Functional brain activation studies described the presence of separate cortical areas responsible for central processing of
peripheral vestibular information and reported their activation and interactions with other sensory modalities and the
changes of this network associated to strategic peripheral or central vestibular lesions. It is already known that cortical
changes induced by acute unilateral vestibular failure (UVF) are various and undergo variations over time, revealing different
cortical involved areas at the onset and recovery from symptoms. The present study aimed at reporting the earliest change
in cortical metabolic activity during a paradigmatic form of UVF such as vestibular neuritis (VN), that is, a purely peripheral
lesion of the vestibular system, that offers the opportunity to study the cortical response to altered vestibular processing.
This research reports [18F]fluorodeoxyglucose positron emission tomography brain scan data concerning the early cortical
metabolic activity associated to symptoms onset in a group of eight patients suffering from VN. VN patients' cortical
metabolic activity during the first two days from symptoms onset was compared to that recorded one month later and to
a control healthy group. Beside the known cortical response in the sensorimotor network associated to vestibular
deafferentation, we show for the first time the involvement of Entorhinal (BAs 28, 34) and Temporal (BA 38) cortices in early
phases of symptomatology onset. We interpret these findings as the cortical counterparts of the attempt to reorient oneself
in space counteracting the vertigo symptom (Bas 28, 34) and of the emotional response to the new pathologic condition
(BA 38) respectively. These interpretations were further supported by changes in patients' subjective ratings in balance,
anxiety, and depersonalization/derealization scores when tested at illness onset and one month later. The present findings
contribute in expanding knowledge about early, fast-changing, and complex cortical responses to pathological vestibular
unbalanced processing.
