The main objective of this study is to investigate efficacy and safety of injecting botulinum toxin towards the sphenopalatine ganglion using MultiGuide in patients with persistent idiopathic facial pain

Inclusion Criteria:

• Persistent Idiopathic Facial Pain fulfilling diagnostic criteria as classified in The International Classification of Headache Disorders, 3rd edition (ICHD-3 beta version) as modified by the authors of this trial. See below.
• Unsatisfactory effect of available treatment methods as evaluated by a neurologist, ENT specialist or maxillofacial surgeon. The patient should have failed treatment with both anticonvulsant as carbamazepine (Tegretol, Carbatrol) and antidepressant as tricyclic antidepressants
• Average Pain intensity ≥4 (0-10) in Numeric Pain Rating Scale (NRS) on the affected side during the 4-week baseline period
• Written informed consent from the patient

Modified diagnostic criteria for PIFP according to The International

Classification of Headache Disorders, 3rd edition (ICHD-3 beta version):

A. Facial and/or oral pain fulfilling criteria B and C.

B. Recurring daily for >2 hr per day for >3 months

C. Pain has both of the following characteristics:

1. Poorly localized and may radiate beyond the trigeminal nerve distribution
2. Dull, aching or nagging quality D. Clinical neurological examination is normal, however patient may denote paresthesia E. A dental cause has been excluded by appropriate investigations; signs of structural pathology or other specific causes of pain are not identified. Minor operation and injury (insignificant trauma e.g. tooth extraction) to the face, maxilla, teeth and gums without a direct causal relationship with the pain regarding both time and site is accepted. F. Not better accounted for by another ICHD-3 diagnosis.

Exclusion Criteria:

• Bilateral symmetrically affected
• Neurological disorders or other related systemic diseases that can explain the pain
• MRI/CT examination confirming intracranial pathology.
• Systemic or local disease or condition that can give a significantly increased risk of complications to the particular procedure
• Not competent to asses informed consent based on neurological assessment
• Psychiatric disorder that prevents the completion of the study
• Pregnancy
• Inappropriate use of contraception
• Breastfeeding
• Abuse or unauthorized use of medication, drugs or alcohol
• Allergy or other hypersensitivity reactions to marcaine, lidocaine, xylocaine, or adrenaline, possibly similar related drugs
• Anatomical factors that prevent or impede the injection
• Known hypersensitivity to botulinum toxin type A or to any of the excipients
• Treatment with drugs that can interact with botulinum toxin type A: aminoglycoside antibiotics, spectinomycin, neuromuscular blockers, both depolarizing (succinylcholine) and non-depolarizing (tubocurarine derivatives), lincosamides, polymyxins, quinidine, magnesium sulfate, anticholinesterases.