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Late stimulation of the sphenopalatine‐ganglion in ischemic rats: Improvement in N‐acetyl‐aspartate levels and diffusion weighted imaging characteristics as seen by MR
Author(s) -
BarShir Am,
Shemesh Noam,
NossinManor Revital,
Cohen Yoram
Publication year - 2010
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.22110
Subject(s) - medicine , stimulation , diffusion mri , occlusion , magnetic resonance imaging , anesthesia , nuclear medicine , stroke (engine) , radiology , mechanical engineering , engineering
Purpose: To assess, by MR spectroscopy (MRS) and diffusion weighted imaging (DWI), the ability of electrical stimulation of the sphenopalatine ganglion (SPG) to augment stroke recovery in transient middle cerebral artery occluded (t‐MCAO) rats, when treatment is started 18 ± 2 h post‐occlusion. Materials and Methods: 1 H‐MRS imaging ( 1 H‐MRSI) and DWI were used to evaluate ischemic brain tissue after SPG stimulation in rats subjected to 2 h of t‐MCAO. Rats were examined by 1 H‐MRSI, DWI, and behavioral tests at 16 ± 2 h, 8 days, and 28 days post‐MCAO. Results: N‐Acetyl‐aspartate (NAA) levels of the stimulated and control rats were the same 16 ± 2 h post‐MCAO (0.52 ± 0.03, 0.54 ± 0.03). At 28 days post‐occlusion, NAA levels were significantly higher in the treated group (0.60 ± 0.04) compared with those of the untreated animals (0.50 ± 0.04; P < 0.05). This effect was more pronounced for regions with low NAA values (0.16 ± 0.03) that changed to 0.32 ± 0.03 ( P = 0.04) for the treated group and to 0.10 ± 0.03 ( P = 0.20) for the controls. DWI data showed better ischemic tissue condition for the treated rats, but the measured parameters showed only a trend of improvement. The MR results were corroborated by behavioral examinations. Conclusion: Our findings suggest that SPG stimulation may ameliorate MR tissue characteristics following t‐MCAO even if treatment is started 18 h post‐occlusion. J. Magn. Reson. Imaging 2010;31:1355–1363. © 2010 Wiley‐Liss, Inc.