Lecture 13- Lower Limb Nerve Injuries and Compression syndrome Flashcards
What are the landmarks for lumbar pucnture?
- Needle inserted between L3/L4
- Lying down on the side
Describe the pain of cauda equina vs conus medularis?
- Cauda equina: Radicular and more severe
- Conus Medullaris: Less severe
Compare the location of the pain for cauda equina and conus medullaris?
- Cauda Equina: unilateral and asyymetric affecting perineum, thighs and legs
- Conus Medullaris: Bilateral, perineum and thighs
Describe the sensory disturbances in cauda equina and cona medullaris?
Cauda equina: Saddle, unilateral and asyymetric
Conus Medullaris: Bilateral saddle distribution
Describe the motor loss for cauda equina and conus medullaris?
Cauda equina: Asymmetric and atrophy
Conus Medullaris: symmetric
Describe how the reflexes are affected in cauda equina and conus medullaris?
Cauda equina: ankle and knee reflex reduced
Conus Medularis: Ankle only reduced
Describe when cauda equina and conus medullaris affects the bowel/bladder function?
Cauda equina: Late
Conus Medullaris: Early
Describe the effect of cauda equina and conus medullaris on the sexual function?
Cauda equina: Impaired but less severe
Conus Medullaris: Impaired but more severe
what are the caused of cuada equina:
Disc herniation, spinal fracture and tumours
Describe the causes of Conus medullaris?
Disc herniation and tumour Also inflammatory condition: 1) Chronic inflammatory demyelinating 2) Polyradiculopath 3) Sarcoidosis
Infections:
CMV, HSV, EBV, Lyme and TB
Name where cauda equina is likely to occur?
L5/S1- disc herniation
name the mechanism in which cuada equina occurs?
- L5/S1 centrel herniation of the nucleus pulpous
- Deformity of the thecal sac impinging on the cuada equina
Describe the lower limb dermatomes?
-More variable than the upper limb
Which dermatome covers knee jerk and ankle jerk?
Knee jerk- L4
Ankle jerk S1
Describe the causes of lumbosacral plexus lesions?
1) child Birth
2) STructural
3) Non-structural
Describe how childbirth is a cause of lumbosacral plexus lesion?
Child birth- prolonged labour and large head affecting the obtrutor nerve causing numbness in the inner thigh
Describe how structural issues cause lumbosacral plexus lesions?
- Haemotoma (on warfarin)
- Abscess
- Malignancy-infiltration
- Trauma
Describe how non-structural issues cause lumbosacral plexus lesions?
- Inflammatory
- Diabetes
- Vasculitis
- Radiotherapy
Describe the presentation if the femoral nerve damage is proximal?
Hip flexors and illipsoas are affected if the damage is proximal
Describe what would be affected if the damage is below the inguinal ring?
-Only knee extension affected if damage below the ligament
Describe what would be affected if the lesions is more distal?
Distal lesions may produce a pure motor or a pure sensory syndrome
Describe the nerve root entrapment in sciatica?
Nerve L5/S1 entrapped
What can be differential diagnosis where pain is in sciatic nerve distribution?
Hip pain- may radiate- NOT below the knee
Sacroilliac joints
What are the possible causes of sciatica type pain?
- Trauma
- Haemotoma
- Rarely sciatic nerve compression per se (pirifformis syndrome)
- Misplaced IM injection
Describe why the piriformis syndrome diagnosis may be conterversial?
- Conterversial as to whether muscle compression per se can cause tingling in the buttock and down leg
- E.G. after exercise or straining or prolonged sitting
- May rarely occur in those with anatomical predisposition
- No diagnosis criteria
