End-stage Stiff-Person Syndrome (SPS) represents the most advanced and debilitating phase of the disease, characterized by significant loss of independence and widespread muscle involvement.
Here's a breakdown of what defines end-stage SPS:
- Loss of Independence: Approximately 65% of individuals with SPS become unable to function independently, highlighting the severe impact of the disease on daily living.
- Widespread Muscle Involvement: In the end stages, few muscles throughout the body are spared from stiffness and spasms.
- Facial and Pharyngeal Involvement: While trismus (lockjaw) is typically absent, the muscles of the face and throat (pharynx) may be markedly affected, potentially leading to difficulties with speech and swallowing.
- Joint Deformities: Prolonged muscle stiffness and spasms can lead to the development of joint deformities.
| Feature | Description |
|---|---|
| Independence | Significant loss, requiring substantial assistance for daily activities. |
| Muscle Involvement | Widespread; few muscles are spared. |
| Facial/Pharyngeal Muscles | May be markedly affected, impacting speech and swallowing. |
| Trismus | Typically absent. |
| Joint Deformities | Possible due to chronic muscle stiffness and spasms. |
In summary, end-stage SPS is marked by severe disability due to widespread and unremitting muscle stiffness, impacting mobility, speech, swallowing, and potentially leading to joint deformities.
