1. Abou Zeid, N., Pirko, I., Erickson, B., Weigand, S. D., Thomsen, K. M., Scheithauer, B., Parisi, J. E., et al. (2012). Diffusion-weighted imaging characteristics of biopsy-proven demyelinating brain lesions. Neurology, 78(21), 1655–62. doi:10.1212/WNL.0b013e3182574f66
One-third of inflammatory demyelinating disease (IDD) lesions in the study demonstrated restricted diffusion, most commonly as an ADC dark arc or ring at the lesion edge. Ten of 13 lesions in the abscess cohort displayed restricted ADC center and bright periphery. This pattern of central restriction was never observed among patients with IDD. A dark ring on ADC was significantly more common in the IDD cohort than in the tumor/abscess cohort. This study puts some numbers to a pattern that I think is well recognized by neuroradiologists…. useful when you see it, but present in a minority of cases.
2. Biesbroek, J. M., Rinkel, G. J. E., Algra, A., & van der Sprenkel, J. W. B. (2012). Risk factors for acute subdural hematoma from intracranial aneurysm rupture. Neurosurgery, 71(2), 264–9. doi:10.1227/NEU.0b013e318256c27d
Sixty three of 1757 patients with subarachnoid hemorrhage had associated acute SDH. Increasing age, an episode of sentinel headache before the index SAH, an aneurysm originating from the posterior communicating artery, and the presence of intracranial hemorrhage on the initial CT scan are risk factors for the development of an acute SDH from aneurysm rupture. Patients with an aneurysm at the basilar or vertebral artery have a very low risk of an acute SDH. Another study that puts some numbers to a diagnosis that I have anecdotally recognized, particularly with respect to the near universal occurrence with anterior circulation aneurysms (0 of 95 posterior circulation aneurysm in this study has associated acute SDH).
3. Funao, H., Nakamura, M., Hosogane, N., Watanabe, K., Tsuji, T., Ishii, K., Kamata, M., et al. (2012). Surgical treatment of spinal extradural arachnoid cysts in the thoracolumbar spine. Neurosurgery, 71(2), 278–84. doi:10.1227/NEU.0b013e318257bf74
Twelve patients with extradural arachnoid cysts of the thoracolumbar spine who underwent surgery between 1988 and 2008 were analyzed. Lesion locations were between T7 and L4. Symptom duration of more than 1 year and a cyst size of more than 5 vertebrae in length led to poor surgical outcomes. The authors noted that these lesions developed because of a dural defect with an associated reactive cyst, and that the location of this dural defect was typically in the central region of the cyst, but not always in the midline.
4. Gölitz, P., Struffert, T., Ganslandt, O., Saake, M., Lücking, H., Rösch, J., Knossalla, F., et al. (2012). Optimized angiographic computed tomography with intravenous contrast injection: an alternative to conventional angiography in the follow-up of clipped aneurysms? Journal of Neurosurgery, 117(1), 29–36. doi:10.3171/2012.3.JNS111895
While the author’s nomenclature of the procedure is somewhat tortured, my interpretation is that they utilized intravenous flat-detector CTA in 14 patients with 19 surgically clipped cerebral aneurysms who were scheduled to undergo angiographic follow-up. The patients underwent 3D rotational IA-DSA, and the following day received a flat-detector IV CTA. The flat-detector CTA assessed all aneurysm remnants as true-positive up to a minimal size of 2.6 × 2.4 mm in accordance with the DSA findings, with a tendency for the flat-detector study to overestimate the size of the aneurysm remnants. While they tout the resolution advantage of flat-detector technique over conventional CTA, they do not mention the contrast advantage that CTA enjoys. The flat-detector technique has also been used for evaluation of stroke patients in the acute setting (Blanc R, Pistocchi S, Babic D, Bartolini B, Obadia M, Alamowitch S, Piotin M. Intravenous flat-detector CT angiography in acute ischemic stroke management. Neuroradiology 2012 Apr;54(4):383-91).
5. Klekamp, J. (2012). Surgical treatment of Chiari I malformation-analysis of intraoperative findings, complications, and outcome for 371 foramen magnum decompressions. Neurosurgery, 71(2), 365–80. doi:10.1227/NEU.0b013e31825c3426
Complications were encountered after 21.8% of operations, the most common complication being a CSF fistula (5.9%). Five patients died within 1 month after decompression, corresponding to a surgical mortality rate of 1.3%. Severe arachnoid scarring, a less experienced surgeon, leaving the arachnoid intact, advanced age, and basilar invagination were seen as independent predictors for a clinical neurological recurrence. 73.6% of patients reported their clinical condition as improved 3 months after the operation, whereas 21.0% considered their status unchanged.
6. Morrow, M. J., & Wingerchuk, D. (2012). Neuromyelitis Optica. Journal of Neuro-Ophthalmology, 32(2), 154–66. doi:10.1097/WNO.0b013e31825662f1
Nice review of the topic with 117 references.
7. Nagakane, Y., Christensen, S., Ogata, T., Churilov, L., Ma, H., Parsons, M. W., Desmond, P. M., et al. (2012). Moving Beyond a Single Perfusion Threshold to Define Penumbra: A Novel Probabilistic Mismatch Definition. Stroke, 1548–1555. doi:10.1161/STROKEAHA.111.643932
62 patients from the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) were studied with baseline PWI and 90 day T2 weighted images which were coregistered. PWI images were divided into 10 Tmax delay strata, and infarct risk defined by the tissue at a given Tmax strata that progressed to infarct on the 90 day study. They found that the probability of infarction is strongly tied to the severity of PWI deficits. A penumbral definition based on Tmax >2 is now considered inadequate. The authors found that infarct risks increased with the severity of perfusion deficits and that in a small population of 11 patients a probabilistic method for infarct volume prediction outperforms all Tmax thresholds statistically, with exception of the Tmax >10 threshold, for which it was only favored by a trend.
If that explanation leaves you lacking, just look at Figure 1; it helped me immensely to visualize what the authors were trying to do.
8. Pang, D., Zovickian, J., Lee, J. Y., Moes, G. S., & Wang, K.-C. (2012). Terminal Myelocystocoele: Surgical Observations and Theory of Embryogenesis. Neurosurgery, 70(6). doi:10.1227/NEU.0b013e31824c02c0
Extremely detailed and meticulous study of 10 patients with terminal myelocystocele, with clinical, surgical, histologic and embryologic correlations.
9. Sun, X., Sun, C., Liu, X., Liu, Z., Qi, Q., Guo, Z., Leng, H., et al. (2012). The frequency and treatment of dural tears and cerebrospinal fluid leakage in 266 patients with thoracic myelopathy caused by ossification of the ligamentum flavum. Spine, 37(12), E702–7. doi:10.1097/BRS.0b013e31824586a8
This single institution retrospective review of 266 patients with thoracic ossification of the ligamentum flavum who underwent surgery. The incidence of dural tear and leakage was 32%. In 65 cases, intraoperative repair did not resolve the leak. 16 of these cases had complications including meningitis, wound dehiscence and CSF pseudocyst. Treatment of continued leaks included a variety of methods, including direct placement of sandbag over the wound to give continuous pressure for 5-7 days.
10. Vadera, S., Moosa, A. N. V., Jehi, L., Gupta, A., Kotagal, P., Lachhwani, D., Wyllie, E., et al. (2012). Reoperative hemispherectomy for intractable epilepsy: a report of 36 patients. Neurosurgery, 71(2), 388–93. doi:10.1227/NEU.0b013e31825979bb
Functional hemispherectomy techniques were developed to reduce the risks inherent with anatomic hemispherectomies, in particular the risk of late-onset superficial siderosis. This report describes the outcomes of 36 patients who underwent reoperative hemispherectomy for continued intractable epilepsy. 19% of the patients were seizure free after conversion to anatomic hemispherectomy, with 45% reporting a marked decrease in seizure frequency. Significantly, 36% of the patients had no improvement in their seizures.
11. Wang, H., Du, R., Stary, J., Gkogkas, C., Kim, D., Day, A., & Frerichs, K. (2012). Dissecting aneurysms of the posterior cerebral artery: current endovascular/surgical evaluation and treatment strategies. Neurosurgery, 70(6), 1581–8. doi:10.1227/NEU.0b013e31824c00f4
The authors report a case series of 9 patients with dissecting aneurysms of the PCA. The aneurysms had a considerable variation in outcome, ranging from death to aneurysm resolution without intervention. They recommend acute endovascular parent vessel sacrifice in patients with a hemorrhagic presentation. New visual field deficits following occlusion or trapping range from 10-20 percent, and increase with occlusion distal to the P2 segment.
