Autonomic Dysfunction in Patients with Vertigo

1 153 JMAJ, April 2006 Vol. 49, No. 4*1 Department of Otolaryngology, University of Tokushima School of Medicine, TokushimaCorrespondence to: Noriaki Takeda MD, PhD, Department of Otolaryngology, University of Tokushima School of Medicine, 3-18-15 Kuramoto,Tokushima-shi, Tokushima 770-8503, Japan. Tel: 81-88-633-7169, Fax: 81-88-633-7170, e-mail: ArticleAutonomic Dysfunction in Patients with VertigoJMAJ 49(4): 153 157, 2006 Noriaki Takeda*1 AbstractAutonomic function and vertebral blood flow were measured in Patients with Vertigo .

2 Based on our findingsobtained in a series of studies, we propose the following hypothesis of sympatho-vascular mechanisms of of the sympathetic nervous system to stress observed in Patients with Vertigo induces asym-metrical blood flow of the vertebral artery. Asymmetrical activity of the sympathetic nervous system observed inpatients with Vertigo also induces asymmetrical blood flow of the vertebral artery. The asymmetrical vertebralblood flow induces asymmetrical activities of the inner ear and/or the vestibular nuclei, resulting in the develop-ment of wordsVertigo, Sympathetic nervous system, Parasympathetic nervous system, Vertebral artery, Stressand a high frequency (P3).

3 Each component wasnormalized by dividing the absolute values oftotal power (T). P2 and P3 were used as an indexof sympathetic and parasympathetic nervousfunctions, respectively. In Patients with vertigoat rest, the normalized power of P2 slightly in-creased and the normalized power of P3 signifi-cantly decreased, in comparison with healthysubjects at rest (Fig. 1). These findings indicatedthat the parasympathetic nervous activity at restwas suppressed in Patients with Vertigo . Yamadaet al.

4 Used power spectral analysis of heart ratevariability and reported that parasympathetichypofunction in Patients with Meniere s , the effects of passive tilt up on the auto-nomic nervous activity were examined in patientswith Vertigo . In healthy subjects, the normalizedpower of P2 increased and the normalized powerof P3 decreased with passive tilt up. These find-ings indicated that the sympathetic nervous ac-tivity was stimulated and the parasympatheticnervous activity was suppressed in response topassive tilt up.

5 On the contrary, in spite of adecrease of the normalized power of P3, passivetilt up did not increase the normalized power ofP2 in Patients with Vertigo (Fig. 2). These find-IntroductionAutonomic Dysfunction has been proposed tobe an underlying mechanism of the developmentof Vertigo , although there is little ,2In the present review, a series of our studies onautonomic nervous activity and the vertebralblood flow in Patients with Vertigo is summarizedand how the Autonomic Dysfunction triggers theonset of Vertigo is Autonomic Dysfunction inPatients with VertigoSystemic Autonomic nervous function was exam-ined in Patients with Vertigo including Meniere spatients by means of power spectral analysis ofheart rate The power spectral density(PSD)

6 Of beat-to-beat heart rate intervals wasanalyzed using a continuous non-invasive fingerblood pressure recording system. A fast-Fouriertransform algorithm was used to compute thePSD. In frequencies up to 5 Hz, the PSD of heartrate variability contains three major components:a low frequency (P1), a middle frequency (P2)154 JMAJ, April 2006 Vol. 49, No. 4 Takeda Ntached to the palm of both hands. Both handswere immersed in iced water for 30 sec. Sub-sequently, palm skin temperature of both handswas recorded at 1 min intervals.

7 Figs. 3 and 4 rep-resent the thermal recordings of both hands in ahealthy subject and a Meniere s patient, respec-tively. There is no difference in the recovery ofpalm skin temperature between right and lefthands of the healthy subject (Fig. 3). However,asymmetrical recovery of palm skin temperaturewas observed in Patients with Meniere s diseaseduring an active spell. After immersion in icedwater, the patient showed an abnormal slowrecovery time in the side affected by Meniere sdisease.

8 Then, the asymmetrical recovery of palmskin temperature disappeared in the intervalbetween active spells in the same patient (Fig. 4).During active spells, a significantly high propor-tion of Meniere s Patients had an anisothermalrecovery of palm skin temperature after immer-sion in iced water, in comparison with that ofhealthy subjects. However, during intervals be-tween active spells, the frequency of aniso-thermal recovery of palm skin temperature inMeniere s Patients did not differ from that ofhealthy subjects (Table 1).

9 Since the palm skintemperature is regulated by anastomotic skinblood flow, and its blood flow through arterio-venous anastomoses is controlled by efferentsympathetic nerve fibers,8 these findings indi-Fig. 1 Normalized power of P2 as an index of sympa-thetic activity (a) and normalized power of P3as an index of parasympathetic activity (b) inhealth subjects (H), Patients with Vertigo (V) andpatients with Meniere s disease (M) at restPoints are means SD. *P 2 Normalized power of P2 as an index of sympa-thetic activity (a) and normalized power of P3as an index of parasympathetic activity (b) inhealth subjects (H), Patients with Vertigo (V) andpatients with Meniere s disease (M) in responseto passive tilt upPoints are means SD.

10 S: supine, U; upright. *P ,**P * **0 HVMUUUSSS(b) (a)**ings indicated that response of the sympatheticnervous system to passive tilt up was et al. also reported that sympatheticresponse to postural changes was suppressed inpatients with Meniere s has been speculated that both mental andphysical stress played an important role in theonset of On the other hand, because ofneurotic personality in Patients with Vertigo , ver-tigo itself can be a Therefore, it is sug-gested that a reciprocal causal relationship be-tween Vertigo and stress induced the suppressionof the parasympathetic nervous activity and therepeated stimulation of the sympathetic nervousactivity.