Coupon Accepted Successfully!


Lumbosacral Cord Syndromes

  1. The spinal cord forms a slight bulge (the conus medullaris) between T10 & L1 vertebral and tapers to an end at the interspace, between L1 & L2 vertebrae.
  2. The L2 to S4 nerve roots arise from conus medullaris and travel downward in a bunch (known as cauda equina) to emerge at successive levels of the lumbosacral spine. So injuries
  3. Above T10 vertebrae cause cord transection
  4. Between T10 and L1 vertebrae cause cord & nerve root lesion
  5. Below L1 vertebrae cause only nerve root lesions.
​Conus Medullaris Syndrome
  1. It is injury to sacral cord (conus) and lumbar nerve roots within the spinal canal. It presents as - Bilateral saddle anesthesia (S3 - S5)
  2. Prominent bladder bowel dysfunction (urinary retention and incontinence with lax anal tone)
  3. Impotence
  4. Bulbocavernosus (S2 - 54) and anal (54 - S5) reflexes are absent.
  5. Muscle Strength is largely preserved
  6. May have preserved bulbocavernosus & micturition reflexes.
​Cauda Equina Syndrome
  1. It is the injury of lumbosacral nerve roots in the spinal canal. It presents as
  2. Low back or radicular pain
  3. Asymmetrical leg weakness and sensory loss
  4. Variable areflexia in the lower limbs
  5. Relative sparing of bladder bowel functions
​Areflexia bladder - bowel & lower limbs
  1. With Symmetrical involvement - Conus medullaris Syndrome
  2. Asymmetrical involvement - Cauda equina syndrome
Muscle group used
for motor grading in
ASIA system
Other Motor Sensory Reflex
C5 Elbow flexion (Biceps, Brachialis) - Deltoid* (arm abduction)
- Supraspmatus (initial arm abduction)
- Infraspinatus* (arm external rotation)
- Lateral shoulder
- Lateral arm
C6 Wrist extension (extensor
carpiradialis longus & brevis)
- Pronator teres (internal forearm rotation)
- Biceps (arm flexion)
Thumb &  index fingers Brachio radialis
C7 Elbow extensor (triceps) Extensor digitorum* (finger extension)
- Wrist flexion
- Middle finger Triceps
C8 Finger flexors (flexor digitorum
Abductor pollicis brevis (abduction D1)
- 1st dorsal interosseous (abduction D2)
- Abductor digit minimi (abduction D5)
- Ring and Little finger  
T1 Hand intrinsic (interossei)/Finger abduction Abductor pollicis brevis
- 1st dorsal interosseous (abduction D2)
- Abductor digit minimi (abduction D5)
- Medial arm  
L2 Hip flexors (iliopsoas) - Hip abduction - Upper anterior thigh  
L3 Knee extensor (quadriceps) Psoas (hip flexion)
- Thigh (hip) adduction
- Anterior knee  
L4 Ankle dorsiflexor (tibialis anterior) Quadriceps* (knee extension)
- Hip adduction
- Medial calf & foot Quadriceps (knee)
L5 Great toe extensors (extensor hallucis longus) Peroneii (foot eversion)
- Tibialis anterior (foot dorsiflexion)
- Gluteus medius (hip abduction)
- Knee flexion
- Toe dorsiflexors
Dorsal surface foot
Lateral calf
- Great toe
S1 Ankle plantar flexors (gastrocneus & soleus) - Abductor hallucis (great toe flexor)
- Gluteus - maximus (hip extension)
Plantar surface foot
- Lateral aspect foot
S2,3,4 - - Rectal tone - Perianal Bulbocavernosus

Test Your Skills Now!
Take a Quiz now
Reviewer Name