Thomas Skoglund

Health status and life satisfaction after decompressive craniectomy for malignant middle cerebral artery infarction

Objectives –  To study the long‐term outcome in patients with malignant middle cerebral artery (MCA) infarction treated with decompressive craniectomy. The outcome is described in terms of survival, impairment, disabilities and life satisfaction.

Longitudinal study of the diffusion tensor imaging properties of the corpus callosum in acute and chronic diffuse axonal injury

Background: Magnetic resonance diffusion tensor imaging (MR-DTI) is used increasingly to detect diffuse axonal injury (DAI) after traumatic brain injury (TBI). Primary objective: The primary objective was to investigate the changes in the diffusion properties of the corpus callosum in the acute phase and 6 months after TBI and to examine the correlation between DTI parameters and clinical outcome. Research design: Longitudinal prospective study. Methods and procedures: MR-DTI was performed in eight patients with suspected DAI within 11 days and at 6 months post-injury. Six controls were also examined. Fractional anisotropy (FA), trace and parallel and perpendicular diffusivity of the corpus callosum were analysed. The main outcome was the extended Glasgow Outcome Scale score, assessed at 6 months. Main outcomes and results: A significant reduction in FA in the corpus callosum was seen in the acute phase in patients compared with the healthy controls. There was no significant change in the parallel or perpendicular eigenvalues or trace. At 6 months, a significant reduction in FA and a significant increase in trace and perpendicular eigenvalues were noticed compared with controls. Conclusions: The diffusion properties of the corpus callosum correlated with clinical outcome in this longitudinal investigation.

Long-time outcome after transient transtentorial herniation in patients with traumatic brain injury

Background:  This study investigates mortality and morbidity in patients with traumatic brain injury (TBI) who developed episode(s) of transtentorial herniation. The transtentorial herniation was defined as a deterioration of consciousness accompanied by uni‐ or bilateral pupil dilatation.

Aspects of the organization of neurons and dendritic bundles in primary somatosensory cortex of the rat

In order to analyze some aspects of the spatial organization in the primary somatosensory cortex of the rat, we have reconstructed the positions of bundles of apical dendrites and neurons in a cortical prisms measuring 0.5 mm x 0.4 mm x cortical thickness, with special reference to a hypothetical columnar organization. Complete series of semithin (0.65 microm) sections were cut, tangentially from the pial surface down to the white matter, stained and digitizalized into a computer and represented as a stack of 2D images. The mean neuron density (N(V)-value) was (60 x 10(3) +/- 15 x 10(3)) neurons/mm3. The mean number of neurons beneath 1 mm2 of cortical surface (NC-value) was (113 x 10(3) +/- 8 x 10(3)) neurons/mm2. Well-defined bundles of apical dendrites emanating from layer V pyramidal cells were observed. The bundles consisted of 3-12 (mean 5 +/- 2) dendrites. The dendrites within a bundle converged while ascending towards the pial surface and reached a maximal close packing in layer IV. Superficially, the packing density decreased again. The mutual positions of the dendrites within the bundles shifted only slightly along their course towards the pial surface. The occurrence of bundles in tangential sections through layer IV was about 190 bundles/mm2 and the average number of neurons per bundle was estimated at approximately 600. However, when calculating Voronoi-diagrams, the number of neurons, which with this mathematical technique, is ascribed to each of the reconstructed dendritic bundles, varied between 200 and 1000. The possibility that the dendritic bundles are centers in cortical cell modules is discussed.

Long-Term Follow-up of a Patient with Traumatic Brain Injury Using Diffusion Tensor Imaging

This case report describes a patient who sustained severe head trauma with diffuse axonal injury (DAI). Examination with magnetic resonance diffusion tensor imaging (MR-DTI), 6 days post-injury, showed a severe reduction in fractional anisotropy (FA) in the rostral pons containing the corticospinal tract, which correlated to the patients severe hemiparesis. By 18 months post-accident, the patient had recovered completely and conventional MRI showed no pathology. However, although her FA values in the rostral pons had increased, they were still not normalized. It seems that a complete normalization of the FA values is not required to achieve clinical recovery, and that MR-DTI seems to be more sensitive to DAI compared to conventional MRI.

Serum Neurofilament Light Protein as a Marker for Diffuse Axonal Injury: Results from a Case Series Study

Diffuse axonal injury (DAI) is an important cause of morbidity in patients with traumatic brain injury (TBI). There is currently no simple and reliable technique for early identification of patients with DAI, or to prognosticate long-term outcome in this patient group. In the present study, we examined acute serum concentrations of neurofilament light (NFL) in nine patients with severe TBI and DAI using a novel ultrasensitive single molecule array (Simoa) assay. The relationships between the NFL concentrations and MRI in the acute stage as well as clinical outcome and magnetic resonance diffusion tensor imaging (MR-DTI) parameters at 12 months were analyzed. We found that the mean NFL concentrations among the patients displayed a 30-fold increase compared with controls, and that NFL completely discriminated between the patients and controls. We also found a relationship between serum NFL and MR-DTI parameters, with higher NFL concentrations in patients with higher trace (R2 = 0.79) and lower fractional anisotropy (FA) (R 2 = 0.83). These results suggest that serum NFL may be a valuable blood biomarker for TBI, reflecting the severity of DAI.

Life Expectancy in Patients with Pituitary Adenoma Receiving Growth Hormone Replacement

OBJECTIVE Hypopituitarism has been associated with increased mortality. The excess mortality may be due to untreated growth hormone (GH) deficiency but also due to various underlying disorders. We therefore analysed mortality in patients with only one underlying disorder, non-functioning pituitary adenoma (NFPA), with and without GH replacement therapy (GHRT). DESIGN AND METHOD Patients with NFPA in the western region of Sweden, 1997-2011, were identified through the National Patient Registry and cross-referenced with several National Health Registries. All patient records were reviewed. Standardised mortality ratios (SMRs) with 95% confidence intervals (CIs) were calculated using the general population as reference. Cox-regression models were performed to identify predictors of mortality. RESULTS A total of 426 NFPA patients with 4599 patient-years were included, of whom 207 had used GHRT and 219 had not received GHRT. Median (range) follow-up in patients with and without GHRT was 12.2 (0-25) and 8.2 (0-27) years, respectively. Other pituitary hormone deficiencies were more frequent in the GHRT group than those in the non-GHRT group. SMR was 0.65 (95% CI, 0.44-0.94; P = 0.018) for the GHRT group and 1.16 (0.94-1.42; P = 0.17) for the non-GHRT group. Direct comparison between the groups showed reduced mortality among those who were GH replaced (P = 0.0063). The SMR for malignant tumours was reduced in the GHRT-group (0.29; 0.08-0.73; P = 0.004) but not in untreated patients. CONCLUSIONS Selection bias explaining some of the results cannot be excluded. However, NFPA patients with GHRT had reduced overall mortality compared with the general population, and death due to malignancy was not increased. This suggests that long-term GHRT is safe in adult patients selected for treatment.

Tumor of the conus medullaris treated with antituberculous therapy

This case report concerns a 21-year-old man developing left leg paresis. Evaluation with magnetic resonance imaging (MRI) showed an intramedullary tumor in the conus region. He was planned for surgery but preoperative investigation indicated he had tuberculosis and the tumor was presumed to be a tuberculoma. Antituberculous therapy was started and the patient improved neurologically. The patient was followed clinically and with consecutive MRI during 2 years and the last MRI showed that the lesion had disappeared completely. Intramedullary tuberculomas are rare but important differential diagnosis in patients with spinal cord mass lesions. The role of medical and surgical treatment of intramedullary tuberculomas is discussed.

3D reconstruction of biological objects from sequential image planes—Applied on cerebral cortex from cat

A prism of cat cerebral cortex was reconstructed with a method for three-dimensional (3D) representation of biological objects. A series of 918 semithin sections were digitized into an image analysis system. The images were aligned and analyzed, and a data base with the coordinates and a classification of the cells was created. The data base (i.e., the cortical prism) was visualized in a 3D graphic terminal, and parameters such as columnar and lamellar organization, clustering, and cell density were analyzed. A neuronal perikaryon and its neurites was reconstructed and shown together with the cortical prism.

Higher glucocorticoid replacement doses are associated with increased mortality in patients with pituitary adenoma

OBJECTIVE Patients with secondary adrenal insufficiency (AI) have an excess mortality. The objective was to investigate the impact of the daily glucocorticoid replacement dose on mortality in patients with hypopituitarism due to non-functioning pituitary adenoma (NFPA). METHODS Patients with NFPA were followed between years 1997 and 2014 and cross-referenced with the National Swedish Death Register. Standardized mortality ratio (SMR) was calculated with the general population as reference and Cox-regression was used to analyse the mortality. RESULTS The analysis included 392 patients (140 women) with NFPA. Mean ± s.d. age at diagnosis was 58.7 ± 14.6 years and mean follow-up was 12.7 ± 7.2 years. AI was present in 193 patients, receiving a mean daily hydrocortisone equivalent (HCeq) dose of 20 ± 6 mg. SMR (95% confidence interval (CI)) for patients with AI was similar to that for patients without, 0.88 (0.68-1.12) and 0.87 (0.63-1.18) respectively. SMR was higher for patients with a daily HCeq dose of >20 mg (1.42 (0.88-2.17)) than that in patients with a daily HCeq dose of 20 mg (0.71 (0.49-0.99)), P = 0.017. In a Cox-regression analysis, a daily HCeq dose of >20 mg was independently associated with a higher mortality (HR: 1.88 (1.06-3.33)). Patients with daily HCeq doses of ≤20 mg had a mortality risk comparable to patients without glucocorticoid replacement and to the general population. CONCLUSION Patients with NFPA and AI receiving more than 20 mg HCeq per day have an increased mortality. Our data also show that mortality in patients substituted with 20 mg HCeq per day or less is not increased.