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Correlation of transcranial color Doppler to n20 somatosensory evoked potential detects ischemic penumbra in subarachnoid hemorrhage.

Di Pasquale P, Zanatta P, Morghen I, Bosco E, Forini E - Open Neurol J (2011)

Bottom Line: Both ratios became <0.65 (p <0.01) when patients showed unilateral images of ischemic penumbra and returned >0.65 if penumbra disappeared.Variations of interhemispheric ratios of MCA resistance and cortical N20 amplitude correlate closely in SAH and allow identification of the reversible ischemic penumbra threshold, when both ratios become <0.65.The correlation is lost when structural damage develops.

View Article: PubMed Central - PubMed

Affiliation: Anaesthesia and Intensive Care Department, Rovigo Hospital, Viale 3 Martiri, 140, 45100 Rovigo, Italy.

ABSTRACT

Background: Normal subjects present interhemispheric symmetry of middle cerebral artery (MCA) mean flow velocity and N20 cortical somatosensory evoked potential (SSEP). Subarachnoid haemorrhage (SAH) can modify this pattern, since high regional brain vascular resistances increase blood flow velocity, and impaired regional brain perfusion reduces N20 amplitude. The aim of the study is to investigate the variability of MCA resistances and N20 amplitude between hemispheres in SAH.

Methods: Measurements of MCA blood flow velocity (vMCA) by transcranial color-Doppler and median nerve SSEP were bilaterally performed in sixteen patients. MCA vascular changes on the compromised hemisphere were calculated as a ratio of the reciprocal of mean flow velocity (1/vMCA) to contralateral value and correlated to the simultaneous variations of interhemispheric ratio of N20 amplitude, within each subject. Data were analysed with respect to neuroimaging of MCA supplied areas.

Results: Both interhemispheric ratios of 1/vMCA and N20 amplitude were detected >0.65 (p <0,01) in patients without neuroimages of injury. Both ratios became <0.65 (p <0.01) when patients showed unilateral images of ischemic penumbra and returned >0.65 if penumbra disappeared. The two ratios no longer correlated after structural lesion developed, as N20 detected in the damaged side remained pathological (ratio <0.65), whereas 1/vMCA reverted to symmetric interhemispheric state (ratio >0.65), suggesting a luxury perfusion.

Conclusion: Variations of interhemispheric ratios of MCA resistance and cortical N20 amplitude correlate closely in SAH and allow identification of the reversible ischemic penumbra threshold, when both ratios become <0.65. The correlation is lost when structural damage develops.

No MeSH data available.


Related in: MedlinePlus

Patient No. 12 showed parallel courses of N20 and 1/vMCA ratios (p <0.01, r = 0.92, C.I. = 0.44 to 0.99). He showed hydrocephalus promptly treated with EVD (point 1) and right parietal oedema (point 2) in MCA area at CT scan (both ratios < 0.65). He maintained N20 amplitude > 1.2 µV on the compromised hemisphere and vasospasm (BFV >120 to 180 cm/sec) was detected corresponding to points 2,3,4,5; the patient had clinical transient lateralizing symptoms corresponding to point 2 and recovered a normal clinical picture in subsequent examinations (points 3 to 6); CT scan performed at point 6 was normal (both ratios > 0.65).
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Figure 7: Patient No. 12 showed parallel courses of N20 and 1/vMCA ratios (p <0.01, r = 0.92, C.I. = 0.44 to 0.99). He showed hydrocephalus promptly treated with EVD (point 1) and right parietal oedema (point 2) in MCA area at CT scan (both ratios < 0.65). He maintained N20 amplitude > 1.2 µV on the compromised hemisphere and vasospasm (BFV >120 to 180 cm/sec) was detected corresponding to points 2,3,4,5; the patient had clinical transient lateralizing symptoms corresponding to point 2 and recovered a normal clinical picture in subsequent examinations (points 3 to 6); CT scan performed at point 6 was normal (both ratios > 0.65).


Correlation of transcranial color Doppler to n20 somatosensory evoked potential detects ischemic penumbra in subarachnoid hemorrhage.

Di Pasquale P, Zanatta P, Morghen I, Bosco E, Forini E - Open Neurol J (2011)

Patient No. 12 showed parallel courses of N20 and 1/vMCA ratios (p <0.01, r = 0.92, C.I. = 0.44 to 0.99). He showed hydrocephalus promptly treated with EVD (point 1) and right parietal oedema (point 2) in MCA area at CT scan (both ratios < 0.65). He maintained N20 amplitude > 1.2 µV on the compromised hemisphere and vasospasm (BFV >120 to 180 cm/sec) was detected corresponding to points 2,3,4,5; the patient had clinical transient lateralizing symptoms corresponding to point 2 and recovered a normal clinical picture in subsequent examinations (points 3 to 6); CT scan performed at point 6 was normal (both ratios > 0.65).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3106352&req=5

Figure 7: Patient No. 12 showed parallel courses of N20 and 1/vMCA ratios (p <0.01, r = 0.92, C.I. = 0.44 to 0.99). He showed hydrocephalus promptly treated with EVD (point 1) and right parietal oedema (point 2) in MCA area at CT scan (both ratios < 0.65). He maintained N20 amplitude > 1.2 µV on the compromised hemisphere and vasospasm (BFV >120 to 180 cm/sec) was detected corresponding to points 2,3,4,5; the patient had clinical transient lateralizing symptoms corresponding to point 2 and recovered a normal clinical picture in subsequent examinations (points 3 to 6); CT scan performed at point 6 was normal (both ratios > 0.65).
Bottom Line: Both ratios became <0.65 (p <0.01) when patients showed unilateral images of ischemic penumbra and returned >0.65 if penumbra disappeared.Variations of interhemispheric ratios of MCA resistance and cortical N20 amplitude correlate closely in SAH and allow identification of the reversible ischemic penumbra threshold, when both ratios become <0.65.The correlation is lost when structural damage develops.

View Article: PubMed Central - PubMed

Affiliation: Anaesthesia and Intensive Care Department, Rovigo Hospital, Viale 3 Martiri, 140, 45100 Rovigo, Italy.

ABSTRACT

Background: Normal subjects present interhemispheric symmetry of middle cerebral artery (MCA) mean flow velocity and N20 cortical somatosensory evoked potential (SSEP). Subarachnoid haemorrhage (SAH) can modify this pattern, since high regional brain vascular resistances increase blood flow velocity, and impaired regional brain perfusion reduces N20 amplitude. The aim of the study is to investigate the variability of MCA resistances and N20 amplitude between hemispheres in SAH.

Methods: Measurements of MCA blood flow velocity (vMCA) by transcranial color-Doppler and median nerve SSEP were bilaterally performed in sixteen patients. MCA vascular changes on the compromised hemisphere were calculated as a ratio of the reciprocal of mean flow velocity (1/vMCA) to contralateral value and correlated to the simultaneous variations of interhemispheric ratio of N20 amplitude, within each subject. Data were analysed with respect to neuroimaging of MCA supplied areas.

Results: Both interhemispheric ratios of 1/vMCA and N20 amplitude were detected >0.65 (p <0,01) in patients without neuroimages of injury. Both ratios became <0.65 (p <0.01) when patients showed unilateral images of ischemic penumbra and returned >0.65 if penumbra disappeared. The two ratios no longer correlated after structural lesion developed, as N20 detected in the damaged side remained pathological (ratio <0.65), whereas 1/vMCA reverted to symmetric interhemispheric state (ratio >0.65), suggesting a luxury perfusion.

Conclusion: Variations of interhemispheric ratios of MCA resistance and cortical N20 amplitude correlate closely in SAH and allow identification of the reversible ischemic penumbra threshold, when both ratios become <0.65. The correlation is lost when structural damage develops.

No MeSH data available.


Related in: MedlinePlus