Transcranial Doppler enhanced thrombolysis for embolic occlusion of major cerebral arteries

SUMMARY

For the treatment of 11 patients with hyperacute embolic occlusion of major cerebral arteries (ten with occlusion of middle cerebral artery and one with occlusion of basilar artery), TCDenhanced thrombolysis (TCDET) was performed in combination with ultrasound irradiation, using diagnostic transcranial Doppler (TCD) (TC2-64B: 2MHz, 100mW/cm(2), pulsed wave) (TCDET group), and the effectiveness of this procedure was compared with that of local intra-arterial fibrinolysis (LIF) in 45 patients with embolic occlusion of the middle cerebral artery (LIF group). Regarding dose of TPA, the LIF group used 1046.7 +/- 607.8 units and the TCDET group 700.0 +/- 431.3 units (p < 0.05). Regarding time technically required to attain recanalization, the LIF group required 68.2 minutes, and the TCDET group 28.6 minutes. A good outcome was noted in 60.8% of the LIF group and 64% of the TCDET group. Haemorrhagic transformation was observed in 7.8% of the LIF group and in 0% of the TCDET group. No complications due to TCD irradiation were observed in the TCDET group. These findings suggest that TCDET can be an effective method of achieving recanalization.

[Superselective fibrinolysis for a middle cerebral artery embolism caused by a left atrial myxoma: case report]

A case of successful treatment by local fibrinolysis of a middle cerebral artery embolism caused by a thrombus from a left atrial myxoma is reported. A 62-year-old woman using a pacemaker and suffering from sick sinus syndrome was admitted on December 29th 1996, complaining of transient restlessness. CT and cerebral angiography revealed no abnormal vascular lesions. Eighteen months after the initial episode, she suffered a sudden onset of left hemiparesis and loss of consciousness. CT scan performed during the second episode revealed no lesions and, in particular, no early CT infarction sign, but emergent cerebral angiography revealed a right middle cerebral artery embolic occlusion. Local fibrinolysis using a tissue plasminogen activator was performed within 3 hours after the beginning of the episode, and partial recanalization was obtained within one hour after initiation of the fibrinolytic therapy. On the first hospital day, though CT revealed a small low-density area in the right basal ganglia, motor deficits gradually improved. Considering the possibility of a cardiac source of the embolism, trans-esophageal echocardiography was performed and revealed a left atrial tumor suspected to be a myxoma. It was removed by surgery on the 34th hospital day. Histological examination proved it to be a myxoma. Nine months after local fibrinolytic therapy, the patient returned to work. The diagnosis of cerebral embolism caused by cardiac myxoma is difficult to make at the time when the patient is first examined after admission. It is also hard to discover during emergent cerebral angiography with fibrinolytic therapy. Therefore, in the case of patients with cerebral embolism for which local fibrinolysis is ineffective, it should be presumed that cardiac myxoma is the source of the embolus. Direct PTA alone may be effective for such tumoral embolism.

[Clinical study of therapeutic time window of local fibrinolysis for acute middle cerebral artery occlusion]

We evaluated the efficacy of local intra-arterial fibrinolysis (LIF) used in tissue plasminogen activator (t-PA) and its indication for acute middle cerebral artery (MCA) occlusion on angiographic degree of leptomeningeal collateral flow in a series of 26 patients (mean age: 67.2 years old). The occlusion types were classified into three types: (1) M 1 proximal occlusion (N = 8) involved the lenticulostriate arteries (LSA), (2) M 1 distal occlusion (N = 6) without involvement of the LSA to M 2 bifurcation, (3) M 2-3 occlusion (N = 12). In M 1 proximal and distal type, 100% patients had complete or partial recanalization till 5.3 and 6 hours, and 91.7% recanalized in M 2-3 type within 3.96 hours from attack on the average. Small cerebral infarction post LIF showed in 50%, but had no clinical change for the worse in all types. There was 65% in excellent or good prognosis on 2 months after attack. Within the range of 600,000-2,400,000 units of t-PA (mean = 1,107,000 units), small hemorrhagic transformation were developed in 5 cases (19.2%) without influence on its outcome. It means that below 2,400,000 units t-PA for LIF were safety amounts. In patients with poor collateral flow in angiographic findings, good prognosis could be possible in 75% within 4 hours (M = 3.96 hours) recanalization on the average. We conclude that LIF used in t-PA would be efficatious in M 1 proximal occlusion within 4 hours of onset and in patients with poor collateral flow when recanalized within 4 hours after attack.

[Persistent carotid-superior cerebellar artery anastomosis presenting with cerebellar ischemic attack: a case of persistent trigeminal artery variant]

A rare case of persistent primitive trigeminal artery variant (PTAV) with cerebellar ischemia is reported. A 23-year-old male complained of sudden dizziness and nausea after playing valley ball. CT scan and MRI on admission revealed no abnormal findings. Left carotid angiography demonstrated a PTAV anastomoting precavernous portion of left internal carotid artery to the left superior cerebellar artery. The 37 cases reported in literature were reviewed to characterise PTAV. Ninety-seven% of the cases arising from precavernous portion of internal carotid artery, and terminated in anterior inferior cerebellar artery in 73%, posterior inferior cerebellar artery in 13.5% and superior cerebellar artery in 13.5%. Approximately 22.2% of patients with PTAV have cerebral aneurysms. The hypotension or mechanical compression of PTAV on playing valley ball with poor vascular supply to the part of cerebellum possibly caused cerebellar ischemia in this case.