Hypoglossal nerve palsy is a clinical syndrome characterized primarily by deviation of the tongue, retraction of the tongue, and dysarthria. The hypoglossal nerve is mainly composed of somatic efferent fibers and innervates both the intrinsic and extrinsic muscles of the tongue, including the styloglossus, hyoglossus, and genioglossus muscles.
I. Etiology
This condition is often triggered by secondary intracranial or extracranial lesions. Cranial nerve palsy (hypoglossal nerve palsy) resulting from cerebrovascular disease, brain tumors, or traumatic brain injury frequently presents in conjunction with hemiplegia. Syringobulbia, early-stage amyotrophic lateral sclerosis (ALS), deep high-cervical trauma, tabes dorsalis, tumors at the base of the tongue, and local inflammation can also directly or indirectly induce hypoglossal nerve palsy.
II. Diagnostic Points
- Unilateral hypoglossal nerve palsy: This is the most common clinical presentation. Upon protrusion, the tongue deviates toward the affected side, accompanied by atrophy of the ipsilateral tongue muscles. If the lesion involves the hypoglossal nucleus, fasciculations may be observed in the atrophied tongue muscles. Because the tongue muscle fibers decussate at the midline and receive bilateral innervation, the functional impairment resulting from a unilateral lesion is usually mild.
- Bilateral hypoglossal nerve palsy is clinically rare. It manifests as complete paralysis of the tongue muscles, with the tongue unable to move and remaining fixed on the floor of the mouth. Articulation is notably impaired, making it difficult to produce lingual sounds; eating is obstructed. Retraction of the tongue may also lead to respiratory difficulty.
3. Treatment Plan
(I) Point Selection and Needling Technique
- **Upper Lianquan (Shanglianquan, extra point)** **Location:** At the midpoint of the line connecting CV23 (Lianquan) and the mental protuberance (chin bone). **Operation:** Use a 30-gauge, 1.5-cun filiform needle. After routine local disinfection, insert obliquely toward the root of the tongue to a depth of approximately 1.2 cun. **Needle sensation:** Distension and pain at the root of the tongue.
- **Taiyang (EX-HN5) penetrating to GB8 (Shuaigu) (bilateral)** **Location:** Taiyang (EX-HN5) is located in the temporal region, in the depression one finger-breadth posterior to the midpoint of the line connecting the lateral end of the eyebrow and the outer canthus. GB8 (Shuaigu) is located in the temporal region, 1.5 cun directly above the apex of the auricle. **Operation:** A 30-gauge, 2.5 cun filiform needle is selected. After routine local disinfection, a transverse (oblique) insertion is made from Taiyang (EX-HN5) toward GB8 (Shuaigu). **Needling sensation:** Local distension and pain.
- **LI4 (Hegu) (Bilateral)** **Location:** On the dorsum of the hand, between the 1st and 2nd metacarpal bones, approximately at the midpoint of the radial side of the 2nd metacarpal bone. **Method:** Use a gauge-30, 2 cun filiform needle. After routine local disinfection, insert obliquely toward SI3 (Houxi) to a depth of about 1.8 cun. **Needling Sensation:** Local distension and soreness.
(2) Treatment Methods
The patient is seated. The points are needled according to the above-mentioned manipulations, and the needles are retained for 40 minutes. During retention, the needles are twisted once. Treatment is given once daily, with 10 sessions constituting one course. After completing a course, a 5-day rest is taken before proceeding to the next course.
IV. Commentary
Simple unilateral hypoglossal nerve palsy responds remarkably well to the aforementioned acupuncture therapy. In clinical practice, most patients develop this condition secondary to cerebrovascular disease or traumatic brain injury, often presenting with concurrent hemiplegia and a more complex clinical picture. Management should follow a comprehensive treatment approach for cerebrovascular disease, combining primary disease management with this set of acupoints (point selection). The recovery period for such patients is relatively prolonged, and tongue function tends to improve gradually alongside the recovery of hemiplegia and language function. Overall, this therapy demonstrates therapeutic benefit for both simple hypoglossal nerve palsy and hypoglossal nerve palsy secondary to intracranial pathology.