SPET Monitoring of Perfusion Changes in Auditory Cortex following Mono- and Multi-Frequency Stimuli

Giuseppe de Rossi; Gaetano Paludetti; Walter di Nardo; Maria L. Calcagni; Daniela di Giuda; Giovanni Almadori; Jacopo Galli

doi:10.1055/s-0038-1629823

Nuklearmedizin - NuclearMedicine, Table of Contents

Nuklearmedizin 1996; 35(04): 112-115
DOI: 10.1055/s-0038-1629823

Original Article

Schattauer GmbH

SPET Monitoring of Perfusion Changes in Auditory Cortex following Mono- and Multi-Frequency Stimuli

SPET Monitoring von Perfusionsänderungen im auditorischen Cortex nach Mono- und Multi-Frequenz Stimuli

Authors

Giuseppe de Rossi

¹From the Nuclear Medicine Institute and the A. Gemelli, Rome, Italy
Gaetano Paludetti

²Otorhinoloaryngology Institute, Policlinico A. Gemelli, Rome, Italy
Walter di Nardo

²Otorhinoloaryngology Institute, Policlinico A. Gemelli, Rome, Italy
Maria L. Calcagni

¹From the Nuclear Medicine Institute and the A. Gemelli, Rome, Italy
Daniela di Giuda

¹From the Nuclear Medicine Institute and the A. Gemelli, Rome, Italy
Giovanni Almadori

²Otorhinoloaryngology Institute, Policlinico A. Gemelli, Rome, Italy
Jacopo Galli

²Otorhinoloaryngology Institute, Policlinico A. Gemelli, Rome, Italy

Abstract

Summary

Aim: In order to assess the relationship between auditory cortex perfusion and the frequency of acoustic stimuli, twenty normally-hearing subjects underwent cerebral SPET. Methods: In 10 patients a multi-frequency stimulus (250-4000 Hz at 40 dB SL) was delivered, while 10 subjects were stimulated with a 500 Hz pure tone at 40 dB SL. The prestimulation SPET was subtracted from poststimulation study and auditory cortex activation was expressed as percent increments. Results: Contralateral cortex was the most active area with multi-frequency and monofrequency stimuli as well. A clear demonstration of a tonotopic distribution of acoustic stimuli in the auditory cortex was achieved. In addition, the accessory role played by homolateral acoustic areas was confirmed. Conclusion: The results of the present research support the hypothesis that brain SPET may be useful to obtain semiquantitative reliable information on low frequency auditory level in profoundly deaf patients. This may be achieved comparing the extension of the cortical areas activated by high-intensity multifrequency stimuli.

Zusammenfassung

Ziel: Zur Aufklärung der Beziehung von regionaler Perfusion des auditorischen Kortex und Frequenz des akustischen Stimulus wurden 20 Normalpatienten mit Hilfe von Hirn-SPECT untersucht. Methoden: Bei je 10 Patienten wurde ein Multifrequenzstimulus (250-2000 Hz bei 60 dB) bzw. ein Monofrequenzstimulus (500 Hz bei 60 dB) verwendet. Die vor der Stimulation akquirierten SPECT-Daten wurden jeweils von den nach der Stimulation akquirierten SPECT-Daten abgezogen und die aditori-sche Kortexaktivation als prozentuale Steigerung ausgedrückt. Ergebnisse: Der kontralaterale Kortex war das am stärksten aktivierte Areal sowohl bei der Multifrequenz- als auch bei der Monofrequenzstimula-tion. Es konnte eine klare tonotopische Verteilung der akustischen Stimuli im auditorischen Kortex demonstriert werden. Zusätzlich konnte die akzessorische Rolle des homolateralen akustischen Kortex bestätigt werden. Schlußfolgerung: Die Ergebnisse dieser Studie unterstützen die Hypothese, daß Hirn-SPECT semiquantitative Informationen im Niederfrequenzbereich auch bei tauben Patienten liefern könnte. Dies kann erreicht werden durch den Vergleich der Ausdehnung aktivierter kortikaler Areale bei Hochintensität-Multifrequenzstimulation.

Key words

Brain SPET - auditory cortex perfusion - mono- and multi-frequency acoustic stimuli

Schlüsselwörter

Hirn-SPECT - Perfusion des auditorischen Kortex - Mono- und Multifrequenz-akustische Stimuli

Full Text

References

References
1 De Rossi G. A new cerebral tomograph: technical features and preliminary experience. Rad Diagn 1992; 33: 236-40.
2 De Rossi G, Giordano A, Calcagni ML, Dinardo W, Paludetti G, Galli J. Brain SPET and auditory cortex perfusion: technical notes and preliminary results. Nucl Med Comm 1994; 15: 565-8.
3 Di Nardo W, Galli J, Paludetti G, Scarano E, De Rossi G, Calcagni ML. SPET ed attivazione acustica della corteccia uditiva. Riv Ori Aud Fon 1994; 14: 1-5.
4 Herzog H, Lamprecht A, Kühn A, Roden W, Vosteen KH, Feinendegen LU. Cortical activation in profoundly deaf patients during cochlear implant demonstrated by H₂ ¹⁵O PET. J Comput Assit Tomogr 1991; 15: 369-75.
5 Kileny P. The frequency specificity of tone PIP Evoked Auditory Brain Stem responses. Ear & Hearing 1991; 2: 270-5.
6 Lauter JL, Herscovitch P, Raichle ME. Tonotopic organization in human auditory cortex revealed by Positron Emission Tomography. Hear Res 1985; 20: 199-203.
7 Le Scao Y, Baulieu JL, Robier A, Pourcelot L, Beutter P. Increment of brain temporal perfusion during auditory stimulation. Eur J Nucl Med 1991; 18: 981-3.
8 Le Scao Y, Robier A, Baulieu JL, Beutter P, Pourcelot L. Cortical perfusion response to an electrical stimulation of the auditory nerve in profoundly deaf patients: study with technetium-99m hexamethylpropylene amine oxime single-photon emission tomography. Eur J Nucl Med 1992; 19: 283-6.
9 Le Scao Y, Jezequel J, Robier A, Baulieu JL, Turzo A, Guias B, Morin PP. Reliability of low-frequency auditory stimulation studies associated with technetium-99m hexamethylpropylene amine oxime single-photon emission tomography. Eur J Nucl Med 1993; 20: 387-90.
10 Papanicolau AC, Baumann SB, Rogers RL. Spatiotemporal source localization of neuro-magnetic fields evoked. VIII Int Conf on Biomagnetism, Miinster 1991 (Abstr).
11 Pantev C, Hoche M, Lukenhoner B, Len-hertz K. Tonotopic organization of the auditory cortex: click versus frequency representation. Science 1989; 246: 486-8.
12 Phelps ME, Maziotta JC, Engel Jr J, Kühl DE. Metabolic response of the brain to visual and auditory stimulation and deprivation. J Cereb Blood Flow Metabol 1981; 1 SI 467-8.
13 Ring HA, George M, Costa DC, Ell PJ. The use of cerebral activation procedures with single photon emission tomography. Eur J Nucl Med 1991; 18: 133-41.
14 Romani GL, Williamson SJ, Kaufman L, Brenner D. Tonotopic organization of human auditory cortex. Science 1982; 216: 1339-40.
15 Talairich J, Szlika G. Atlas d’anatomie stéréotaxique du téléencéphale. Paris: Mas-son; 1967
16 Terkildsen K, Osterhammel P. Far field electrocochleography frequency specificity of the response. Scand Audiol 1975; 4: 167-72.
17 Van Derdbritt JFC, Brocaar MP, Van Zanten GA. The relation between the pure-tone audiogram and the click auditory brainstem response threshold in cochlear hearing loss. Audiology 1987; 26: 1-10.
18 Walzi EM, Woolsey CN. Cortical auditory areas of the monkey as determined by electrical stimulation of nerve fibers in osseous spiral lamina and by click stimulation. Fed Proc 1943; 2: 52-4.