Can marijuana help paraplegics recover?

I happened to meet a person who became a paraplegic 13 years
ago in a diving accident.  But he had recovered enough to be
able to walk by himself now, though he still needs crutches
most of the time.

He had used marijuana to keep himself happy despite his
accident.  But I wondered if there was a causal
connection.

Nerual connections will grow when stimulated.  A drug
like marijuana will modify neural activity, and
maybe it is possible that it could provide stimulation,
helping the lost connections grow.

Could therapy provided while the patient was "under the
influence" lead to recovery?  (I don't mean marinol
type stuff, but something that provided actual
drug-impact causing "high"s, i.e. changed neural behavior.)