Spinal muscular atrophy type I mimicking critical illness neuropathy in a paediatric intensive care neonate: electrophysiological features.

We report the case of a neonate with spinal muscular atrophy type I (SMA type I or Werdnig-Hoffman disease) who was initially misdiagnosis as having critical illness neuropathy. Electromyography (EMG) showed a moderate loss of voluntary and motor unit potentials of both neurogenic and myopathic appearance. Nerve conduction studies revealed the presence of a severe sensory-motor axonal neuropathy.