Proton magnetic resonance spectroscopy and transcranial magnetic stimulation for the detection of upper motor neuron degeneration in ALS patients

J Neurol Sci. 2001 Sep 15;190(1-2):21-7. doi: 10.1016/s0022-510x(01)00568-8.


Transcranial magnetic stimulation (TMS) was compared to proton magnetic resonance spectroscopy (1H-MRS) for the detection of upper motor neuron loss or dysfunction in 49 ALS patients classified according to the El Escorial criteria. Abnormal NAA/Cho ratios were detected in 53% of ALS patients. Abnormal TMS results (i.e. cortical inexcitability or prolonged CMCT's) were obtained in 63% of ALS patients. If one or both methods were considered for diagnosis of upper motor neuron degeneration/dysfunction, the percentage of abnormal findings was 77%, whilst in 39% of all patients both methods produced abnormal results. Compared to TMS, 1H-MRS detected more patients with upper motor neuron involvement in the suspected El Escorial subgroup (42% versus 25%), whereas TMS detected more patients with upper motor neuron involvement in the possible (81% versus 50%), probable (71% versus 57%) and definite El Escorial subgroup (71% versus 64%). We conclude that the combined use of 1H-MRS and TMS increases diagnostic accuracy for the detection of upper motor neuron involvement in ALS patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Amyotrophic Lateral Sclerosis / metabolism*
  • Amyotrophic Lateral Sclerosis / pathology*
  • Amyotrophic Lateral Sclerosis / physiopathology
  • Aspartic Acid / analogs & derivatives*
  • Aspartic Acid / metabolism
  • Choline / metabolism
  • Electric Stimulation / methods*
  • Female
  • Humans
  • Magnetic Resonance Spectroscopy / instrumentation
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Middle Aged
  • Motor Cortex / metabolism
  • Motor Cortex / pathology
  • Motor Cortex / physiopathology
  • Motor Neurons / metabolism
  • Motor Neurons / pathology*
  • Neural Conduction / physiology
  • Peripheral Nerves / pathology
  • Peripheral Nerves / physiopathology
  • Predictive Value of Tests
  • Pyramidal Cells / metabolism
  • Pyramidal Cells / pathology*
  • Transcranial Magnetic Stimulation*


  • Aspartic Acid
  • N-acetylaspartate
  • Choline