Emergency Medicine

NECK INJURIES

226 Surgical Emergencies

(a) use reinforcement (Jendrassik’s manoeuvre) before

concluding that a reflex is absent, e.g. ask the patient to

clench the teeth hard or hold the knees together when testing

a reflex.

5 Describe sensory deficit by dermatomes:

(i) Assess sensation by testing pain fibres using pinprick

(spinothalamic tracts), and examine fine touch or joint position

sense (posterior columns).

(ii) Dermatomes C5–T1 supply the upper limb (see Table 8.6).

(iii) Dermatomes C4 and T2 are adjacent on the front of the chest at

the level of the first and second ribs.

6 The myotomes, ref lexes and dermatomes in the leg are described on p. 331.

7 Cervical spine imaging:

(i) Lateral cervical spine X-ray:

(a) make sure an adequate view is obtained and that all seven

cervical vertebrae and the C7/T1 junction are visualized. A

swimmer’s view may be required

(b) look for appropriate alignment of the cervical spine

longitudinal lines. Anterior displacement of >3 mm implies

ligament disruption and cervical spine instability (see Fig.

8.1)

(c) observe the bony vertebrae for signs of fractures such as

wedge and teardrop. Examine the soft-tissue shadows in front

of the vertebral bodies (see Fig. 8.1):

• the retropharyngeal space should be <5 mm between C1
  and C4/C5

Table 8.5 Reflexes in the upper limb

Reflex Root

Biceps C5, (C6)

Supinator (C5), C6

Triceps (C6), C7, C8

Table 8.6 Dermatomes supplying the upper limb

Root Dermatomal distribution

C5 Outer upper arm

C6 Outer forearm

C7 Middle finger

C8 Inner forearm

T1 Inner upper arm