Cerebral autoregulation dynamics in acute ischemic stroke after rtPA thrombolysis.
BACKGROUND
To investigate whether there is: (1) a specific temporal course of cerebral dysautoregulation in acute ischemic stroke, and (2) a separate detrimental effect of recombinant tissue plasminogen activator (rtPA) on autoregulation dynamics in this situation.


METHODS
We studied 16 patients with acute middle cerebral artery (MCA) occlusion and rtPA thrombolysis (intra-arterial or intravenous application, or both). Controls were 71 healthy adults and 11 patients with minor stroke not receiving rtPA. Dynamic autoregulation was recorded from spontaneous fluctuations of blood pressure and MCA flow velocity (transcranial Doppler) using two well-described approaches (index Mx, phase shift). Three measurements were performed (study 1: 20 +/- 9 h of ictus; study 2: 64 +/- 10 h; study 3: 112 +/- 7 h).


RESULTS
Two groups of clinical outcome were identified: good (modified Rankin scale <or=2, n = 9, MCA infarct volume = 14 +/- 16%), poor (modified Rankin scale >2, n = 7, MCA infarct volume = 62 +/- 21%). In the good outcome group, no relevant changes in Mx and phase were observed on both MCA sides compared with controls. In the poor outcome group, the index Mx deteriorated over studies 1-3 on affected sides, with worse values compared to the controls (p < 0.05). Phase was already impaired on affected sides of poor outcome patients in study 1 (p < 0.01 vs. controls) and tended to decrease further until study 3. Phase also decreased moderately on contralateral sides in poor outcome patients from studies 1 to 3 (p < 0.05, nonsignificant compared with controls).


CONCLUSIONS
Cerebral autoregulation is increasingly impaired, mainly on the affected side, over the first 5 days of major ischemic stroke after unsuccessful rtPA thrombolysis. It is bilaterally preserved in minor stroke after successful rtPA thrombolysis, indicating no separate detrimental effect of rtPA on the cerebral autoregulatory mechanism.
Department of Neurology, Neurocenter, University of Freiburg, Freiburg, Germany. matthias.reinhard@uniklinik-freiburg.de
Matthias
M
Reinhard
Christoph
C
Wihler
Markus
M
Roth
Andreas
A
Harloff
Wolf-Dirk
WD
Niesen
Jens
J
Timmer
Cornelius
C
Weiller
Andreas
A
Hetzel
D000208:Acute Disease; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006706:Homeostasis; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D007261:Infusions, Intra-Arterial; D007262:Infusions, Intravenous; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000627:therapeutic use; D015912:Thrombolytic Therapy / Q000009:adverse effects; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial
D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator