Canalolithiasis and cupulolithiasis have been proposed to be causative mechanisms of BPPV. Anatomical and physiological features of otoconia are reviewed. Three layers, the columnar fibers, gelatin membrane, and otolithic membrane, are known as overlaying structures on the macular sensory epithelia. The supporting cell plays an essential role in otoconial formation. It secretes granules containing calcium as a precursor of otoconia. A number of proteins are involved in the production and growth of otoconia, such as Otoconin-90 and CB-D28K. Alterations of the endolymphatic environment, ototoxic drugs, carbonic anhydrase, hormones, aging, or gene mutation lead to degeneration or deformity of otoconia. Hydrodynamic and physiological features of otoconia existing within the semicircular canal or attaching to the cupula have been studied using mathematical models and amphibian semicircular canals. These studies showed that canalolithiasis is potentially the most relevant mechanism of BPPV in terms of the long latency and short duration of nystagmus. Human temporal bone sections had been studied to demonstrate deposits on the cupula or within the canal lumen. Otoconia were also found in the posterior canal lumen that was opened during canal plugging surgery. Clarification of the basic characters of otoconia is essential for elucidating the clinical picture of BPPV.
Primary position upbeat nystagmus (PPUN) is an important indication of central nervous system disorder. We herein report a case of PPUN accompanied with multiple sclerosis. The case was a 32-year-old female. Nausea, vomiting, and numbness of the upper limbs developed on January 14, 2004. Upbeat nystagmus was observed in the primary and supine positions. She was hospitalized on January 27, because abnormal signals in the medulla oblongata and tegmentum mesencephali were noted on brain MRI imaging. After steroid pulse treatment was started, her neurological symptoms and PPUN disappeared. She was discharged from hospital on February 13.
We experienced a case of Ménière's disease; the patient complained of attacks of hearing loss and vertigo that occurred depending on weather changes. However, a relationship between the disease and weather factors has not been previously reported. We report a case of delayed endolymphatic hydrops that was affected by the weather; we observed vestibular and cochlear symptoms during the clinical course. We recorded the relationship between weather factors (temperature, atmospheric pressure, and humidity) and vestibulocochlear symptoms in the patient for 2.5 years beginning from January, 2002. A significant relationship was observed between the atmospheric pressure data and the vestibulocochlear symptoms; this was greater than that for other factors such as temperature and humidity. The atmospheric pressure showed a high value when the patient experienced vestibular symptoms and a low value with cochlear symptoms. The vestibulocochlear symptoms were aggravated when the pressure changed by more than 10 hPa (increase or decrease) for several days. Based on the results of this study, a change in atmospheric pressure is considered to cause vestibulocochlear symptoms accompanied by an increase in endolymphatic hydrops. This change in endolymphatic hydrops is thought to be caused by a low atmospheric pressure in the middle ear and a corresponding high atmospheric pressure in the inner ear. It is difficult to accept that vertiginous disease is caused only by weather factors. The present case indicates a possibility for the prediction of vertiginous attacks by focusing on changes in atmospheric pressure.
We treated 44 cases of vestibular Ménière's disease with prostaglandin I2 (PGI2), a vasodialator, at a dose of 120μg per day for more than two months (mean: 8.0 months). The long-term administration of constant daily amounts of PGI2 attained good long-term results in vertigo according to the criteria of the Japan Society for Equilibrium Research. The results were as follows: the administration of PGI2 completely controlled vertigo in 65.9% (29/44) and improved it in 29.5% (13/44); however, four cases suffered from the typical type of Meniere's disease thereafter (9.1%: 4/44). The objective findings of nystagmus were also reduced in 85.7% (24/28) after PGI2 treatments. PGI2 was significantly more effective in patients with a vertigo duration within 120 min and -SP/AP negative results on electro-cochleogram (ECoG) than the others. On the contrary, patients with a vertigo duration of more than 120 min and -SP/AP positive results on ECoG experienced cochlear symptoms together with vertiginous sensations later. These patients should be treated with an oral osmotic diuretic, isosorbide. These findings suggest that cases presently diagnosed as vestibular Ménière's disease could include at least two kinds of oto-pathologies; vascular disease and endolymphatic hydrops.
Benign paroxymal positional vertigo (BPPV) so-called canalolithiasis and cupulolithiasis, usually occurs after head trauma or viral vestibular neuritis. The first aim of this study was to investigate the difference in bone mineral density measurement between BPPV and patients with other peripheral vestibular disorders, and the second aim was to study a possible relationship between BPPV and osteoporosis. This study included forty patients, consisting of 16 women and 24 men. Sixteen patients comprised 10 pre-menopausal women whose median age was 37.4±7.4 and 6 post-menopausal women whose median age was 52.2±1.9. Twenty-four patients consisted of 9 middle aged men whose median age was 41.6±11.2 and 15 older men whose median age was 73.7±7. The diagnosis of osteoporosis was confirmed by bone mineral density measurement via dual x-ray absorptiometry of the radius bone. BPPV was compared with other peripheral vestibular disorders using bone mineral density measurement. Our results showed the level of calcium in female BPPV patients was not significantly lower than that in age-matched with other peripheral disorders patients. However, the level of calcium in male BPPV patients was significantly lower than that in age-matched male patients with other peripheral disorders (p<0.01). These data show that bone mineral density measurement in vertigo men patients is useful not only to predict the stage of osteoporosis but also to prevent BPPV.