Hi, thanks for writing to HCM.
It is possible to have tingling & numbness in the leg along with sexual dysfunction
in case of a massive CENTRAL disc prolapse
at the level of L4-L5 or L5-S1. But mild to moderate disc dessication may cause tingling & numbness when it impinges on the nerve root
but never results in Impotence.
The cause for impotence in your fiance's case could be something else. I suggest you to consult an Urologist
for further evaluation and management of impotence.
Hope this information is helpful. Good day