No shinkei geka. Neurological surgery
-
In 30 patients undergoing neurosurgical intervention, the authors evaluated the hemodynamics in the circle of Willis by transcranial Doppler sonography. By avoiding confusion with collateral effects, the transcranial Doppler sonography yielded direct and more significant information concerning the intracranial hemodynamics than extracranial Doppler sonography. Therefore, it made possible to detect intracranial occlusive lesions with less false findings. ⋯ Transcranial Doppler sonography was considered to contribute to the establishment of a protocol for early diagnosis and treatment of vasospasm. Transcranial Doppler sonography was also utilized as a useful tool for classification of arteriovenous malformation from the viewpoint of hemodynamics, namely high-flow or low-flow and with or without steal phenomenon. Transcranial Doppler sonography appears sufficiently promising to justify further development and utilization in cerebrovascular surgery.
-
Brainstem auditory evoked potentials (BAEP), somatosensory evoked potentials (SEP) and EEG were recorded sequentially in cat with mass-induced intracranial hypertension in correlation with mass volume, intracranial pressure (ICP), systemic blood pressure (BP) and size of the pupils. 1) As the intracranial pressure was raised by expansion of a supratentorial epidural balloon, suppression of cortical SEP (CSEP) and pupillary abnormality appeared first, EEG, waves IV and III of BAEP and wave III of short latency SEP (SSEP) were suppressed in this order. 2) As far as wave IV of BAEP remained and decompression was started within 30 minutes after peaks of CSEP completely suppressed, changes in P1 and N1 of CSEP were reversible. 3) Further raising of ICP was followed by loss of waves IV and III of BAEP and wave III of SSEP in this order. Simultaneously with loss of wave III in SSEP, systemic blood pressure dropped rapidly. ⋯ These results suggest that for the patient with disturbed consciousness caused by supratentorial mass lesion, decompressive procedure should be started before wave V of BAEP and brainstem components of SEP disappear. EP monitor seems to be useful clinical method for preventing irreversible change of the brain in patients with coma caused by supratentorial mass lesions.