Changes in Interictal Cerebral Blood Flow in Patients with Epilepsy / 대한간질학회지

PURPOSE: To evaluate the cerebral hemodynamic changes during interictal period in patients with epilepsy, we investigated changes in cerebral blood flow velocities by transcranial Doppler sonography (TCD). METHODS: Blood flow velocities and pulsatility indecies were measured in both anterior cerebral arteries, middle cerebral arteries, posterior cerebral arteries, internal carotid arteries, and basilar artery using TCD in 21 patients with epilepsy and 21 age and sex matched normal adults. We also evaluated the effects of seizure type, seizure frequency, EEG findings, and anticonvulsant medication on cerebral blood flow velocities. RESULTS: The blood flow velocities of cerebral arteries were decreased in patients, but the pulsatility indecies weren't different. Cerebral blood flow velocities were influenced by seizure type, EEG findings, or anticonvulsant medication. CONCLUSION: Our study demonstrates that cerebral blood flow velocities might be decreased during interictal period in patients with epilepsy, and suggests that TCD is an useful method for the investigation of the cerebral hemodynamic changes in epilepsy.

Simultaneous Insonation of One MCA through Bilateral Temporal Bone Windows Using M-mode TCD

BACKGROUND: Transcranial Doppler ultrasonography (TCD) is limited by insufficient ultrasound penetration through the temporal bone. Recent studies have revealed poor temporal bone windows in 5~30% of patients. In about 38% of the patients with poor temporal bone windows, a temporal window was unilaterally absent. The aim of the present study was to compare the mean flow velocities (MFV) of the middle cerebral arteries (MCA) obtained through the ipsilateral temporal bone window with those obtained through the contralateral one using M-mode TCD. METHODS: Eighteen patients (mean age, 28 y; age range, 21~40 y) who had adequate bilateral temporal bone windows were enrolled and 36 MCAs were investigated. The investigators tried to detect the MCA through the ipsilateral and contralateral temporal windows with two 2-MHz probes simultaneously (ipsilateral insonation and contralateral one, respectively). RESULTS: The MCA MFV measured by ipsilateral insonation was 72.58 +/- 9.78 cm/sec and that demonstrated by contralateral insonation was 70.94 +/- 9.79 cm/sec. Even though the differences between MFVs by either side insonation was 2.25~3.94% (0~13.11%) and had significant difference statistically, those were within side-to-side limit of 30% generally considered as abnormal. The mean bitemporal diameter (BTD) was 130.72 +/- 3.75 cm (126~142 cm). We obtained similar waveforms in the reverse direction to those of ipsilateral insonation at 95.33 +/- 5.19 mm of depths (72.97 +/- 4.23% of BTD) during contralateral insonation. CONCLUSIONS: The demonstration of the MCA through the contralateral insonation provides an opportunity to obtain significant mean flow velocities in patients with absent or insufficient temporal bone window unilaterally.

Cerebral Vasoreactivity by Transcranial Doppler and Brain SPECT in Patients with Unilateral Carotid Stenosis

BACKGROUND: Cerebral vasoreactivity (CVR) is known as having insufficient hemodynamic circulation. However, available information for its clinical interpretation is scant. We attempted to find the relationship of CVR with parameters such as stenosis degree and collateral patterns. METHODS: This study was prospectively conducted in 37 patients with more than 50% angiographically proven unilateral carotid stenosis. The relative change of mean flow velocity before and after an acetazolamide challenge was calculated by transcranial Doppler sonography (TCD) and the results were compared with single photon emission computed tomography (SPECT) results. The degree of stenosis and collateral flow patterns were estimated and classified by conventional angiography. RESULTS: The CVR of middle cerebral artery (MCA) was significantly decreased in the ipsilateral side to the carotid stenosis (p<0.05). The CVR impairment was more severe when symptomatic stenosis was present (p=0.04). There was a significant correlation between the degree of carotid stenosis and the CVR (p<0.01). In the area of impaired CVR by SPECT, the estimated CVR was significantly lower (p<0.05), even to the negative value, implying that there is an actually steal phenomenon in that area. CONCLUSIONS: TCD is a useful tool for the assessment of CVR, which can give diverse clinical information based upon the degree of stenosis.

Stereotactic Evacuation of Spontaneous Intracerebral Hemorrhage

The best treatment modality for spontaneous intracerebral hemorrhage still remains to be controversial. Stereotactic surgery can be performed safely and easily but its indication and optimal timing of operation have to be determined. We treated 80 patients with spontaneous intracerebral hemorrhage by stereotactic surgery from October 1994 to December 1997. We investigated clinical status of the patients before and after surgery, amount of hematoma, evacuation rate, timing of operation, transcranial Doppler sonography(TCD), and computerized tomography(CT) findings. The results were as follows: 1) The outcome of early surgery(within 24 hours of bleeding) was better than that of late surgery(after 24 hours of bleeding)(p=0.034). 2) The outcome was better in the patient with higher evacuation rate(p=0.014). 3) TCD monitoring showed beneficial effect of surgery on hemodynamic status. We conclude that the early surgery within 24 hours after bleeding is correlated with the better outcome, and TCD monitoring is useful for evaluation of perioperative hemodynamic change.