<figure class="wp-block-audio"></figure>

1. Chalif EJ, Murray RD, Mozaffari K, et al. Malignant pineal parenchymal tumors in adults: a National Cancer Database analysis. Neurosurgery 2022;90:80 7–15

Pineal parenchymal tumors (PPTs) are rare tumors of the pineal gland that account for <1% of primary central nervous system tumors in adults. Although these tumors are heterogeneous and display a wide degree of morphological variation, the World Health Organization (WHO) Classification of Tumors separates these into 5 distinct histological entities: pineocytoma (WHO grade I), PPT of intermediate differentiation (PPTID, WHO grade II/III), pineoblastoma (PB, grade IV), papillary tumor of the pineal region (PTPR, WHO grade II/III), and the recently characterized desmoplastic myxoid SMARCB1-mutant.

The National Cancer Database was queried for histologically confirmed PPT diagnosed from 2007 to 2016. Univariate and multivariate Cox regressions were used to evaluate the prognostic impact of covariates. Kaplan–Meier survival curves were generated for comparative subanalyses.

Of the 251 patients who met inclusion criteria, 172 had PPTs of intermediate differentiation (PPTID) and 79 had pineoblastoma. A plurality of patients with pineoblastomas were treated with trimodal therapy (39.1%), whereas patients with PPTID were commonly treated with either surgery alone or surgery and radiation (33.7% each). Factors independently associated with improved overall survival include younger patient age, female sex, lower comorbidity score, lower tumor grade, and treatment with surgery or radiation. Subanalyses confirm the effect of radiation on survival in patients with grade III PPTID with subtotal resection; however, no survival benefit of adjuvant radiation is demonstrated in patients with grade II PPTID with subtotal resection.

The authors conclude that although radiotherapy and surgery were found to increase survival in all patients with PPT, there was no demonstrable survival benefit of adjuvant radiation in surgically treated patients with grade II PPTID.

6 figures, 2 tables with no imaging

2. Hannan CJ, Hammerbeck-Ward C, Pathmanaban ON, et al. Multiple meningiomas as a criterion for the diagnosis of neurofibromatosis type 2 and other tumor predisposition syndromes. Neurosurgery 2022;90:79 3–99

Neurofibromatosis type 2 (NF2) is a tumor predisposition syndrome, with affected individuals developing schwannomas, meningiomas, and spinal ependymomas. Although the presence of bilateral vestibular schwannomas has long been accepted to be pathognomonic of the condition, there are additional clinical criteria that can lead to the diagnosis of NF2, in the absence of bilateral vestibular schwannomas. A previous study of more than 1300 patients with NF2 demonstrated that the most common of these additional criteria are the presence of a unilateral vestibular schwannomas (UVS) in combination with multiple meningiomas (MM) or with ≥2 nonintradermal schwannomas (NIDS), as well as those presenting with MM in conjunction with a positive family history or the presence of other NF2-associated tumors.

However, it is way more complicated:

Schwannoma tumors from patients with schwannomatosis have been found to harbor somatic mutations in SMARCB1 or the neurofibromin-2 gene (schwannomatosis-1).

Loss of leucine zipper-like transcriptional regulator 1 (LZTR1) function can predispose to the development of autosomal dominant multiple schwannomas (schwannomatosis-2).

A significant minority of patients meeting NF2 diagnostic criterion the basis of the presence of unilateral vestibular schwannoma and other schwannomas actually have an underlying diagnosis of LZTR1-associated schwannomatosis. Similarly, patients suspected of having NF2 presenting with MM may in fact be afflicted by SMARCB1-associated schwannomatosis or clear cell meningiomatosis in association with a pathogenic variant (PV) in SMARCE1.

A total of 31 of 131 patients presenting with a unilateral vestibular schwannoma and MM had a non-refuted diagnosis of NF2 after molecular studies, in comparison with 85 of 96 patients presenting with unilateral vestibular schwannoma and ≥2 nonintradermal schwannomas. Fifty percent of patients presenting with a UVS and ≥2 nonintradermal schwannomas with NF2 developed bilateral VS, compared with only 26% of those who presented with a UVS and MM. In total, 11 of 152 patients presenting with MM without fulfilling NF2 criteria were found to have a pathogenic variant in SMARCE1, and 7 of 152 were confirmed to have mosaic NF2.

The authors demonstrate for the first time that there is a significant difference in the proportion of patients with a nonrefuted diagnosis of NF2 in those who present with UVS and MM, as compared with those who present with UVS and ≥2 NIDS; 100% of those presenting with UVS and MM had a nonrefuted NF2 diagnosis, in comparison with 89% of those presenting with UVS and ≥2 NIDS. This work confirms the previous observation regarding the specificity of UVS with ≥2 NIDS as a diagnostic criterion for NF2; at least 11% of patients presenting in this manner will not have NF2, and this further highlights the need for testing for pathogenic variant in LZTR1 in this population.

3 figures, no imaging

3. Kimura K, Kubo Y, Dobashi K, et al. Angiographic, cerebral hemodynamic, and cognitive outcomes of indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic Moyamoya disease. Neurosurgery 2022;90:67 6–83

The objectives were to determine angiographic, cerebral hemodynamic, and cognitive outcomes of indirect revascularization surgery alone for adult patients with misery perfusion due to ischemic MMD (indirect revascularization group -IDR group) and to test the superiority of indirect revascularization surgery for cognitive improvement by conducting comparisons with historical control patients who had undergone direct revascularization surgery (DR group) through prospective cohort study with historical controls. As a reminder, misery perfusion is defined as cerebral autoregulatory capacity is exhausted, and cerebral blood supply in insufficient to meet metabolic demand.

Twenty adult patients with cerebral misery perfusion underwent encephaloduro-myo-arterio-pericranial-synangiosis alone. Cerebral angiography through arterial catheterization, brain perfusion single-photon emission computed tomography, and neuropsychological testing were performed preoperatively and at 6 months postoperatively.

In 17 patients of the IDR group, collateral flows that were newly formed after surgery on angiograms fed more than one-third of the middle cerebral artery (MCA) cortical territory. In the IDR group, perfusion in the MCA territory was significantly increased after surgery, and the difference in MCA perfusion between before and after surgery was significantly greater compared with the DR group. Improved cognition was significantly more frequent in the IDR group (65%) than in the DR group (31%).

They conclude that indirect revascularization surgery alone forms sufficient collateral circulation, improves cerebral hemodynamics, and recovers cognitive function in adult patients with misery perfusion due to ischemic MMD. The latter 2 beneficial effects may be higher when compared with patients undergoing direct revascularization surgery.

2 tables, 4 figures with catheter angio, with PET and SPECT

4. Bonney PA, Briggs RG, Wu K, et al. Pathophysiological mechanisms underlying idiopathic normal pressure hydrocephalus: a review of recent insights. Front Aging Neurosci 2022;14(April):1–10. Available from: https://www.frontiersin.org/articles/10.3389/fnagi.2022.866313/full

iNPH classically presents with the clinical triad of gait disturbance, urinary incontinence, and dementia, with gait disturbance typically presenting first and cognitive manifestations arising later. The hallmark of the disease is an enlarged ventricular system without an increase in intracranial pressure (ICP). Despite progress in characterizing iNPH and its natural history, its pathophysiology has not been clearly defined.

Diagnostic radiographic features include ventricular enlargement with an Evans index of 0.3 or greater. Other common findings on brain imaging include a callosal angle of 90 degrees or less, periventricular hyperintensities, and enlargement of the temporal horns. A trial of CSF drainage is often undertaken to aid in the diagnosis, commonly via the lumbar subarachnoid space. Clinical benefit after temporary CSF drainage is strongly predictive of improvement in at least one symptom after shunting. In patients unable or unwilling to receive a shunt, serial lumbar punctur