease: Brain MRI scan,
• Vascular causes: CT myelogram; spinal angiogram.
25 May 2015 Spinal Cord Diseases 60

61. ASANTENI SANA
TO BE CONTINUED