Olfactory nerve disorder is a clinical condition characterized by anosmia, hyperosmia, parosmia, and phantosmia, resulting from olfactory nerve injury due to various causes.
The causes of olfactory nerve disorders are numerous. The most common include common cold, allergic rhinitis, atrophic rhinitis, aura of epilepsy, schizophrenia, hysteria, neurasthenia, and nasal polyps. Other causes include arhinencephaly, olfactory aging (e.g., in the elderly), meningioma, pituitary tumor, tumor of the orbital surface of the frontal lobe, chronic basal arachnoiditis of the skull, increased intracranial pressure, tumors of the hippocampal gyrus and uncus of the temporal lobe, metastatic carcinoma, and olfactory hallucination during Qigong practice.
Diagnostic Criteria
The main manifestations include the following 4 types:
I. Anosmia
The patient experiences a marked reduction or complete loss of smell, often accompanied by diminished taste for sour, sweet, bitter, and salty.
Hyperosmia (Olfactory Hypersensitivity)
Hyperosmia, characterized by heightened sensitivity to any odor and causing extreme discomfort, is a clinically rare olfactory disorder. Some consider it may be a symptom of increased intracranial pressure.
3. Parosmia
The patient presents with parosmia, typically perceiving unpleasant odors, often occurring during the recovery phase of anosmia. This condition may also be seen in cases of head trauma, during the course of tabes dorsalis, or following administration of amidopyrine.
After delivery, sometimes also seen in pregnant women, considered to be related to endocrine factors.
4. Olfactory hallucination
The patient experiences phantom smells (olfactory hallucinations) that are not actually present, often perceived as unpleasant odors such as “burning rubber,” “burning wool,” or “rotten duck eggs.” This symptom may occur in the aura of epilepsy, schizophrenia, hysteria, and neurasthenia. In recent years, some practitioners of “Xiang Gong” (scent qigong) have reported smelling jasmine or sandalwood fragrances that are not actually present while in a qigong state. Many cases of phantom smells are often precursors of organic brain diseases, particularly as a distinctive manifestation of lesions in the temporal lobe hippocampus and uncus, thus having important localizing diagnostic significance.
[Treatment]
I. Acupoints and Needling Techniques
1. GV25 (Sùliáo): Located at the tip of the nose. Use a 32-gauge, 1-cun needle. After routine local disinfection, insert rapidly due to the sensitivity of this point, then advance slowly without rotation along the nasal cartilage toward the nasal bone to a depth of approximately 0.8 cun. Needle sensation: distending and stinging pain in the nasal bridge.
2. Yingxiang (LI20, bilateral): Located 0.5 cun lateral to the ala nasi, in the nasolabial groove. Use two 30-gauge, 1 cun filiform needles. Perform routine local disinfection. Insert the needle at a slight oblique angle toward the ala nasi (note: this point is relatively painful; the needling technique for Suliao [GV25] may be applied), to a depth of approximately 0.8 cun. Needle sensation: distending and sharp pain in the maxillary region.
3. GB20 (Bilateral): Located on the posterior neck, in the depression between the upper ends of the sternocleidomastoid and trapezius muscles, level with GV16 (Fengfu). Use two 30-gauge, 2-cun filiform needles. Perform standard local disinfection, then insert obliquely toward the spine to a depth of approximately 1.8 cun (due to the thick skin of the neck, swift insertion is essential; after entering the skin, use a pushing method to avoid bending the needle). Needling sensation: distension and soreness in the neck, possibly radiating to the ipsilateral posterior head.
4. LI4 (Hegu) (bilateral): Located on the dorsum of the hand, between the 1st and 2nd metacarpal bones, near the midpoint of the 2nd metacarpal bone. Use two 30-gauge, 1.5 cun filiform needles. Perform routine local disinfection. Insert obliquely toward the thenar eminence to a depth of approximately 1.3 cun. Needle sensation: distension and pain in the thenar eminence area.
Methods
The patient is seated. The aforementioned acupoints are inserted according to the standard method, and the needles are retained for 40 minutes. The needles are twisted once during retention, then removed. Treatment is administered once daily, with 6 sessions constituting one course. A 3-day rest is taken before the next course.
Commentary
Acupuncture can be effective for certain patients with olfactory disorders. However, the underlying cause of olfactory dysfunction should first be identified. For instance, nasal polyps require surgical treatment; acute or chronic rhinitis and brain tumors should be treated by first addressing the primary lesions before acupuncture is administered. Acupuncture is more effective for general inflammation, hysteria (where adjunctive suggestive therapy can significantly enhance outcomes), neurasthenia, and schizophrenia. For practitioners of Fragrance Qigong who experience olfactory hallucinations in a qigong state, no treatment is necessary, as the hallucinations will resolve once the practice is discontinued.