Characteristics
Identifying muscles are those muscles that are only supplied by a corresponding nerve root. In the event of a failure of an identifying muscle, it is therefore possible to determine exactly which nerve root must be constricted. One can therefore determine the exact height of the herniated disc.
Between the cervical vertebrae C5/C6, the nerve root C6 emerges from the cervical spine, which can then be compressed in case of a herniated disc. The characteristic muscles for the nerve root C6 are, on the one hand, the brachioradialis muscle, which is responsible for weak flexion in the elbow joint and inward and outward rotation of the forearm (pronation and supination). And on the other hand the M. biceps brachii, which also causes flexion in the forearm and is also considered the strongest muscle in the outward rotation of the forearm (supination). Associated reflexes are the radial periosteal reflex and the biceps tendon reflex, which can then also be weakened or even impossible to trigger.
Diagnosis
First of all, a precise clinical-neurological examination including strength test, testing of the reflexes and exact determination of existing paralysis and numbness. If the examination confirms the suspicion of a slipped disc, a computer tomography (CT) or a magnetic resonance tomography (MRT) can be performed for further diagnosis. MRI is usually preferred, since soft tissue and the intervertebral disc can be better visualized.
On the other hand, CT allows a better assessment of bones and bony attachments. However, an imaging examination is not always necessary. For a conservative therapy approach, which is preferably chosen before surgery, no imaging is necessary. Imaging is only obligatory in the case of persistent symptoms, neurological disorders or surgery.