PMID- 12538413
OWN - NLM
STAT- MEDLINE
DCOM- 20030306
LR  - 20190513
IS  - 0006-8950 (Print)
IS  - 0006-8950 (Linking)
VI  - 126
IP  - Pt 2
DP  - 2003 Feb
TI  - Remote changes in cortical excitability after stroke.
PG  - 470-81
AB  - Changes in the cerebral metabolism and the excitability of brain areas remote 
      from an ischaemic brain lesion have been reported in animals and humans and 
      implicated as a mechanism relevant to functional recovery. The aim of the present 
      study was to determine whether changes in the inhibitory and excitatory activity 
      in motor cortex of the non-affected hemisphere are present in stroke patients, 
      and whether these changes are related to the extent of the patients' recovery of 
      function. Transcranial magnetic stimulation (TMS) was used to study the first 
      dorsal interosseus muscle (FDI) of the non-affected hand in 13 patients with good 
      recovery of hand function after stroke, and was compared with left hemispheric 
      stimulation in 13 healthy age-matched volunteers. In the first experiment, 
      paired-pulse TMS with the conditioning stimulus (CS) set at 80% of the subject's 
      motor threshold (MT) and interstimulus intervals (ISIs) of 2, 3, 10 and 15 ms was 
      used. In the second experiment, different intensities of CS were used to study 
      its inhibitory effect on a succeeding suprathreshold test stimulus at an ISI that 
      was kept constant at 2 ms. In a third experiment, the rise in motor evoked 
      potential (MEP) amplitudes with increasing stimulus intensities was measured. In 
      two additional control experiments, the effect of left versus right hemispheric 
      stimulation in normal volunteers and good versus poor recovery of hand function 
      in patients after stroke on the excitability of inhibitory and excitatory 
      activity was studied. MT, mean test MEP and recruitment curves were similar in 
      patients and healthy volunteers. In those patients with good recovery, 
      paired-pulse excitability was increased at ISIs of 2 and 3 ms, similar to healthy 
      volunteers at ISIs of 10 and 15 ms. When tested with different CS intensities at 
      an ISI of 2 ms, inhibitory activity was similar in patients and healthy subjects 
      at small CS intensities, but faded rapidly at higher CS intensities in patients. 
      In contrast, in patients with poor recovery, this increase in cortical 
      excitability at higher CS intensities was not seen. The similarity of MT, mean 
      test MEP and recruitment curves in patients and healthy volunteers indicates that 
      the overall corticomotoneuronal excitability has not changed in patients. The 
      similarity of the inhibitory effect at low CS intensities in the patients with 
      good recovery and healthy subjects, and the steeper increase of conditioned MEP 
      amplitude at higher CS intensities in the recovering patients suggest that in the 
      patients' contralesional motor cortex the balance of excitatory and inhibitory 
      activity was shifted towards an increase of excitatory activity in the neuronal 
      circuits tested at ISIs of 2 and 3 ms. This shares similarities to mechanisms 
      implicated as relevant for reorganizational processes after experimental brain 
      injury and may be relevant for functional recovery after stroke. The absence of 
      changes in cortical excitability in patients with poor recovery supports the 
      relevance of our findings for recovery.
FAU - Butefisch, Cathrin M
AU  - Butefisch CM
AD  - Neurological Therapeutic Center, Department of Neurology, Heinrich-Heine 
      University, Dusseldorf, Germany. cathrin.buetefisch@uni-duesseldorf.de
FAU - Netz, Johannes
AU  - Netz J
FAU - Wessling, Marion
AU  - Wessling M
FAU - Seitz, Rudiger J
AU  - Seitz RJ
FAU - Homberg, Volker
AU  - Homberg V
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Brain
JT  - Brain : a journal of neurology
JID - 0372537
SB  - IM
MH  - Adult
MH  - Aged
MH  - Brain Infarction/pathology/*physiopathology
MH  - Case-Control Studies
MH  - Electromyography
MH  - Evoked Potentials, Motor
MH  - Female
MH  - Functional Laterality
MH  - Hand/physiopathology
MH  - Humans
MH  - Magnetics
MH  - Male
MH  - Middle Aged
MH  - Motor Cortex/*physiopathology
MH  - Neural Inhibition
MH  - Recovery of Function
MH  - Recruitment, Neurophysiological
EDAT- 2003/01/23 04:00
MHDA- 2003/03/07 04:00
CRDT- 2003/01/23 04:00
PHST- 2003/01/23 04:00 [pubmed]
PHST- 2003/03/07 04:00 [medline]
PHST- 2003/01/23 04:00 [entrez]
AID - 10.1093/brain/awg044 [doi]
PST - ppublish
SO  - Brain. 2003 Feb;126(Pt 2):470-81. doi: 10.1093/brain/awg044.