Local anaesthesia decreases nerve growth factor induced masseter hyperalgesia

Abstract The aim of this investigation was to evaluate the effects of local anaesthesia on nerve growth factor (NGF) induced masseter hyperalgesia. Healthy participants randomly received an injection into the right masseter muscle of either isotonic saline (IS) given as a single injection (n = 15) or an injection of NGF (n = 30) followed by a second injection of lidocaine (NGF + lidocaine; n = 15) or IS (NGF + IS; n = 15) in the same muscle 48 h later. Mechanical sensitivity scores of the right and left masseter, referred sensations and jaw pain intensity and jaw function were assessed at baseline, 48 h after the first injection, 5 min after the second injection and 72 h after the first injection. NGF caused significant jaw pain evoked by chewing at 48 and 72 h after the first injection when compared to the IS group, but without significant differences between the NGF + lidocaine and NGF + IS groups. However, the mechanical sensitivity of the right masseter 5 min after the second injection in the NGF + lidocaine group was significantly lower than the second injection in the NGF + IS and was similar to the IS group. There were no significant differences for the referred sensations. Local anaesthetics may provide relevant information regarding the contribution of peripheral mechanisms in the maintenance of persistent musculoskeletal pain.

Download Full-text

Effects of nerve growth factor experimentally-induced craniofacial muscle sensitization on referred pain frequency and number of headache days: A double-blind, randomized placebo-controlled study

Cephalalgia ◽

10.1177/0333102418758481 ◽

2018 ◽

Vol 38 (14) ◽

pp. 2006-2016 ◽

Cited By ~ 6

Author(s):

FG Exposto ◽

M Masuda ◽

EE Castrillon ◽

P Svensson

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Isotonic Saline ◽

Experimental Period ◽

Referred Pain ◽

Controlled Study ◽

Mechanical Sensitivity ◽

Double Blind ◽

Nerve Growth ◽

Pain Frequency

Objective To assess if repeated intramuscular injections of nerve growth factor into the temporalis and masseter muscles increase mechanical sensitivity and entropy scores. Furthermore, to investigate if increased mechanical sensitivity would lead to increased prevalence of referred pain in the studied individuals. Finally, if increased muscle sensitization would lead to an increase in number of headache days during the experimental period. Methods The present double-blind, randomized placebo-controlled study recruited 16 healthy participants who were injected with nerve growth-factor, on 2 days, into the masseter and temporalis muscles and isotonic saline on the contralateral side. Mechanical sensitivity was assessed at seven different time-points (total of 21 days) by application of three different forces to 15 different sites of both muscles. Participants were asked after each force application if they experienced referred pain and were asked to keep a headache diary during the experimental period. Results In summary, a) repeated intramuscular injections of nerve-growth-factor caused an increase in mechanical sensitivity for the masseter but not the temporalis muscle, and an increase in entropy scores when compared to the isotonic saline side. b) Both referred pain frequency and number of headache days were not increased following nerve-growth-factor injections. Conclusions These findings support the idea that mechanical sensitization in the masseter and temporalis muscles differs following injections of nerve growth factor. Furthermore, referred pain and headache frequency do not seem to be related to nerve growth factor sensitization in this model. These findings support the idea that in healthy individuals referred pain may be an epiphenomenon of the muscle in response to noxious input.

Download Full-text

Human recombinant nerve growth factor (Cenegermin) in a patient affected by primary congenital glaucoma with neurotrophic keratopathy

European Journal of Ophthalmology ◽

10.1177/1120672121999344 ◽

2021 ◽

pp. 112067212199934

Author(s):

Ivano Riva ◽

Eleonora Micheletti ◽

Riccardo Fausto ◽

Carlo Bruttini ◽

Giovanni De Angelis ◽

...

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Congenital Glaucoma ◽

Eye Drops ◽

Nerve Growth ◽

Primary Congenital Glaucoma ◽

Complete Restoration ◽

New Treatment ◽

The Right ◽

Neurotrophic Keratopathy

Purpose: To report a case of neurotrophic keratopathy (NK) in a patient affected by primary congenital glaucoma (PCG) who undergone glaucoma drainage implant surgery. NK was successfully treated with human recombinant Nerve Growth Factor (Cenegermin) eye drops. Case report description: A 46-years-old patient affected by primary congenital glaucoma underwent Ahmed glaucoma valve implantation in the right eye, after several unsuccessful surgeries to control intraocular pressure (IOP) since the age of three. Surgical intervention was performed without complications, and IOP was well-controlled post-operatively. However, 1 month after surgery, he developed NK with stromal ulceration, initially treated with a topical combination of preservative-free artificial tears and antibiotic ointment. As NK did not resolve, a new treatment with Cenegermin 20 µg/ml eye drops, 6 times daily, was started. Outcome: NK completely resolved after 8 weeks of Cenegermin treatment, with complete restoration of corneal integrity and improvement of corneal sensitivity and transparency. Visual acuity in the operated eye reverted to the pre-operative value. Conclusion: Cenegermin was extremely effective in restoring corneal integrity in this PCG patient with NK.

Download Full-text