Lateral semicircular canal benign paroxysmal positional vertigo and direction changing positional nystagmus, with the ultimate objective to know whether or not central nervous system lesions could be diagnosed based on these findings

Abstract

Lateral semicircular canal benign paroxysmal positional vertigo reveals atypically direction changing positional nystagmus (geotropic and apogeotropic). Furthermore, this condition used to be recognized as the clinical sign of posterior cranial fossa lesions, in particular, lesions of the brainstem and cerebellum. On the other hand, a good number of clinical reports indicate, nowadays, that such positional nystagmus is more likely to be caused by peripheral vestibular lesions and this has become widely well-known. For instance, geotropic direction changing positional nystagmus is caused by canalolithiasis and apogeotropic direction changing nystagmus is associated with cupulolithiasis. Some textbooks argue whether or not such positional nystagmus could represent central nervous system findings and signs, and this still remains controversial. We therefore tried to examine states of nystagmus based on a review of clinical papers and deliberate the clinical significance and diagnostic value of nystagmus. Base on the results of our literature research we were unable to determine whether or not nystagmus findings could suggest central nervous system lesions. We concluded that, notwithstanding direction changing positional nystagmus, the best approach would be to consider each situation again from the beginning, taking the patient's present history in greater detail and performing neurological and neuro-otological examinations on each patient, which could provide the most important information to doctors regarding dizzy patients.

Characteristics and utility of combined duplex color-coded ultrasonography in the cervical rotational position with head MRI and MRA in the differential diagnosis of apogeotropic direction-changing positional nystagmus

“…Because of the close relationship between the vestibulocochlear nerve and the oculomotor system in the lower cerebellum, such as in the cerebellar vermis, a detailed neuro-otological examination that includes electro-oculography (ENG) may detect abnormalities in visual eye movements, such as pursuit eye movements, optokinetic nystagmus and the visual suppression test ( Okada and Koizuka, 2015 ). In the present study, VOG results were used to determine the differential diagnosis of the differentiation of central and peripheral symptoms.…”

“… Okada and Koizuka (2015) stated that the diagnosis of apogeotropic DCPN requires a positional nystagmus test, positioning nystagmus test, follow-up observation, interview, recheck of neuro-otological findings, and imaging diagnosis. MRI and MRA of the brain are the most useful imaging modalities for detecting central lesions.…”