There are several other types of motor neuron diseases as well.
Overview
Conditions that affect the motor neurons are described as motor neuron diseases.
Motor neurons are located throughout the length of the spinal cord in columns described asanterior horns.
David Osberg / Getty Images
Some motor neuron diseases affect only the upper motor neurons, whereas others affect primarily the lower motor neurons.
Some, like ALS, affect both.
The condition begins in the hands more often than the feet.
It is not certain just how common PLS is, but it is less common than ALS.
PLS tends to progress more slowly than ALS, with patients commonly living about a decade with their symptoms.
Other conditions, such as hereditary spastic paraparesis, will also need to be ruled out.
As a result, someone with progressive bulbar palsy will start having difficulty speaking, swallowing and chewing.
Limb weakness may also become evident as the disease progresses, with both upper and lower motor neuron signs.
Myasthenia gravisis an autoimmune neuromuscular disorder that may cause similar symptoms at early stages.
Thankfully, due to aggressive vaccinations, this virus has largely been eradicated.
Some people who have had the disease may later develop a pop in of weakness known as post-polio syndrome.
This may be due to aging or injury causing the relatively few surviving motor neurons to die.
The disorder only affects older people who have had polio in the past.
It is usually not life-threatening.
Kennedys Disease
Kennedy’s disease is due to anX-linked genetic mutationthat affects the androgen receptor.
The disorder causes slowly progressive weakness and pain of the muscles closest to the torso.
The face, jaw, and tongue are also involved.
Because it is X-linked, Kennedys disease generally affects men.
Spinal Muscular Atrophy
Spinal muscular atrophyis an inherited disease that predominantly begins during childhood.
It is brought on by defects in the SMN1 gene and is inherited in an autosomal recessive pattern.
This leads to weakness and muscle wasting.
Progressive Muscular Atrophy
Progressive muscular atrophy (PMA) affects only the lower motor neurons.
Progressive weakness is a common symptom.
Progressive muscular atrophy is less common than ALS and has a better prognosis.
Since upper motor neurons are not affected, upper motor neuron signs such as rigidity do not occur.
The symptoms of PMA are similar to those of other conditions.
Diagnosis and Treatment
There is no curative treatment for motor neuron disease.
Medical therapy focuses on controlling symptoms of the disease and preventing complications.
You may feel alone if you’ve been diagnosed with a motor neuron disease.
People with motor neuron diseases need support.
Awareness of motor neuron diseases is rising.
Measures such as the Orphan Drug Act are directing more attention to these less common conditions.
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Genetic and Rare Diseases Information Center.Progressive bulbar palsy.
National Institute of Neurological Disorders and Stroke.Post-Polio Syndrome Fact Sheet.
Garg N, Park SB, Vucic S, et al.Differentiating lower motor neuron syndromes.J Neurol Neurosurg Psychiatry.
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