- Objectives To examine whether shaking the head during the DH exam (HSDH) may improve diagnosis of posterior semicircular canal benign paroxysmal positional vertigo (pBPPV) in patients with a negative Dix-Hallpike (DH) examination. Study Design A prospective cohort clinical study on consecutive patients with dizziness, who were seen by 2 experienced neurotologists. Patients underwent a complete neurotology examination, including positioning testing with roll test and DH. Patients with a negative DH underwent a HSDH. Patients with a positive DH (Group 1) or only with a positive HSDH (Group 2) underwent a particle reposition maneuver (PRM), which was a modification of the Epley maneuver. Variables including sex, age, the duration of symptoms until diagnosis, and the number of visits required until cure were examined in each group. Setting A tertiary dizziness clinic and in 2 private clinics. Subjects and Methods All patients diagnosed with pBPPV. Main Outcome Measures DH test after head shaking and comparison of variables between the 2 study groups. Results Sixty nine patients were diagnosed with pBPPV (Group 1). Twelve additional patients were negative on DH but were found positive on HSDH (Group 2), improving the diagnostic yield by 14.8%. There was no statistical relation between the 2 groups and the variables examined; however, there was a trend for longer duration of symptoms (44.3 versus 64 d) and less visits until cure (1.5 versus 1.7 visits) in Group 2. Conclusion Patients with a negative DH should undergo a HSDH. Patients only diagnosed as pBPPV by a positive HSDH may represent a subgroup with a milder form of disease.