Neck torsion may lead to greater postural deficits in individuals with persistent traumatic neck pain due to abnormal cervical afferent input. The Smooth pursuit neck torsion test abbreviated as SPNT helps to determine the presence of disturbances in eye movement and postural stability. It is thought to test proprioceptive function, particularly for controlling static and dynamic head and neck positions.
Tjell et al. (1998) found a sensitivity of 90% and a specificity of 91% in a group of traumatic neck pain patients with dizziness compared to a mixed group of patients with vertigo, central nervous system findings, Meniere’s disease, and healthy subjects. Although it seems to have high accuracy to diagnose cervicogenic dizziness, it is the only study evaluating this test so far. For this reason, we give it a moderate clinical value in practice.
To conduct the SPNT the patient is in a sitting position on a moving stool. The patient’s head is kept in a horizontal position and the head rotation is introduced to a maximum of 45° by turning the patient’s chair. The therapist instructs the patient to trace a slowly moving target with his eyes in right or left horizontal direction while the patient’s head is kept steady. This test is done in neutral torso position, torso turned to the right, and torso turned to the left side. This test is positive in the clinical setting in case dizziness is reproduced in the torsion position compared to neutral. Be aware that in a laboratory setting, the outcome measure is the velocity of the corrective saccades which can only be done with special instruments.
Next to the Smooth Pursuit Neck Torsion Test, your dizziness exam should include the following assessments: