superficial peroneal-ramus intermedius lesion?

[Emanuil Giuris <giuris@SPARK.NET.GR>]

I saw a patient with numbness at the ramus intermedius dorsalis of the
right superficial peroneal nerve. No potential could be recorded from that
ramus and normal potentials could be recorded from right ramus medialis and
from ramus medialis and intermedius on the left. The patient, female 60y,
told me that she has that pain already 3 weeks, it is getting better and
that pressure just medial of the right external malleolus causes pain and
the aforementioned numbness. No history of trauma, no palpable tumor. I
would be grateful for any ideas as to causation. Could it be a small
shwannoma, would you suggest surgical exploration even if patient gets
better?
As to the needles: Dumitru(AAEM official and EMG book author), who uses
preferentially monopolars, says that he does not value the interference
pattern examination, and that MUP analysis is the important thing. I read
about the monopolar-concentric differences as to the MUP features, but I
wonder if there is an effect on the fullness of the interference pattern at
maximal effort. Maybe the monopolars show a less reduced interference
pattern and are less sensitive for neurogenic lesions as far as the
interference pattern is concerned.

Emanuil Giuris
giuris@spark.net.gr