title: A Study of Cortical Excitability, Central Motor Conduction, and Cortical Inhibition Using Single Pulse Transcranial Magnetic Stimulation in Patients with Early Frontotemporal and Alzheimer's Dementia.
abstract: BACKGROUND
  Degenerative cortical dementias affect several million people worldwide. Early diagnosis and categorization are essential for initiating appropriate pharmacological and nonpharmacological treatment so that deterioration can be postponed, and disability adjusted life years can be saved both for the patient and for the caregiver. Therefore, an early, simple, noninvasive biomarker will serve as a boon.
  
  
  METHODS
  Patients who satisfied probable Alzheimer's disease (AD) or frontotemporal dementia (FTD) using international consensus criteria for FTD and National Institute of Neurological Disorders and Stroke-AD and Related Disorders Association criteria for AD were evaluated using single pulse transcranial magnetic stimulation with figure of eight coil and motor evoked potential from right first dorsal interossei. Resting threshold (MT), central motor conduction time (CMCT), and silent period (SP) were evaluated.
  
  
  RESULTS
  Resting MT and SP are reduced in patients with Alzheimer's disease whereas CMCT is prolonged in patients with FTD and SP is in the lower limit of normal in both conditions.
  
  
  CONCLUSIONS
  The patterns of central motor conduction and MT are distinctly different in patients with early Alzheimer's disease (AD) and FTD.
authors.affiliation: Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Sadanandavalli Retnaswami
authors.initials: SR
authors.lastname: Chandra
authors.affiliation: Department of Clinical Neurosciences, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Thomas Gregor
authors.initials: TG
authors.lastname: Issac
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: B C
authors.initials: BC
authors.lastname: Nagaraju
authors.affiliation: Department of Biostatistics, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
authors.forename: Mariamma
authors.initials: M
authors.lastname: Philip
keywords: AD-Alzheimer's dementia; central motor conduction time; cortical inhibition; frontotemporal dementia; transcranial magnetic stimulation