What does HFMSE measure in SMA?

HFMSE assesses 33 motor activities on a 0-66 scale; scores >0 indicate meaningful function. A ≥3 point increase is a meaningful clinical improvement on drug therapy.

How does SMN2 copy number affect SMA severity?

1 copy: type 1 (most severe, no sitting); 2 copies: type 1-2; 3 copies: type 2-3; 4 copies: type 3-4. Each additional copy partially compensates for SMN1 loss.

What is the CHOP-INTEND scale used for?

CHOP-INTEND (Children Hospital of Philadelphia Infant Test of Neuromuscular Disorders) is used for SMA type 1 infants; scores 0-64 with ≥4 point improvement considered meaningful.

When should presymptomatic SMA be treated?

Presymptomatic treatment (detected by newborn screening) provides dramatically better outcomes; gene therapy or nusinersen initiated before symptom onset preserves motor neurons.

What respiratory monitoring is required in SMA?

FVC% predicted by age and ambulatory status, peak cough flow, overnight oximetry/capnography for nocturnal hypoventilation, and swallowing assessment guide respiratory and nutritional management.

Spinal Muscular Atrophy Motor Function Calculator (HFMSE)

Calculates the Hammersmith Functional Motor Scale Expanded (HFMSE) for spinal muscular atrophy types 2-3, assessing motor milestones and tracking response to nusinersen, risdiplam, or onasemnogene therapy.

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Frequently Asked Questions

What does HFMSE measure in SMA?

How does SMN2 copy number affect SMA severity?

What is the CHOP-INTEND scale used for?

When should presymptomatic SMA be treated?

What respiratory monitoring is required in SMA?