Ultraschall Med 2007; 28 - V_9_3
DOI: 10.1055/s-2007-989058

Cerebellar autoregulation dynamics – TCD monitoring of the posterior inferior cerebellar artery (PICA)

M Reinhard 1, Z Waldkircher 1, B Guschlbaur 1, A Hetzel 1
  • 1University of Freiburg, Dept. of Neurology, Freiburg, Germany

Objectives: Cerebral autoregulation is a key protective mechanism for regular brain function. Despite the functional importance of the cerebellum, its autoregulatory ability has not been systematically studied in humans so far. This study simultaneously investigates cerebellar and cerebral autoregulation using transcranial Doppler (TCD) monitoring.

Methods: 12 healthy adults (8 woman, aged 23–51yrs) were studied. Cerebellar/cerebral blood flow velocity was assessed by simultaneous TCD monitoring of the posterior inferior cerebellar artery (PICA) and the ipsilateral middle cerebral artery (MCA) using a 2MHz probe attached to a custom-built headframe. The PICA was identified by transnuchal duplexsonography beforehand using preassigned criteria. Blood pressure was measured non-invasively using a fingerplethysmograph. Autoregulation was assessed using two established approaches (phase and gain of respiratory-induced 0.1Hz oscillations and correlation coefficient index Dx of spontaneous fluctuations).

Results: The PICA could be identified on at least one side in all 12 persons. Phase was 36±10° both for the PICA and MCA (p=0.97, Wilcoxon test), gain was 0.85±0.19 in the PICA and 0.87±0.19 in the MCA (p=0.97). Also the autoregulation index Dx did not differ between PICA and MCA (p=0.79).

Conclusions: To the best of our knowledge, this is the first report of cerebellar hemodynamic monitoring by TCD. Cerebellar autoregulation dynamics appear to be similar to that of the cerebrum in healthy adults. Future studies will examine whether cerebellar autoregulation is specifically impaired in various diseases like migraine or acute cerebellar infarction.