Table 2

Main mimics of MND based on experience of approximately 1000 patients seen in a tertiary referral clinic, and with the key clue to alternative diagnosis listed

Predominant signsMimic disorderKey clues
LMNBenign fasciculationsNo weakness
Multifocal motor neuropathy with conduction blockWeakness greater than wasting and predilection for finger extensors, slowly progressive
Neuralgic amyotrophySevere pain at onset and arrest of progression
Kennedy's syndrome (spinobulbar muscular atrophy)Very slow progression with gynaecomastia, and often prominent chin fasciculations
Motor-predominant CIDPSymmetrical, fluctuating, mild sensory features, slowed conduction velocity
Inclusion body myositisSlowly progressive, predilection for quadriceps and medial forearms especially with serum creatine kinase >1000 IU/l
UMNHereditary spastic paraparesisYounger-onset, slowly progressive, minimal upper limb involvement, especially with family history
Primary progressive multiple sclerosisSlowly progressive, often with sensory features, especially where there is possible MRI evidence of demyelination and positive CSF oligoclonal bands
MixedCervical myeloradiculopathyProminent neck pain especially with sphincter involvement. May be pure motor
  • CIDP, chronic inflammatory demyelinating polyradiculoneuropathy; CSF, cerebrospinal fluid; LMN, lower motor neurone; MND, motor neurone disease; UMN, upper motor neurone.