| Craig GR and Nielsen MS, 1991, UK | 2 patients with severe head injury | Observational | ICU with and without cervical collar | Significant rise in ICP in both cases | Only two patients used in study |
| Raphael JH and Chotai R, 1994, UK | 9 patients scheduled for elective spinal anaesthesia | Randomised cross over study | CSF pressure | Significant rise in CSF pressure with cervical collar p=0.01 | Small numbers Measurements made in lateral decubitus position |
| Davies G et al, 1996, UK | 19 patients with severe head injury | Observational | Rise in intracranial pressure | Significant rise in ICP with cervical collar. Mean −4.5 mm Hg p=0.001 | Small numbers Excluded patient with ICP >30 mm Hg |
| Kolb JC et al, 1999, USA | 20 adult patients undergoing lumbar puncture | Observational | CSF pressure in lumbar subarachnoid space | Significant rise in CSF pressure with cervical collar. Mean −24.7 mm Hg p=0.001 | Patients tested in lateral decubitus position Small numbers |