Effects of microvascular decompression versus radiofrequent thermocoagulation of the pterygopalatine ganglion in patients with persistent, drug-resistent, Sluder*s neuralgia: a pilot study

Sluder's neuralgia(SN) is, although rare, a disorder well known to
otolaryngologists and neurologists. SN is an invalidating condition, in which
pain is incessant.
The specific cause of SN remains unknown, but several mechanisms have been
suggested to play a role in its etiology. The most consistent and likely theory
is that the pterygopalatine ganglion (PPG) is the main route for SN and its
associated parasympathetic symptoms. Patients with SN can have adequate pain
relief with farmacological therapy, however, some patients require surgical
treatment because of persistent, drug-resistant SN. Previous studies have shown
that treatment directed against the PPG, such as radiofrequent
thermocoagulation, can be effective in patients with SN.
However, most treatments only provide temporary pain relief, and repeated
surgical procedures are sometimed needed to establish long lasting pain relief.
Examination of the anatomic relations of the PPG reveals that it lies in close
contact with a remarkably tortuous portion of the maxilllary artery along its
course in the pterygopalatine fossa. This fact supports the hypothesis that
vascular compression of the PPG by a loop of the maxillary artery, can account
for the manifestations of SN.
Vascular compression syndromes are associated with a variety of other disorders
such as trigeminal neuralgia, and previous studies have shown that these
disorders can be treated succesfully with microvascular decompression (MVD).

Main objective of this study is to assess the effects of MVD versus RF of the
pterygopalatine ganglion in management of patients with persistent,
drug-resistant SN in terms of pain reduction and improvement of quality of
life.

A pilot study will be carried out in 24 patients with persistent, drug
resistant SN.
To exclude pathology as a causative factor for the pain and in order to be
prepared for anatomical variations in the involved area, all patients will
undergo CT and MRI or MRA.
All patients will initially be treated with lidocaine nose drops for four
weeks, after which they will be randomly assigned to one of two treatment arms:
1)MVD of the pterygopalatine ganglion and 2) RF of the pterygopalatine
ganglion. The follow-up period after MVD will be six months. Pain relief and
improvement of quality of life will be assessed via questionnaires filled out
at inclusion and at one week, 3 and 6 months follow-up.

Microvascular decompression of the pterygopalatine ganglion by means of
insertion of a piece of temporal muscle between the pterygopalatine ganglion
and the maxillary artery and clipping of the artery itself; to ensure
discontinuation of contact between the pterygopalatine ganglion and the
maxillary artery.

Risks include the standard risks of anaesthesia and the risks of MVD and RF.
The risks of MVD involve the usual risks of sinus surgery such as intra- and
postoperative bleeding due to injury of the artery, postoperative sinusitis,
paraesthesia of the palate and face, oroantral fistula, dental injury and
theoretically entering the orbit. However, these complication rates are very
low.
Complications of RF are rare, and include epistaxis, hemathoma in the involved
area or hypesthesia of the palate.

Burden includes a hospital admission for approximately three days and
undergoing CT and MRI or MRA, as well as taking time to fill out the
questionnaires at inclusion and during follow-up