The vestibular system, which is the link between the inner ear and the brain, helps the body maintain its balance. When people experience vestibular symptoms, ie, symptoms of balance disorder, it can develop into persistent postural-perceptual dizziness (PPPD), a chronic disorder where patients experience dizziness and non-spinning vertigo, particularly during moving, maintaining an upright posture, and when exposed to complex visual stimuli. However, not all individuals suffering from vestibular symptoms go on to develop PPPD, and it is not clear if people showing exacerbating factors for PPPD tend to develop PPPD or not. 

Recently, a research team comprising Assistant Professor Kayoko Kabaya, Dr Masaki Kondo, Dr Shinichi Iwasaki, and other researchers from Nagoya City University, Japan, analyzed medical records of patients who were tested for vestibular symptoms for the first time to identify predictive factors for developing PPPD later on, and explore the possibility that patients showing exacerbating factors early on are more likely to develop chronic PPPD following the onset of vestibular symptoms. An article detailing the research appears on the University’s website.

“PPPD is often severe and resistant to treatment. We believe that it is important to provide preventive interventions before PPPD develops, and wanted to identify the characteristics of patients who are prone to PPPD,” said Kabaya, the lead author of the study.

This paper was published in the journal Laryngoscope Investigative Otolaryngology.

In their study, the severity of the symptoms experienced by the patients was evaluated using the Niigata PPPD Questionnaire (NPQ), which involved questions on the exacerbating factors (upright posture, movement, and visual stimulation). Additionally, the perception of handicap due to dizziness was evaluated using a self-assessment scale called “The Dizziness Handicap Inventory.” The patients were then followed up for more than 3 months, and the NPQ scores of patients developing PPPD during the follow-up were compared with that of patients who did not develop PPPD. 

The box plots show that there was a clear difference between the NPQ and DHI scores of patients who developed PPPD and those who did not PPPD during the follow-up period, as measured by the researchers.

More than half of the patients reported experiencing exacerbating factors shortly after the vestibular symptoms, worsening their symptoms. About 10% of these patients developed PPPD during the follow-up period, and the exacerbating factors were found to have a more severe effect on the vestibular symptoms in these patients. Notably, the NPQ scores of those who developed PPPD were significantly higher than that of those who did not. 

“Our results suggest that patients who develop PPPD are likely to have its exacerbating factors at the early stages of the disease following the onset of vestibular symptoms,” said Kabaya. 

With these findings, the researchers are optimistic that their study could help establish preventive measures against the disease.

“PPPD is a disease that causes long-term social loss and occurs following acute vestibular symptoms. Based on our finding that patients with exacerbating factors during acute vestibular symptom are more likely to develop PPPD, our study could encourage the development of intervention protocols for such patients before they develop PPPD,” said Kabaya. 

Original Paper: Kabaya K, Tamai H, Okajima A, et al. Presence of exacerbating factors of persistent perceptual-postural dizziness in patients with vestibular symptoms at initial presentation. Laryngoscope Investigative Otolaryngology. 2022;1-7.

Source: Nagoya City University, Laryngoscope Investigative Otolaryngology

Image: Nagoya City University, Laryngoscope Investigative Otolaryngology