Motor neuron disease Flashcards
What is motor neuron disease?
Motor neuron disease is a neurological condition of unknown cause that can present with both upper and lower motor neuron signs.
At what age does motor neuron disease typically present?
It rarely presents before 40 years.
What are the recognized patterns of motor neuron disease?
Patterns include amyotrophic lateral sclerosis (ALS), progressive muscular atrophy, and bulbar palsy.
What is the most common presentation of ALS?
Asymmetric limb weakness is the most common presentation of ALS.
What signs indicate motor neuron disease?
A mixture of lower motor neuron and upper motor neuron signs.
What muscle wasting is common in motor neuron disease?
Wasting of the small hand muscles/tibialis anterior is common.
What are fasciculations?
Fasciculations are involuntary muscle contractions that can occur in motor neuron disease.
What sensory signs/symptoms are present in motor neuron disease?
There is an absence of sensory signs/symptoms, although vague sensory symptoms may occur early in the disease (e.g. limb pain).
Do external ocular muscles get affected in motor neuron disease?
No, external ocular muscles are not affected.
What cerebellar signs are present in motor neuron disease?
There are no cerebellar signs.
What happens to abdominal reflexes in motor neuron disease?
Abdominal reflexes are usually preserved.
Is sphincter dysfunction an early feature of motor neuron disease?
No, sphincter dysfunction, if present, is a late feature.
How is the diagnosis of motor neuron disease made?
The diagnosis is clinical, but nerve conduction studies can help exclude a neuropathy.
What do electromyography results show in motor neuron disease?
Electromyography shows a reduced number of action potentials with increased amplitude.
Why is MRI performed in suspected motor neuron disease cases?
MRI is usually performed to exclude the differential diagnosis of cervical cord compression and myelopathy.
What is motor neuron disease?
A neurological condition of unknown cause presenting with upper and lower motor neuron signs.
It rarely presents before 40 years and includes patterns like amyotrophic lateral sclerosis, progressive muscular atrophy, and bulbar palsy.
What is Riluzole used for?
It prevents stimulation of glutamate receptors and is mainly used in amyotrophic lateral sclerosis.
It prolongs life by about 3 months.
What type of respiratory care is used for motor neuron disease?
Non-invasive ventilation, usually BIPAP, is used at night.
Studies have shown a survival benefit of around 7 months.
What is the preferred method for nutritional support in motor neuron disease?
Percutaneous gastrostomy tube (PEG) is the preferred way to support nutrition.
It has been associated with prolonged survival.
What is the prognosis for motor neuron disease?
The prognosis is poor, with 50% of patients dying within 3 years.
What is motor neuron disease?
Motor neuron disease is a neurological condition of unknown cause which can present with both upper and lower motor neuron signs.
At what age does motor neuron disease typically present?
It rarely presents before 40 years.
What are the recognized patterns of motor neuron disease?
The recognized patterns include amyotrophic lateral sclerosis, primary lateral sclerosis, progressive muscular atrophy, and progressive bulbar palsy.
What percentage of motor neuron disease patients have amyotrophic lateral sclerosis?
50% of patients.
What are the typical signs of amyotrophic lateral sclerosis?
Typically LMN signs in arms and UMN signs in legs.
What gene is responsible for familial cases of amyotrophic lateral sclerosis?
The gene responsible lies on chromosome 21 and codes for superoxide dismutase.
What type of signs are present in primary lateral sclerosis?
UMN signs only.
What type of signs are present in progressive muscular atrophy?
LMN signs only.
Which muscles are affected first in progressive muscular atrophy?
Distal muscles before proximal.
What is the prognosis for progressive muscular atrophy?
Carries the best prognosis.
What is progressive bulbar palsy?
Palsy of the tongue, muscles of chewing/swallowing, and facial muscles due to loss of function of brainstem motor nuclei.
What is the prognosis for progressive bulbar palsy?
Carries the worst prognosis.
