Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about spinal muscular atrophy.

And if you want to follow along with written notes on this topic,

you can follow along at ZeroDefinals.com slash SMA

or in the neurology section of the zero definals pediatrics book.

So let's get straight into it.

Spinal muscular atrophy, or SMA, is a rare autosomal recessive condition

that causes a progressive loss of motor neurons causing progressive muscular weakness.

Spinal muscular atrophy affects the lower motor neurons in the spinal cord. This means there will be lower motor neuron signs such as

fasciculations, reduced muscle bulk, reduced tone, reduced power and reduced or absent reflexes.

There are four categories of spinal muscular atrophy that are numbered from the most to the least

severe. Spinal muscular atrophy type 2 is the most common type. SMA type 1 has an onset in the first few months of life, usually

progressing to death within two years. SMA type 2 has an onset in the first 18 months.

Most patients never walk but they do survive into adulthood.

SMA type 3 has an onset after the first year of life.

Most walk without support but subsequently lose that ability.

Respiratory muscles are less affected and life expectancy is close to normal.

SMA type 4 has an onset in the patient's 20s. Most will retain the ability

to walk short distances but require a wheelchair for mobility. Everyday task can lead to significant

fatigue. Respiratory muscles and life expectancy are not affected. Let's talk about management.

There's no cure for spinal muscular atrophy. Management is supportive and involves the

multidisciplinary team. Physiotherapy can be helpful in maximizing strength in the muscles

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