Neuralgia Arnold Clinical Trial
Official title:
Cryoneurolysis of Arnold's Nerve and Follow-up by Tractography: Feasibility Study
According to the World Health Organization (WHO), headaches are one of the most common
nervous system disorders. The therapeutic strategy is well established for certain
subcategories of headache. On the other hand, when headaches become refractory, some nerves
may become the target of targeted therapies. This is the case of the Arnold nerve, also
called the great occipital nerve, which is involved in certain pathologies, both
physiopathologically and therapeutically. The Arnold nerve infiltration has a relatively
short duration of effectiveness (about 1 month on average), some teams have reported the
interest of achieving a destruction of the Arnold nerve by radio frequency, with extended
durations of efficiencies to several months. The use of cryoneurolysis has been known for a
long time and its effectiveness in the management of cranio-facial pain is already reported.
It is thus possible to obtain, at the end of the cryoanalgesia needle, very low temperatures
around -40 ° C, which leads to the formation of an ice cube and, where appropriate, the
freezing of the structures (nerves among others) to the needle contacts. This induces the
formation of microcrystals leading to irreversible lesions of vasa-nervorums resulting in an
endoneural edema. In the long run, it appears a Wallerian degeneration without destruction of
this endoneurum. This is associated with the lack of destruction of the structure of the
Schwann cell. Nerve regeneration is possible.
The diffusion MRI study allows tractographic reconstruction of the nerves. This is the only
imaging technique that focuses on the fibrillar structure of the nerves, thus enabling the
detection of nerves throughout its path. It is a morphological imaging technique nevertheless
it also allows a quantitative analysis of the nerve through certain parameters.
The Investigators hypothesize that the cryoneurolysis of the Arnold nerve will result in the
disappearance of visualization of the nerve by MRI tractography. The effect of cryoneurolysis
on Arnold nerves, as on other peripheral nerves through diffusion MRI has never been
described. The follow-up of MRI patients who had undergone cryoneurolysis would make it
possible to study the behavior of these nerves after cryoneurolysis, and to correlate the
aspect in tractography with the clinical data. Painful recurrence can then be correlated with
visualization of the nerves by MRI.
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