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Hypotension associated with autonomic dysfunction: A possible cause of vertigo?
1086
Correspondence
Hypotension associated with autonomic dysfunction: a possible cause of vertigo? Dear Editor, A possible role of hypotension associated with an autonomic dysfunction in the genesis of some cases of sensorineural hearing loss has been hypothesised [1] and to some extent demonstrated by our group [2,3] in the recent years. The occurrence of a sudden sensorineural impairment of ‘‘idiopathic’’ nature in young subjects free from vascular risk factors could find on this basis a reliable explanation: a brusque decrease of blood pressure (BP) could elicit an abnormal reaction in a terminal vascular district sensitive to BP-dependent sympathetic effects, thus leading to a spastic condition responsible for a labyrinthine ischemia. According to the anatomical continuity between cochlear and vestibular partition of the inner ear, a similar mechanism could reliably be applied to the latter, not only explaining some cases of otherwise unexplanable vertigo but even contributing in clarifying the etiopathogenesis of some cases of classified vertigo. As concerns hypotension, it has already been associated to vertigo, but was tendentially interpreted as an effect of vertebrobasilar insufficiency on vestibular nuclei [4]; as to autonomic responses, a recent report of Pappas [5] emphasises the frequent possibility of an autonomic dysfunction-related vertigo. According to this study [5] and to our knowledge, hypotension does not seem to be directly considered as responsible for an autonomic dysfunctional reaction, whereas therapeutic attempts apparently aiming to enhance BP values are widely reported [6]. In our opinion both conditions seem to concur in creating a prolonged ischemia able to overcome the effects of the inner ear fluids in maintaining oxygen saturation. If the above mentioned mechanisms are considerable as a possible cause either of transient unbalance or of a more severe and permanent damage, we could even hypothesise that a short-lasting hypoxygenation might be involved in the genesis of a vestibular migraine, whereas a prolonged ischemia might even in some cases originate a known and frequent affection possibly caused by vascular factors as Benign Paroxysmal Positional Vertigo. In conclusion, the suspect of such an origin of vestibular doi:10.1016/j.mehy.2004.07.004
symptoms should be considered and in some cases lead to add an ambulatory BP monitoring to the standard diagnostic procedures, in order to avoid a systemic vasodilator pharmacological treatment which could have some adverse effects on the function of the inner ear.
References [1] Pirodda A, Saggese D, Giausa G, Ferri GG, Nascetti S, Gaddi A. Can hypotension episodes cause cochlear damage in young subjects? Med Hypotheses 1997;48:195–6. [2] Pirodda A, Ferri GG, Modugno GC, Gaddi A. Hypotension and sensorineural hearing loss: a possible correlation. Acta Otolaryngol 1999;119:758–62. [3] Pirodda A, Ferri GG, Modugno GC, Borghi C. Systemic hypotension and the development of acute sensorineural hearing loss in young healthy subjects. Arch Otolaryngol Head Neck Surg 2001;127:1049–52. [4] Ito F, Tanaka K, Kamada H. Vertigo secondary to hypotension: the relationship between therapeutic effects and hearing. Auris Nasus Larynx 1998;25:161–7. [5] Pappas D. Autonomic related vertigo. Laryngoscope 2003;113:1658–71. [6] Grubb BP, Karas B. Clinical disorders of the autonomic nervous system associated with orthostatic intolerance: an overview of classification, clinical evaluation and management. PACE 1999;22:51–9.
Antonio Pirodda Department of Surgical and Anaesthesiological Sciences University of Bologna, Italy Policlinico S. Orsola-Malpighi via Massarenti n.9 Bologna 40138, Italy Tel.: +39 051 6364152; fax: +39 051 6363525 E-mail address: [email protected] Cristina Brandolini Department of Surgical and Anaesthesiological Sciences University of Bologna, Italy Giovanni Carlo Modugno Department of Surgical and Anaesthesiological Sciences, University of Bologna, Italy
Correspondence
Hypotension associated with autonomic dysfunction: a possible cause of vertigo? Dear Editor, A possible role of hypotension associated with an autonomic dysfunction in the genesis of some cases of sensorineural hearing loss has been hypothesised [1] and to some extent demonstrated by our group [2,3] in the recent years. The occurrence of a sudden sensorineural impairment of ‘‘idiopathic’’ nature in young subjects free from vascular risk factors could find on this basis a reliable explanation: a brusque decrease of blood pressure (BP) could elicit an abnormal reaction in a terminal vascular district sensitive to BP-dependent sympathetic effects, thus leading to a spastic condition responsible for a labyrinthine ischemia. According to the anatomical continuity between cochlear and vestibular partition of the inner ear, a similar mechanism could reliably be applied to the latter, not only explaining some cases of otherwise unexplanable vertigo but even contributing in clarifying the etiopathogenesis of some cases of classified vertigo. As concerns hypotension, it has already been associated to vertigo, but was tendentially interpreted as an effect of vertebrobasilar insufficiency on vestibular nuclei [4]; as to autonomic responses, a recent report of Pappas [5] emphasises the frequent possibility of an autonomic dysfunction-related vertigo. According to this study [5] and to our knowledge, hypotension does not seem to be directly considered as responsible for an autonomic dysfunctional reaction, whereas therapeutic attempts apparently aiming to enhance BP values are widely reported [6]. In our opinion both conditions seem to concur in creating a prolonged ischemia able to overcome the effects of the inner ear fluids in maintaining oxygen saturation. If the above mentioned mechanisms are considerable as a possible cause either of transient unbalance or of a more severe and permanent damage, we could even hypothesise that a short-lasting hypoxygenation might be involved in the genesis of a vestibular migraine, whereas a prolonged ischemia might even in some cases originate a known and frequent affection possibly caused by vascular factors as Benign Paroxysmal Positional Vertigo. In conclusion, the suspect of such an origin of vestibular doi:10.1016/j.mehy.2004.07.004
symptoms should be considered and in some cases lead to add an ambulatory BP monitoring to the standard diagnostic procedures, in order to avoid a systemic vasodilator pharmacological treatment which could have some adverse effects on the function of the inner ear.
References [1] Pirodda A, Saggese D, Giausa G, Ferri GG, Nascetti S, Gaddi A. Can hypotension episodes cause cochlear damage in young subjects? Med Hypotheses 1997;48:195–6. [2] Pirodda A, Ferri GG, Modugno GC, Gaddi A. Hypotension and sensorineural hearing loss: a possible correlation. Acta Otolaryngol 1999;119:758–62. [3] Pirodda A, Ferri GG, Modugno GC, Borghi C. Systemic hypotension and the development of acute sensorineural hearing loss in young healthy subjects. Arch Otolaryngol Head Neck Surg 2001;127:1049–52. [4] Ito F, Tanaka K, Kamada H. Vertigo secondary to hypotension: the relationship between therapeutic effects and hearing. Auris Nasus Larynx 1998;25:161–7. [5] Pappas D. Autonomic related vertigo. Laryngoscope 2003;113:1658–71. [6] Grubb BP, Karas B. Clinical disorders of the autonomic nervous system associated with orthostatic intolerance: an overview of classification, clinical evaluation and management. PACE 1999;22:51–9.
Antonio Pirodda Department of Surgical and Anaesthesiological Sciences University of Bologna, Italy Policlinico S. Orsola-Malpighi via Massarenti n.9 Bologna 40138, Italy Tel.: +39 051 6364152; fax: +39 051 6363525 E-mail address: [email protected] Cristina Brandolini Department of Surgical and Anaesthesiological Sciences University of Bologna, Italy Giovanni Carlo Modugno Department of Surgical and Anaesthesiological Sciences, University of Bologna, Italy