Ingvar Olafsson - Academia.edu (original) (raw)

Papers by Ingvar Olafsson

Hereditary cystatin C amyloid angiopathy is a dominant disorder caused by the deposition of cysta... more Hereditary cystatin C amyloid angiopathy is a dominant disorder caused by the deposition of cystatin C in the brain arteries or arterioles of patients, leading to strokes at an early age.

15th International & 14th European Congress of Endocrinology, May 1, 2012

Laeknabladid, Sep 1, 2013

Laeknabladid, Apr 1, 2016

15th International & 14th European Congress of Endocrinology, May 1, 2012

World Neurosurgery, Feb 1, 2017

Primary spinal tumors are rare. Symptoms depend on the size and location of the tumor. A patient ... more Primary spinal tumors are rare. Symptoms depend on the size and location of the tumor. A patient presented with a rare clinical finding, Brown-Séquard syndrome. The symptoms were caused by an extramedullary tumor compressing on the thoracic spinal cord. Pathologic examination showed cavernous hemangioma with growth both intradurally and extradurally. This is an extremely rare finding; to our knowledge, only 1 case report has been published before in which a spinal cavernous hemangioma had intradural and extradural growth. The clinical symptoms of Brown-Séquard syndrome have not been described before in the findings of spinal cavernous hemangiomas.

Acta Anaesthesiologica Scandinavica, Feb 13, 2017

A populationbased study on epidemiology of intensive care unit treated traumatic brain injury in ... more A populationbased study on epidemiology of intensive care unit treated traumatic brain injury in Iceland.

Journal of Healthcare Engineering, 2017

This paper illustrates the feasibility and utility of combining cranial anatomy and brain functio... more This paper illustrates the feasibility and utility of combining cranial anatomy and brain function on the same 3D-printed model, as evidenced by a neurosurgical planning case study of a 29-year-old female patient with a low-grade frontal-lobe glioma. We herein report the rapid prototyping methodology utilized in conjunction with surgical navigation to prepare and plan a complex neurosurgery. The method introduced here combines CT and MRI images with DTI tractography, while using various image segmentation protocols to 3D model the skull base, tumor, and five eloquent fiber tracts. This 3D model is rapid-prototyped and coregistered with patient images and a reported surgical navigation system, establishing a clear link between the printed model and surgical navigation. This methodology highlights the potential for advanced neurosurgical preparation, which can begin before the patient enters the operation theatre. Moreover, the work presented here demonstrates the workflow developed at the National University Hospital of Iceland, Landspitali, focusing on the processes of anatomy segmentation, fiber tract extrapolation, MRI/CT registration, and 3D printing. Furthermore, we present a qualitative and quantitative assessment for fiber tract generation in a case study where these processes are applied in the preparation of brain tumor resection surgery.

Laeknabladid, Oct 2, 2020

Woman in her thirties presented to the emergency room with a two-week history of worsening headac... more Woman in her thirties presented to the emergency room with a two-week history of worsening headache and diplopia. For eight years she had suffered from progressive weight gain, diabetes and hypertension that didn’t improve with lifestyle modification. A lumbar puncture demonstrated increased intracranial pressure and MRI a pituitary adenoma. Physical examination was consistent with Cushing’s syndrome and endocrine workup confirmed Cushing’s disease. Treatment was complex, including unsuccessful pituitary surgery and gamma knife radiosurgery, and eventually bilateral adrenalectomy with subsequent development of Nelsons syndrome. This case illustrates the diagnostic delay that many patients with CD suffer from.

Nature Communications, Apr 27, 2022

The original version of this Article contained an error in Fig. 3, in which the blue and red tren... more The original version of this Article contained an error in Fig. 3, in which the blue and red trend lines on the left plot were incorrect. In addition, the text "Dorsalgia variants" in the table should have been italicized and underlined. The correct version of Fig. 3 is: which replaces the previous incorrect version: This has been corrected in both the PDF and HTML versions of the Article.

Nature Communications, Feb 22, 2017

Lumbar disc herniation (LDH) is common and often debilitating. Microdiscectomy of herniated lumba... more Lumbar disc herniation (LDH) is common and often debilitating. Microdiscectomy of herniated lumbar discs (LDHsurg) is performed on the most severe cases to resolve the resulting sciatica. Here we perform a genome-wide association study on 4,748 LDHsurg cases and 282,590 population controls and discover 37 highly correlated markers associating with LDHsurg at 8q24.21 (between CCDC26 and GSDMC), represented by rs6651255[C] (OR ¼ 0.81; P ¼ 5.6 Â 10 À 12) with a stronger effect among younger patients than older. As rs6651255[C] also associates with height, we performed a Mendelian randomization analysis using height polygenic risk scores as instruments to estimate the effect of height on LDHsurg risk, and found that the marker's association with LDHsurg is much greater than predicted by its effect on height. In light of presented findings, we speculate that the effect of rs6651255 on LDHsurg is driven by susceptibility to developing severe and persistent sciatica upon LDH.

Laeknabladid, Feb 4, 2022

BACKGROUND: Cerebral venous sinus thrombosis (CSVT) is the cause of 0.5%-1% of all strokes. CSVT ... more BACKGROUND: Cerebral venous sinus thrombosis (CSVT) is the cause of 0.5%-1% of all strokes. CSVT can cause haemorrhage, cerebral infarction and increased intracranial pressure. Due to a variety of symptoms, CSVT can be difficult to diagnose. The purpose of this study was to examine the incidence of CSVT in Iceland 2008-2020, risk factors, symptoms, treatment and outcome. METHODS: A retrospective reviewing of medical records of those diagnosed with CSVT from 1. January 2008 to 31. December 2020, was performed. Sex, age at diagnosis, symptoms, known risk factors, imaging results, treatment and outcome were studied. Statistical processing was performed with Excel and Rstudio. RESULTS: Overall, 31 patients were diagnosed with CSVT (22 women). The mean incidence was 0.72/100.00 per year. The mean age was 34.3 years (14-63 years). The most common symptom was headache (87%), other symptoms included focal symptoms and seizures. The most common risk factor was the use of oral contraceptives (73%). Four patients had no risk factor. The most commonly affected sinus was the transverse-sinus (74%). All patients were treated with anticoagulants. Most received heparin or low-molecular-weight heparin then succeeded by warfarin or NOACs. Three months after diagnosis, 87% of the patients scored 0-2 on the modified Rankin Scale. One patient died as a result of CSVT. DISCUSSION: The incidence of CSVT in Iceland is in accordance with other studies. Headache was the most common symptom and oral contraceptives the most common risk factor among women. Most patients made a good recovery, which suggests a timely diagnosis and appropriate treatment for CSVT in Iceland.

Growth hormone & IGF research, 2010

Laeknabladid, Sep 5, 2016

Cerebral arteriovenous malformations (AVMs) are uncommon but can cause intracerebral hemorrhage w... more Cerebral arteriovenous malformations (AVMs) are uncommon but can cause intracerebral hemorrhage with grave disability or death. AVMs can even cause focal neurological symptoms, seizures and headache. The treatment of AVMs is complex. The most common treatment forms are microsurgery, stereotactic radiotherapy and endovascular embolization. The best treatment in each case can include a combination of the mentioned treatment forms. New studies indicate that no intervention is the best option in unruptured AVMs. In this article we discuss the epidemiology, diagnosis and treatment of cerebral AVMs.

Methods in molecular biology, 2018

Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebr... more Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebral cortex and leptomeninges. This condition is age-related, especially prevalent in Alzheimer's disease (AD), and the main feature of certain hereditary disorders (i.e., HCHWA-I). The vascular smooth muscle cells (VSMCs) appear to play a vital role in the development of CAA, which makes them well suited as an experimental model to study the disease and screen for possible remedies. We describe two different methods for isolating and culturing human VSMCs: First, using the human umbilical cord as an easy source of robust cells, and secondly, using brain tissue that provides the proper cerebral VSMCs, but is more problematic to work with. The umbilical cord also provides human umbilical vascular endothelial cells (HUVEC), useful primary cells for vascular research. Finally, the maintenance, preservation, and characterization of the isolated vascular cells are described.

Clinical Case Reports, Jul 6, 2017

Our objective is to report a case of thyrotoxicosis following pituitary adenectomy for Cushing 0 ... more Our objective is to report a case of thyrotoxicosis following pituitary adenectomy for Cushing 0 s disease, the only pediatric case to our knowledge. No thyroid antibodies were detected, and the thyrotoxicosis was successfully treated for 3 months with no relapse after 5 years of follow-up. The cause of thyrotoxicosis remains unknown.

Laeknabladid, Jun 1, 2011

Humana Press eBooks, 2012

Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebr... more Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebral cortex and leptomeninges. This condition is age-related, especially prevalent in Alzheimer's disease (AD), and the main feature of certain hereditary disorders (i.e., HCHWA-I). The vascular smooth muscle cells (VSMCs) appear to play a vital role in the development of CAA, which makes them well suited as an experimental model to study the disease and screen for possible remedies. We describe two different methods for isolating and culturing human VSMCs. First, using the human umbilical cord as an easy source of robust cells, and secondly, using brain tissue that provides the proper cerebral VSMCs, but is more problematic to work with. The umbilical cord also provides human umbilical vascular endothelial cells (HUVECs), useful primary cells for vascular research. Finally, the maintenance, preservation, and characterization of the isolated vascular cells are described.

Biomedizinische Technik, Jan 7, 2013

Hereditary cystatin C amyloid angiopathy is a dominant disorder caused by the deposition of cysta... more Hereditary cystatin C amyloid angiopathy is a dominant disorder caused by the deposition of cystatin C in the brain arteries or arterioles of patients, leading to strokes at an early age.

15th International & 14th European Congress of Endocrinology, May 1, 2012

Laeknabladid, Sep 1, 2013

Laeknabladid, Apr 1, 2016

15th International & 14th European Congress of Endocrinology, May 1, 2012

World Neurosurgery, Feb 1, 2017

Primary spinal tumors are rare. Symptoms depend on the size and location of the tumor. A patient ... more Primary spinal tumors are rare. Symptoms depend on the size and location of the tumor. A patient presented with a rare clinical finding, Brown-Séquard syndrome. The symptoms were caused by an extramedullary tumor compressing on the thoracic spinal cord. Pathologic examination showed cavernous hemangioma with growth both intradurally and extradurally. This is an extremely rare finding; to our knowledge, only 1 case report has been published before in which a spinal cavernous hemangioma had intradural and extradural growth. The clinical symptoms of Brown-Séquard syndrome have not been described before in the findings of spinal cavernous hemangiomas.

Acta Anaesthesiologica Scandinavica, Feb 13, 2017

A populationbased study on epidemiology of intensive care unit treated traumatic brain injury in ... more A populationbased study on epidemiology of intensive care unit treated traumatic brain injury in Iceland.

Journal of Healthcare Engineering, 2017

This paper illustrates the feasibility and utility of combining cranial anatomy and brain functio... more This paper illustrates the feasibility and utility of combining cranial anatomy and brain function on the same 3D-printed model, as evidenced by a neurosurgical planning case study of a 29-year-old female patient with a low-grade frontal-lobe glioma. We herein report the rapid prototyping methodology utilized in conjunction with surgical navigation to prepare and plan a complex neurosurgery. The method introduced here combines CT and MRI images with DTI tractography, while using various image segmentation protocols to 3D model the skull base, tumor, and five eloquent fiber tracts. This 3D model is rapid-prototyped and coregistered with patient images and a reported surgical navigation system, establishing a clear link between the printed model and surgical navigation. This methodology highlights the potential for advanced neurosurgical preparation, which can begin before the patient enters the operation theatre. Moreover, the work presented here demonstrates the workflow developed at the National University Hospital of Iceland, Landspitali, focusing on the processes of anatomy segmentation, fiber tract extrapolation, MRI/CT registration, and 3D printing. Furthermore, we present a qualitative and quantitative assessment for fiber tract generation in a case study where these processes are applied in the preparation of brain tumor resection surgery.

Laeknabladid, Oct 2, 2020

Woman in her thirties presented to the emergency room with a two-week history of worsening headac... more Woman in her thirties presented to the emergency room with a two-week history of worsening headache and diplopia. For eight years she had suffered from progressive weight gain, diabetes and hypertension that didn’t improve with lifestyle modification. A lumbar puncture demonstrated increased intracranial pressure and MRI a pituitary adenoma. Physical examination was consistent with Cushing’s syndrome and endocrine workup confirmed Cushing’s disease. Treatment was complex, including unsuccessful pituitary surgery and gamma knife radiosurgery, and eventually bilateral adrenalectomy with subsequent development of Nelsons syndrome. This case illustrates the diagnostic delay that many patients with CD suffer from.

Nature Communications, Apr 27, 2022

The original version of this Article contained an error in Fig. 3, in which the blue and red tren... more The original version of this Article contained an error in Fig. 3, in which the blue and red trend lines on the left plot were incorrect. In addition, the text "Dorsalgia variants" in the table should have been italicized and underlined. The correct version of Fig. 3 is: which replaces the previous incorrect version: This has been corrected in both the PDF and HTML versions of the Article.

Nature Communications, Feb 22, 2017

Lumbar disc herniation (LDH) is common and often debilitating. Microdiscectomy of herniated lumba... more Lumbar disc herniation (LDH) is common and often debilitating. Microdiscectomy of herniated lumbar discs (LDHsurg) is performed on the most severe cases to resolve the resulting sciatica. Here we perform a genome-wide association study on 4,748 LDHsurg cases and 282,590 population controls and discover 37 highly correlated markers associating with LDHsurg at 8q24.21 (between CCDC26 and GSDMC), represented by rs6651255[C] (OR ¼ 0.81; P ¼ 5.6 Â 10 À 12) with a stronger effect among younger patients than older. As rs6651255[C] also associates with height, we performed a Mendelian randomization analysis using height polygenic risk scores as instruments to estimate the effect of height on LDHsurg risk, and found that the marker's association with LDHsurg is much greater than predicted by its effect on height. In light of presented findings, we speculate that the effect of rs6651255 on LDHsurg is driven by susceptibility to developing severe and persistent sciatica upon LDH.

Laeknabladid, Feb 4, 2022

BACKGROUND: Cerebral venous sinus thrombosis (CSVT) is the cause of 0.5%-1% of all strokes. CSVT ... more BACKGROUND: Cerebral venous sinus thrombosis (CSVT) is the cause of 0.5%-1% of all strokes. CSVT can cause haemorrhage, cerebral infarction and increased intracranial pressure. Due to a variety of symptoms, CSVT can be difficult to diagnose. The purpose of this study was to examine the incidence of CSVT in Iceland 2008-2020, risk factors, symptoms, treatment and outcome. METHODS: A retrospective reviewing of medical records of those diagnosed with CSVT from 1. January 2008 to 31. December 2020, was performed. Sex, age at diagnosis, symptoms, known risk factors, imaging results, treatment and outcome were studied. Statistical processing was performed with Excel and Rstudio. RESULTS: Overall, 31 patients were diagnosed with CSVT (22 women). The mean incidence was 0.72/100.00 per year. The mean age was 34.3 years (14-63 years). The most common symptom was headache (87%), other symptoms included focal symptoms and seizures. The most common risk factor was the use of oral contraceptives (73%). Four patients had no risk factor. The most commonly affected sinus was the transverse-sinus (74%). All patients were treated with anticoagulants. Most received heparin or low-molecular-weight heparin then succeeded by warfarin or NOACs. Three months after diagnosis, 87% of the patients scored 0-2 on the modified Rankin Scale. One patient died as a result of CSVT. DISCUSSION: The incidence of CSVT in Iceland is in accordance with other studies. Headache was the most common symptom and oral contraceptives the most common risk factor among women. Most patients made a good recovery, which suggests a timely diagnosis and appropriate treatment for CSVT in Iceland.

Growth hormone & IGF research, 2010

Laeknabladid, Sep 5, 2016

Cerebral arteriovenous malformations (AVMs) are uncommon but can cause intracerebral hemorrhage w... more Cerebral arteriovenous malformations (AVMs) are uncommon but can cause intracerebral hemorrhage with grave disability or death. AVMs can even cause focal neurological symptoms, seizures and headache. The treatment of AVMs is complex. The most common treatment forms are microsurgery, stereotactic radiotherapy and endovascular embolization. The best treatment in each case can include a combination of the mentioned treatment forms. New studies indicate that no intervention is the best option in unruptured AVMs. In this article we discuss the epidemiology, diagnosis and treatment of cerebral AVMs.

Methods in molecular biology, 2018

Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebr... more Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebral cortex and leptomeninges. This condition is age-related, especially prevalent in Alzheimer's disease (AD), and the main feature of certain hereditary disorders (i.e., HCHWA-I). The vascular smooth muscle cells (VSMCs) appear to play a vital role in the development of CAA, which makes them well suited as an experimental model to study the disease and screen for possible remedies. We describe two different methods for isolating and culturing human VSMCs: First, using the human umbilical cord as an easy source of robust cells, and secondly, using brain tissue that provides the proper cerebral VSMCs, but is more problematic to work with. The umbilical cord also provides human umbilical vascular endothelial cells (HUVEC), useful primary cells for vascular research. Finally, the maintenance, preservation, and characterization of the isolated vascular cells are described.

Clinical Case Reports, Jul 6, 2017

Our objective is to report a case of thyrotoxicosis following pituitary adenectomy for Cushing 0 ... more Our objective is to report a case of thyrotoxicosis following pituitary adenectomy for Cushing 0 s disease, the only pediatric case to our knowledge. No thyroid antibodies were detected, and the thyrotoxicosis was successfully treated for 3 months with no relapse after 5 years of follow-up. The cause of thyrotoxicosis remains unknown.

Laeknabladid, Jun 1, 2011

Humana Press eBooks, 2012

Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebr... more Cerebral amyloid angiopathy (CAA) results from amyloid accumulation within arteries of the cerebral cortex and leptomeninges. This condition is age-related, especially prevalent in Alzheimer's disease (AD), and the main feature of certain hereditary disorders (i.e., HCHWA-I). The vascular smooth muscle cells (VSMCs) appear to play a vital role in the development of CAA, which makes them well suited as an experimental model to study the disease and screen for possible remedies. We describe two different methods for isolating and culturing human VSMCs. First, using the human umbilical cord as an easy source of robust cells, and secondly, using brain tissue that provides the proper cerebral VSMCs, but is more problematic to work with. The umbilical cord also provides human umbilical vascular endothelial cells (HUVECs), useful primary cells for vascular research. Finally, the maintenance, preservation, and characterization of the isolated vascular cells are described.

Biomedizinische Technik, Jan 7, 2013