Neck Pain, Cervical Disc Herniation, & Cervical Radiculopathy
Cervical disc herniation occurs most frequently at the level of C6-C7. It also can occur at C5-C6. The patient will complain of neck pain due to nerve root irritation with pain radiating to the ipsilateral upper extremity. The patient may complain of numbness, paresthesia, and weakness. Coughing, sneezing, and neck movements make the pain worse. A careful examination of the patient is important. Each nerve involved will show its effect on the motor power, the sensation, and the reflexes.
A herniated disc at the C3-C4 bulge will affect the C4 nerve root and cause a sensory deficit around the shoulder area. Additionally, the diaphragm is largely supplied by the C4 nerve root, which could affect the respiratory system. A herniated disc at the C4-C5 bulge affects the C5 nerve root and can affect sensation around the shoulder area. The biceps reflex is primarily C5 and will affect the motor functions of the deltoid and in elbow flexion. A herniated disc at the C5-C6 bulge will affect the C6 nerve root. A herniated disc here will affect the sensation in the index finger and the thumb, the brachioradialis reflex, as well as C6 wrist extension and elbow flexion.
A herniated disc at the C6-C7 bulge affects the C7 nerve root, and will cause sensory issues at the middle finger. Motor functions of elbow extension (triceps) and wrist flexion and finger extension will be impaired. The brachioradialis (C6) and triceps (C7) reflexes will be additionally affected. A herniated disc at the C7-T1 bulge affects the C8 nerve root and will cause sensory issues of the medial two fingers and the medial part of the forearm. A bulge here will affect the motor functions of C8 finger flexion. A herniated disc at the T1-T2 bulge will affect the T1 nerve root, this will affect the motor functions of the T1 interossei muscles (abduction and adduction) — the patient will not be able to spread the fingers or bring them closer together.