Background & Aims
Orofacial Pain (OFP) affects 15% of the general population with high prevalence in young and middle-aged women. OFP can be difficult to diagnose due to varied signs and symptoms, complex anatomy of the region and lack of objective testing in most cases. The underlying etiology and pathogenesis in idiopathic OFP is unknown, hence, treatment is nonspecific and outcomes unsatisfactory. Small fiber neuropathy (SFN) is a disorder of thinly myelinated A-delta and non-myelinated C- fibers, and can manifest as sensory and autonomic neuropathies, and abnormal nerve fiber density in skin biopsy. SFN has been shown to involve the orofacial region and has been demonstrated in idiopathic burning mouth syndrome, where abnormal nerve fiber density was noted in tongue biopsy specimen in affected patients. This study aims to assess the presence of OFP in patients with chronic sensory and autonomic neuropathies and assess the correlation between OFP, skin biopsy and autonomic dysfunction.
Methods
This is a retrospective chart review of patients from the SFN registry which is maintained by the Neurology Department at Massachusetts General Hospital (MGH), Boston, USA.
All patients in this Registry from 2018- 2020 were included. The charts of these patients were reviewed by OFP specialist for presence of OFP.
Inclusion criteria: Patients of all gender and ages who have undergone diagnostic skin biopsy for SFN at MGH.
Exclusion criteria: OFP due to known pathology.
Primary outcome: Prevalence of OFP in patients with chronic sensory and autonomic neuropathies. Secondary outcome: Correlation between OFP and skin biopsy, dysautonomia, headaches, and chronic nociceptive pains
Biostatistical Analysis: Data was de-identified. Mean, range, frequencies were used for calculating descriptive variables. Statistical comparison was performed using student t-test for continuous variables and chi-squared test for categorical variables. Statistical significance was set at p value<0.05.
Results
Charts of 450 patients with sensory and autonomic neuropathies were reviewed. 22.67% (n=102) had OFP. The mean (range) age at biopsy in patients with OFP was 48.36 (20-81) years, female: male ratio 3.25:1. 84.3 % (86/102) patients were Caucasians, and 6.8% (7/102) were Latinos/Hispanic. There was no significant difference in mean age (p value =0.822), gender predilection (p value =0.129), mean BMI (p value =0.138), and racial (p value=0.721) or ethnic predilection (p value=0.642) between patients with OFP when compared with the ones without OFP. Most OFP patients (73.53%) were either overweight or obese (BMI >25). More OFP patients had negative skin biopsy results (p value<0.05). No significant differences were noted in the presence of headaches, peripheral neuropathies and nociceptive pain, and dysautonomia between patients with and without OFP.
Conclusions
OFP and sensory and autonomic neuropathies can be overlapping conditions. Recognizing the coexistence of these conditions in patients can help understand the underlying pathophysiology. Presence of autonomic symptoms in more than half the patients signify a possible centralized pain phenomenon rather than just a peripheral insult. A multidisciplinary team to include neurologists and OFP specialists is pivotal in understanding the correlation, if present, between sensory and autonomic neuropathies, skin biopsy testing, autonomic function testing, and presence of OFP. This can help understand the underlying cause in some idiopathic facial pain conditions.
Limitations: There is a possibility that this study underestimates the prevalence of OFP in this cohort who underwent work up for SFN and hence the data can be skewed due to more patients with typical length-dependent neuropathic symptoms.
References
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Presenting Author
Annika Rosén
Poster Authors
Shruti Handa
BDS, DMD
Massachusetts General Hospital, Harvard School of Dental Medicine
Lead Author
Megan Heffernan
Athinoula A. Martinos Center for Biomedical Imaging
Lead Author
Summer Tan
Harvard school of dental medicine
Lead Author
David A. Keith DMD
BDS
Massachusetts General hospital/Harvard school of dental medicine
Lead Author
Annika Rosén
Universitetet i Bergen
Lead Author
Topics
- Specific Pain Conditions/Pain in Specific Populations: Orofacial Pain