EMG, MRI, Arteriogram
Pain is another clinical sign to take into account. Quite constantly root avulsions are associated to severe pain, mainly referred to the hand since the lower roots are mostly avulsed.
This pain is therefore an indirect sign of root avulsion and, since it may frequently reach unbearable levels for the patient, it needs to be treated as early as possible in specialized pain clinics.
X ray are useful to detect sequelae of skeletal injuries that can interfere with plexus repair (callus on the clavicle) or to suggest a double level lesions
(fracture of the scapula for suprascapular nerve, head of the humerus for axillary nerve and diaphysis of the humerus for radial nerve).
Fracture of transvers processes of the spine is normally associated to very proximal root lesions. A radiological study of diaphragm function is mandatory to
detect possible lesions of phrenic nerve that can be associated with avulsion of C5 root.
The huge improvement in imaging given by 3D MRI allowed in the last years to detect with a high level of precision root avulsions. MyeloTAC still gives a good support in diagnosing preganglionic lesions.
Electrophysiological studies may give an important support in the diagnosis of the level of lesions but unfortunately even the evoked potential studies cannot precisely detect a preganglionic lesion that
is the crucial point in brachial plexus lesions. Anyway EMG may be useful in the first months after injuries to eventually detect possible spontaneous recovery.
In presence of vascular lesions with lack of radial pulse it is important to study the vascularization of the arm through Doppler exam. or arteriograms mainly to know
the exact definition of the collateral vessel formation; this will be of paramount importance during the surgical dissection of the plexus in order to avoid reducing the vascular support to the arm.
MRI can nowaday precisely detect not only the root avulsion (C8 and T1 in this case) but even mild irreguarity of the roots
(C7 in this case) giving useful information about the quality of the root stumps.