MRI findings after hyperbaric oxygen-induced seizures.
Hyperbaric oxygen-induced seizures are classified as generalized, tonic-clonic seizures. They are believed to cause no residual neurologic damage, although this has not been investigated in depth. We used different MRI sequences to determine whether hyperbaric oxygen-induced seizures in mice caused brain structural changes. Experimental animals were exposed to a pressure of 6 atmospheres absolute breathing oxygen, and were randomly assigned to two groups in which MRI was performed immediately after the appearance of seizures or 7 days later. Control groups were not exposed to hyperbaric oxygen. Our MRI protocols included T2*-weighted images, T2 maps, diffusion-weighted echo-planar pulse sequence, and contrast-enhanced T1-weighted images. Both the cortex and the hippocampus were analyzed. T2 values of the hippocampus and the cortex in the hyperbaric oxygen-exposed groups showed a small but statistically significant decrease compared with the control groups immediately after seizures (p<0.01). One week after seizures, enhancement following contrast injection was significantly higher both in the cortex and the hippocampus in the hyperbaric oxygen-exposed groups compared with the control groups (p<0.01). Hippocampal and cortex T2 values 7 days after seizures were similar to control group values. No differences were found among the other sequences. We conclude that hyperbaric oxygen-induced seizures result in delayed injury to the blood-brain barrier. Elucidation of the mechanisms and significance of this injury will necessitate further investigation.
Israel Naval Medical Institute, IDF Medical Corps, Haifa, Israel. liranura@gmail.com
Liran
L
Domachevsky
Chaim G
CG
Pick
Nathan
N
Peled
J M
JM
Gomori
Amir
A
Abramovich
Catherine
C
Tempel-Brami
D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D006931:Hyperbaric Oxygenation / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D011897:Random Allocation; D012640:Seizures / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*