MIRROR MOVEMENTS IN X-LINKED KALLMANNS-SYNDROME .2. A PET STUDY

To investigate the mechanism of mirror movements seen in X-linked Kall mann's syndrome, we measured changes of regional cerebral blood flow w ith (H2O)-O-15-PET. We studied six right-handed Kallmann male subjects and six matched right-handed control subjects during an externally pa ced finger opposition task. The analyses were done both on a single su bject and a group basis. The Kallmann group showed a strong primary mo tor cortex (M1) activation contralateral to the voluntarily moved hand but there was also a significant degree of M1 activation ipsilateral to the voluntarily moved hand, i.e. contralateral to the mirroring han d. However, when comparing contralateral to ipsilateral M1 activation, the M1 activation contralateral to the voluntarily moved hand was sig nificantly stronger in the controls, significant increases in rCBF wer e seen in the contralateral M1 during voluntary movement of either han d; a small ipsilateral M1 activation was found in two out of six norma l subjects when they moved their left hand. In a second experiment it was shown that in two out of two Kallmann subjects, passive movements of the right hand resulted in left M1 activation that was similar to t he activation in the left M1 when subjects made mirror movements with their right hand. This suggests, but does not prove, that the small bu t significant activation of the ipsilateral M1 in Kallmann's subjects may be due to sensory feedback from the involuntarily mirroring hand.