Juha Ohman

Tampere University Hospital (Tays) · Neurosciences, Neurosurgery

Background: Post-traumatic hydrocephalus (PTH) is a well-known complication of head injury. The percentage of patients experiencing PTH in trauma cohorts (0.7-51.4%) varies greatly in the prior literature depending on the study population and applied diagnostic criteria. The objective was to determine the incidence of surgically treated PTH in a c...

Background Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) technique used for evaluating changes in the white matter in brain parenchyma. The reliability of quantitative DTI analysis is influenced by several factors, such as the imaging protocol, pre-processing and post-processing methods, and selected diffusion parameters. The...

Background: Serotonergic antidepressants may predispose to bleeding but the effect on traumatic intracranial bleeding is unknown. Methods: The rate of intracranial bleeding in patients with antidepressant medication was compared to patients not antidepressants in a cohort of patients with acute head injury. This association was examined by using a...

Objective This study examined the prevalence of preexisting conditions that could affect premorbid brain health, cognition, and functional independence among older adults with mild traumatic brain injury (MTBI), and the relationship between preexisting conditions, injury characteristics, and emergency department (ED) discharge location (home versus...

Background: Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) technique used for evaluating changes in the white matter in brain parenchyma. The reliability of quantitative DTI analysis is influenced by several factors, such as the imaging protocol, pre-processing and post-processing methods, and selected diffusion parameters. Of...

Objective: To examine the population-based incidence, complications, and total, direct hospital costs of chronic subdural hematoma (CSDH) treatment in a neurosurgical clinic during a 26-year period. The aim was also to estimate the necessity of planned postoperative follow-up computed tomography (CT). Methods: A retrospective cohort (1990-2015) of...

Objective Preexisting health conditions are associated with worse outcome following mild traumatic brain injury (MTBI), which is especially important in MTBI management among older adults. This study focused on older adults who presented to an emergency department (ED) following uncomplicated MTBI, examining the relationship between clinical signs...

Objective There is enormous research and clinical interest in blood-based biomarkers of mild traumatic brain injury (MTBI) sustained in sports, daily life, or military service. We examined the reliability of a commercially available assay for S100B used on the same samples by two different laboratories separated by 2 years in time. Methods and Pro...

Objective To assess possible long-term excess mortality and causes of death of patients with chronic subdural hematoma (CSDH).MethodsA retrospective study (1990–2015) of adult patients (n = 1133, median age = 76 years old, men = 65%) with CSDH identified by ICD-codes and verified by medical records. All patients were followed until death or the end...

Background: Serotonergic antidepressants (SA), especially selective serotonin reuptake inhibitors (SSRIs) may increase the risk of bleeding but the effect on traumatic intracranial bleeding is not known. Materials and methods: We determined the association between SA and traumatic intracranial bleeding using combined retrospective and prospectiv...

Background and purpose: Prediction of intracranial aneurysm growth risk can assist physicians in planning of follow-up imaging of conservatively managed unruptured intracranial aneurysms. We therefore aimed to externally validate the ELAPSS (Earlier subarachnoid hemorrhage, aneurysm Location, Age, Population, aneurysm Size and Shape) score for pre...

Objectives: The purpose of this study was to determine the unique characteristics of violence-related traumatic brain injuries (TBI). Methods: All consecutive patients who underwent head CT due to an acute head injury (n=3023) at the Emergency Department of Tampere University Hospital (Aug 2010-Jul 2012) were included. A detailed retrospective data...

Objective: To determine the population-based epidemiology of chronic subdural hematoma (CSDH) over a 26-year period. Methods: A retrospective study of all adult patients [≥ 18 years old Pirkanmaa (Finland) residents] with a diagnosis of CSDH between 1990 and 2015. The cases were identified by using ICD-codes. Detailed data collection was performed...

Background: This study documents pre-injury health, psychiatric, substance abuse, and neurological problems of older adults who were evaluated within an emergency department following a suspected mild traumatic brain injury (MTBI). We hypothesized that a substantial minority of older adults would present with preexisting medical problems that could...

Background: Attrition bias refers to the systematic influence of study participants who are lost to follow-up on estimates of disease trajectory or treatment effect. Attrition is common in longitudinal research and few studies have addressed the presence and impact of attrition bias on the field of mild traumatic brain injury (MTBI). The main objec...

Objective: Serotonergic antidepressants (SAs) are commonly prescribed for depressive and anxiety disorders. There is evidence that SAs increase the risk of upper gastrointestinal tract bleeding and spontaneous intracranial hemorrhage. The literature on the possible risk of traumatic intracranial bleeding in patients using SAs is sparse. Methods: A...

Background: There is considerable interest in the use of blood biomarkers as diagnostic screening tests for mild traumatic brain injury (MTBI). Neurofilament light (NF-L) may have diagnostic and prognostic potential as a blood biomarker for MTBI. Elevated NF-L is associated with several neurological disorders associated with older age, however, whi...

NNeurofilament light (NF-L) might have diagnostic and prognostic potential as a blood biomarker for mild traumatic brain injury (MTBI). However, elevated NF-L is associated with several neurological disorders associated with older age, which could confound its usefulness as a TBI biomarker. We examined whether NF-L is elevated differentially follow...

Objective: To determine the population-based epidemiology of chronic subdural hematoma (CSDH) over a 26-year period. Methods: A retrospective study of all adult patients [≥ 18 years old Pirkanmaa (Finland) residents] with a diagnosis of CSDH between 1990 and 2015. The cases were identified by using ICD-codes. Detailed data collection was performe...

Objective: To determine the population-based epidemiology of chronic subdural hematoma (CSDH) over a 26-year period. Methods: All adult patients (≥18 years old Pirkanmaa residents) with a diagnosis of CSDH between 1990 and 2015 were retrospectively included. The cases were identified by using ICD-codes. Detailed data collection was performed from m...

Abstract: Background: TBI is the most common cause of permanent disability in people under the age of 40 years. In developed countries, TBI causes more loss of productive life-years than cancer, cerebrovascular diseases, and HIV/AIDS combined. Objective: To update the Finnish Guidelines on TBI. Methods: A multidisciplinary working group includ...

Introduction Mild Traumatic Brain Injury (MTBI) has been categorized as complicated when injury severity criteria are mild [i.e., Glasgow Coma Scale (GCS) and the duration of loss of consciousness (LOC) and post-traumatic amnesia (PTA)], but an intracranial abnormality is identifiable on acute computed tomography (CT). Past studies have shown varia...

Objective: To investigate the accuracy of serum glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), tau, neurofilament light (NFL), and S100B for identifying computed tomography-positive (CT-positive) traumatic lesions in patients with mild traumatic brain injury (MTBI). Methods: Three hundred twenty-seven ad...

Objective: Falls are a common cause of emergency department visits and traumatic brain injury (TBI) in older adults. We investigated the accuracy of serum glial fibrillary acidic protein (GFAP) for identifying computed tomography-positive (CT-positive) traumatic lesions in older adult patients (≥60 years) with suspected mild traumatic brain injury...

Objective: The clinical utility of serum S100B as a decision rule for emergency head computed tomography (CT) has been a major focus of interest. The Scandinavian Guidelines for Initial Management of Minimal, Mild, and Moderate Traumatic Brain Injury in Adults (Scandinavian Guidelines; published in 2013) recommended an evidence-based cutoff of 0.1u...

Introduction Certain pre-existing health conditions confer risk for worse outcome following mild traumatic brain injury (MTBI). Little is known, however, about the association between pre-injury health conditions and outcome from MTBI in older adults. This study examined the association between pre-injury health conditions and subacute outcome foll...

Objective: Some patients suffer repeated traumatic brain injuries (TBI) with cumulative detrimental consequences. We examined the characteristics of patients with reoccurring TBIs to identify possible risk factors for repeated brain trauma. Methods: Inception cohort of patients who underwent head CT due to an acute head injury (N=2,908) at the Eme...

Background: We present a single-centre experience of procedural complications suffered by patients undergoing endovascular treatment for a ruptured saccular intracranial aneurysm at Tampere University Hospital, Finland, between 2000 and 2014. Method: From 2000 to 2014, we treated 1,253 patients with aneurysmal subarachnoid haemorrhage, 491 of wh...

Link to the full-text guideline: http://www.kaypahoito.fi/web/kh/suositukset/suositus?id=hoi18020#s15

Objectives: To characterize the clinical utility of Sport Concussion Assessment Tool 3 (SCAT3) baseline and normative reference values for the assessment of acute concussion; and to identify the sensitivity of each SCAT3 subcomponent to the acute effects of concussion. Design: Prospective cohort. Methods: The day-of-concussion SCAT3 results (n=27...

Background: Over the years, the consensus has generally been that Finland is a country with a significantly high incidence of aneurysmal subarachnoid haemorrhage (SAH) when compared to the rest of the world, excluding Japan. Most of the traditionally cited Finnish incidence studies are several decades old and have clear differences in their method...

The mediodorsal nucleus of the thalamus (MD) with its extensive connections to the lateral pFC has been implicated in human working memory and executive functions. However, this understanding is based solely on indirect evidence from human lesion and imaging studies and animal studies. Direct, causal evidence from humans is missing. To obtain direc...

Background: Fall-induced injuries in patients are increasing in number and they often lead to serious consequences, such as cervical spine injuries (CSI). CSI diagnostics remain a challenge despite improved radiological services. Purpose: Our aim is to define the incidence and risk factors for diagnostic errors among patients who died following...

Objective: The incidence of intracranial abnormalities after mild traumatic brain injury (TBI) varies widely across studies. This study describes the characteristics of intracranial abnormalities (acute/pre-existing) of a large representive head injury sample CT-imaged in an emergency department (ED). Methods: CT scans were systematically analyze...

Objective To examine the relation between day of injury concussion symptomology and prolonged recovery. Design Prospective cohort. Setting Finnish professional ice hockey league. Participants SCAT3 baseline and post-injury testing has been mandatory in the Finnish ice hockey league since 2013. Of the reported injuries, between seasons 2013-2016,...

Objective To characterise the baseline to post-concussion variation of each SCAT3 symptom. Design Prospective cohort. Setting Finnish professional ice hockey league. Participants SCAT3 baseline testing has been mandatory in the Finnish hockey league since 2013. The league recommends day of injury testing for all players with suspected concussion...

Objective To characterise whether individual SCAT3 baseline scores are more useful than normative reference values following acute concussion. Design Prospective cohort. Setting Finnish professional male ice hockey league. Participants SCAT3 baseline testing has been mandatory in the league since 2013. The league recommends day of injury testing...

Several alternative techniques exist to reconstruct skull defects. The complication rate of the cranioplasty procedure is high and the search for optimal materials and techniques continues. To report long-term results of patients who have received a cranioplasty using autologous adipose-derived stem cells (ASCs) seeded on beta-tricalcium phosphate...

Background: Cervical spine injuries of variable severity are common among patients with an acute traumatic brain injury (TBI). We hypothesized that TBI patients with positive head CT scans would have a significantly higher risk of having an associated cervical spine fracture compared to patients with negative head CT scans. Methods: This widely g...

Traumatic spinal cord injuries (SCIs) lead to axonal damage at the trauma site, as well as disconnections within the central nervous system. While the exact mechanisms of the long-term pathophysiological consequences of SCIs are not fully understood, it is known that neuronal damage and degeneration are not limited to the direct proximity of the tr...

Objectives: The Scandinavian Guidelines for Initial Management of Minimal, Mild, and Moderate Traumatic Brain Injury in Adults (Scandinavian guidelines) were published in 2013. The guidelines are evidence and consensus-based and for the first time incorporate serum S100B measurement as part of emergency department (ED) triage of head injury (HI) pa...

Objectives: The Sport Concussion Assessment Tool–3rd Edition (SCAT3) is widely used to evaluate the acute effects of concussion. This study examined which SCAT3 component has the most utility in day of injury concussion recognition, and whether pre-injury individual SCAT3 baseline scores are more useful than normative reference values in the sideli...

Objectives: A substantial number of traumatic brain injuries (TBI) are caused by violence-related incidents. The purpose of this study was to determine the unique characteristics of violence-related TBIs with an emphasis on possible preventable risk factors. Methods: All consecutive patients who underwent head CT due to an acute head injury (N=3,02...

Objective: Patients with aneurysmal subarachnoid hemorrhage (aSAH) experience high mortality and morbidity. Neuroinflammation causes brain damage expansion after aSAH. Due to the complexity of the inflammatory response multiple biomarkers are needed to evaluate its' progression. We studied inflammatory process after aSAH by measuring two inflammato...

Super-refractory status epilepticus is a condition characterized by recurrence of status epilepticus despite use of deep general anesthesia and it has high morbidity and mortality rates. We report a case of a 17-year old man with a prolonged super-refractory status epilepticus which eventually resolved after commencing deep brain stimulation of the...

Objective: To examine the relation between day of injury concussion symptomology and prolonged recovery. Design: Prospective cohort Setting: Finnish professional ice hockey league. Participants: SCAT3 baseline and post-injury testing has been mandatory in the Finnish ice hockey league since 2013. Of the reported injuries, between seasons 2013-2016,...

Objective: To characterize whether individual SCAT3 baseline scores are more useful than normative reference values following acute concussion. Design: Prospective cohort Setting: Finnish professional male ice hockey league. Participants: SCAT3 baseline testing has been mandatory in the league since 2013. The league recommends day of injury testing...

Objective: To characterize the baseline to post-concussion variation of each SCAT3 symptom Design: Prospective cohort Setting: Finnish professional ice hockey league. Participants: SCAT3 baseline testing has been mandatory in the Finnish hockey league since 2013. The league recommends day of injury testing for all players with suspected concussion....

Objectives: To examine test–retest reliability of the SCAT3 for two consecutive seasons using a large sample of professional male ice hockey players, and to make recommendations for interpreting change on the test. Design: A cross-sectional descriptive study. Methods: Preseason baseline testing was administered in the beginning of the seasons 2...

Objective: The number of cervical spine injuries (CSIs) is increasing. CSIs are associated with high morbidity and mortality. Identifying those who are at risk for CSI related death can help develop national and international interventions and policies to reduce mortality. Methods: To determine the trends in the incidence and the characteristics o...

Objective: To study the concurrence of computer tomography (CT)-detectible cervical spine fractures and traumatic brain injury (TBI). We hypothesized that TBI patients with positive head CT scans would have a significantly higher risk of having a concurrent cervical spine fracture compared to TBI patients with negative head CT scans. Methods: This...

Background: Deep brain stimulation (DBS) of the anterior nucleus of thalamus (ANT) is an evolving treatment option in refractory focal epilepsy. Due to poor visualization of ANT in traditional MRI sequences used for movement disorder surgery, targeting of ANT is mainly based on stereotactic atlas information. Sophisticated 3T MRI methods enable vi...

Background: Deep brain stimulation (DBS) of the anterior nucleus of the thalamus) (ANT) has been suggested as a treatment option in refractory epilepsy. The targeting of ANT is especially challenging due to its poor visualization in commonly used MRI sequences, lack of easily observable symptom relief during surgery and high degree of anatomical v...

Objectives: The Sport Concussion Assessment Tool – 3rd Edition (SCAT3) is widely used to evaluate for the acute effects of concussion. We aimed to characterize day of injury SCAT3 subscores in relation to previously published normative reference values using a large sample of professional male ice hockey players. All scoreable SCAT3 components were...

Background: The purpose of this study was to determine if there is an association between pre-injury health problems and injury severity in mild traumatic brain injury (MTBI) patients evaluated in the Emergency Department (ED). Specifically, we evaluated whether certain pre-existing health factors (e.g., older age, psychiatric or neurologic disease...

Introduction: To compare open-ended symptom reporting to endorsement of symptoms on a standardized post-concussion questionnaire. Method: Seventy-four previously healthy adults with mild traumatic brain injuries (MTBI) between the ages of 18 and 60 years (mean age=37.0, SD=11.8; 39.2 % female) and 39 controls (with ankle injuries, mean age=40.1, S...

Objective: Chronic inflammation has earlier been detected in ruptured intracranial aneurysms. A previous study detected both dental bacterial DNA and bacterial-driven inflammation in ruptured intracranial aneurysm walls. The aim of this study was to compare the presence of oral and pharyngeal bacterial DNA in ruptured and unruptured intracranial a...

Objective: Aneurysmal subarachnoid hemorrhage (aSAH) is a common cause of long-term disability and death. After primary hemorrhage, secondary brain injury is the main cause of mortality and morbidity. Despite extensive research, reliable prognostic biomarkers are lacking. We measured ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) levels in aSAH...

Background context: The number of cervical spine injuries (CSIs) is increasing. CSIs are associated with high morbidity and mortality. Identifying those who are at risk for CSI-related death can help develop national and international interventions and policies to reduce mortality. Purpose: To determine the trends in the incidence and the charac...

This prospective longitudinal study reports recovery from mild traumatic brain injury (MTBI) across multiple domains in a carefully selected consecutive sample of 74 previously healthy adults. The patients with MTBI and 40 orthopedic controls (i.e., ankle injuries) completed assessments at 1, 6, and 12 months after injury. Outcome measures included...

Patients treated with deep brain stimulation (DBS) provide an opportunity to study affective processes in humans with "lesion on demand" at key nodes in the limbic circuitries, such as at the anterior thalamic nuclei (ANT). ANT has been suggested to play a role in emotional control with its connection to the orbitofrontal cortex and the anterior ci...

Background: Deep brain stimulation of the anterior nucleus of the thalamus (ANT) is an emerging therapy for refractory focal epilepsy. However, the most optimal target for stimulation has not been unambiguously described. Objective: In the present study, we investigated the correlation between the stimulation site and outcome in order to define...

Objectives: To determine normative reference values for the Sport Concussion Assessment Tool-3rd Edition (SCAT3) using a large sample of professional male ice hockey players. Design: A descriptive cross-sectional study. Methods: Preseason baseline testing was administered individually to 304 professional male ice hockey players. Results: The...

Background: Following mild traumatic brain injury (MTBI), head computed tomography (CT) is used to identify gross structural brain damage and aid decision making on emergency treatment. Our objective was to describe the type and location of both acute and pre-existing intracranial abnormalities of patients who sustained head trauma and underwent co...

Mild traumatic brain injury (MTBI) is a public health problem. Outcome from MTBI is heterogeneous in part due to pre-injury individual differences that typically are not well described or understood. Pre-injury health characteristics of all consecutive patients (N=3,023) who underwent head CT due to acute head trauma in the emergency department of...

Objective: To study the concurrence of CT (computed tomography)-detectible cervical spine injuries (CSI) and traumatic brain injury (TBI). We hypothesized that CT-positive TBI patients would have a significantly higher risk of having a concurrent CSI compared to CT-negative TBIs. Methods: This retrospective study included 3023 consecutive patient...

Mild traumatic brain injury (MTBI) is a public health problem. Outcome from MTBI is heterogeneous in part due to pre-injury individual differences that typically are not well described or understood. Pre-injury health characteristics of all consecutive patients (N=3,023) who underwent head CT due to acute head trauma in the emergency department...

The purpose of this study was to examine the clinical significance of retrograde amnesia (RA) in patients with acute mild traumatic brain injuries (MTBI). An emergency department sample of patients (n = 75), aged 18-60 years, with no pre-morbid medical or psychiatric conditions, who met the WHO criteria for MTBI were enrolled in this prospective, d...

Resilient individuals manifest adaptive behavior and are better able to recover from adversity. The association between resilience and outcome from mild traumatic brain injury (MTBI) is examined, and the reliability and validity of the Resilience Scale and its short form in MTBI research is evaluated. Patients with MTBI (n=74) and orthopedic contro...

Deep brain stimulation (DBS) is a minimally invasive and reversible method to treat an increasing number of neurological and psychiatric disorders, including epilepsy. Targeting poorly defined deep structures is based in large degree on stereotactic atlas information, which may be a major source of inconsistent treatment effects. In the present stu...

Diffusion tensor imaging (DTI) is prone to numerous systemic confounding factors that should be acknowledged to avoid false conclusions. To investigate the possible effects of age, gender, smoking, alcohol consumption, and education on cerebral DTI parameters in a generally healthy homogenous sample with no neurological or psychiatric diseases. For...