This study was a large single-center, prospective, controlled study. It was carried out in the Second Affiliated Hospital of Nanchang University. From March 2019 to March 2022, 132 “unexplained” dizziness patients and 121 patients with explained dizziness were enrolled, additionally,132 healthy volunteers without dizziness were recruited as normal controls. All patients recruited for the study voluntarily and signed an informed consent form. The ethics committee of the Second Affiliated Hospital of Nanchang University approved our research protocol [approval number (2019) 009].
We did a series of examinations (such as Dix–Hallpike maneuver, pure tone audiometry, an orthostatic hypotension test, a videonystagmography, caloric test parameters, video head impulse-test results, or vestibular-evoked potential measure of otolith function, carotid ultrasound, transcranial Doppler sonography, brain magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), 24-hour dynamic electrocardiogram, echocardiography) on all patients with dizziness and detailed medical history inquiry, routine laboratory examinations, psychological/psychiatric evaluations, etc. After the burden of diagnosis and evaluation, the patient’s dizziness remains “unexplained”, which was considered for inclusion in the study. Also, the Valsalva maneuver is required, as it is the basis for determining whether RLS exists or not. Nevertheless, with a definite diagnosis of dizziness, including benign positional paroxysmal vertigo (BPPV), vestibular neuritis, vestibular migraine, Meniere’s disease, bilateral vestibular dysfunction, vestibular paroxysm, orthostatic hypotension, stroke, cerebellar ataxia, sudden deafness, cervical spondylosis, cardiogenic dizziness and combined tumor, endocrine, blood system, liver or kidney failure, patients with psychiatric disorder (such as suicide idea, addict, etc.) and other possible dizziness diseases have been excluded from our study, as well as pregnant woman and pulmonary arteriovenous malformation (PAVF), patent ductus arteriosus (PDA) also have been excluded.
We did a series of examinations (such as Dix–Hallpike maneuver, pure tone audiometry, an orthostatic hypotension test, a videonystagmography, caloric test parameters, video head impulse-test results, or vestibular-evoked potential measure of otolith function, carotid ultrasound, transcranial Doppler sonography, brain magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), 24-hour dynamic electrocardiogram, echocardiography) on all patients with dizziness and detailed medical history inquiry, routine laboratory examinations, psychological/psychiatric evaluations, etc. After the burden of diagnosis and evaluation, the patient’s dizziness remains “unexplained”, which was considered for inclusion in the study. Also, the Valsalva maneuver is required, as it is the basis for determining whether RLS exists or not. Nevertheless, with a definite diagnosis of dizziness, including benign positional paroxysmal vertigo (BPPV), vestibular neuritis, vestibular migraine, Meniere’s disease, bilateral vestibular dysfunction, vestibular paroxysm, orthostatic hypotension, stroke, cerebellar ataxia, sudden deafness, cervical spondylosis, cardiogenic dizziness and combined tumor, endocrine, blood system, liver or kidney failure, patients with psychiatric disorder (such as suicide idea, addict, etc.) and other possible dizziness diseases have been excluded from our study, as well as pregnant woman and pulmonary arteriovenous malformation (PAVF), patent ductus arteriosus (PDA) also have been excluded.
