Brainstem hypoperfusion in severe symptomatic vasospasm following aneurysmal subarachnoid hemorrhage: role of basilar artery vasospasm.

BACKGROUND: The hemodynamic effects of vertebrobasilar vasospasm are ill defined. The purpose of this study was to determine the effects of basilar artery (BA) vasospasm on brainstem (BS) perfusion. METHODS: Forty-five patients with delayed ischemic neurological deficits (DIND) following aneurysmal subarachnoid hemorrhage (SAH) underwent cerebral angiography prior to decision-making concerning endovascular treatment. BA diameter was compared with baseline angiogram. Regional brainstem (BS) cerebral blood flow (CBF) was qualitatively estimated by (99m)Tc ethyl cysteinate dimer single photon emission computed tomography (ECD-SPECT). FINDINGS: Delayed BS hypoperfusion was found in 22 (48.9%) of 45 patients and BA narrowing of more than 20% was found in 23 (51.1%). Seventeen of 23 (73.9%) patients with BA narrowing of more than 20% experienced BS hypoperfusion compared to 6 of 22 (27.3%) patients with minimal or no narrowing (p = 0.0072). Patients with severe and moderate BS hypoperfusion had higher degree of BA narrowing compared to patients with normal BS perfusion and mild BS hypoperfusion (p < 0.001). The three-month outcome of patients n-22) with BS hypoperfusion was significantly worse compared to patients (n-23) with unimpaired (p = 0.0377, odd ratio for poor outcome 4, 1.15-13.9 95% confidence interval). INTERPRETATION: These findings suggest that the incidence of BA vasospasm in patients with severe symptomatic vasospasm is high and patients with significant BA vasospasm are at higher risk to experience BS ischemia. Further studies should be done to evaluate the effects of endovascular therapy on BS perfusion and the impact of BS ischemia on morbidity and mortality of patients with severe symptomatic vasospasm.

Spontaneous cerebellar hemorrhage due to a juvenile pilocytic astrocytoma: case report and review of the literature.

A 13-year-old boy presented to the emergency room with headaches and ataxia. Imaging studies revealed a cerebellar hemorrhage within a posterior fossa tumor. The patient underwent complete resection of this lesion and made a full recovery. Microscopic examination of this lesion revealed a juvenile pilocytic astrocytoma.

Atypical hemifacial microsomia associated with Chiari I malformation and syrinx: further evidence indicating that chiari I malformation is a disorder of the paraaxial mesoderm. Case report and review of the literature.

The authors present the first known reported case of hemifacial microsomia associated with a Chiari I malformation and syrinx. A 14-year-old girl presented with progressive torticollis of 3 years' duration and headaches exacerbated by exercise. Computerized tomography scanning and magnetic resonance imaging revealed extensive craniofacial and vertebral abnormalities, including aplasia of the floor of the left middle fossa and posterior fossa cranium, articulation of the left mandibular condyle with the left temporal lobe, and progressive development of a Chiari I malformation with associated syringomyelia. The patient first underwent posterior fossa decompression, duraplasty, and occipitocervical fusion. This procedure was later followed by reconstruction of the floor of the left middle fossa and temporomandibular joint. The patient's outcome was excellent. In this case report the authors review the complex embryological development of craniofacial and craniovertebral structures, and emphasize the use of a staged approach to treat pathophysiological consequences of this congenital anomaly.

Cerebrovascular effects of the bradykinin analog RMP-7 in normal and irradiated dog brain.

The effects of an intravenous (i.v.) injection of the bradykinin analog RMP-7 (100 ng/kg) were assessed in normal dogs and dogs with focal, radiation-induced brain lesions. A dose of 20 Gy was delivered to a point 0.75 cm from a removable interstitial 125I source; parameters relating to blood flow and permeability were quantified using computed tomography 2-8 weeks after irradiation. Blood flow-related endpoints included regional cerebral blood flow (rCBF), mean transit time of blood and vascular volume, while endpoints related to permeability included blood-to-brain transfer constant (Ki), brain-to-blood transfer constant and plasma volume. In unirradiated brain, an i.v. bolus of RMP-7 administered through the left cephalic vein induced a rapid and transient hypotension and a statistically significant increase in vascular volume; no alterations in any parameter related to permeability were observed. After irradiation, changes in rCBF after RMP-7 depended upon time after exposure, effects presumably due to changing morphology in the irradiated tissues. In the radiation lesions, significant increases in Ki were observed 5 minutes after injection of RMP-7, but those increases were not related to time after irradiation or alteration in blood flow-related parameters. Our results showed that RMP-7 selectively increased permeability in already damaged vasculature without affecting the extent or volume of radiation-induced vasogenic edema. These data suggest that RMP-7 may provide an effective means to enhance the delivery of compounds to an already compromised brain while not exacerbating the potential adverse effects of pre-existing vasogenic edema.