Motor cortex excitability in Alzheimer disease: one year follow-up study

Seventeen patients affected by Alzheimer disease (AD) underwent two transcranial magnetic stimulation (TMS) studies separated by an interval of 12 months, in order to monitor possible changes in motor cortex excitability. After the first examination, all patients were treated with cholinesterase inhibitor drugs. Motor threshold (MT), amplitude of motor evoked potentials and central motor conduction time were considered. After one year, the mean MT values showed a decrease significantly correlated with the severity of cognitive involvement, evaluated by means of the Mini Mental State Examination (MMSE). The difference in MT between the two recording sessions showed no significant correlation with the difference in MMSE score. One year of treatment with cholinesterase inhibitor drugs did not stop the progressive increase in motor cortex excitability. Serial analysis of TMS might represent a method to monitor the rate of change in motor cortex excitability in patients with AD.

[1]  P. Delwaide,et al.  Motor cortex inhibition is not impaired in patients with Alzheimer’s disease: evidence from paired transcranial magnetic stimulation , 1999, Journal of the Neurological Sciences.

[2]  E Magni,et al.  Mini‐Mental State Examination: a normative study in Italian elderly population , 1996, European journal of neurology.

[3]  H J Testa,et al.  A clinical role for 99mTc-HMPAO SPECT in the investigation of dementia? , 1998, Journal of neurology, neurosurgery, and psychiatry.

[4]  M. Dam,et al.  Regional cerebral blood flow study with 99mTc-hexamethyl-propyleneamine oxime single photon emission computed tomography in Alzheimer's and multi-infarct dementia. , 1990, European neurology.

[5]  G. Caruso,et al.  Evaluation of the motor cortex by magnetic stimulation in patients with Alzheimer disease , 1996, Journal of the Neurological Sciences.

[6]  M. Caramia,et al.  Towards a neurophysiological marker of amyotrophic lateral sclerosis as revealed by changes in cortical excitability. , 1997, Electroencephalography and clinical neurophysiology.

[7]  Pedro C. Miranda,et al.  Magnetic stimulation in Alzheimer’s disease , 1997, Journal of Neurology.

[8]  M. Folstein,et al.  Clinical diagnosis of Alzheimer's disease , 1984, Neurology.

[9]  D J Wyper,et al.  Longitudinal changes in cognitive function and regional cerebral function in Alzheimer's disease: a SPECT blood flow study. , 1996, Journal of psychiatric research.

[10]  J. Liepert,et al.  Motor cortex disinhibition in Alzheimer's disease , 2001, Clinical Neurophysiology.

[11]  H. Siebner,et al.  Age-related decrease in paired-pulse intracortical inhibition in the human primary motor cortex , 2001, Neuroscience Letters.

[12]  Nick C Fox,et al.  Using serial registered brain magnetic resonance imaging to measure disease progression in Alzheimer disease: power calculations and estimates of sample size to detect treatment effects. , 2000, Archives of neurology.

[13]  B L Holman,et al.  The scintigraphic appearance of Alzheimer's disease: a prospective study using technetium-99m-HMPAO SPECT. , 1992, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[14]  P. Rossini,et al.  Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application. Report of an IFCN committee. , 1994, Electroencephalography and clinical neurophysiology.

[15]  C. Cool,et al.  Single SPECT measures of cerebral cortical perfusion reflect time-index estimation of dementia severity in Alzheimer's disease. , 2000, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[16]  Raffaele Ferri,et al.  Transcranial magnetic stimulation in Alzheimer disease: motor cortex excitability and cognitive severity , 2001, Neuroscience Letters.