A Systematic Review and Meta-Analysis of the Pathology Underlying Aneurysm Enhancement on Vessel Wall Imaging.

Intracranial aneurysms are common, but only a minority rupture and cause subarachnoid haemorrhage, presenting a dilemma regarding which to treat. Vessel wall imaging (VWI) is a contrast-enhanced magnetic resonance imaging (MRI) technique used to identify unstable aneurysms. The pathological basis of MR enhancement of aneurysms is the subject of debate. This review synthesises the literature to determine the pathological basis of VWI enhancement. PubMed and Embase searches were performed for studies reporting VWI of intracranial aneurysms and their correlated histological analysis. The risk of bias was assessed. Calculations of interdependence, univariate and multivariate analysis were performed. Of 228 publications identified, 7 met the eligibility criteria. Individual aneurysm data were extracted for 72 out of a total of 81 aneurysms. Univariate analysis showed macrophage markers (CD68 and MPO, p = 0.001 and p = 0.002), endothelial cell markers (CD34 and CD31, p = 0.007 and p = 0.003), glycans (Alcian blue, p = 0.003) and wall thickness (p = 0.030) were positively associated with enhancement. Aneurysm enhancement therefore appears to be associated with inflammatory infiltrate and neovascularisation. However, all these markers are correlated with each other, and the literature is limited in terms of the numbers of aneurysms analysed and the parameters considered. The data are therefore insufficient to determine if these associations are independent of each other or of aneurysm size, wall thickness and rupture status. Thus, the cause of aneurysm-wall enhancement currently remains unknown.

Basilar artery perforator aneurysms: a comparison with non-perforator saccular aneurysms.

BACKGROUND: Basilar artery perforator aneurysms (BAPAs) are rare. There is no systematic description of their presentation, imaging, natural history and outcomes and how these compare to conventional non-perforator aneurysms. Thus, the authors in this study aimed to compare BAPAs to non-perforator aneurysms. METHODS: Cases were identified from a prospective neurovascular database, notes and imaging retrospectively reviewed and compared to a consecutive series of patients with non-perforator aneurysms. Blood volume on CT and vessel wall imaging (VWI) were compared to controls. RESULTS: 9/739 patients with aneurysmal subarachnoid haemorrhage (aSAH) harboured BAPAs. Compared to 103 with aSAH from posterior circulation aneurysms, they were more likely to be male (6/9, p = 0.008), but of equal severity (4/9 poor grade, p = 0.736) and need of CSF drainage (5/9, p = 0.154). Blood volume was similar to controls (30.2 ml vs 26.7 ml, p = 0.716). 6/9 BAPAs were initially missed on CTA. VWI showed thick (2.9 mm ± 2.7) bright enhancement (stalk ratio 1.05 ± 0.12), similar to controls with ruptured aneurysms (0.95 ± 0.23, p = 0.551), and greater than unruptured aneurysms (0.43 ± 0.11, p < 0.001). All were initially managed conservatively. Six thrombosed spontaneously. Three grew and had difficult access with few good endovascular options and were treated through a subtemporal craniotomy without complication. None rebled. At 3 months, all presenting in poor grade were mRS 3-4 and those in good grade mRS 1-2. CONCLUSIONS: Despite their small size, BAPAs present with similar volume SAH, WFNS grade and hydrocephalus to other aneurysms. They are difficult to identify on CTA but enhance strikingly on VWI. The majority thrombosed. Initial conservative management reserving treatment for growth was associated with no rebleeds or complications.

Desminopathy presenting as late onset bilateral facial weakness, with diagnosis supported by lower limb MRI.

A 63 year old male presented with a 20 year history of facial weakness and several years of nasal regurgitation and dysphonia. Examination revealed bilateral facial weakness with nasal speech. Serum creatine kinase was 918 U/L. Neurophysiological studies suggested a myopathy and biopsy of the left vastus lateralis showed serpentine basophilic inclusions in the sarcoplasm and strong oxidative enzyme activity suggesting mitochondria accumulation. The muscle MRI showed selective fatty replacement within semitendinosus, gastrocnemius and soleus indicative of a desminopathy. A heterozygous missense variant c.17C>G (p.Ser6Trp) was identified within DES, predicted to be pathogenic in silico and previously described in a family with distal limb weakness. There are no previous case reports of desminopathy presenting with facial weakness, to our knowledge. Diagnosis was suggested following myoimaging of clinically unaffected muscles. Our study highlights the importance of muscle MRI in the diagnostic evaluation of muscle disease and further expands the known phenotypic heterogeneity of desminopathies.

The Resolution of Oculomotor Nerve Palsy Caused by Unruptured Posterior Communicating Artery Aneurysms: A Cohort Study and Narrative Review.

OBJECTIVE: Recovery of oculomotor nerve palsy after microsurgical and endovascular treatment has been studied in numerous small series of predominantly ruptured aneurysms. Little consideration has been given to the distinction between ruptured and unruptured aneurysms. This study examines the influence of treatment modality on oculomotor palsy recovery as a result of unruptured posterior communicating artery aneurysms. METHODS: Patients who presented between 2003 and 2015 with an oculomotor palsy secondary to an unruptured posterior communicating artery aneurysm were identified from the hospital database. A keyword search for "posterior communicating artery aneurysm" and "oculomotor nerve palsy OR third nerve palsy" using the PubMed database was performed for the narrative review. RESULTS: The cohort study and narrative review identified 15 and 179 eligible patients, respectively. Surgically treated patients in the cohort study did not have a significantly better rate of complete palsy resolution than those who had been coiled (P = 0.08). In the review, clipping of the aneurysm resulted in a higher rate of complete palsy resolution (70.0%; 95% confidence interval [CI], 60.7%-79.3%) than did coiling (46.5%; 95% CI, 36.0%-57.0%). Patients who presented with an aneurysm <7 mm had a higher rate of complete palsy resolution compared with aneurysms >7 mm (68.6%; 95% CI, 57.7%-79.5% vs. 44.3%; 95% CI, 32.7%-55.9%). Patients presenting with a complete palsy (49.4%; 95% CI, 38.6%-60.2%) had a lower rate of recovery than did those with a partial palsy (71.4%; 95% CI, 60.2%-82.6%). CONCLUSIONS: In this narrative review, surgical clipping of unruptured posterior communicating artery aneurysms was associated with a higher rate of associated oculomotor palsy recovery than was endovascular treatment.

'The worm that got away': parainfectious atypical optic neuritis associated with schistosomiasis infection.

Although optic neuritis is commonly associated with multiple sclerosis, patients with atypical optic neuritis require further investigations to exclude other associated conditions. We report a woman presenting with cough, fatigue, atypical optic neuritis with chiasmitis. She responded partially to corticosteroids and we subsequently found she had a ground-glass lung nodule. Follow-up CT scan of thorax at 12 months showed new parenchymal lung lesions that suggested schistosomiasis. Further questioning by a respiratory physician identified, in retrospect, a previous exposure history; serological testing confirmed schistosoma infection. She was treated with praziquantel and slowly improved clinically, with radiological improvement in the optic chiasm, regression of the parenchymal lung lesions but with the ground glass nodule unchanged. We diagnosed parainfectious optic neuritis associated with schistosomiasis, based upon exposure history, serological confirmation and radiological features, together with the response to treatment, and having excluded other causes of an atypical optic neuritis.

Adult-Onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia Caused by a Novel R782G Mutation in CSF1R.

We report a new family with autosomal dominant inheritance of a late onset rapidly progressive leukodystrophy in which exome sequencing has revealed a novel mutation p.R782G in the Colony-Stimulating Factor 1 Receptor gene (CSF1R). Neuropathology of two affected family members showed cerebral white matter degeneration with axonal swellings and pigmented macrophages. The few recently reported families with CSF1R mutations had been previously labelled "hereditary diffuse leukencephalopathy with axonal spheroids" (HDLS) and "pigmentary orthochromatic leukodystrophy" (POLD), disorders which now appear to form a disease continuum. The term "adult-onset leukoencephalopathy with axonal spheroids and pigmented glia" (ALSP) has been proposed to encompass this spectrum. As CSF1R regulates microglia this mutation implies that dysregulation of microglia is the primary cause of the disease.

Use of Hydrocoil in small aneurysms: procedural safety, treatment efficacy and factors predicting complete occlusion.

Coil technology has been directed to reduce recurrence rates and we have seen the introduction of trials comparing the efficacy of surface modified versus bare platinum coils (BPC). This article reports on one treatment strategy in the treatment of small aneurysms by the placement of Hydrocoil across the neck of the aneurysm. Procedural safety, treatment efficacy and factors which predict complete occlusion are evaluated. We retrospectively identified a subgroup of small aneurysms treated over a four-year period. Analysis comparing aneurysms treated with Hydrocoil and BPC versus Hydrocoil alone was undertaken. Eighty-five aneurysms were coiled; 62% with Hydrocoil alone, 38% in combination with BPC. At six-month follow-up, overall 50% were completely occluded, 39.5% had a neck remnant and 10.5% had a residual aneurysm. Complete occlusion was identified in 39% in the Hydrocoil and BPC group compared to 56% in the Hydrocoil alone group. In 56/76 (74%) cases analysed, Hydrocoil loop successfully bridged the neck of the aneurysm in which 38/76 (68%) of these were completely occluded at six-month follow-up. Thirteen procedure-related complications occurred. Aneurysms treated with Hydrocoil alone resulted in fewer recurrences compared with a combination of Hydrocoil and BPC. These data suggest that the technique of positioning Hydrocoil at the neck of the aneurysm increases the probability of complete occlusion and is therefore a strong predictor of aneurysm occlusion. In our experience, this technique did not demonstrate an increased risk of intra-procedural rupture or thrombo-embolic complications compared to conventional embolization with BPC.

Spontaneous regression of a cystic hypoglossal schwannoma causing unilateral tongue atrophy.

A 60-year-old lady presented with intermittent headaches. Examination revealed striking marked unilateral tongue atrophy. Magnetic resonance imaging (MRI) revealed a cystic lesion in the hypoglossal canal and a provisional diagnosis of cystic hypoglossal schwannoma made. Annual surveillance scans showed stable appearances but surprisingly at 3 years they showed a significant reduction in the size of the lesion. Most patients with hypoglossal schwannomas present with ipsilateral hypoglossal nerve palsy; careful cranial nerve examination is vital in diagnosing such rare lesions. Little is known of their natural history, with most lesions undergoing surgery. This case highlights spontaneous regression following non-operative management.

Pilocytic astrocytoma originating at the cavernous sinus.

We report a case of histologically proven pilocytic astrocytoma arising within the cavernous sinus, confirmed radiographically and at operation. We discuss the implications in the context of previous reports of ectopic glioma origin. In particular, the possiblity of glioma development within glial cell islands in the peripheral segment of cranial nerves is explored.

Giant tumefactive perivascular spaces.

BACKGROUND AND PURPOSE: The brain perivascular spaces (PVSs) are pial-lined, interstitial fluid-filled structures that accompany penetrating arteries. When enlarged, they may cause mass effect and can be mistaken for more ominous pathologic processes. The purpose of this study was to delineate the broad clinical and imaging spectrum of this unusual condition. METHODS: Thirty-seven cases of giant PVSs were identified from 1988 to 2004 and were retrospectively reviewed. Clinical data collected included patient demographics, presenting symptoms, and follow-up. Histopathologic data were reviewed when available. Images were evaluated for size and location of the giant PVSs, associated mass effect, hydrocephalus, adjacent white matter changes, and contrast enhancement. RESULTS: There were 24 men and 13 women with an age range of 6-86 years, (mean 46 years). The most common presenting feature was headache (15 patients). Thirty-two cases had multilocular clusters of variably sized cysts. Five lesions were unilocular. All lesions had signal intensity comparable to CSF and did not enhance. The most common location for the giant PVSs was the mesencephalothalamic region (21/36). Fourteen were located in the cerebral white matter; two were in the dentate nuclei. Nine giant mesencephalothalamic PVSs had associated hydrocephalus, which required surgical intervention. CONCLUSION: Giant tumefactive PVSs most often appear as clusters of variably sized cysts that are isointense relative to CSF and do not enhance. They are most common in the mesencephalothalamic region and may cause hydrocephalus. Although they may have striking mass effect, giant PVSs should not be mistaken for neoplasm or other diseases.

Transcranial approach for venous embolization of dural arteriovenous fistulas.

OBJECT: Transvenous embolization is effective in the treatment of an intracranial dural arteriovenous fistula (DAVF). Access to the fistula via the internal jugular vein (IJV) may be limited by associated dural sinus thrombosis; a transcranial approach has been developed for venous embolization in such a situation. The authors report their experiences with the use of a transcranial approach for venous embolization of DAVFs. METHODS: Ten patients with DAVFs underwent craniectomy and embolization procedures in which direct sinus puncture was performed. The DAVFs were located inside the dura mater that constituted the walls of the transverse sinus in five cases, the superior sagittal sinus in four cases, and the superior petrosal sinus in one case. All DAVFs drained directly into a sinus with secondary reflux into leptomeningeal veins. In all cases, the fistula could not be accessed from the IJVs. Craniectomy was performed in an operating room and, in seven cases, subsequent enlargement of the craniectomy was required. Sinus catheterization was performed after the patient had been transferred to the angiography room. The DAVFs were embolized using coils only in five patients, glue only in two patients, and both coils and glue in three patients. Angiographic confirmation that embolization of the fistula was successful was obtained in all cases. A transient complication occurred during the first case after sinus catheterization was attempted in the operating room. CONCLUSIONS: The transcranial approach allows straightforward access to DAVFs located on superficial dural sinuses that are inaccessible from the IJVs. The effectiveness of this approach is similar to that of the standard retrograde venous approach. The correct location and adequate extent of the craniectomy are essential for success to be achieved using this technique.