Abstract Details

Title Habituation Deficit of the Nociceptive R2 Blink Reflex: Functional Changes in Patients with Phobic Postural Vertigo (PPV)

Topic Neuro-ophthalmology/Neuro-otology

Presentation(s) P06 - (-)

Poster/Presentation
Number 006

Objective

Background BACKGROUND: Habituation deficit is generally considered to reflect cortical overexcitability or central sensitization and was described in several chronic pain conditions such as migraine or tension-type headache. Phobic postural vertigo (PPV) is often followed by organic vertigo disease such as vestibular neuritis, vestibular migraine, Menieres disease and it was hypothesized that hypersensitivity to movement perception is one important mechanism leading to PPV. Insufficient blink reflex habituation in PPV patients would confirm cortical overexcitability and may hint at central sensitization as one pathophysiological mechanism for the development of this disease.

Design/Methods DESIGN/METHODS: We investigated 60 patients with PPV and compared them to age- and sex-matched healthy volunteers. The habituation pattern was examined using the nociceptive blink reflex (nBR). The R2 response of the nBR was analyzed by specific stimulation of A?- fibers in the area of V1 on both sides of the forehead using a block design (10 blocks each 6 pain stimuli; block distance 2 minutes each). The R2 response was examined in each case depending on the first block and the habituation was defined as a decrease in R2 response of the sequence blocks compared to block 1.

Results RESULTS: Patients with PPV reported a decreased subjective pain threshold. The preliminary analysis of the nBR showed a lack of habituation in patients with PPV compared with 20 healthy controls in terms of a decreased the area under the curve (AUC). We could not identify differences in regard to latency.

Conclusions CONCLUSIONS: Our analysis indicates habituation deficits in patients with PPV, which could explain part of the pathophysiological mechanisms associated with this disease and demonstrates biological changes in this predominantly considered somatoform disorder.

Authors/Disclosures
Mark Obermann, MD, FAAN (Department of Neurology, Klinikum Weser-Egge) PRESENTER	No disclosure on file
Steffen Naegel, MD (Alfried Krupp Krankenhaus)	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Zaza Katsarava, MD	Zaza Katsarava, MD has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Allergan. Zaza Katsarava, MD has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Lilly. Zaza Katsarava, MD has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Zaza Katsarava, MD has received personal compensation in the range of $500-$4,999 for serving as a Consultant for TEVA. Zaza Katsarava, MD has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Lilly. Zaza Katsarava, MD has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Teva. Zaza Katsarava, MD has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Novartis.
Dagny N. Holle, MD	Dr. Holle has nothing to disclose.
	No disclosure on file

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