When should I consider referring a patient with suspected SMA to a specialist for further evaluation?

When considering a referral for a patient with suspected spinal muscular atrophy (SMA), which is a neuromuscular disorder, focus on symptoms of progressive muscle weakness and motor development issues. While SMA is not explicitly named in the provided guidelines, the criteria for referring patients with suspected neurological conditions presenting with similar symptoms are outlined.

• For babies and children:
  • Refer immediately to paediatric services if a baby aged under 1 year presents with acute-onset hypotonia (floppiness) ².
  • If a baby aged under 1 year has hypotonia (floppiness) that has been present for weeks or months and is accompanied by weakness (e.g., feeding and breathing difficulties), refer urgently to paediatric services ².
  • Refer children immediately for neurological assessment if they have sudden-onset or rapidly progressive (hours to days) limb or facial weakness ².
  • Refer children urgently for neurological assessment if they have progressive limb weakness ².
  • Children with motor development regression should be referred to a paediatric neurodevelopmental service or paediatric neurology, depending on locally agreed pathways ².
  • Consider referring children to a child development service if they are not sitting unsupported by 8 months (corrected for gestational age), are not walking independently by 15 months (girls) or 18 months (boys) (corrected for gestational age), or show early asymmetry of hand function before 1 year (corrected for gestational age) ².
  • Any child with features suggestive of neurological disorders other than cerebral palsy should be referred to a specialist in paediatric neurology ¹.
• For adults:
  • Refer adults immediately for neurological assessment and assessment of bulbar and respiratory function if they present with rapidly (within 4 weeks) progressive symmetrical limb weakness ².
  • For adults with slowly (within weeks to months) progressive limb or neck weakness, refer for an assessment for neuromuscular disorders ².
  • If there is any evidence of swallowing impairment alongside slowly progressive weakness, refer urgently ².
  • Refer immediately if there is breathlessness at rest or when lying flat in conjunction with slowly progressive weakness ².
  • If motor neurone disease (MND) is suspected, which shares some symptomatic overlap with SMA, refer the person without delay and specify the possible diagnosis in the referral letter; contact the consultant neurologist directly if urgent ³. Symptoms that may suggest MND include progressive muscular weakness, loss of dexterity, falls or trips, speech or swallowing problems, muscle problems (weakness, wasting, twitching, cramps, stiffness), and breathing problems ³.