Mode of SMA Disease:
a shared narrative among patients.

Without treatment, motor function decline in Spinal Muscular Atrophy (SMA) Type II and III is inevitable.1
It’s a story all too familiar, but what does it look like?

Take a journey through progressive motor function loss in late-onset SMA Type II and III adults.

Change in HFMSE score

1 0 -1 -2 -3 -4 -5 0 10 20 30 40 Type III Type II Combined Months

1.71 - point decrease

at 36 months (maximum score = 66)

Mouse over
to view

1. Motor function preservation is vital.

The prognosis in untreated SMA is often proportional to the maximum motor function achieved.2

2. Motor function progressively declines.

In this prospective cohort study, 79 patients declined by an average of: –0.54 points over 24 months (NS) and –1.71 points over 36 months (p=0. 01) on the HFSME.1

3. Decline occurs across phenotypes and ages.

There was no significant difference in change between SMA types or ages.1

4. How do the numbers translate to experience?

For an SMA Type III patient diagnosed during infancy, such decline could mean loss of ambulation in the next few years.3

5. What does it mean?

It can mean everything. In fact, two SMA Type II subjects and one SMA Type III subject lost the ability to sit, while five SMA Type III subjects lost the ability to walk during this study.1

6. How can I help?

Understanding the motor functions patients value most and want to preserve in their lives is the place to begin.

SMA II (n=41), SMA III (n=38), Overall (N=79)

Adapted from Kaufmann et. al. 2012

Type III Type II Combined

Take a journey through progressive motor function loss in late-onset SMA Type II and III adults.

Change in HFMSE score

Swipe for
more data

1. Motor function preservation is vital.

The prognosis in untreated SMA is often proportional to the maximum motor function achieved.2

2. Motor function progressively declines.

In this prospective cohort study, 79 patients declined by an average of: –0.54 points over 24 months (NS) and –1.71 points over 36 months (p=0. 01) on the HFSME.1

3. Decline occurs across phenotypes and ages.

There was no significant difference in change between SMA types or ages.1

4. How do the numbers translate to experience?

For an SMA Type III patient diagnosed during infancy, such decline could mean loss of ambulation in the next few years.3

5. What does it mean?

It can mean everything. In fact, two SMA Type II subjects and one SMA Type III subject lost the ability to sit, while five SMA Type III subjects lost the ability to walk during this study.1

6. How can I help?

Understanding the motor functions patients value most and want to preserve in their lives is the place to begin.

Untreated patients with Type III SMA with symptom onset at 18 to 36 months may stand and walk independently at some point but often lose this function over time.4 Due to SMA’s natural progressive decline, the probability of being ambulatory at 15 years post-symptom onset is 48.9%. With a disease duration of 25 years, this further declines to 30.3%.3 The shared narrative of decline in SMA is clear. Left untreated, it leads to a series of gradual and irreversible losses of motor function that patients may only recognize years later.5,6 

Ambulation is key for patients, but other everyday activities are too.

  • In a patient survey consisting of 812 replies from 16 countries, 8 out of 10 patients reported stabilisation would represent major progress from treatment.7
  • Some functions patients wish to stabilise include: performing transfers on their own, turning in bed alone, dressing & using the restroom independently.7

SMA is always at work, but so are we. Seeking opportunities to preserve motor function is the first step to making a difference for your patients.

Which motor functions are the most important?

The top three functions to preserve were:

  • self-feeding (37%),
  • washing independently  (28%)
  • and using a keyboard  (26%)7.

Learn about treating adults with SMA:

References
1. Kaufmann, P., et al. "Prospective cohort study of spinal muscular atrophy types 2 and 3." Neurology 79.18 (2012): 1889-1897.
2. Kolb, S., et al. "Spinal muscular atrophy." Neurologic clinics 33.4 (2015): 831-846.
3. Zerres, K., et al. "A collaborative study on the natural history of childhood and juvenile onset proximal spinal muscular atrophy (type II and III SMA): 569 patients." Journal of the neurological sciences 146.1 (1997): 67-72.
4. Darras, B., et al., eds. Neuromuscular disorders of infancy, childhood, and adolescence: a clinician's approach. Elsevier, 2014.
5. Wadman, R., et al. "Muscle strength and motor function throughout life in a cross‐sectional cohort of 180 patients with spinal muscular atrophy types 1c–4." European journal of neurology 25.3 (2018): 512-518.
6. Vuillerot, C., et al. "Responsiveness of the motor function measure in patients with spinal muscular atrophy." Archives of physical medicine and rehabilitation 94.8 (2013): 1555-1561.
7. Rouault, F., et al. "Disease impact on general well-being and therapeutic expectations of European type II and type III spinal muscular atrophy patients." Neuromuscular Disorders 27.5 (2017): 428-438.