Ms. Thanh, 50, experienced coughing and breathlessness. Doctors in the US initially diagnosed her with rhinopharyngitis. While some symptoms improved, her hoarseness progressively worsened, leading to near complete voice loss. Seeking further evaluation, she traveled to Tam Anh General Hospital in Ho Chi Minh City. There, a laryngeal stroboscopy revealed reduced mucosal wave and vocal cord vibration, along with congested lesions.

Professor Doctor Tran Phan Chung Thuy, Director of the Ear, Nose, and Throat (ENT) Center, diagnosed Ms. Thanh with spasmodic dysphonia. This condition is a form of focal dystonia affecting the larynx, where vocal muscles contract involuntarily due to central motor dysregulation, resulting in an abnormal voice. The incidence is approximately 1/100,000, commonly affecting middle-aged individuals, with women accounting for 80% of cases.

According to Professor Chung Thuy, spasmodic dysphonia is often overlooked or mistaken for laryngitis and other voice disorders. This is due to its non-specific, intermittent symptoms and overlapping clinical presentations.

Diagnosis of the condition is frequently delayed. Currently, no specific diagnostic test is available. Diagnosis primarily relies on a specialized voice evaluation combined with laryngeal stroboscopy, a thorough medical history, and a clinical examination.

Professor Chung Thuy (left) observes the screen during botox injection for Ms. Thanh at the clinic. *Photo: Tam Anh General Hospital*

Doctor Huynh Hoang Minh, from the ENT Center, inserted a flexible endoscope through the patient's nose. Following this, Professor Chung Thuy precisely injected an appropriate amount of botox through the skin into the cricothyroid muscle in the patient's larynx, targeting both the left and right sides. The entire procedure was completed in approximately 15-20 minutes.

After the injection, Ms. Thanh underwent physical therapy and voice rehabilitation at the hospital. She received guidance on exercises to reduce vocal cord tension when coughing and to lessen vocal cord edema when attempting to speak. Post-intervention, patients are advised to avoid spicy or hot foods and cold beverages, and to attend all scheduled follow-up appointments.

Over two weeks after receiving the botox injection, Ms. Thanh was able to speak audibly and clearly. Her hoarseness and breathlessness significantly reduced. Professor Chung Thuy noted that voice quality continues to improve notably over 1-2 months. The therapeutic effect typically lasts for about 3-6 months before a repeat injection is needed. Due to her excellent recovery, Ms. Thanh returned to the US and subsequently came back to Vietnam for follow-up examinations to maintain the treatment's effectiveness.

Professor Chung Thuy re-examines Ms. Thanh. *Photo: Tam Anh General Hospital*

Professor Chung Thuy explained that prior to the availability of botox, spasmodic dysphonia was primarily managed with oral medications or surgery, but these methods offered limited effectiveness. Botox injections into the laryngeal muscles help to reduce abnormal spasms, thereby improving voice quality.

In the past, botox injections guided by electromyography had limited accuracy and made optimizing the dosage challenging. Currently, flexible endoscopic injection allows doctors to directly visualize the laryngeal muscles, enabling more precise positioning and reducing post-injection complications.

The majority of laryngeal dystonia cases are idiopathic or spontaneous. Doctors recommend that individuals experiencing symptoms such as difficulty speaking, voice tremors, hoarseness, or aphonia seek early consultation with an ENT specialist. This ensures timely diagnosis and treatment, which helps prevent chronic vocal cord damage.

Uyen Trinh

*Patient's name has been changed