Differences in the Head Roll Test, Bow and Lean Test, and Null Plane between Persistent and Transient Geotropic...

Area of Science:

• Neurology
• Ophthalmology
• Vestibular System

Background:

• Persistent geotropic direction-changing positional nystagmus (DCPN) shares characteristics with cupulopathy, but its cause remains unclear.
• Understanding the pathogenesis of persistent DCPN is crucial for accurate diagnosis and treatment.

Purpose of the Study:

• To investigate the relationship between head roll test, bow and lean test results, and the null plane side in persistent and transient geotropic DCPN.
• To determine the lesion side and understand the mechanism of persistent geotropic DCPN.

Main Methods:

• Comparison of head roll test, bow and lean test, and null plane side results between 25 patients with persistent geotropic DCPN and 41 with transient geotropic DCPN.
• Analysis of nystagmus characteristics in different head positions.

Main Results:

• Bowing and leaning nystagmus were significantly more frequent in the persistent DCPN group.
• Fewer persistent DCPN patients (16.0%) showed stronger nystagmus on the same side for both head roll test and null plane.
• Direction of bowing nystagmus and stronger head roll test nystagmus on the same side were less common in persistent DCPN.

Conclusions:

• Determining the lesion side in persistent geotropic DCPN is difficult when nystagmus and null plane directions are opposite.
• Further research is required to elucidate cupular position relative to head rotation and anatomical positioning in persistent DCPN.