Neuroanatomical correlates of verbal fluency in early Alzheimer's disease and normal aging.

Verbal fluency (VF) impairments occur early in Alzheimer's disease (AD) and to a lesser extent also in normal aging. However, the neural underpinnings of these impairments are not fully understood. The present study evaluated whether VF impairments in early AD and normal aging rely upon common or different neuroanatomical correlates. We examined the association between VF performance and brain structure in 18 mild AD patients and 24 healthy elderly. Linear regressions were performed between accuracy and time intervals in VF scores and structural measurements of cerebral gray matter (GM) and white matter (WM) using MRI. Results showed that semantic VF correlated exclusively with GM in cerebellum, left temporal fusiform cortex, and WM in uncinate fasciculus, inferior fronto-occipital fasciculus and corpus callosum. Phonemic VF showed unique associations between intervals and WM in left-hemisphere tracts. The association between GM in hippocampus, subcortical structures and semantic accuracy differentiated patients from controls. Results showed that VF impairments are primarily associated with same structural brain changes in AD as in healthy elderly but at exaggerated levels. However, specific VF deficiencies and their underlying neural correlates exist and these clearly differentiate the initial stages of AD.

Magnetic Resonance Volumetry: Prediction of Subjective Memory Complaints and Mild Cognitive Impairment, and Associations with Genetic and Cardiovascular Risk Factors.

BACKGROUND/AIMS: Subjective memory complaints (SMC) are strong predictors of mild cognitive impairment (MCI) and subsequent Alzheimer's disease. Our aims were to see if fully automated cerebral MR volume measurements could distinguish subjects with SMC and MCI from controls, and if probable parental late-onset Alzheimer's disease (LOAD), apolipoprotein E ε4 genotype, total plasma homocysteine, and cardiovascular risk factors were associated with MR volumetric findings. METHODS: 198 stroke-free subjects comprised the control (n = 58), the SMC (n = 25) and the MCI (n = 115) groups. Analysis of covariance and receiver operating characteristic curve was used to see if MR volumetry distinguished subjects with SMC and MCI from controls. RESULTS: Subjects with SMC and MCI had significantly larger lateral ventricles and smaller hippocampal volumes than controls. The area under the curve in subjects with SMC and MCI compared to that of controls was less than 0.68 for all volumes of intracranial structures. There was an interaction between sex and probable parental LOAD for hippocampal volume, with a significant association between probable parental LOAD and hippocampal volume in women. CONCLUSIONS: Fully automated MR volumetry can distinguish subjects with SMC and MCI from controls in a general population, but insufficiently to assume a clear clinical role. Research on sporadic LOAD might benefit from a sex-specific search for genetic risk factors.

A new non-craniotomy model of subarachnoid hemorrhage in the pig: a pilot study.

Subarachnoid hemorrhage (SAH) from rupture of an intracranial arterial aneurysm is a devastating disease affecting young people, with serious lifelong disability or death as a frequent outcome. Large animal models that exhibit all the cardinal clinical features of human SAH are highly warranted. In this pilot study we aimed to develop a non-craniotomy model of SAH in pigs suitable for acute intervention studies. Six Norwegian Landrace pigs received advanced invasive hemodynamic and intracranial pressure (ICP) monitoring. The subarachnoid space, confirmed by a clear cerebrospinal fluid (CSF) tap, was reached by advancing a needle below the ocular bulb through the superior orbital fissure and into the interpeduncular cistern. SAH was induced by injecting 15 mL of autologous arterial blood into the subarachnoid space. Macro- and microanatomical investigations of the pig brain showed a typical blood distribution consistent with human aneurysmal SAH (aSAH) autopsy data. Immediately after SAH induction ICP sharply increased with a concomitant reduction in cerebral perfusion pressure (CPP). ICP returned to near normal values after 30 min, but increased subsequently during the experimental period. Signs of brain edema were confirmed by light microscopy post-mortem. None of the animals died during the experimental period. This new transorbital injection model of SAH in the pig mimics human aSAH and may be suitable for acute intervention studies. However, the model is technically challenging and needs further validation.

Mild cognitive impairment, risk factors and magnetic resonance volumetry: role of probable Alzheimer's disease in the family.

BACKGROUND/AIMS: Late-onset Alzheimer's disease (LOAD) comprises sporadic LOAD and familial LOAD. We wanted to determine whether total plasma homocysteine (Hcy), cardiovascular risk factors and volumetric analyses of cerebral magnetic resonance imaging (MRI) were differently associated with mild cognitive impairment (MCI) in subjects from families with aggregation of LOAD (probable familial LOAD) and MCI in subjects from families without LOAD (probable sporadic LOAD). METHODS: A total of 103 subjects with MCI without known stroke or other apparent causative diseases were included as cases together with 58 controls. The cases were stratified into 3 groups according to the number of biological relatives with probable LOAD on one side of the family. Cerebral MRI was obtained from all. The case groups were compared to the control group in sex-specific analyses of covariance. RESULTS: Hcy was significantly elevated in all cases compared to controls, except for women with probable familial LOAD. These women also had significantly smaller hippocampal volume and significantly larger lateral ventricles, unlike the women in the other case groups. CONCLUSIONS: Our findings suggest that research on Hcy, cardiovascular risk factors and other potential risk factors for LOAD might benefit from distinguishing between sporadic and familial LOAD.

The paediatric wrist revisited--findings of bony depressions in healthy children on radiographs compared to MRI.

BACKGROUND: The presence of erosions is used for diagnosis and monitoring of disease activity in juvenile idiopathic arthritis (JIA). Assessment of carpal bone erosions in children is challenging due to lack of normal references. OBJECTIVE: To define normal appearances of bony depressions in the wrist on radiographs and MRI. MATERIALS AND METHODS: MRI and radiography of the wrist were performed in 88 healthy children, 5-15 years of age. We assessed the number of bony depressions within the carpals/proximal metacarpals on both modalities, separately and combined. RESULTS: A total of 75 carpal depressions were identified on radiography compared to 715 on MRI. The number of bony depressions identified radiographically showed no statistically significant difference across age-groups. Within the metacarpals, there was no significant difference between bony depressions identified by MRI or radiography, except at the bases of the second metacarpal. CONCLUSION: Bony depressions that resemble erosions are normal findings in the wrist in children. MRI identifies more depressions than radiographs in the carpus. Some bony depressions occur at typical locations and should be accounted for when assessing the wrist in JIA to avoid overstaging.

Health consumption in Sami speaking municipalities and a control group with regard to medical imaging.

OBJECTIVES: The Northern Norway Regional Health Authority trust aims to offer a high quality specialist health care to all inhabitants. The objective of this study was to document the consumption of medical imaging [conventional radiography (CR), computerised tomography (CT), magnetic resonance (MR), ultrasound (US)]. METHODS: The eight municipalities in northern Norway included in the administration area of the Sami language law (Sami group - 132,490 persons/year in the period 2003-2009, mean/year 19,363 inhabitants) were matched with a control group of 11 municipalities (non-Sami group - 135,539 persons/year, mean/year 18,927 inhabitants). Population data was accessed from Statistics Norway. Data on imaging exams were derived from a regional database including production data from all public and private institutions within the region. All four main modality groups (CR, CT, MR, US) were analysed. Variations for imaging frequency on each modality were compared between the Sami and non-Sami municipalities. RESULTS: A total of 278,832 exams were performed during study period. The age adjusted exam rate (all modalities) was significantly higher (p < 0.001) in non-Sami (females and males) group. There was no difference with regard to conventional radiography (CR) (p = 0.855). Whereas MR (p < 0.001) imaging was more common in the Sami group, CT (p < 0.001) and US (p = 0.003) exams were more frequently used in the control group. CONCLUSION: People living in Sami speaking communities experienced significantly less CT and US exams, but had more MR exams than the control group. A relatively high physical activity, obesity and a lower risk of cancer may be explanations.

[Diagnostic challenges in a man with subarachnoidal haemorrhage]. / Diagnostiske utfordringer hos en mann med subaraknoidalblødning.

A 39-year-old man with multiple sclerosis was admitted to the Neurological department because of sudden and intense headache, photophobia, nausea and vomiting. A subarachnoidal haemorrhage was suspected and cerebral CT scanning showed small amounts of subarachnoidal blood distributed symmetrically over both cerebral hemispheres - an unusual location for aneurismal bleeding. Liquor analysis revealed erythrocytes, positive bilirubin and slightly elevated protein. Subsequent cerebral MRI showed no signs of aneurysm, vascular malformation, venous sinus thrombosis or infarction. An intraarterial cerebral angiography was then performed and showed bilateral widespread segmental vasoconstriction in the anterior, middle and posterior cerebral arteries. A diagnostic workup on systemic vasculitis was negative. The patient's good general condition in spite of extensive angiographic findings rendered the diagnosis cerebral vasculitis unlikely. A state of reversible cerebral segmental vasoconstriction was suspected and the patient was treated with the calcium antagonist nifedipine and observed for four weeks. Cerebral angiography was then repeated and found to be normal. This case report highlights a less recognized and probably underdiagnosed cause of subarachnoidal bleeding.