Increment of brain temporal perfusion during auditory stimulation

Scao, Y. Le; Baulieu, Jean-Louis; Robier, A.; Pourcelot, L.; Beutter, P

doi:10.1007/bf00180420

Cited by 7 publications

(2 citation statements)

References 5 publications

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“…In a recent study (Le Scao et al 1991), we did not observe any significant asymmetry between the left and the right side in eight patients without neurological problems. However, it is important that certain facts be borne in mind if such hypoperfusion is to be interpreted correctly: I.…”

Section: Discussioncontrasting

confidence: 47%

Postoperative assessment of cerebral blood flow in subarachnoid haemorrhage by means of99mTc-HMPAO tomography

et al. 1993

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Regional hypoperfusion is a very frequent complication of subarachnoid haemorrhage (SAH), being related to vasospasm in the majority of cases. Twenty-six patients who were admitted for SAH underwent follow-up with technetium-99m hexamethylpropylene amine oxime single photon emission tomography (SPECT) 3 and 8 days after surgery. Fifteen patients of these had one more examination 15 days after surgery. The degree of hypoperfusion was quantified using an index of asymmetry which allow the comparison of two symmetrical regions of interest (ROIs) on the transaxial slice which presented the greatest perfusion defect. Comparison of CT data, transcranial Doppler data and clinical signs with the perfusion as quantified by 99mTc-HMPAO SPECT indicates that a difference in counts of less than 10% between the two symmetrical ROIs is of no diagnostic value. Follow-up of the brain perfusion clearly shows that the most pronounced hypoperfusion was observed just after surgery, with progressive normalization at 8 and 15 days after surgery. 99mTc-HMPAO SPECT performed 8 days after surgery allows prediction of the clinical outcome. For these reasons, 99mTc-HMPAO SPECT, which is the only method for follow-up of cerebral perfusion in routine clinical practice, should be the first examination to be performed after surgery in patients with SAH.

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Section: Discussioncontrasting

confidence: 47%

Postoperative assessment of cerebral blood flow in subarachnoid haemorrhage by means of99mTc-HMPAO tomography

et al. 1993

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“…A rather uniform bilateral activation of the temporal cortex after pure tones and electrical stimuli, was reported by Le Scao et al (7)(8)(9). On the contrary, PET investigations and previous personal studies with SPET, proved an asymmetrical cortical stimulation, with a statistically significant higher increase in contralateral regions (2)(3)(4)6).…”

Section: T a B mentioning

confidence: 80%

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

Paludetti¹,

Nardo²,

Calcagni³

et al. 1996

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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.

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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

et al. 1992

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Brain activation procedures associated with single photon emission tomography (SPET) have recently been developed in healthy controls and diseased patients in order to help in their diagnosis and treatment. We investigated the effects of a promontory test (PT) on the cerebral distribution of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) in 7 profoundly deaf patients, 6 PT+ and one PT-. The count variation in the temporal lobe was calculated on 6 coronal slices using the ratio (Rstimulation-Rdeprivation)/Rdeprivation where R = counts in the temporal lobe/whole-brain count. A count increase in the temporal lobe was observed in all patients and was higher in all patients with PT+ than in the patient with PT-. The problems of head positioning and resolution of the system were taken into account, and we considered that the maximal count increment was related to the auditory cortex response to the stimulus. Further clinical investigations with high-resolution systems have to be performed in order to validate this presurgery test in cochlear implant assessment.

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Increment of brain temporal perfusion during auditory stimulation

Cited by 7 publications

References 5 publications

Postoperative assessment of cerebral blood flow in subarachnoid haemorrhage by means of99mTc-HMPAO tomography

Postoperative assessment of cerebral blood flow in subarachnoid haemorrhage by means of99mTc-HMPAO tomography

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

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

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