BPPV may appear at any time from childhood to senility, but the idiopathic form is typically a disease of old age, peaking in the sixth to seventh decades. More than 90% of all cases are classified as degenerative or idiopathic, with preponderance in women. Sometimes it can be secondary to other causes such as post head injury or vestibular neuritis. BPPV also occurs strikingly often in cases of extensive bed rest in connection with other illnesses or after operations. About 10% of the spontaneous cases and 20% of the trauma cases show a bilateral, generally asymmetrically pronounced BPPV.
BPPV is elicited by extending the head or positioning the head or body toward the affected ear. Rotatory vertigo and nystagmus occur after such positioning with a short latency of seconds in the form of a crescendo/decrescendo course of maximally 30-60 seconds. The beating direction of the nystagmus depends on the direction of gaze; it is primarily rotating when gaze is to the undermost ear and mostly vertical to the forehead during gaze to the uppermost ear. The nystagmus corresponds to an excitation of the posterior canal of the undermost ear.
Heavy, inorganic particles or otoconia of specific weight, which become detached as a result of trauma or spontaneous degeneration from the utricular otoliths of the cupula. ...