Brian P. Jacob, David C. Chen, Bruce Ramshaw, Shirin Towfigh (eds.) - The SAGES Manual of Groin Pain-Springer International Publishing (2016)

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M. Hibner and C. Coyne
Table 11.1. Ancillary testing [ 6 – 9 ].
Test How to perform Comments
Pudendal nerve
motor
terminal
latency
( PNMTL )
Measures speed of impulse
conduction between ischial
spine and pelvic floor.
Performed with St. Mark’s
electrode
High inter- and intraobserver
variability. Test
unreliable due to inability
to measure the length of
pudendal nerve
Quantitative
sensory
testing
Magnetic
resonance
imaging
(anatomic)
Magnetic
resonance
imaging
(functional)
Warm detection test—based
on patient’s perception of
change in temperature
Two point discrimination
test—based on patient’s
ability to distinguish
between one and two points
1.5 and 3 T MR with specific
pelvic floor protocols
Magnetic resonance
neurography—novel
technique to enhance image
of neurovascular bundle
using water properties of
the nerve
Used in diagnosis of other
neuropathic conditions
but not validated for
pudendal nerve
Pudendal nerve smaller
than resolution of MRI.
Studies on normal
subjects not done
Studies on normal subjects
not done
MRI can provide more detailed information along the pathway of the
pudendal nerve, including scarring, inflammation, and entrapment.
Magnetic resonance neurography (MRN) may also help identify the
pudendal nerve along its pathway. Often the nerve is too small to be
viewed accurately, unless it is grossly damaged and enlarged. In addition,
MRN is typically performed in highly specialized centers, as it
requires radiologists to be familiar with specific neuroanatomy to accurately
interpret the images.
The Nantes Criteria The Nantes Criteria for diagnosing pudendal
nerve entrapment was established by Professor Roger Robert in Nantes,
France. He is one of the pioneers of surgical treatment of pudendal neuralgia.
Table 11.2 lists these criteria, which have been validated [ 10 ].
Patients who meet these criteria are more likely to respond positively to
surgical options than those who partially meet these criteria.