Primary Lateral Sclerosis

Neurol Clin. 2015 Nov;33(4):749-60. doi: 10.1016/j.ncl.2015.07.007. Epub 2015 Sep 8.


Primary lateral sclerosis is characterized by insidious onset of progressive upper motor neuron dysfunction in the absence of clinical signs of lower motor neuron involvement. Patients experience stiffness; decreased balance and coordination; mild weakness; and, if the bulbar region is affected, difficulty speaking and swallowing, and emotional lability. The diagnosis is made based on clinical history, typical examination findings, and diagnostic testing negative for other causes of upper motor neuron dysfunction. Electromyogram is normal, or only shows mild neurogenic findings in a few muscles, not meeting El Escorial criteria. Treatment is largely supportive.

Keywords: Motor neuron disease; Neuroimaging; Primary lateral sclerosis; Pseudobulbar affect; Spastic quadriparesis; Upper motor neuron disease.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Diagnosis, Differential
  • Electromyography
  • Female
  • Humans
  • Middle Aged
  • Motor Neuron Disease / diagnosis*
  • Motor Neuron Disease / physiopathology*
  • Neuroimaging
  • Severity of Illness Index