aetiology
Last reviewed 01/2018
Spinal cord lesions at T1 level:
- syringomyelia
- compression of T1 segment due to cervical spondylosis, neurofibroma
- tumour
- motor neurone disease
Root lesions eg T1 compression by a disc lesion
Brachial plexus lesions:
- trauma, irradiation, infiltration
- thoracic outlet obstruction
- Klumpke's paralysis
Peripheral nerve lesions:
- median lesions, ulnar nerve lesions
- peripheral motor neuropathy
Myopathy:
- distal myopathy
- myotonic dystrophy (forearms are more often affected than the hands)
Trophic disorders:
- disuse eg arthritis
- ischaemia eg vasculitis
- shoulder-hand syndrome
Note that in discriminating an ulnar nerve lesion from a T1 root lesion remember that in a T1 root lesion there is no sensory loss that affects the hand.