Mononeuropathies Flashcards
What is the normal function of the radial nerve?
Motor: 3
Sensory: 1
Motor:
- Wrist extension
- Finger extension
- Brachioradialis
Sensory:
-Radial half of dorsum
What can cause radial nerve mononeuropathy? (3)
Entrapment in spiral groove (humerus)
Trauma
Saturday night palsy
Describe the clinical features of radial nerve palsy. (7)
Wrist drop
Finger drop
NO pain
Weakness in:
- Wrist extension
- Finger extension
- Elbow flexion in mid-pronation
Sensory change in:
-Radial half of dorsum
What is the normal function of the ulnar nerve?
Motor: 3
Sensory: 2
MOTOR: Wrist flexion Intrinsic hand muscles, e.g. -Finger abduction -Thumb adduction
SENSORY:
Ulnar side:
-1.5 fingers on palm
-2.5 fingers on dorsum
What can cause ulnar nerve mononeuropathy?
Entrapment in ulnar groove (by medial epicondyle)
Elbow trauma
Describe the clinical features of ulnar nerve mononeuropathy. (7)
History of elbow trauma
Weak grip
Motor weakness in:
- Index finger abduction
- Little finger abduction
- Wrist flexion
- Thumb adduction
Sensory change in:
-Ulnar side (1.5 fingers on palm, 2.5 fingers on dorsum)
Describe the normal function of the median nerve.
Motor: 4
Sensory: 2
MOTOR: LOAF muscles: -Flexion at MCPs -Thumb opposition -Thumb abduction -Thumb flexion
SENSORY:
Radial side:
-3.5 fingers on palm
-Fingertips 2 and 3 on dorsum
What can cause a median nerve mononeuropathy? (2)
Carpal tunnel syndrome (entrapment in carpal tunnel)
Trauma
Describe the clinical features of a median nerve mononeuropathy. (6)
Intermittent night pain
Numbness and tingling
Symptoms relieved by shaking hand
Weak grip
Positive tests:
- Tinel’s sign
- Phalen’s test
What is Tinel’s sign?
What does it indicate?
Tingling in the median nerve distribution elicited by tapping over the median nerve
Median nerve palsy
What is Phalen’s test?
What is a positive result?
What does it indicate?
Forced wrist flexion: press dorsal sides of hands together for 30-60 seconds
Positive: tingling in the median nerve distribution; indicates median nerve palsy
What is the normal function of the anterior interosseos nerve?
Motor: 2
Sensory: 1
MOTOR:
Flexion at MCP joints
Thumb flexion
SENSORY:
None
What can cause an anterior interosseous nerve palsy?
Forearm trauma
Describe the clinical features of an anterior interosseous nerve palsy. (5)
Pain
Weak grip of keys
NO sensory change
Positive tests:
- Tinel’s sign
- Phalen’s test
What is the normal function of the femoral nerve?
Motor: 3
Sensory: 1
MOTOR:
Quadriceps (knee extension)
Iliopsoas (hip flexion)
Adductor magnus (hip adduction)
SENSORY:
Lateral side of shin
What can cause a femoral nerve mononeuropathy? (2)
Trauma
Haemorrhage
Describe the clinical features of a femoral nerve mononeuropathy. (4)
Motor weakness in:
- Knee extension
- Hip flexion
- Hip adduction
Sensory change in:
-Lateral side of shin
What is the normal function of the common peroneal nerve?
Motor: 2
Sensory: 1
MOTOR: Tibialis anterior (ankle dorsiflexion) Extensor hallucis longus (big toe extension)
SENSORY:
Lateral shin around the knee
What can cause a common peroneal nerve mononeuropathy? (3)
Entrapment (fibular head)
Knee trauma
Knee surgery
Describe the clinical features of a common peroneal nerve mononeuropathy.
History of:
- Trauma
- Surgery
- External compression
Acute onset
Foot drop
Sensory disturbance
NO pain
Weakness in:
- Foot dorsiflexion
- Great toe extension
How do you differentiate between a common peronoeal nerve mononeuropathy and an L5 palsy? (2)
Both have weakness in foot dorsiflexion, BUT L5 ALSO HAS:
- Weakness in foot inversion
- Sensory change in medial shin
Define mononeuritis multiplex.
Simultaneous or sequential development of neuropathies in 2 or more nerves
List 6 causes of mononeuritis multiplex.
Diabetes mellitus Vasculitis Rheumatoid disease Infections (e.g. hep C, HIV) Sarcoidosis Lymphoma
What are the 3 important nerves in the thigh, arising from the lumbar plexus?
What are their spinal nerve roots?
Femoral nerve (L2, 3, 4) Obturator nerve (L2, 3, 4) Lumbosacral trunk (L4, 5)
