Lecture 12: Motor Neuron Disease Flashcards
1
Q
ALS breakdown
A
- Amytrophy: muscle wasting LMN
- Lateral sclerosis: loss of lateral corticospinal tract UMN
2
Q
Treatment
A
Riuzole
- increases lifespan by 3 months
- NMDA antagonist
3
Q
Features of MND
A
- characterised by upper +/- lower MN loss
- sensation is preserved
- Few groups of MN spared: sphincter control, extraocular muscles
4
Q
Symptoms
A
(-) muscle weakness, cramps, flaccid paralysis
(+) hyper reflexia, spastic paralysis
5
Q
Diagnosis
A
- Not definitive
- Rule out other diseases
- Motoneuronal degeneration determined by:
- clinical tests
- electrophysiological tests
6
Q
Types
A
- sporadic: 95%
- familial: 5%
7
Q
Sporadic
A
- middle-late onset
- Slight preference for males
- UMN +/- LMN loss
- muscle weakness, cramps, wasting, paralysis
- death within 2 yrs due to resp-related illnesses
8
Q
Spinal Muscular Atrophy
A
- progressive loss of LMNs
- Types: infantile and juvenile
- recessive mutation in SMN1
9
Q
Hypotheses on Causes of MND
A
- genetics
- excitotoxicity
- oxidative stress
10
Q
Excitotoxicity
A
- Loss of glial glutamate transporters -> excessive glutamate -> act on NMDA receptors -> cell death
Although: - only some reports of decreased glutamate transporters and increased glutamate in CSF
- NMDA antagonist only extends like by 90 days:?
11
Q
Oxidative Stress
A
- SOD-1 scavenges free-radicals
-> mutation in SOD-1 -> increase in free radicals -> cell injury
Although: - SOD1 mutation kill other cells too -> not specific to MN death as seen in MND