What causes lstv

What is Low Slow Tremulous Voice (LSTV)?

Low Slow Tremulous Voice (LSTV), sometimes referred to as functional dysphonia or vocal tremor, is a voice disorder characterized by a voice that is consistently soft, breathy, and exhibits a noticeable tremor or shakiness. Individuals with LSTV often struggle with vocal projection, experiencing fatigue quickly when speaking. The voice may sound weak, unstable, and lack the usual resonance and clarity. It's important to distinguish LSTV from other voice disorders, such as those caused by structural abnormalities of the vocal cords or neurological diseases, although sometimes symptoms can overlap.

Understanding the Causes of LSTV

The exact cause of LSTV is not always definitively known, but it is generally understood to be a functional voice disorder. This means that there are no visible structural abnormalities or neurological diseases directly causing the vocal dysfunction. Instead, the problem lies in how the voice is produced and managed.

Breath Support Issues

A primary contributing factor to LSTV is inadequate or uncoordinated breath support. Effective voice production relies on a steady and controlled airflow from the lungs to vibrate the vocal cords. When breath support is weak, irregular, or not properly managed, the vocal cords do not receive the consistent pressure needed for optimal vibration. This can lead to a breathy quality, as air escapes around the vocal cords without fully vibrating them, and a tremulous quality as the vocal mechanism struggles to maintain a stable vibration.

Laryngeal Muscle Tension

Another significant factor is excessive tension in the muscles surrounding the larynx (voice box). The vocal cords are controlled by a complex network of intrinsic and extrinsic laryngeal muscles. In LSTV, these muscles may be held too tightly, or there might be an imbalance in their coordination. This tension can restrict the vocal cords' ability to vibrate freely and efficiently. The muscles may overcompensate for poor breath support by gripping too tightly, further exacerbating the problem and leading to the characteristic tremor.

Psychological and Emotional Factors

While LSTV is not solely a psychological disorder, emotional states can significantly influence its manifestation and severity. Stress, anxiety, and nervousness can lead to increased muscle tension throughout the body, including the laryngeal area. For individuals predisposed to LSTV, these emotional factors can trigger or worsen their vocal symptoms. The fear or awareness of having a shaky voice can also create a feedback loop, where the anxiety about the voice itself causes more tension and tremor.

Learned Vocal Habits

In some cases, LSTV may develop from learned vocal habits. This can occur if a person has, for example, habitually spoken with inadequate breath support or excessive tension due to environmental factors, prolonged illness, or even imitation. Over time, these habits can become ingrained, leading to the persistent symptoms of LSTV even when the original cause is no longer present.

Contributing Factors and Risk Factors

While not direct causes, certain factors can contribute to or increase the likelihood of developing LSTV:

• Vocal Strain: Prolonged or improper use of the voice, such as shouting or speaking for extended periods without rest, can contribute to vocal fatigue and muscle imbalances.
• Stress and Anxiety: As mentioned, these can directly impact muscle tension and breath control.
• Dehydration: Insufficient fluid intake can affect the lubrication of the vocal cords, making them more prone to irritation and inefficient vibration.
• Environmental Factors: Exposure to irritants like smoke or dry air can negatively impact vocal health.

Diagnosis and Treatment

Diagnosing LSTV typically involves a comprehensive evaluation by a speech-language pathologist (SLP). This usually includes a detailed patient history, perceptual assessment of the voice (listening to its quality, pitch, loudness, and breathiness), and sometimes instrumental assessments like acoustic analysis or aerodynamic measurements. An otolaryngologist (ENT doctor) may also examine the vocal cords to rule out any structural or neurological issues.

Treatment for LSTV primarily focuses on voice therapy. The goals of therapy include:

• Improving Breath Support: Learning diaphragmatic breathing techniques to provide a steady and controlled airflow.
• Reducing Laryngeal Tension: Implementing relaxation exercises for the neck, shoulders, and laryngeal muscles.
• Optimizing Vocal Cord Vibration: Using exercises to promote efficient and resonant vocal fold closure and vibration.
• Addressing Psychological Factors: Incorporating strategies to manage stress and anxiety related to voice use.

In most cases, consistent participation in voice therapy can lead to significant improvement in voice quality and function for individuals experiencing LSTV.