Prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) in a middle-aged population with overweight and normal liver enzymes, and diagnostic accuracy of noninvasive proxies.

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing at an alarming rate. Elevated liver enzymes are a primary reason to refer patients for further testing. However, liver enzymes within the normal range do not exclude the presence of MASLD. We examined the prevalence of MASLD in a middle-aged population with overweight and normal liver enzymes. In addition, we examined the accuracy of 4 sets of noninvasive proxies for MASLD. We included 1017 participants from the Netherlands epidemiology of obesity cohort study with body mass index ≥25 kg/m2 and liver enzymes (asparate aminotransferase, alanine aminotransferase, gamma-glutamyltranspeptidase) within normal range. The diagnostic accuracy of biomarker scores (fatty liver index, liver fat score [LFS], STEATO-ELSA, and hepatic steatosis index) was determined against elevated hepatic triglyceride content measured by 1proton magnetic resonance spectroscopy. Participants (mean age 56 years, 49% women), had a median body mass index of 29.6 kg/m2 and a median hepatic triglyceride content of 4.4%. MASLD was present in 42% of participants and was more common in men than women, with respectively 47% and 36% being affected. The LFS showed the highest accuracy with an area under the curve of 0.72. We identified metabolic syndrome as the prime predictor for MASLD with an odds ratio of 2.95 (95% confidence interval 2.20-3.98). The prevalence of MASLD in middle-aged men and women with overweight and liver enzymes within the normal range is over 40%. LFS showed the highest accuracy to detect MASLD, but, overall, biomarker scores performed relatively poor. The presence of metabolic syndrome was the prime predictor of MASLD.

Avoiding selection bias in metabolomics studies: a tutorial.

BACKGROUND: Metabolomics techniques are increasingly applied in epidemiologic research. Many available assays are still relatively expensive and therefore measurements are often performed in small patient population studies such as case series or case-control designs with strong participant selection criteria. Subsequently, metabolomics data are frequently used to assess secondary associations for which the original study was not explicitly designed. Especially in these secondary analyses, there is a risk that the original selection criteria and the conditioning that takes place due to this selection are not properly accounted for which can lead to selection bias. AIM OF REVIEW: In this tutorial, we start with a brief theoretical introduction on the issue of selection bias. Subsequently, we demonstrate how selection bias can occur in metabolomics studies by means of an investigation into associations of metabolites with total body fat in a nested case-control study that was originally designed to study effects of elevated fasting glucose. KEY SCIENTIFIC CONCEPTS OF REVIEW: We demonstrate that standard analytical methods, such as stratification or adjustment in regression analyses, are not suited to deal with selection bias and may even induce the bias when analysing metabolite-phenotype relationships in selected groups. Finally, we show that inverse probability weighting, also known as survey weighting, can be used in some situations to make unbiased estimates of the outcomes.

Obstructive hydrocephalus at the anterior third ventricle caused by dilated veins from an arteriovenous malformation.

A dilated thalamostriate--internal cerebral vein complex, draining a right frontoparietal arteriovenous malformation, caused a physical block at the foremen of Monroe and was the cause of obstructive hydrocephalus. It represents a new mechanism of obstructive hydrocephalus formation in patients with arteriovenous malformations, which has not been previously reported. There was no history of subarachnoid hemorrhage. Embolization, followed by resection, was successfully carried out. This case was reported because of its unusual nature and to discuss potential problems to be avoided in dealing with intraventricular arteriovenous malformations.

Cerebral arterial spasm--a controlled trial of nimodipine in patients with subarachnoid hemorrhage.

We enrolled 125 neurologically normal patients with intracranial aneurysms in a multi-institution, prospective, double-blind, randomized, placebo-controlled trial within 96 hours of their subarachnoid hemorrhage, to determine whether treatment with the calcium blocker nimodipine would prevent or reduce the severity of ischemic neurologic deficits from arterial spasm. A deficit from cerebral arterial spasm that persisted and was severe or caused death by the end of the 21-day treatment period occurred in 8 of 60 patients given placebo and in 1 of 56 given nimodipine (P = 0.03, Fisher's exact test). Analysis of the amount of basal subarachnoid blood on pre-entry CAT scans in patients with deficits from spasm showed that an increase in subarachnoid blood was not associated with a worse neurologic outcome among patients who received nimodipine, unlike the situation in patients given a placebo. There were no side effects from nimodipine. We conclude that nimodipine should be given to patients who are neurologically normal after subarachnoid hemorrhage in order to reduce the occurrence of severe neurologic deficits due to cerebral arterial spasm.

Intracranial hemorrhage following attempted embolization and removal of large arteriovenous malformations.

Two cases of intracranial hemorrhage following staged flow reduction procedures for large arteriovenous malformations are presented. Possible causes of bleeding in these cases are discussed. We suggest that the staged removal of large arteriovenous malformations may not prevent hemorrhagic complications in certain cases.

Sixth nerve palsy complicating percutaneous thermal ablation of the trigeminal nerve rootlet.

Two patients, an 81-year-old man and a 77-year-old woman, developed sixth nerve palsies after radiofrequency trigeminal gangliolysis for trigeminal neuralgia. Both sixth nerve palsies resolved spontaneously within four to seven months. The combination of postoperative trigeminal nerve deficits and transient oculomotor nerve palsies can mimic parasellar mass lesions and lead to unnecessary neuroradiologic investigation in the early postoperative period.

Traumatic dissection of the internal carotid artery treated by ECIC anastomosis.

A patient with traumatic dissection of the left internal carotid artery (ICA) was treated by extracranial-intracranial (ECIC) anastomosis. Anastomosis was performed because the near total occlusion of the left ICA was associated with a cerebral transient ischemic attack. At surgery, an embolus was found in a cortical branch of the middle cerebral artery and was removed at the time of the ECIC. Traumatic dissection of the ICA is briefly reviewed.

Varied CT appearance of aneurysms of the vein of Galen in infancy.

An aneurysm of the vein of Galen can have a varied CT appearance in infancy. The classical picture is a spherical posterior third ventricular mass with the density of circulating blood contiguous with a dilated straight sinus and with uniform contrast enhancement. With varying degrees of thrombosis of the aneurysm which may occur in late infancy, the mass can change in density and the dilated straight sinus disappear. With total thrombosis, a precontrast hyperdense rim develops with a low density. The rim enhances but the low density center does not change with contrast infusion. Our experience in three patients with this spectrum of CT findings will be demonstrated and correlated with clinical findings and angiography.

Metastasis of a rectal carcinoid to the posterior fossa.

We report the metastasis of a rectal carcinoid to the dura mater of the posterior fossa. The clinical presentation was unusual because of a 10-year latent period between resection of the primary rectal tumor and symptoms and signs of the posterior fossa metastasis; the radiological findings were atypical of a metastasis. Gastrointestinal carcinoids, apudomas, and the concept of the APUD endocrine cell family are reviewed.

Observations on moyamoya disease: a case treated with superficial temporal-middle cerebral artery anastomosis.

A 24-year-old Caucasian woman with Moyamoya disease was treated by a superficial temporal, middle cerebral artery anastomosis. Her pre and postoperative angiograms revealed that the telangiectatic network in the region of the basal ganglion served as a transcerebral collateral circulation from the internal carotid artery proximal to its occlusion to the cortical branches of the middle cerebral artery. The transit through two capillary systems (basal ganglia and cortical) explains the slow circulation time. Prompt venous drainage was seen to occur once a more direct collateral supply was established by the superficial temporal-middle cerebral artery anastomosis.

Unilateral internal carotid arterial occlusion: special considerations.

Cases of patients with unilateral internal carotid arterial occlusion and contralateral internal carotid arterial stenosis are reviewed. Forty-two percent presented with a fixed neurological deficit. The deficit was referable to the side of occlusion in 92% and to the side of stenosis in 8%. Eleven percent had a neurological complication following carotid endarterectomy on the side of the stenotic lesion. The neurological complication was referable to the side of stenosis in 67% and to the side of occlusion in 33%. Patients have been followed for an average of 19 months and have not developed any additional TIA's or strokes in the followup period. There may be a role for an extracranial-intracranial bypass (ECIC) on the occluded side prior to an endarterectomy on the stenotic side if a poor collateral situation exists. An ECIC should be done in patients who remain symptomatic following carotid endarterectomy on the stenotic side. These data do not support doing ECIC in asymptomatic patients with unilateral carotid arterial occlusion.

The microsurgical removal of intramedullary spinal hemangioblastomas. Report of twelve cases and a review of the literature.

From 1969 to 1975, 12 patients were operated upon at the Kantonsspital Zürich by the senior author (MGY) for intramedullary spinal hemangioblastoma with the help of microtechnique. The purpose of this paper is to describe in detail the surgical technique and the results, and to comment on the historical, clinical, pathological, and radiological aspects of spinal hemangioblastoma and the complex of von Hippel-Lindau's Disease (multiple angiomatosis of retina, central nervous system, and viscera) with which it is associated.

Arteriovenous malformations of vein of Galen: microsurgical treatment.

The surgical technic used at the neurosurgical clinic in Zürich in eradicating arteriovenous malformations of the vein of Galen is described. It is based on experience with nine cases. The surgical approach is made posteriorly. The right occipital lobe is retracted laterally from the falx cerebri. The multiple feeding vessels demonstrated in the angiogram are occluded; first, on the right side, then the left, and finally beneath the malformation. The draining vein of Galen is not occluded or removed. The use of the operating microscope is essential.

Expansion of an air-filled subdural space during nitrous oxide anesthesia.

The long-term administration of nitrous oxide anesthesia during craniotomy as well as following closure of the parietal craniotomy flap (under no tension) leads to significant expansion of the residual air bubble trapped under the dura. A case is presented in which an extracerebral avascular space, filled only with gas, caused a marked shift of the intracranial structures and uncal herniation secondary to nitrous oxide anesthesia during craniotomy and postcraniotomy angiography.