Mechanistic Rationale and Clinical Efficacy of Hyperbaric Oxygen Therapy in Chronic Neuropathic Pain: An Evidence-Based Narrative Review

Table 1

Classification of chronic primary pain [4, 5].

Diagnostic entity	Subcategory
Chronic widespread pain	(i) Fibromyalgia
CRPS	(i) CRPS-1; (ii) CRPS-2
Chronic primary headache or orofacial pain	(i) Chronic migraine; (ii) Chronic tension-type headache; (iii) Trigeminal autonomic cephalalgias; (iv) Chronic primary temporomandibular disorder pains; (v) Burning mouth syndrome; (vi) Chronic primary orofacial pain
Chronic primary visceral pain	(i) Chronic primary chest pain syndrome; (ii) Chronic primary epigastric pain syndrome; (iii) Irritable bowel syndrome; (iv) Chronic primary abdominal pain syndrome; (v) Chronic primary bladder pain syndrome; (vi) Chronic primary pelvic pain syndrome
Chronic primary musculoskeletal pain	(i) Chronic primary low back pain; (ii) Chronic primary cervical pain; (iii) Chronic primary thoracic pain; (iv) Chronic primary limb pain

CRPS: chronic regional pain syndrome. Underlined: conditions included in this review.