What Are the Symptoms of Motor Neuron Disease?

Motor neuron disease (MND) presents a range of clinical symptoms that primarily affect the nerves responsible for voluntary muscle movements. These symptoms can vary depending on the type and progression of the disease, but they typically fall into several key categories.

1. Motor Impairments

One of the most noticeable signs of MND is progressive muscle dysfunction. This includes muscle atrophy, involuntary muscle twitches or fasciculations, stiffness in the limbs, and difficulty with walking or maintaining balance. Patients may also experience reduced manual dexterity and coordination.

2. Speech and Swallowing Difficulties

Speech-related issues are common among individuals with motor neuron disease. These can include dysarthria (difficulty forming words), atrophy of the tongue muscles, tongue tremors, slurred speech, and trouble swallowing. These symptoms can lead to frequent choking or coughing, especially during meals, and are often linked to bulbar palsy.

3. Upper Motor Neuron Signs

Patients may exhibit signs of upper motor neuron involvement, such as hyperreflexia (overactive tendon reflexes), positive pathological reflexes (like the Babinski sign), and increased muscle tone or spasticity. These symptoms typically contribute to stiffness and difficulty with controlled movements.

4. Preservation of Autonomic Function

Interestingly, autonomic functions remain largely unaffected in most cases of MND. This means that sensory perception, bladder and bowel control, and sexual function typically remain intact, distinguishing MND from other neurological disorders that impact these systems.