234 injury (1987) 18,234 ~fifl~e~i~ Great &&in

Hyperaesthesia associated of the neck

with hyperextension injuries

M. Reich1 and M. J. Allen

Leicester Royal infirmary

INTRODUCTION HYPEREXTENSION injuries commonly occur as part of so-called ‘whiplash’ injuries in road traffic accidents. They may also occur in sport when the face strikes an object or another player and the head is pushed back- wards. This type of injury causes various degrees of soft-tissue, bony and occasionally neurological damage. The symptoms are pain in the neck, often radiating to both arms and occasionally to the interscapular region of the chest. Such pain is usually accompanied by marked spasm of cervical muscles. Occasionally there are transitory abnormalities of reflexes and sensation in one or both upper extremities. Some reports describe reduction in sensation (Gay and Abbot, 1953; McNeal, 1971).

Recently two patients were seen with severe hyper- aesthesia in the arms following hyperextension injuries of the neck sustained at sport. As far as the authors are aware this symptom has not been described previously.

CASE REPORTS Case 1 An l&year-old male presented to the A&E Department shortly after a horse-riding accident in which he sustained a hyperextension injury to the neck as a result of his forehead striking a low branch while riding at speed. After a period of unconsciousness he complained of neck pain accompanied by severe bilateral hyperaesthesia in the C4 to Tl dermatomes. This was such that light contact with his skin was painful. Movement in his arms was normal but power could not be fully tested as he found any touch painful. However, he was able to lift his arms against gravity.

Radiographs of the skull and cervical spine were normal. After observation overnight his symptoms had settled and he was discharged home. He has had no further symptoms due to this injury.

Case 2 A 23-year-old man who plays for one of this country’s pre- mier American football teams collided with an opponent, forcefully hyperextending his heck. He immediately fell to the ground and complained of pain in his neck and arms. He was brought to the A&E Department wearing a protective collar.

Examination found him to be fully conscious with no clinical abnormality of the cervical spine. He complained of bilateral hyperaesthesia in the C4 to T2 dermatomes so severe that even fight touch with cotton wool was excruciatingly painful. Initially he was unable to move his arms. Objective

testing proved impossible. The rest of his neurological ex- amination was completely normal. The radiographs of the cervical spine were unremarkable.

Over the next 3 hours the hyperaesthesia eased consider- ably, especially on the left side. He was able to move his arms against gravity. Although he found it too painful to put on his shirt he insisted on taking his own discharge.

On review 3 days later he had no pain in his neck and the hyperaesthesia on the left had practically gone. However, the right arm was still hyperaesthetic and there was a definite decrease of power (grade 3 to 4) in this limb. His symptoms did not cease for a further 10 days. He has now returned to playing for his team and has had no residual trouble.

DlSCUSSlON Two cases are described in which hyperextension of the neck was followed by hyperaesthesia. This correlation has not been reported previously in the literature.

It is difficult to explain the reasons for such symp- toms and signs. McNeal (1971) points out that in pa- tients following a hyperextension jerk, pain radiating down the arms does not necessarily indicate nerve root pressure, but may be referred pain due to ligamentous injury.

However, Braaf and Rosner (1958) claim that the referred symptoms are mechanical and result from compression or irritation of cervical nerve roots. They feel that the irritation of cervical nerve roots leads to a reflex mechanism acting through the sympathetic ner- vous system whereby any cervical nerves are stimu- lated, producing mainly sensory symptoms. However, the exact anatomical and physiological pathways are unknown. It is poSsible that such a mechanism caused the symptoms in our patients.

REFERENCES Braaf M. M. and Rosner S (1958) Whiplash injury of the

neck. Symptoms, diagnosis, treatment and progress. NY State J. Med. 58, 1501.

Gay J. R. and Abbott K. H. (1953) Common whiplash injuries of the neck. J. Am. Med. Assoc. 152, 1698.

McNeai I. (1971) The whiplash syndrome. Or&p. C&n. North Am. 2, 389-403.

Paper accepted 25 September 1986.

Requests for reprints should be addressed to: Mr M. J. Allen, FRCS, Consultant in Accident and Emergency, The kicester Royal infirmary, Leicester LEl 5WW.