Improved Detectability of Brain Stem Ischemia by Combining Axial and Coronal Diffusion-Weighted Imaging

Background and Purpose: To evaluate the benefit of a coronal diffusion-weighted imaging (DWI) in addition to standard axial DWI for the detection of brain stem infarctions. Methods: A retrospective analysis of patients with symptoms consistent with acute and subacute brain stem infarction who received magnetic resonance imaging, including axial and coronal DWI. Diffusion restrictions were identified by 2 independent raters blinded for the final clinical diagnosis in 3 separate reading steps: axial DWI, coronal DWI, and combined axial and coronal DWI. Lesion location and certainty level were both documented for each reading step. In cases of reader disagreement, an additional consensus reading was performed. Results: Two hundred thirty-nine patients were included. Of these, 124 patients (51.9%) were clinically diagnosed with brain stem infarction. Sensitivity, specificity, positive, and negative predictive values were best for combined DWI assessment (90.3%, 99.1%, 99.1%, and 90.5%) compared with axial (85.5%, 94.9%, 94.6%, and 85.8%) and coronal DWI alone (87.9%, 96.5%, 96.5%, and 88.1%). Diffusion restriction on combined DWI was diagnosed in 112/124 patients compared with 106/124 on axial DWI and 109/124 on coronal DWI. Interobserver agreement for the detection of brain stem lesions was the highest in the combined rating step (Cohen κ coefficient=0.94). Conclusions: Coronal DWI sequences might improve the detection rate of brain stem infarction compared with standard axial DWI. The combined coronal and axial DWI provides the best detection rate while minimally increasing scan times.

Endovascular Treatment of Unruptured Intracranial Aneurysms

We report the clinical and angiographic results of endovascular treatment of unruptured intracranial aneurysms. Over a three-year period, 80 unruptured aneurysms in 74 patients were electively treated with endovascular management. One aneurysm was diagnosed during investigations for a second ruptured aneurysm, 54 aneurysms were incidentally discovered, 18 aneurysms presented with symptoms of mass effect and seven aneurysms presented with symptoms of brain stem ischemia. Mean size of the 80 unruptured aneurysms was 12.5±8.0 mm (range, 2–39 mm). Thirty-six aneurysms (45%) were small (<10 mm), 38 aneurysms (47.5%) were large (10–25 mm), and six aneurysms (7.5%) were giant (25–39 mm). Forty-eight wide-necked aneurysms (60%) were coiled with the aid of a supporting device. The mortality rate was 1.25%, and the overall morbidity was 1.25%. Of these, one of the patients suffered a stroke, leading to severe disability (1.25%). In one patient, the aneurysm ruptured during treatment, resulting in death. Initial aneurysm occlusion was complete (100%) in 76.25% aneurysms, nearly complete (90%–98%) in 10% aneurysms and incomplete (60%–85%) in 13.75% aneurysms. Follow-up angiography was available in 67 patients with 73 treated aneurysms (91.25%) from one to 36 months (mean 9.3 months); partial reopening occurred in 7.5%, mainly large and giant aneurysms (5.5%). Additional coiling was performed in four aneurysms. There were no complications in additional treatments. At 14.1-month clinical follow-up (range, 2 to 36 months), mRS score was 0 in 78.75% patients, 1 in 10% patients, 2 in 8.75% and 3 in 1.25%. There was no aneurysmal rupture during the follow-up period. Endovascular treatment of unruptured intracranial aneurysms has low procedural mortality and morbidity rates.

Rebleeding and Ischemia after Acute Endovascular Treatment of Ruptured Dissecting Subarachnoid Vertebral Artery Aneurysms

Dissection aneurysms of the vertebral artery represent 3.2% of all cerebral aneurysms and 28% of intracranial dissection aneurysms. Dissection of the vertebral artery in its intracranial segment (V4) usually causes a subarachnoid hemorrhage (SAH) from subadventiatial extension of the vessel wall hematoma. Rarely (one case in seven), the symptomatology is characterized by brain stem ischemia from the vertebral artery and/or postero-inferior cerebellar artery occlusive dissection. The high rebleeding (18–33% with a 10+/-5 day interval between the first and the second bleeding) and mortality (>45%) rates 1, 13 of this disease prompt emergency treatment usually consisting in endovascular coiling of the dissection aneurysm and/or the dissected segment of the parent vessel. Herein we report our experience in endovascular coiling of acutely ruptured dissecting aneurysms of the vertebral artery dissection in V4 segment. We focus the discussion on the risk of rebleeding and the ischemic complications that my occur after endovascular or surgical treatment.

Neck Extension and Rotation in Sudden Infant Death Syndrome and Other Natural Infant Deaths

It has been hypothesized that some cases of sudden infant death syndrome (SIDS) are a result of neck extension and/or rotation that causes vertebral artery (VA) compression and brain stem ischemia. There is a paucity of relevant literature on this topic. Therefore, our aim was to compare neck rotation and extension in SIDS and other natural infant deaths. Cases of SIDS and other natural infant deaths within the San Diego SIDS Research Project database were analyzed retrospectively with respect to neck and body position as reported by the trained, experienced scene investigators and/or the caretakers who discovered the infants. Information was used from 246 SIDS cases and 56 cases of other natural deaths. Simultaneous neck extension and rotation was not reported in either group. When data regarding neutral/flexed/extended position and rotation of the neck were combined, no significant differences were found between the two groups ( P = 0.94); 40% of the SIDS cases and 41% of the other natural death cases were found with the neck either extended or rotated (odds ratio [OR] 0.97, [reference group = neck either neutral or flexed, and not rotated], 95% confidence interval [CI] 0.45, 2.11). There were also no significant differences between the groups when neck rotation and neck extension were analyzed independent of one another. Neck rotation among cases found in the prone position was common and was not significantly different between the two groups (49% of 146 SIDS cases, 58% of 24 other natural death cases, P = 0.38, OR 0.68, 95% CI 0.28, 1.62). Neck rotation among infants found in the supine position occurred one-third as often in the SIDS group (9% of 33 cases) as in the other natural death group (29% of 14 cases); however, the difference was not significant ( P = 0.17; OR 0.25, 95% CI 0.05, 1.31). Although our analysis does not exclude VA compression and brain stem ischemia in some cases of SIDS, we found no evidence to affirm its importance. This study demonstrates the importance of meticulous scene descriptions, including neck position.