Werdnig-Hoffmann disease

From Paeds.co.uk the online paediatrician's encyclopaedia

Jump to: navigation, search

Werdnigg-Hoffman is the most severe form of Spinal Muscular Atrophy (SMA). Progressive loss of brainstem and spinal motor neurones results in worsening weakness.

  • Also known as Spinal Muscular Atrophy type I and previously Infantile Spinal Muscular Atrophy.

See also the associated article: Spinal Muscular Atrophy.


Lower motor neurones only are affected in Wernig-Hoffman. Progressive destruction results in weakness and reduced movements.

  • An abnormal 'Survival Motor Neurone' (SMN) gene has been implicated.

Clinical Features and Diagnosis

Progressive weakness and reduced movement are the primary features, sometimes evident in-utero.

  • Reduced foetal movement (final trimester)
  • Hypotonia in all muscle groups
    • Never able to sit upright
  • Impaired swallow / feeding
  • Respiratory impairment
  • Weak cry
  • Reduced reflexes / areflexia

Diagnosis is based on clinical suspicion

  • EMG: Denervation and fibrillation
  • Creatinine-Kinase: normal or elevated
  • SMN gene mutation

Treatment and Prognosis

Prognosis is poor. Multidisciplinary supportive treatment is required, including genetic counselling.

  • 95% mortality at 18 months
  • Mechanism of death is commonly due to respiratory impairment or infections.

See also the associated article: Spinal Muscular Atrophy.

Personal tools