Periodic alternating nystagmus and vestibulo-spinal system facilitating activity.
OBJECTIVE
Periodic alternating nystagmus has been associated with the instability of the velocity storage mechanism, which is known to play an important role in both the vestibulo-oculomotor and the optokinetic systems. In the present study we looked for a possible spinal equivalent to PAN.


RESULTS
In 3 PAN patients, the H-reflex amplitude proved to be slightly but significantly influenced by nystagmus direction, in that it was greater when the nystagmus was beating toward the stimulation side.


CONCLUSIONS
This finding suggests that projections from velocity storage may play a role not only in the ocular motor but also in assisting postural stability through the vestibulo-spinal system.
Versino
M
M
Dipartimento Scienze Neurologiche, Università di Pavia, Pavia, Italy. mversino@unipv.it
Romani
A
A
Callieco
R
R
Alfonsi
E
E
Beltrami
G
G
Manfrin
M
M
Cosi
V
V
D000293:Adolescent; D000368:Aged; D000704:Analysis of Variance; D004558:Electric Stimulation; D005260:Female; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000503:physiopathology*; D013116:Spinal Cord / Q000503:physiopathology*; D014722:Vestibule, Labyrinth / Q000503:physiopathology*