Most common cause of death in amyotropic lateral sclerosis is
**Core Concept**
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting the motor neurons, leading to muscle weakness and paralysis. The **respiratory system** is particularly vulnerable due to the involvement of diaphragmatic and accessory muscles.
**Why the Correct Answer is Right**
The most common cause of death in ALS is respiratory failure, often due to the inability of the diaphragm and other respiratory muscles to function properly. This leads to inadequate ventilation, resulting in **hypoxia** and **hypercapnia**.
**Why Each Wrong Option is Incorrect**
**Option A:** Not specified, but typically other options like cardiac arrest or sepsis are less common causes of death in ALS.
**Option B:** Similarly, not specified, but usually, it would be an incorrect choice as the primary cause of death.
**Option D:** Not the most common cause, as ALS primarily affects motor neurons, not directly causing death through other means.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that ALS patients often require **non-invasive ventilation** to support breathing as the disease progresses, highlighting the critical role of respiratory management in their care.
**Correct Answer:** D. Respiratory failure.