Toshinori Nakahara

Delayed hyperemia causing intracranial hypertension after cardiopulmonary resuscitation

OBJECTIVE To clarify whether early or delayed failure of cerebral perfusion after cardiopulmonary resuscitation (CPR) occurs in humans and contributes to secondary brain damage. DESIGN Prospective, repeated-measures study. SETTING Intensive care unit of Hiroshima University School of Medicine. PATIENTS Eight comatose patients who had undergone successful resuscitation from cardiac arrest. INTERVENTIONS All patients underwent transcranial Doppler sonography examination. The intracranial cerebral pressure (ICP) and jugular venous oxygen saturation (SO2) also were continuously monitored in five patients and three patients, respectively. MEASUREMENTS AND MAIN RESULTS In each patient, we measured the mean flow velocity of the middle cerebral artery transcranially and the mean flow velocity of the internal carotid artery, high in the neck, using transcranial Doppler sonography. The pulsatility index for each measurement was also calculated. The first examinations were performed within 4 to 12 hrs of CPR, and repeat examinations were performed approximately every 12 hrs. The initial mean flow velocities of the middle cerebral artery and the initial mean flow velocities of the internal carotid artery were relatively low, with relatively high pulsatility indices. The mean flow velocities of the middle cerebral artery began to increase at 12 to 24 hrs after CPR and peaked 24 to 120 hrs after CPR. A simultaneous increase in mean flow velocities of the internal carotid artery was observed during this period. The pulsatility index in both arteries dropped significantly during peak mean flow velocity of the middle cerebral artery. In six of seven patients with an abnormal increase (> 100 cm/ sec) in peak mean flow velocity of the middle cerebral artery, the ratio of mean flow velocity of the middle cerebral artery to mean flow velocity of the internal carotid artery was < 3. This value tended to be lower in patients with poor outcomes. An increased mean flow velocity of the middle cerebral artery, with a ratio of < 3 for mean flow velocity of the middle cerebral artery to mean flow velocity of the internal carotid artery, was defined as hyperemia. Although the mean flow velocity of the internal carotid artery was not measured, another patient with an abnormal increase in mean flow velocity of the middle cerebral artery revealed a high jugular venous SO2 value of 83.5%, also representing hyperemia. All ICP values were within the normal range 4 to 12 hrs after CPR and tended to increase before peak mean flow velocity of the middle cerebral artery. The two patients with the lowest ratios of mean flow velocity of the middle cerebral artery to mean flow velocity of the internal carotid artery showed significant increases in ICP after the peak mean flow velocity of the middle cerebral artery. These two patients subsequently developed brain death. CONCLUSIONS Delayed hyperemia occurs in humans after resuscitation from cardiac arrest. Our data suggest that this delayed hyperemia can lead to intracranial hypertension and occasionally acute brain swelling, contributing to a poor outcome. A high mean flow velocity of the middle cerebral artery with a low ratio of mean flow velocity of the middle cerebral artery to mean flow velocity of the internal carotid artery may be predictive of critical hyperemia. As an indirect method of measuring cerebral blood flow transcranial Doppler sonography can be used to adjust treatment for failure of cerebral perfusion after resuscitation.

Cerebral Fat embolism studied by magnetic resonance imaging, transcranial doppler sonography, and single photon emission computed tomography. Case Report

Cerebral fat embolism syndrome is an uncommon complication of trauma. We present a patient who developed cerebral fat embolism syndrome secondary to long-bone fractures. Although computed tomography of the brain failed to show any intracranial lesion, magnetic resonance imaging (MRI) detected scattered, high-signal-intensity lesions on T2-weighted images. 99mTc-d, 1-hexamethyl-propylene amine oxine single photon emission computed tomography (99mTc-HMPAO SPECT) and transcranial Doppler sonography (TCD) demonstrated low cerebral blood flow in the acute stage. MRI, 99mTc-HMPAO SPECT, and TCD correlated well with the clinical course of cerebral fat embolism syndrome.

Steal phenomenon in a traumatic carotid-cavernous fistula.

A patient with head injury presented with computed tomography findings of a diffuse severe infarction of the left cerebral hemisphere in which the cerebral hemodynamics can be evaluated by transcranial Doppler sonography. Serial angiograms revealed a carotid-cavernous fistula, with a complete steal phenomenon. The unusual complication of a traumatic carotidcavernous fistula is discussed.

Endoscopic resection of intraventricular ependymal cyst presenting with psychosis

BACKGROUND Intracranial ependymal cysts are rare lesions generally located in the cerebral parenchyma, juxtraventricular region, or subarachnoid space; but no case of a purely intraventricular ependymal cyst has been reported. CASE REPORT A case of intraventricular ependymal cyst presenting with symptoms of psychosis is reported. The patients symptoms resolved almost completely following endoscopic resection of the cyst. The embryologic basis of the development of an ependymal cyst inside the ventricle and its histologic characteristics are discussed. Possible mechanism of psychosis in this case is also discussed. CONCLUSION Minimally invasive techniques, as in this case, may be useful in refractory psychotic cases with cystic lesions.

Intrauterine Depressed Skull Fracture

Two cases of intrauterine depressed fracture are presented. In each case, the mother had no history of abdominal trauma during pregnancy, the children were delivered normally without the use of forcep

Stent-assisted angioplasty for intracranial atherosclerosis

We report on two patients with intracranial atherosclerosis of the carotid artery or vertebral artery treated with stent-assisted angioplasty. Both patients have severe intracranial atherosclerosis (>70%) with refractory symptoms despite optimal medical treatment. In both patients, a coronary balloon-expandable stent was successfully placed using a protective balloon technique without procedural complications. The patients were asymptomatic and neurologically intact at a mean clinical follow-up of 13 months. Follow-up angiograms did not show restenosis 3 or 4 months after procedure, respectively. Stent-assisted angioplasty for intracranial atherosclerosis in the elective patient has proven effective, with an acceptable low rate of morbidity and mortality.

Cerebral circulation in moyamoya disease: A clinical study using transcranial doppler sonography

Transcranial Doppler sonography was performed on eight patients diagnosed as Moyamoya disease. Angiographically, the patients-four adults (mean age 42) and four children (mean age 7.7)-underwent a complete six- or five-vessel angiographic study. The results showed the following: (1) Despite the presence of stenosis, all middle cerebral arteries showed very low-flow velocity compared to their ipsilateral distal internal carotid arteries. In adult cases, the difference was very significant (p < 0.02). (2) Relatively high-flow velocity was observed in the posterior cerebral arteries of children, and in the ophthalmic arteries of adult cases. (3) In several occasions, very low-flow velocity values were still detected despite the fact that with angiography, the respective arterial segments were hardly opacified. The relation and discrepancy between these results and the angiographic findings, and the potential application of transcranial doppler in assessing and grading the severity of moyamoya disease are discussed.

Transcranial doppler sonography in carotid-cavernous fistulas: Analysis of five cases

Transcranial doppler sonography was performed transorbitally in five patients clinically diagnosed as unilateral carotid-cavernous fistula. Dural arteriovenous malformation related-shunts were detected in all the patients. In the normal eyes, the only doppler signals observed at an insonation depth of 45 to 55 mm were those of the ophthalmic artery. In the affected eyes, abnormal doppler signals with relatively higher flow velocity and lower resistance were observed. In three of the cases, these abnormal signals showed a flow directed anteriorly or away from the cavernous sinus, consistent with changes in the ophthalmic veins caused by the presence of the shunts. In two cases, however, the observed flows were directed posteriorly, the normal direction of these veins. The possible explanations for this discrepancy are discussed in relation with angiographic findings. The use of transcranial doppler might provide a better understanding about hemodynamic changes in carotid cavernous fistulas.

Coil embolization of a large, wide-necked aneurysm using a double coil-delivered microcatheter technique in combination with a balloon-assisted technique

The present paper describes a double coil-delivered microcatheter technique used in combination with a balloon-assisted technique to treat a patient with a large, wide-necked basilar tip aneurysm with detachable coil treatment. The aneurysm was completely occluded using this technique. There was no recanalization or any neurological deterioration within 12 months of embolization.

Cerebrospinal Fluid Enhancement on Fluid Attenuated Inversion Recovery Images After Carotid Artery Stenting with Neuroprotective Balloon Occlusions: Hemodynamic Instability and Blood-Brain Barrier Disruption

PurposeA rare complication of carotid artery stenting (CAS), prolonged reversible neurological symptoms with delayed cerebrospinal fluid (CSF) space enhancement on fluid attenuated inversion recovery (FLAIR) images, is associated with blood–brain barrier (BBB) disruption. We prospectively identified patients who showed CSF space enhancement on FLAIR images.MethodsNineteen patients—5 acute-phase and 14 scheduled—underwent 21 CAS procedures. Balloon catheters were navigated across stenoses, angioplasty was performed using a neuroprotective balloon, and stents were placed with after dilation under distal balloon protection. CSF space hyperintensity or obscuration on FLAIR after versus before CAS indicated CSF space enhancement. Correlations with clinical factors were examined.ResultsCSF space was enhanced on FLAIR in 12 (57.1%) cases. Postprocedural CSF space enhancement was significantly related to age, stenosis rate, acute-stage procedure, and total occlusion time. All acute-stage CAS patients showed delayed enhancement. Only age was associated with delayed CSF space enhancement in scheduled CAS patients.ConclusionsIschemic intolerance for severe carotid artery stenosis and temporary neuroprotective balloon occlusion, causing reperfusion injury, seem to be the main factors that underlie BBB disruption with delayed CSF space enhancement shortly after CAS, rather than sudden poststenting hemodynamic change. Our results suggest that factors related to hemodynamic instability or ischemic intolerance seem to be associated with post-CAS BBB vulnerability. Patients at risk for hemodynamic instability or with ischemic intolerance, which decrease BBB integrity, require careful management to prevent intracranial hemorrhagic and other post-CAS complications.