Jostein Kråkenes

IL‐6: an early marker for outcome in acute ischemic stroke

Objectives –  Inflammation plays an important role in the pathophysiology of stroke. We correlated interleukin (IL)‐6, IL‐10, C‐reactive protein (CRP) and T‐lymphocyte subtype levels in acute ischemic stroke patients with stroke volume and clinical outcome.

Magnetic Resonance Imaging Assessment of Craniovertebral Ligaments and Membranes After Whiplash Trauma

Study Design. Review article. Objectives. To review the literature on soft tissue lesions of the upper cervical spine in whiplash trauma with focus on imaging. Summary of Background Data. Whiplash injury is associated with chronic impairment in a substantial number of patients. There are different opinions as to the nature and prognosis of this condition, and the role of diagnostic imaging is debated. Methods. Review the literature on the anatomic source of the chronic whiplash syndrome. Review the literature on imaging of the upper cervical spine, emphasizing on the authors own research. Results. MRI shows structural changes in ligaments and membranes after whiplash injury, and such lesions can be assessed with reasonable reliability. Lesions to specific structures can be linked with specific trauma mechanisms. There is a correlation between clinical impairment and morphologic findings. Conclusion. Whiplash trauma can damage soft tissue structures of the upper cervical spine, particularly the alar ligaments. Structural lesions in this area contribute to the understanding of the chronic whiplash syndrome.

MRI assessment of normal ligamentous structures in the craniovertebral junction

We have established an imaging protocol in order to characterise the normal ligamentous structures in the craniovertebral junction. Thirty volunteers without a history of car accident or head or neck trauma underwent MR imaging with 2-mm-thick proton-density-weighted sections in three orthogonal planes. The alar ligaments were clearly seen in every case and had three different configurations in cross-section: round, ovoid or wing-like. A broadening from lateral to medial in the coronal plane was observed in all cases. The transverse ligament was clearly demonstrated in 26 out of 30 cases. The ligament was flattened where it arched across the dens. Towards the insertions the ligament twisted into an oblique-horizontal orientation. The lower tectorial membrane had a median portion merging with the dura, and a lateral portion separated from it. Between the dens and clivus this membrane either merged totally with dura or was partly separated from it by a thin layer of fat. The posterior atlanto-occipital membrane was clearly demonstrated. It either merged with the dura or was partly or totally separated from it by a fat layer. The anterior atlanto-occipital membrane was inconsistently seen and could not be evaluated. Our refined MR protocol improves the visualisation of the craniovertebral ligamentous structures, and may in the future give new insight into post-traumatic neck disorders up to now poorly understood.

CT and MR Imaging Features of Primary Central Nervous System Lymphoma in Norway, 1989–2003

BACKGROUND AND PURPOSE: Studying imaging findings of non–acquired immunodeficiency syndrome (AIDS) primary central nervous system lymphoma (PCNSL), we hypothesized that the imaging presentation has changed with the increasing incidence of PCNSL and is related to clinical factors (eg, time to diagnosis and the patients being diagnosed alive or at postmortem examination). MATERIALS AND METHODS: Chart and histologic reviews of patients recorded as having PCNSL during 1989–2003 in the Norwegian Cancer Registry identified 98 patients with non-AIDS PCNSL; 75 had available imaging. CT and MR images from the first diagnostic work-up after onset of symptoms but before histologic diagnosis were reviewed. RESULTS: CT and/or MR imaging in the 75 patients revealed no lesion in 10 (13%), a single focal lesion in 34 (45%), multiple focal lesions in 26 (35%), and disseminated lesions in 5 (7%) patients. All together, we identified 103 focal lesions (single/multiple): 63% in white matter, 56% abutting the ventricular surface, and 43% in the frontal lobes); 100% (102/102 lesions evaluated with contrast) showed contrast enhancement. The median time from imaging to diagnosis for patients with no, single, multiple, or disseminated lesions was 32, 3, 5, and 3 weeks, respectively (P = .01). Patients with no or disseminated lesions were more often diagnosed at postmortem examination (P = .06). Imaging findings were practically unchanged during the consecutive 5-year periods. CONCLUSIONS: White matter periventricular contrast-enhancing single or multiple focal lesions were typical of non-AIDS PCNSL. No or disseminated lesions heightened the risk of delayed or postmortem diagnosis. Although the incidence of non-AIDS PCNSL has increased, its presentation at imaging remains unchanged.

MR analysis of the transverse ligament in the late stage of whiplash injury.

Purpose: To analyse and classify structural changes in the transverse ligament in the late stage of whiplash injury by use of high-resolution MRI, and to evaluate the reliability of our classification. Material and Methods: Ninety-two whiplash-injured (2–9 years previously, mean 6 years) and 30 non-injured individuals underwent proton-weighted MR imaging of the craniovertebral junction in three orthogonal planes. Structural changes in the transverse ligaments were graded twice (grades 1–3) based on increased signal, independently by 3 radiologists with a 4-month interval. Inter- and intraobserver statistics were calculated by ordinary and weighted kappa (K). Results: Image quality was excellent in 109 cases and slightly reduced in 13. Twenty-two out of 30 ligaments in the control group were classified as normal (73%) compared with only 32 out of 92 in the injured group (36%). Two or all 3 observers agreed in their grading in 101 out of 122 ligaments (83%). Intraobserver agreement (weighted K) was fair to good (0.33–0.73). Pair-wise interobserver agreement was fair (0.24–0.39). Reasons for divergent grading were insufficient knowledge of normal variations, low signal intensity in the peridental soft tissue obscuring the ligament and interpretation flaw. Conclusion:Whiplash trauma can damage the transverse ligament. By use of high-resolution proton-weighted MR images such lesions can be detected and classified. The reliability of this classification still needs improvement.

Pilomyxoid Astrocytoma: Expanding the Imaging Spectrum

BACKGROUND AND PURPOSE: Pilomyxoid astrocytoma (PMA) is a recently described variant of pilocytic astrocytoma (PA) with unique clinical and histopathologic characteristics. Because the histopathology of PMA is distinct from that of PA, we hypothesized that PMAs would display distinctive imaging characteristics. We retrospectively reviewed the imaging findings in a large number of patients with PMA to identify these characteristics. MATERIALS AND METHODS: CT and MR images, pathology reports, and clinical information from 21 patients with pathology-confirmed PMA from 7 institutions were retrospectively reviewed. CT and MR imaging findings, including location, size, signal intensity, hemorrhage, and enhancement pattern, were tabulated. RESULTS: Patients ranged in age from 9 months to 46 years at initial diagnosis. Sex ratio was 12:9 (M/F). Twelve of 21 (57%) tumors were located in the hypothalamic/chiasmatic/third ventricular region. Nine (43%) occurred in other locations, including the parietal lobe (2/21), temporal lobe (2/21), cerebellum (2/21), basal ganglia (2/21), and fourth ventricle (1/21). Ten (48%) tumors showed heterogeneous rim enhancement, 9 (43%) showed uniform enhancement, and 2 (9%) showed no enhancement. Five (24%) masses demonstrated intratumoral hemorrhage. CONCLUSION: This series expands the clinical and imaging spectrum of PMA and identifies characteristics that should suggest consideration of this uncommon diagnosis. One third of patients were older children and adults. Almost half of all tumors were located outside the typical hypothalamic/chiasmatic region. Intratumoral hemorrhage occurred in one quarter of patients. PMA remains a histologic diagnosis without definitive imaging findings that distinguish it from PA.

AIDS-related primary central nervous system lymphoma: a Norwegian national survey 1989–2003

BackgroundPrimary central nervous system lymphoma (PCNSL) is a frequent complication in acquired immunodeficiency syndrome (AIDS). The objective of this survey was to investigate incidence, clinical features, radiological findings, histologic diagnosis, treatment and outcome for all patients with histologically verified AIDS-related PCNSL diagnosed in Norway in 1989–2003.MethodsWe identified the patients by chart review of all cases recorded as PCNSL in The Norwegian Cancer Registry (by law recording all cases of cancer in Norway) and all cases recorded as AIDS-related PCNSL in the autopsy registry at a hospital having 67% autopsy rate and treating 59% of AIDS patients in Norway, from 1989 to 2003. Histologic material and radiological images were reviewed. We used person-time techniques to calculate incidence rates of PCNSL among AIDS patients based on recordings on AIDS at the Norwegian Surveillance System for Communicable Diseases (by law recording all cases of AIDS in Norway).ResultsTwenty-nine patients had histologically confirmed, newly diagnosed AIDS-related PCNSL in Norway from 1989–2003. Only 2 patients had this diagnosis established while alive. AIDS patients had 5.5% lifetime risk of PCNSL. Their absolute incidence rate of PCNSL per 100 person-years was 1.7 (95%CI: 1.1–2.4) and decreased during the consecutive 5-year periods from 3.6, to 2.5, and to 0.4 (p < 0.001). Median survival from initial symptom of PCNSL was 2.3 months, but one patient was still alive 4 years after completed radiotherapy.ConclusionThis is the first national survey to confirm decreasing incidence of AIDS-related PCNSL. Despite dismal survival in most patients, the possibility of long term survival should prompt more aggressive diagnostics in suspected PCNSL.

Acoustic neuroma-treatment modalities : Surgery, gamma-knife or observation ?

We present our results of 211 patients with acoustic neuroma over a period of 10 years, 1988-97. We operated on 100 and 111 had Gamma-knife (GK) treatment (69 were available to follow-up). The results are excellent for surgery on small and intracanalicular tumours. In tumours of the same size, surgery and GK treatment give comparable, but somewhat different, results. In the GK group of 54 primary treated patients, 3 patients had to be operated on and another 4 developed hydrocephalus. A group of 35 acoustic tumours was observed for more than 3 years. Nineteen did grow (54%). Hearing was unchanged in 23%. We performed surgery in 11 patients and gave 2 patients GK treatment because of tumour growth of >2 mm in diameter a year. We conclude that either treatment is effective for small and medium-sized acoustic neuromas. Hearing preservation was best in the GK-treated group (80%), compared to only 12.5% in the group operated via the suboccipital route. Larger tumours and most medium-sized tumours should be operated, as should smaller tumours with persistent symptoms of vertigo and pain. Medical contraindications to surgery or reluctance to undergo surgery make GK treatment a good alternative. Treatment of residual tumours with the GK could also be a solution to a difficult problem.

Neuroborreliosis with vasculitis causing stroke-like manifestations.

49 ally, no pathoanatomic substrate of dysosmia was detected. Although a promising option, induction of dysgeusia as a treatment of obesity has to be rejected, because it impedes life quality and may not be helpful in each patient, since eating habits are influenced by more than a single mechanism and since in some patients, induction of dysgeusia might even increase appetite [10]. This case shows that stroke in the left parietal region results in acute bilingual long-term dysgeusia and partial dysosmia. Dysgeusia reduces appetite and weight.

Expanding cava septi pellucidi and cava vergae in children: report of three cases.

Three children with hydrocephalus and expanding cysts of the cavum septi pellucidi and cavum vergae are reported. In all the patients, the hydrocephalus was present before the persistent cava started to expand. The cava increased gradually, until they became cystic, but their growth did not affect the size of the ventricles. Two of the patients were treated with internal cystoventricular shunts, causing a prompt collapse of the cysts but no change in the concomitant hydrocephalus. In the third patient, the persistent cava started to expand only when a previously implanted ventriculoperitoneal shunt failed temporarily. The cyst disappeared when the shunt resumed its function. The possible mechanisms underlying the expansive growth of persistent cava are discussed. We propose the theory that the growth of the cava in our patients may be the result, rather than the cause, of the hydrocephalus.