1. Safain MG, Roguski M, Heller RS, Malek AM. Flow Diverter Therapy With the Pipeline Embolization Device Is Associated With an Elevated Rate of Delayed Fluid-Attenuated Inversion Recovery Lesions. Stroke. 2016;47(3):789–97. doi:10.1161/STROKEAHA.115.010522.

Forty-one consecutive patients undergoing aneurysm treatment with the Pipeline Embolization Device and a comparison group of 78 Neuroform stent-mediated embolizations were studied. Serial magnetic resonance images were assessed for the presence of newly occurring diffusion-weighted imaging and fluid-attenuated inversion recovery (FLAIR) lesions. Pipeline patients were more likely to have new ipsilateral FLAIR lesions at all time points studied, and 34% (14/41) of Pipeline patients experienced a new FLAIR lesion when compared with 10% (8/78) of Neuroform stent-coil patients. No patient in either group developed a new permanent neurological deficit. They conclude that PED is associated with continued new and independent ipsilateral FLAIR signal abnormalities, and that these lesions were independent from any previous DWI or FLAIR lesion, suggesting a persistent delayed and de novo source generation process. This was in stark contrast with Neuroform-stent–assisted coil embolization, which had almost no rat new FLAIR burden.

Worrisome……prudent follow up recommended!

2. Auriel E, Charidimou A, Gurol ME, et al. Validation of Clinicoradiological Criteria for the Diagnosis of Cerebral Amyloid Angiopathy-Related Inflammation. JAMA Neurol. 2016;73(2):197–202. doi:10.1001/jamaneurol.2015.4078.

They modified the previously proposed clinicoradiological criteria and retrospectively analyzed clinical medical records and FLAIR and gradient-echo scans obtained from individuals with CAA-ri and noninflammatory CAA at two referral centers. Participants included 17 individuals with pathologically confirmed CAA-ri and 37 control group members with pathologically confirmed noninflammatory CAA. In the CAA-ri group, 14 of 17 (82%) met the criteria for both probable and possible CAA-ri. Sensitivity and specificity was 82%and 97%, respectively, for the probable criteria and sensitivity and specificity of 82%and 68%, respectively, for the possible criteria.

Their findings also indicate that small DWI hyperintense lesions or gadolinium enhancement cannot be relied upon for the diagnosis. They conclude that the present data support using empirical immunosuppressive therapy (and avoiding brain biopsy) for patients meeting the criteria proposed for probable CAA-ri. A reasonable follow-up approach would be to consider brain biopsy in empirically treated patients who fail to respond to corticosteroid therapy within 3 weeks.  3 Figures and 2 Tables.

Criteria for probable CAA-ri:

1. Presence of ≥1 of the following clinical features: headache, decrease in consciousness, behavioral change, or focal neurological signs and seizures; the presentation is not directly attributable to an acute ICH
2. MRI shows unifocal or multifocal WMH lesions (cortico-subcortical or deep) that areasymmetric and extend to the immediately subcortical white matter; the asymmetry is not dueto past ICH
3. Presence of ≥1 of the following corticosubcortical hemorrhagic lesions: cerebral macrobleed, cerebral microbleed, or cortical super
4. Age ≥40 y
5. ficial siderosis
6. Absence of neoplastic, infectious, or other cause

3. Fransen PSS, Berkhemer OA, Lingsma HF, et al. Time to Reperfusion and Treatment Effect for Acute Ischemic Stroke. JAMA Neurol. 2016;73(2):190. doi:10.1001/jamaneurol.2015.3886.

The authors analyzed the MRCLEAN data (multicenter, randomized clinical open-label trial of intra-arterial treatment vs no intra-arterial treatment in 500 patients) to evaluate the influence of time from stroke onset to the start of treatment and from stroke onset to reperfusion on the effect of intra-arterial treatment (IAT). The time to the start of treatment was defined as the time from onset of symptoms to groin puncture (TOG). The time from onset of treatment to reperfusion (TOR) was defined as the time to reopening the vessel occlusion or the end of the procedure in cases for which reperfusion was not achieved. Main outcome was the modified Rankin Scale (mRS) score for functional outcome. Among 500 patients (median age, 67 years), the median time to start of treatment was 260 minutes; median time from onset of treatment to reperfusion 340 minutes. The adjusted risk difference was 25.9% when reperfusion was reached at 3 hours, 18.8% at 4 hours, and 6.7 at 6 hours. Putting it another way, the absolute risk difference for a good outcome is reduced by 6% per hour of delay. It will not surprise you that their conclusion is that patients with acute ischemic stroke should undergo an immediate diagnostic workup and IAT in case of intracranial arterial vessel occlusion.

The next three papers relate to normal pressure hydrocephalus:

4. Farahmand D, Sæhle T, Eide PK, Tisell M, Hellström P, Wikkelsö C. A double-blind randomized trial on the clinical effect of different shunt valve settings in idiopathic normal pressure hydrocephalus. J Neurosurg. 2015;124(February): [Epub ahead of print] August 28. doi:10.3171/2015.1.JNS141301.

In this prospective double-blinded, randomized, controlled, double-center study on patients with iNPH, a ventriculoperitoneal shunt with an adjustable Codman Medos Valve was implanted in 68 patients randomized into 2 groups. In 1 group the valve setting was initially set to 20cm H2O and reduced to 4 cm H2O over the course of the 6-month study period. In the other group the valve was kept at a medium level of 12 cm H2O during the whole study period. Fifty-five patients (81%) completed the study. There were no significant differences between the 2 groups preoperatively or at any time postoperatively. Both groups exhibited significant clinical improvement after shunt insertion at all valve settings.  They conclude that improvement after shunt placement in these patients was evident within 3 months, irrespective of valve setting, and lowering the setting to below 12 cm H2O did not further improve outcomes.

5. Jaraj D, Agerskov S, Rabiei K, et al. Vascular factors in suspected normal pressure hydrocephalus: A population-based study. Neurology. 2016;86(7):592–9. doi:10.1212/WNL.0000000000002369.

1,235 persons aged 70 years or older were examined with CT of the brain between 1986 and 2000. They identified 55 persons with hydrocephalic ventricular enlargement consistent with iNPH. Among these, 26 had clinical signs that fulfilled international guideline criteria for probable iNPH. Each case was matched to 5 controls from the same sample, based on age, sex, and study cohort. Hydrocephalic ventricular enlargement was related to hypertension moderate to severe WMLs and DM.  They conclude that vascular mechanisms are probably involved in the pathophysiology of iNPH.

6. Saper CB. The Emperor has no clothes. Ann Neurol. 2016;79(2):165–166. doi:10.1002/ana.24603.

Now for something completely different:  This editorial is in response to a mailing from the American Academy of Neurology regarding iNPH which states that “Ventricular Shunting Appears to Be Helpful in Patients with iNPH”. Dr. Saper is very skeptical of the treatment of iNPH considering that the literature consists of 3 class III studies (prospective, not blinded or placebo controlled) that support shunting, and all of the rest were class IV (retrospective, nonrandomized, not blinded or controlled), giving rise to a level C recommendation of “possibly effective”.  They also found a risk of serious adverse events of 11%. He concludes that neurologists should consider a moratorium on shunting procedures for iNPH until evidence of efficacy is obtained in a rigorous, randomized, placebo-controlled trial.

7. Hirshman BR, Tang JA, Jones LA, et al. Impact of medical academic genealogy on publication patterns: An analysis of the literature for surgical resection in brain tumor patients. Ann Neurol. 2016;79(2):169–77. doi:10.1002/ana.24569.

“Academic genealogy” refers to the linking of scientists and scholars based on their dissertation supervisors. The authors performed a PubMed search to identify US authors who have contributed peer-reviewed articles on a neurosurgery topic that remains controversial: the value of maximal resection for high-grade gliomas (HGGs). Training information for each key author (defined as the first or last author of an article) was collected. Authors were recursively linked to faculty mentors to form genealogies.  They identified 108 articles with 160 unique key authors. Authors who were members of 2 genealogies (14% of key authors) contributed to 38% of all articles. One genealogy (neurosurgery) supported maximal resection, while the other genealogy (radiation oncology) was less likely to support maximal resection. They note that care should be taken in the evaluation of medical literature disproportionately shaped by members of medical academic genealogies.

Nice demonstration of the mentor effect.

8. Kushnirsky M, Nguyen V, Katz JS, et al. Time-delayed contrast-enhanced MRI improves detection of brain metastases and apparent treatment volumes. J Neurosurg. 2016;124(2):489–495. doi:10.3171/2015.2.JNS141993.

Fifty-three volumetric MRI studies from 38 patients undergoing SRS for brain metastases were evaluated. All studies used 0.1-mmol/kg gadobenate dimeglumine (MultiHance; Bracco Diagnostics) immediately after injection, followed by 2 more axial T1-weighted sequences after 5-minute intervals (final image acquisition commenced 15 minutes after contrast injection). The studies were randomized and examined separately by 3 radiologists, who were blinded to the temporal sequence. Each radiologist recorded the number of brain metastases detected per scan. The increase in brain metastases numbers between Scans 2 and 3 ranged from 1 to 9. Between Scans 1 and 3, additional tumors were seen on 43.1% of scans. They conclude that lesion number, volume, and conspicuity increase with a time delay following the administration of MultiHance on both 1.5-T and 3-T magnets and they recommend that postcontrast MR images be acquired between 10 and 15 minutes after injection.

Takes us back to the CT days, when a real delay after injection to imaging makes a huge difference in conspicuity of lesions. Give the blood brain barrier time to be broken!

9. Kepler CK, Vaccaro AR, Chen E, et al. Treatment of isolated cervical facet fractures: a systematic review. J Neurosurg Spine. 2016;24(2):347–354. doi:10.3171/2015.6.SPINE141260.

With this systematic review the authors’ aim was to determine the optimal clinical care for patients with isolated fractures of the cervical facets.

Concerning their three questions:

What is the best method of reduction of facet fracture- dislocations? While closed methods of reduction have been reported to be successful, open methods are more successful either as a primary means of reduction or when closed methods have failed to either reduce a fracture or maintain reduction.

What is the best method of stabilization of the injury? After reduction has been achieved, an anterior or a combined anterior-posterior approach for treatment provides better stabilization than a posterior-only approach.

Which treatment yields the best clinical outcome? Operative treatment has been shown to yield better radiographic outcomes (alignment, reduction). There is insufficient evidence to allow for a comparison between treatments based on clinical outcome measures.

Keep in mind that the papers evaluated were all evidence level III or IV.