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Lee H. Monsein, Alex Y. Razumovsky, Stacey J. Ackerman, Haring J. W. Nauta and Daniel F. Hanley

✓ Vessel identification during a transcranial Doppler (TCD) ultrasound examination is usually based on well-established inferential criteria without confirmation by imaging. Part of a routine study involves taking measurements from the M1 segment of the middle cerebral artery (MCA) and the A1 segment of the anterior cerebral artery (ACA) at the points of maximum mean linear blood flow velocity (LBFV). The authors tested the hypothesis that insonation is from the midpoints of the M1 and A1 segments during clinical TCD examinations.

Conventional hand-held TCD examinations were performed on five volunteers. The points of maximum mean LBFV of the M1 and A1 segments of the MCA and ACA were located. Measurements were also taken from the midpoints of the M1 and A1 segments using a magnetic resonance (MR) imaging-guided stereotactic TCD technique. Values for depths of insonation and maximum mean LBFV obtained with the two techniques were compared. There was no significant difference between the two techniques for the measured values of depth of insonation of either the individual vessels (p > 0.11) or the aggregate (p = 0.46). There was a significant difference between the aggregate maximum mean LBFV measurements (p = 0.0022). The hand-held technique systematically produced higher maximum mean LBFV than the MR-guided stereotactic technique. The authors conclude that when using traditional criteria for TCD examination of the ACA and MCA, the points of insonation approximate the middle of the A1 and M1 segments.

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Amy Lee, Andrea E. Van Pelt, Alex A. Kane, Thomas K. Pilgram, Daniel P. Govier, Albert S. Woo and Matthew D. Smyth

Object

Deformational plagiocephaly (DP) is the leading cause of head shape abnormalities in infants. Treatment options include conservative measures and cranial molding. Pediatric neurosurgeons and craniofacial plastic surgeons have yet to agree on an ideal therapy, and no definable standards exist for initiating treatment with helmets. Furthermore, there may be differences between specialties in their perceptions of DP severity and need for helmet therapy.

Methods

Requests to participate in a web-based questionnaire were sent to diplomates of the American Board of Pediatric Neurological Surgery and US and Canadian members of the Pediatric Joint Section of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons and the American Cleft Palate–Craniofacial Association. Questions focused on educational background; practice setting; volume of DP patients; preferences for evaluation, treatment, follow-up; and incentives or deterrents to treat with helmet therapy. Six examples of varying degrees of DP were presented to delineate treatment preferences.

Results

Requests were sent to 302 neurosurgeons and 470 plastic surgeons, and responses were received from 71 neurosurgeons (24%) and 64 plastic surgeons (14%). The following responses represented the greatest variations between specialties: 1) 8% of neurosurgeons and 26% of plastic surgeons strongly agreed with the statement that helmet therapy is more beneficial than conservative therapy (p < 0.01); and 2) 25% of neurosurgeons and 58% of plastic surgeons would treat moderate to severe DP with helmets (p < 0.01).

Conclusions

Survey responses suggest that neurosurgeons are less likely to prescribe helmet therapy for DP than plastic surgeons. Parents of children with DP are faced with a costly treatment decision that may be influenced more strongly by referral and physician bias than medical evidence.

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Vittorio M. Morreale, Barbara H. Herman, Violette Der-Minassian, Miklós Palkovits, Phillip Klubes, David Perry, Attila Csiffary and Alex P. Lee

✓ A tumor model involving stereotactically implanted culture-reared tumor cells is presented. Stainless steel cannulas were stereotactically and permanently implanted into the caudate nucleus of 30 rats. The animals were separated into two groups. In Group I, 15 animals received a 10-µl injection containing 106 C6 glioblastoma cells (five rats), 106 Walker 256 breast carcinoma cells (five rats), or cell medium (five rats). The coordinates were A(+1.5), L(+3.0), and DV(−5.0). In Group II, the coordinates were changed to A(+1.0), L(+3.0), and DV(−5.0) and the same number of rats received a 1-µl injection containing 105 cells of each tumor in an attempt to produce more focal tumors. Two weeks after implantation, brain sections were stained with cresyl violet and a subset was stained for glial fibrillary acidic protein (GFAP). A computerized morphometric analysis system was used to quantify tumor size. In Group I, the mean C6 tumor areas (± standard error of the mean) at specific coordinates were (in sq mm): A(+4.7) 0.4 ± 0.2; A(+3.7) 3.5 ≥ 1.1; A(+2.7) 5.7 ± 1.7; A(+1.7) 9.5 ± 2.3; A(+0.7) 7.5 ± 3.2; A(−0.3) 3.7 ± 2.9; and A(−1.3) 0.3 ± 0.3. A nearly identical tumor mass and extension into the brain was produced in rats injected with Walker 256 cells. Similar C6 tumor areas were indicated in adjacent sections stained with cresyl violet and GFAP. Tumor was found in the caudate nucleus in all 10 rats, but not in the nucleus accumbens, fornix, or hippocampus. In Group II animals, tumor magnitude and extension into the brain were greatly reduced. The 106 cells in the 10-µl volume was the most reliable tumor load for obtaining uniform tumors in different animals. The similarity of tumor distribution across different animals was indicated by the low variance of tumor area at specific anteroposterior coordinates. Reproducible and well-circumscribed caudate nucleus tumors were produced using this stereotactic procedure.