Enhanced late components of AEFs associated with the temporal lobe lesions.
We recorded auditory evoked magnetic fields (AEFs) by presenting pure tone bursts once every 4000 ms in 11 patients with a brain lesion in or in the vicinity of the auditory cortex. AEFs on the damaged side revealed several enhanced deflections in late-latency AEFs (slow AEFs), peaking at approximately 320 (DI), 1030 (D2) and 1600 (D3) ms post-stimulus in eight patients. All the dipoles of slow AEFs were concentrated in the superior temporal regions which were not involved by brain lesions. D1, D2 and D3 dipoles were uniformly upward, downward and upward, respectively. The dipole moment varied from 12 to 122 nAm and had no consistent relationship with latency. This is the first report describing slow AEFs in cases with temporal lobe lesions.
Kamada
K
K
Department of Neurosurgery, School of Medicine, Hokkaido University, Kita-Ku, Kita 15, Nishi-5, Sapporo 060-8638, Japan.
Takeuchi
F
F
Harada
T
T
Qiao
B
B
Houkin
K
K
Kuriki
S
S
Iwasaki
Y
Y
Mitsumori
K
K
D001303:Auditory Cortex / Q000473:pathology / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000503:physiopathology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology*