Neuro-otologic symptoms such as dizziness, hearing loss, or tinnitus give rise to
peripheral change-induced neuroplasticity or central pathology-induced structural
or functional changes. In this regard, functional neuroimaging modalities such as
positron emission tomography (PET), functional magnetic resonance imaging
(fMRI), magnetoencephalography (MEG), quantitative electroencephalography
(qEEG), or functional near infrared spectroscopy have provided researchers with
possibility to observe neuro-otologic disease-induced central functional changes.
Among these methods, PET and fMRI are advantageous over qEEG or MEG
with regard to spatial resolution, while qEEG and MEG are advantageous over
PET or fMRI with regard to temporal resolution. Also, fMRI or MEG is not
suitable for patients with implanted devices, whereas PET is not ideal for
repetitive measures due to radiation hazard. In other words, as these modalities
are complementary to one another, researchers should choose optimum imaging
modality on a case by case basis. Hereinafter, representative functional neuroimaging
modalities and their application to neuro-otologic research will be
summarized.
The binding of anti-GD1b IgG antibody to the cerebellar granular area or spinocerebellar Ia fibers in the peripheral nerves may cause the prominent cerebellar ataxia, mild quadriparesis and sensory dominant neuropathy. A 31-year woman presented with severe cerebellar ataxia and prominent apogeotropic positional nystagmus/vertigo. Increased anti-GD1b antibody IgG in her serum was noted. 18F-flurodeoxyglucose positron emission tomography (FDG-PET) showed decreased uptake in cerebellum. It is the first case of central positional nystagmus with anti-GD1b IgG antibody.