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Systematic computed tomography angiographic (CTA) studies investigating variation in internal carotid artery (ICA) luminal diameters (LDs) are scarce. Knowledge of the normal intra-individual LD variability would provide a cut-off value for detection of more subtle collapses. In addition, low intra-individual variability would allow using contralateral LD as a reference for estimation of stenosis degree in cases where ipsilateral measurement is hampered. Therefore, our aim was to investigate intra-individual LD variation of normal ICA. We retrospectively collected multidetector high-speed CTAs of 104 patients younger than 40 years who were considered not to have carotid pathology. We carried out independent measurements of the common carotid artery (CCA) and ICA LDs bilaterally from axial source images by two observers, analysing side-to-side LD differences from averaged double measurements with a paired t test. We discovered no significant side-to-side LD differences. In the female group, the mean differences (mm) with 95 % confidence intervals were 0.08 (0.00, 0.17) for CCA and 0.03 (−0.04, 0.11) for ICA, with ICA LD standard deviation of 0.4 mm. In the male group, these were: 0.06 (−0.04, 0.17), 0.02 (-0.07, 0.11) and 0.4 mm, respectively. We detected no ICA agenesis. The intrinsic intra-individual variation of the LD of normal ICA is minimal. This uniformity may serve as the basis for detection of subtle grades of side-to-side variation caused by pathology.

Chiari type I malformation is a frequent incidental finding commonly associated with craniosynostosis. However, there seems to be a paucity of literature concerning the asymmetry of tonsillar herniation in patients with non-syndromic single-suture craniosynostosis. To study the asymmetry in this cohort, measurements of the right and left tonsils were made from sagittal images from both pre-operative and post-operative images from 11 patients with non-syndromic single-suture craniosynostosis. Pre-operatively, the mean difference between the caudal descent of all tonsils ranged from 0 to 7 mm, with a mean difference between sides of 2.45 mm. In three cases, cerebellar tonsils were symmetrically herniated. Post-operatively, the mean difference between caudal descent of all tonsils ranged from 0 to 4 mm, with a mean difference between sides of 1.45 mm. Four were symmetrically herniated. In patients with non-syndromic single-suture craniosynostosis, the tonsillar herniation is asymmetric in the majority of cases. Asymmetry of cerebellar tonsil herniation is a frequent finding in this cohort. The right tonsil is more inferiorly located in majority of cases, with predominance to the synostotic suture side in asymmetric craniosynostosis cases.

We sought to examine the pre- and postoperative changes of cerebellar tonsillar herniation by MR imaging in asymptomatic pediatric patients with nonsyndromic, single-suture craniosynostosis (N-SSSC), who underwent cranial vault remodeling surgery without suboccipital decompression. We required cerebellar tonsillar herniation through foramen magnum ≥3 mm for Chiari type I malformation (CMI). We hypothesized that the increase of intracranial volume by cranial vault remodeling would correct the asymptomatic CMI.We identified 9 patients among 121 N-SSSC children undergoing craniofacial surgery from January 2004 to October 2010 with CMI. However, two of them were excluded from the study due to missing postoperative MR images. In the final study population, six were males, five were scaphocephalic, while two were diagnosed with coronal synostosis.In four of the cases, the CMI was decreased in postoperative MR imaging varying from 6 to 12 mm. In three cases, the herniation remained stable. The median change of cerebellar tonsillar herniation was -6.5 mm.We conclude that asymptomatic patients with existing CMI may benefit from cranial vault remodeling surgery alone increasing the intracranial volume.

Few studies have focused on the neurodevelopment of infants on peritoneal dialysis (PD). Infants are the most demanding patient group on PD and thus are vulnerable to neurological sequelae. We studied 21 patients

Nine immunocompetent patients with acute herpes zoster encephalitis (HZE) were studied with the help of neurological, neuroradiological and neuropsychological investigations. All patients were treated with acyclovir. Neuropsychological performance was compared with that of a group of 16 healthy controls. Computed tomography of the head showed infarct-like hypodense lesions in two patients, involving the internal capsule in one case and the temporoparietal cortex and white matter in another. Hypoperfusion shown by single photon emission computed tomography, mostly involving the frontal areas bilaterally, was seen in six of the seven patients examined. Hyperperfusion as seen in herpes simplex encephalitis was not encountered. One patient remained mildly demented, but all the other patients recovered relatively well. Neuropsychological examination after acyclovir treatment showed a decline in memory and speed of cognitive processes, without circumscribed neuropsychological deficits. Six of the nine patients showed behavioural disinhibition, and mood changes were also observed. Memory impairment in HZE was not as global or as severe as is described after encephalitis due to herpes simplex virus. In HZE both the brain perfusion pattern and the neuropsychological test profile showed features compatible with subcortical dysfunction.

One hundred and one persons infected with human immunodeficiency virus (HIV-1), in whom other central nervous system infections or diseases were excluded, underwent brain CT and/or MRI at various stages of HIV-1 infection: 29 were asymptomatic (ASX), 35 had lymphadenopathy syndrome (LAS), 17 had AIDS-related complex (ARC), and 20 had AIDS. A control group of 32 HIV-1-seronegative healthy persons underwent brain MRI. The most common finding was brain atrophy, found in 9% of controls, and 31% of ASX cases, 29% of LAS, 59% of ARC and 70% of AIDS. Even the difference between the ASX or LAS groups and controls was significant. The changes were bilateral and symmetrical, and they were more severe at later stages of infection. Infratentorial atrophy was seen in the early stages; supratentorial atrophy became more pronounced at ARC, and generalized atrophy was typical of AIDS. Non-specific small hyperintense foci were found on MRI in 13% of controls and 6-15% of the infected groups. Larger, diffuse, bilateral white matter infiltrates were detected in 4 demented patients with AIDS. Four patients with AIDS and 1 with LAS had focal hyperintense lesions in the internal capsules, lentiform nuclei or thalamus, often bilateral on MRI. One patient with AIDS, examined with CT only, had low density in the lentiform nucleus. Loss of brain parenchyma can occur at an early stage of HIV-1 infection, and the atrophic process becomes more intense at later stages (ARC and AIDS). Parenchymal infiltration, seen as hyperintense areas on MRI, is most often associated with severe clinical symptoms, in the later stages of the disease.

A double-blind, randomized, parallel study was conducted to evaluate the safety and diagnostic utility of gadodiamide injection (a nonionic chelate of gadolinium and diethylenetriamine pentaacetic acid bis-(methylamide) [Gd-DTPA-BMA]) when administered IV for MRI of the central nervous system (CNS) at doses of 0.1 mmol/kg body weight (b. w.) or 0.3 mmol/kg b. w. A total of 24 patients received the lower dose and 23 the higher dose. Gadodiamide injection was administered to patients referred for MRI due to known or suspected CNS lesions. No clinically significant difference in blood parameters or efficacy was found between the two groups. The number of patients with adverse events other than discomfort was higher in the 0.3 group compared with the 0.1 group. In the 0.1 group, none of the 24 patients experienced any adverse events other than discomfort, and in the 0.3 group, 5 of 23 patients (21.7%) experienced a total of five adverse events other than discomfort. All adverse events were of mild or moderate intensity. Postinjection MR scans provided new information that affected patient management in the case of 6 patients in the 0.1 group and 9 in the 0.3 group.