Temporal Lobe Volume Research Articles

The adverse effects of reduced cerebral perfusion on cognition and brain structure in older adults with cardiovascular disease

BackgroundIt is well established that aging and vascular processes interact to disrupt cerebral hemodynamics in older adults. However, the independent effects of cerebral perfusion on neurocognitive function among older adults remain poorly understood. We examined the associations among cerebral perfusion, cognitive function, and brain structure in older adults with varying degrees of vascular disease using perfusion magnetic resonance imaging (MRI) arterial spin labeling (ASL).Materials and methods52 older adults underwent neuroimaging and were administered the Mini Mental State Examination (MMSE), the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), and measures of attention/executive function. ASL and T1-weighted MRI were used to quantify total brain perfusion, total brain volume (TBV), and cortical thickness.ResultsRegression analyses showed reduced total brain perfusion was associated with poorer performance on the MMSE, RBANS total index, immediate and delayed memory composites, and Trail Making Test B. Reduced frontal lobe perfusion was associated with worse executive and memory function. A similar pattern emerged between temporal lobe perfusion and immediate memory. Regression analyses revealed that decreased total brain perfusion was associated with smaller TBV and mean cortical thickness. Regional effects of reduced total cerebral perfusion were found on temporal and parietal lobe volumes and frontal and temporal cortical thickness.DiscussionReduced cerebral perfusion is independently associated with poorer cognition, smaller TBV, and reduced cortical thickness in older adults.ConclusionProspective studies are needed to clarify patterns of cognitive decline and brain atrophy associated with cerebral hypoperfusion.

Radiation-induced temporal lobe injury after intensity modulated radiotherapy in nasopharyngeal carcinoma patients: a dose-volume-outcome analysis

BackgroundTo identify the radiation volume effect and significant dosimetric parameters for temporal lobe injury (TLI) and determine the radiation dose tolerance of the temporal lobe (TL) in nasopharyngeal carcinoma (NPC) patients treated with intensity modulated radiation therapy (IMRT).MethodsTwenty NPC patients with magnetic resonance imaging (MRI)-diagnosed unilateral TLI were reviewed. Dose-volume data was retrospectively analyzed.ResultsPaired samples t-tests showed all dosimetric parameters significantly correlated with TLI, except the TL volume (TLV) and V75 (the TLV that received ≥75 Gy, P = 0.73 and 0.22, respectively). Receiver operating characteristic (ROC) curves showed V10 and V20 (P = 0.552 and 0.11, respectively) were the only non-significant predictors from V10 to V70 for TLI. D0.5cc (dose to 0.5 ml of the TLV) was an independent predictor for TLI (P < 0.001) in multivariate analysis; the area under the ROC curve for D0.5cc was 0.843 (P < 0.001), and the cutoff point 69 Gy was deemed as the radiation dose limit. The distribution of high dose ‘hot spot’ regions and the location of TLI were consistent.ConclusionsA D0.5cc of 69 Gy may be the dose tolerance of the TL. The risk of TLI was highly dependent on high dose ‘hot spots’ in the TL; physicians should be cautious of such ‘hot spots’ in the TL during IMRT treatment plan optimization, review and approval.

Dementia in Down's syndrome: an MRI comparison with Alzheimer's disease in the general population.

BackgroundDown’s syndrome (DS) is the most common genetic cause of intellectual disability. People with DS are at an increased risk of Alzheimer’s disease (AD) compared to the general population. Neuroimaging studies of AD have focused on medial temporal structures; however, to our knowledge, no in vivo case–control study exists comparing the anatomy of dementia in DS to people with AD in the general population. We therefore compared the in vivo brain anatomy of people with DS and dementia (DS+) to those with AD in the general population.MethodUsing MRI in 192 adults, we compared the volume of whole brain matter, lateral ventricles, temporal lobes and hippocampus in DS subjects with and without dementia (DS+, DS-), to each other and to three non-DS groups. These included one group of individuals with AD and two groups of controls (each age-matched for their respective DS and general population AD cohorts).ResultsAD and DS+ subjects showed significant reductions in the volume of the whole brain, hippocampus and temporal lobes and a significant elevation in the volume of the lateral ventricle, compared to their non-demented counterparts. People with DS+ had a smaller reduction in temporal lobe volume compared to individuals with AD.ConclusionsDS+ and AD subjects have a significant reduction in volume of the same brain regions. We found preliminary evidence that DS individuals may be more sensitive to tissue loss than others and have less ‘cognitive reserve’.

Neural correlates of obsessive–compulsive related dysfunctional beliefs

There have been few attempts to integrate neurobiological and cognitive models of obsessive-compulsive disorder (OCD), although this might constitute a key approach to clarify the complex etiology of the disorder. Our study aimed to explore the neural correlates underlying dysfunctional beliefs hypothesized by cognitive models to be involved in the development and maintenance of OCD. We obtained a high-resolution magnetic resonance image from fifty OCD patients and 30 healthy controls, and correlated them, voxel-wise, with the severity of OC-related dysfunctional beliefs assessed by the Obsessive Beliefs Questionnaire-44. In healthy controls, significant negative correlations were observed between anterior temporal lobe (ATL) volume and scores on perfectionism/intolerance of uncertainty and overimportance/need to control thoughts. No significant correlations between OBQ-44 domains and regional gray matter volumes were observed in OCD patients. A post-hoc region-of-interest analysis detected that the ATLs was bilaterally smaller in OCD patients. On splitting subjects into high- and low-belief subgroups, we observed that such brain structural differences between OCD patients and healthy controls were explained by significantly larger ATL volumes among healthy subjects from the low-belief subgroup. Our results suggest a significant correlation between OC-related dysfunctional beliefs and morphometric variability in the anterior temporal lobe, a brain structure related to socio-emotional processing. Future studies should address the interaction of these correlations with environmental factors to fully characterize the bases of OC-related dysfunctional beliefs and to advance in the integration of biological and cognitive models of OCD.

Selective Worsening of Brain Injury Biomarker Abnormalities in Cognitively Normal Elderly Persons With β-Amyloidosis

The appearance of β-amyloidosis and brain injury biomarkers in cognitively normal (CN) persons is thought to define risk for the future development of cognitive impairment due to Alzheimer disease (AD), but their interaction is poorly understood. To test the hypothesis that the joint presence of β-amyloidosis and brain injury biomarkers would lead to more rapid neurodegeneration. DESIGN Longitudinal cohort study. Population-based Mayo Clinic Study of Aging. One hundred ninety-one CN persons (median age, 77 years; range, 71-93 years) in the Mayo Clinic Study of Aging who underwent magnetic resonance, fludeoxyglucose F 18 (FDG) positron emission tomography (PET), and Pittsburgh Compound B (PiB) PET imaging at least twice 15 months apart. Participants were grouped according to the recommendations of the National Institute on Aging-Alzheimer Association preclinical AD criteria based on the presence of β-amyloidosis, defined as a PiB PET standardized uptake value ratio (SUVr) greater than 1.5, alone (stage 1) or with brain injury (stage 2 + 3), defined as hippocampal atrophy or FDG hypometabolism. We also studied a group of patients with mild cognitive impairment (n = 17) or dementia (n = 9) from the Mayo Clinic Study of Aging or the Mayo Alzheimer Center with similar follow-up times who had undergone comparable imaging and had a PiB PET SUVr greater than 1.5. Rate of change of cortical volume on volumetric magnetic resonance images and rate of change of glucose metabolism on FDG PET scan results. There were 25 CN participants with both high PiB retention and low hippocampal volume or FDG hypometabolism at baseline (preclinical AD stages 2 + 3). On follow-up scans, the preclinical AD stage 2 + 3 participants had greater loss of medial temporal lobe volume and greater glucose hypometabolism in the medial temporal lobe compared with the other CN groups. The changes were similar to those in the cognitively impaired participants. Extratemporal regions did not show similar changes. Higher rates of medial temporal neurodegeneration occur in CN individuals who, on their initial scans, had abnormal levels of both β-amyloid and brain injury biomarkers. Although preclinical AD is currently only a research topic, the description of its brain structural changes will be critical for trials designed to prevent or forestall dementia due to AD.

Novel multi-atlas automatic segmentation of medial temporal lobe volume change in Alzheimer's disease

Novel multi-atlas automatic segmentation of medial temporal lobe volume change in Alzheimer's disease

Novel multi-atlas automatic segmentation of medial temporal lobe volume change in Alzheimer's disease

Novel multi-atlas automatic segmentation of medial temporal lobe volume change in Alzheimer's disease

Does body shaping influence brain shape? Habitual physical activity is linked to brain morphology independent of age

Objectives. Physical activity (PA) was found to influence human brain morphology. However, the impact of PA on brain morphology was mainly demonstrated in seniors. We investigated healthy individuals across a broad age range for the relation between habitual PA and brain morphology. Methods. Ninety-five participants (19–82 years) were assessed for self-reported habitual PA with the “Baecke habitual physical activity questionnaire”, and T1-weighted magnetic resonance images were evaluated with whole brain voxel based morphometry for gray and white matter volumes and densities. Results. Regression analyses revealed a positive relation between the extent of physical activity and gray matter volume bilaterally in the anterior hippocampal and parahippocampal gyrus independent of age and gender. Age as well as leisure and locomotion activities were linked to enhanced white matter volumes in the posterior cingulate gyrus and precuneus, suggesting a positive interaction especially in seniors. Conclusions. Habitual physical activity is associated with regional volumetric gray and white matter alterations. The positive relation of hippocampal volume and physical activity seems not to be restricted to seniors. Thus, habitual physical activity should be generally considered as an influencing factor in studies investigating medial temporal lobe volume and associated cognitive functions (memory), especially in psychiatric research.

Influence of magnetic field strength and image registration strategy on voxel‐based morphometry in a study of Alzheimer's disease

Multi-centre data repositories like the Alzheimer's Disease Neuroimaging Initiative (ADNI) offer a unique research platform, but pose questions concerning comparability of results when using a range of imaging protocols and data processing algorithms. The variability is mainly due to the non-quantitative character of the widely used structural T1-weighted magnetic resonance (MR) images. Although the stability of the main effect of Alzheimer's disease (AD) on brain structure across platforms and field strength has been addressed in previous studies using multi-site MR images, there are only sparse empirically-based recommendations for processing and analysis of pooled multi-centre structural MR data acquired at different magnetic field strengths (MFS). Aiming to minimise potential systematic bias when using ADNI data we investigate the specific contributions of spatial registration strategies and the impact of MFS on voxel-based morphometry in AD. We perform a whole-brain analysis within the framework of Statistical Parametric Mapping, testing for main effects of various diffeomorphic spatial registration strategies, of MFS and their interaction with disease status. Beyond the confirmation of medial temporal lobe volume loss in AD, we detect a significant impact of spatial registration strategy on estimation of AD related atrophy. Additionally, we report a significant effect of MFS on the assessment of brain anatomy (i) in the cerebellum, (ii) the precentral gyrus and (iii) the thalamus bilaterally, showing no interaction with the disease status. We provide empirical evidence in support of pooling data in multi-centre VBM studies irrespective of disease status or MFS.

Evaluation of memory impairment in aging adult survivors of childhood acute lymphoblastic leukemia treated with cranial radiotherapy.

Cranial radiotherapy (CRT) is a known risk factor for neurocognitive impairment in survivors of childhood cancer and may increase risk for mild cognitive impairment and dementia in adulthood. We performed a cross-sectional evaluation of survivors of childhood acute lymphoblastic leukemia (ALL) treated with 18 Gy (n = 127) or 24 Gy (n = 138) CRT. Impairment (age-adjusted score >1 standard deviation below expected mean, two-sided exact binomial test) on the Wechsler Memory Scale IV (WMS-IV) was measured. A subset of survivors (n = 85) completed structural and functional neuroimaging. Survivors who received 24 Gy, but not 18 Gy, CRT had impairment in immediate (impairment rate = 33.8%, 95% confidence interval [CI] = 25.9% to 42.4%; P < .001) and delayed memory (impairment rate = 30.2%, 95% CI = 22.6% to 38.6%; P < .001). The mean score for long-term narrative memory among survivors who received 24 Gy CRT was equivalent to that for individuals older than 69 years. Impaired immediate memory was associated with smaller right (P = .02) and left (P = .008) temporal lobe volumes, and impaired delayed memory was associated with thinner parietal and frontal cortices. Lower hippocampal volumes and increased functional magnetic resonance imaging activation were observed with memory impairment. Reduced cognitive status (Brief Cognitive Status Exam from the WMS-IV) was identified after 24 Gy (18.5%, 95% CI = 12.4% to 26.1%; P < .001), but not 18 Gy (8.7%, 95% CI = 4.4% to 15.0%; P = .11), CRT, suggesting a dose-response effect. Employment rates were equivalent (63.8% for 24 Gy CRT and 63.0% for 18 Gy CRT). Adult survivors who received 24 Gy CRT had reduced cognitive status and memory, with reduced integrity in neuroanatomical regions essential in memory formation, consistent with early onset mild cognitive impairment.

Plasma homocysteine is directly correlated with white matter hyperintensity and lateral ventricular volume, and inversely correlated with regional brain volumes in folic acid fortified, cognitively intact older adults

Folic acid (FA) fortification has reduced the prevalence of hyperhomocysteinemia (HHcy) in the United States, but plasma homocysteine (Hcy) remains a modifiable risk factor for cognitive impairment and dementia. We investigated associations between white matter hyperintensity (WMH) and regional brain volumes, determined by structural MRI scans, and Hcy in cognitively intact, community dwelling older adults exposed to FA fortification (N=191, age 72±6y, Mini Mental State Score &gt;;25). Mean Hcy was 8.6±3.7 μmol/L and 8.3% had HHcy (&gt;;13 μmol/L). Mean RBC folate was 544±150 ng/ml and none was folate deficient (&lt;160 ng/ml). Determinants of Hcy were age, education, vitamin B12, and creatinine. Folate was not correlated with Hcy. When controlling for age, gender, education, intracranial volume, folate, B12, and creatinine, Hcy was directly correlated with WMH (p=0.03) and lateral ventricular volume (p≤0.02), and inversely correlated with hippocampus (p≤0.08), amygdala (p≤0.01), basal ganglia (p≤0.06), and medial temporal lobe (p≤0.04) volumes. These results indicate that in folate replete, cognitively intact older adults, HCY is associated with WMH and structural deficits in and around the medial temporal lobe. It remains to be determined if Hcy predicts loss of volume in these brain regions and associated cognitive functions over time. NIH AG023501, AG032289; Hillblom Foundation; Private Foundation

Gray matter volume reduction reflects chronic pain in trigeminal neuralgia

Trigeminal neuralgia (TN) is supposedly caused by an ectatic blood vessel affecting the trigeminal nerve at the root entry zone of the brain stem. Recent evidence suggests an additional central component within trigeminal pain-processing in the pathophysiology of TN. Therefore, we aimed to identify specific brain regions possibly associated with the development or maintenance of TN using magnetic resonance imaging (MRI) voxel-based morphometry (VBM). Sixty patients with classical TN were compared to 49 healthy controls. Eighteen patients had TN with concomitant constant facial pain, a condition previously described as a predictor of worse treatment outcome. We found gray matter (GM) volume reduction in TN patients compared to healthy controls in the primary somatosensory and orbitofrontal cortices, as well as the in the secondary somatosensory cortex, thalamus, insula, anterior cingulate cortex (ACC), cerebellum, and dorsolateral prefrontal cortex. GM volume decrease within the ACC, parahippocampus, and temporal lobe correlated with increasing disease duration in TN. There were no differences comparing patients with and without concomitant constant facial pain. No GM increase was found comparing patient subgroups with each other and with healthy controls. The observed changes probably reflect the impact of multiple, daily attacks of trigeminal pain in these patients similar to what was previously described in other chronic pain conditions and may be interpreted as adaptation mechanism to chronic pain in regard to neuronal plasticity. The ACC, parahippocampus and temporal lobe volume reduction in parallel with disease duration may point to a pivotal role of these structures in chronic pain.

Analysis of dosimetric factors associated with temporal lobe necrosis (TLN) in patients with nasopharyngeal carcinoma (NPC) after intensity modulated radiotherapy

BackgroundThe radiation tolerance dose-volume in brain remains unclear for nasopharyngeal carcinoma (NPC) patients treated with intensity modulated radiotherapy (IMRT). We performed this study to investigate dosimetric factors associated with temporal lobe necrosis (TLN) in NPC patients treated with IMRT.MethodsFrom 2001 to 2008, 870 NPC patients were treated with IMRT. For the whole group, 40 patients have developed MRI-diagnosed TLN, and 219 patients were followed-up more than 60 months. Predictive dosimetric factors for TLN were identified by using univariate and multivariate analysis in these 259 patients.ResultsBy univariate analyses, rVX ( percent of temporal lobes receiving ≥ X Gy) and aVX ( absolute volumes of temporal lobes receiving ≥ X Gy, values of X considered were 10, 20, 30, 40, 50, 60, 66 and 70) were all significantly associated with TLN. Multivariate analysis by logistic regression showed that rV40 and aV40 were significant factors for TLN. All dosimetric factors in current serials were highly correlated one another (p < 0.001). The 5-year incidence of TLN for rV40 <10% or aV40 <5 cc is less than 5%. The incidence for rV40 ≥ 15% or aV40c ≥ 10c is increased significantly and more than 20%.ConclusionsIn this study, all dosimetric factors were highly correlated, rV40 and aV40 were independent predictive factors for TLN, IMRT with rV40 <10% or aV40 <5 cc in temporal lobe is relatively safe.

Exhaustive search of the SNP-sNP interactome identifies epistatic effects on brain volume in two cohorts.

The SNP-SNP interactome has rarely been explored in the context of neuroimaging genetics mainly due to the complexity of conducting approximately 10(11) pairwise statistical tests. However, recent advances in machine learning, specifically the iterative sure independence screening (SIS) method, have enabled the analysis of datasets where the number of predictors is much larger than the number of observations. Using an implementation of the SIS algorithm (called EPISIS), we used exhaustive search of the genome-wide, SNP-SNP interactome to identify and prioritize SNPs for interaction analysis. We identified a significant SNP pair, rs1345203 and rs1213205, associated with temporal lobe volume. We further examined the full-brain, voxelwise effects of the interaction in the ADNI dataset and separately in an independent dataset of healthy twins (QTIM). We found that each additional loading in the epistatic effect was associated with approximately 5% greater brain regional brain volume (a protective effect) in both the ADNI and QTIM samples.

Medial temporal lobe volume predicts rate of learning in Rey-AVLT

The medial temporal lobe (MTL) has been assigned a central role in human episodic memory and learning. Evidence for this comes from PET and fMRI studies as well as lesion studies. This study aimed at comparing the effect of atrophy at repeated trials of a supraspan test of memory. Included in the study were patients with Alzheimer’s Disease, Mild Cognitive Impairment, and Subjective Memory Disorders as well as Controls (n = 116). The supraspan test used was the Rey Auditory Verbal Learning test (RAVLT). Comparisons between extreme groups with high (Stanine 6 - 9) and low (Stanine 1 - 4) intracranial proportions (IP) of MTL were made at the five trials of RAVLT. There was a significantly higher rate of learning among subjects with high MTL IP compared to those with low MTL IP in both hemispheres. There was no difference in the rate of list learning performance due to education or age and interestingly: the list learning rates among subjects with high/low Lateral Temporal Lobe IPs were almost similar. The hemispheric differences regarding learning rate were small and insignificant. Results are discussed in terms of hippocampal involvement in associative processes necessary in supraspan list learning.

Anatomical substrates of cognitive and clinical dimensions in first episode schizophrenia

To explore gray (GM) and white matter (WM) abnormalities and the relationships with neuropsychopathology in first-episode schizophrenia (FES). Nineteen patients with first episode of non-affective psychosis and 18 controls underwent a magnetic resonance voxel-based morphometry. Additionally, WM fractional anisotropy (FA) was calculated. For correlative analysis, symptoms and neuropsychological performances were scored by PANSS and by a comprehensive neuropsychological assessment respectively. Patients showed significantly decreased volume of left temporal lobe and disarray of all major WM tracts. Disorganized PANSS factor was inversely related to left cerebellar GM volume (corrected P = 0.03) and to WM FA of the left cerebellum, inferior fronto-occipital fasciculi (IFOF), and inferior longitudinal fasciculi (corrected P < 0.05). PANSS negative factor was inversely related to FA in the IFOF and superior longitudinal fasciculi (corrected P < 0.05). Impairment in facial emotion identification showed associations with temporo-occipital GM volume decrease (corrected P = 0.003) and WM disarray of superior and middle temporal gyri, anterior thalamic radiation, and superior longitudinal fasciculi (corrected P < 0.05). Speed of processing and visual memory correlated with WM abnormalities in fronto-temporal tracts. These results confirm how the structural development of key brain regions is related to neuropsychopathological dysfunction in FES, consistently with a neurodevelopmentally derived misconnection syndrome.

Long-Term Memory Deficits and Early Onset Dementia in Aging Adult Survivors of Childhood Acute Lymphoblastic Leukemia Treated with Cranial Irradiation

AbstractAbstract 664 Background:Survivors of childhood acute lymphoblastic leukemia (ALL) who received prophylactic cranial radiation therapy (CRT) are at increased risk for deficits in neurocognitive skills, including attention, working memory and processing speed. As survivors age, global brain injury from CRT may reduce cognitive reserve, placing them at risk for early onset dementia or long-term memory deficits. The prevalence of dementia and memory abnormalities in adult survivors of childhood ALL has not previously been established. Methods:Analyses were conducted on 265 of 445 (60%) eligible survivors of childhood ALL (median age 36 years, range 26–54 years; 52% female) treated with 18Gy (n=127) or 24Gy (n=138) CRT with a median time from CRT of 30 years (range 15–46 years). Participants completed the Wechsler Memory Scale IV, including the Brief Cognitive Status Exam (BSCE), and the Wechsler Abbreviated Scale of Intelligence (WASI). Age-adjusted standard scores were calculated and the BSCE was also adjusted for education level. Prevalence of memory impairment (<1 SD below age-expected mean), stratified by RT dose exposure, is reported and logistic regression used to identify risk factors for impairment. A subset of survivors (n=85) completed brain magnetic resonance imaging (MRI), including assessment of hippocampal volume, cortical thickness, white matter volume, diffusion tensor imaging, and functional MRI (fMRI) during a cued-recall memory task. Results:Survivors who received 24 Gy CRT had increased impairment on global measures of both short-term recall (33%; p<0.001) and long-term recall (30%; p<0.001), while no increase in impairment was seen after 18Gy. Impaired short-term recall was associated with smaller right (p=0.02) and left (p<0.01) temporal lobe volumes, while impaired long-term recall was associated with thinner parietal and frontal cortices. On subtests evaluating narrative memory (i.e. story recall) and design memory, increasing RT dose (24 vs. 18Gy) was associated with an increased prevalence of long-term memory impairment (narrative: 28% vs. 12%, p=0.001; designs: 13% vs. 3.2%, p=0.003). However, no CRT dose response was identified for short term narrative and design memory. Survivors with impaired long-term memory for designs demonstrated a compensatory increase in left hippocampal fMRI activation (p=0.005), and the effect was greater in the higher dose group (p = 0.04). The mean score for long-term narrative memory among survivors who received 24Gy was equivalent to the mean score of a 70–74 year old adult population. Neither young age (0–4 years) at CRT (Odds Ratio [OR] 1.4, 95% confidence interval [CI] 0.8–2.7), time from CRT (OR 1.0, 95% CI 0.9–1.1) nor intrathecal methotrexate exposure (OR 3.9, 95% CI 0.4–36.1) were significantly associated with long-term memory deficits. Reduced cognitive status (by BSCE) was identified after 18Gy (9%, p=0.11) and 24Gy (18%, p<0.001), suggesting a CRT dose-response effect. On diffusion tensor imaging, increased radial diffusivity in the frontal, parietal and temporal regions, an inverse measure of white matter integrity, was associated with reduced BSCE. Current employment rates were equivalent (63%) in both CRT dose groups, suggesting no difference in functional status. Conclusions:Aging adult survivors of ALL who received 24Gy CRT have reduced cognitive status and significant impairment in short-term and long-term memory. There appears to be a dose response effect selective for long-term narrative and design memory, but not for short term narrative and design memory. These patterns are consistent with early onset of age-related (long-term) memory loss, and early stage dementia, yet at a median age of only 36 years. After 24Gy, survivors have the narrative memory equivalent to a 70 year-old in the general population. Survivors with memory impairment demonstrated reduced integrity on structural and functional neuroimaging in anatomical regions established as essential for memory formation and long-term recall. However, these memory impairments do not seem to affect functional status (employment rates) suggesting that, rather than frank dementia, deficits in middle adulthood are consistent with mild cognitive impairment (MCI). Longitudinal evaluation of this population is needed as MCI often progresses into early onset dementia with age. Disclosures:No relevant conflicts of interest to declare.

A Prospective Study of Cerebral, Frontal Lobe, and Temporal Lobe Volume and Neuropsychologic Performance in Children With Primary Brain Tumors Treated With Cranial Radiation

A Prospective Study of Cerebral, Frontal Lobe, and Temporal Lobe Volume and Neuropsychologic Performance in Children With Primary Brain Tumors Treated With Cranial Radiation

The diagnostic value of medial temporal volume change in Alzheimer's disease

Objective To study the metastructure volumes of medial temporal lobe in diagnosis the patients with Alzheimer's disease (AD) using 3 dimensional MRI. Methods 23 AD patients according to DSM-IV criteria and 23 normal controls (NC) were examined with 3D-MRI. Hippocampus formation, amygdala, entorhinal cortex (EC), perirhinal cortex (PC), and cornu temporale were measured with 3D-MRI. Results Sensitivity and specificity of diagnosis AD were 73.9%, 97% (Hippocampus formation); 39.1%, 95.7% (amygdala); 73.9%, 95.7% (EC); 95.7%, 87.0% (PC) and 34.8%, 39.1% (cornu temporale). Overall discriminate function = cornu temporal ×3.887+ PC×5.960-EC×0.074+ amygdale ×3.489 + hippocampus formation ×6.656-22.449. Over-all-accuracy was 91.3%. Conclusion The total volume of PC can better diagnosis the mild to moderate AD than other structure of medial temporal lobe.The changes of the medial temporal lobe volume could be used in diagnosis the patients with Alzheimer's disease. Key words: Alzheimer's disease; Temporal lobe; Entorhinal cortex; Diagnosis

Effective surgical intervention for schizophrenia‐like symptoms and low event‐related potentials caused by arachnoid cyst

ARACHNOID CYSTS CAN occur wherever there is arachnoid tissue, although nearly half of all arachnoid cysts arise in the temporal fossa–Sylvian fissure. In general, clinical manifestations of arachnoid cyst are often mild. Several articles have suggested that there is an etiological relationship between arachnoid cyst and psychiatric symptoms.1 A 24-year-old man first presented with compulsive checking at the age of 21 years. In addition, he had experienced delusions of persecution and auditory hallucinations. He had no neurological abnormality and was treated with antipsychotic medication. The antipsychotics, however, did not improve the psychotic symptoms. At that time, computed tomography showed an arachnoid cyst in his left middle cranial fossa. The basic rhythm on electroencephalogram (EEG) was posterior dominant alpha wave. The psychotic symptoms were considered to be caused by the arachnoid cyst because of the antipsychotics' low effectiveness. Magnetic resonance imaging (MRI) showed a large anteromedial left temporal fossa arachnoid cyst (80 mm in diameter) expanding into the left Sylvian fissure. Event-related potentials (ERP), such as P300, and mismatch negativity (MMN) were low in amplitude. Some reports have suggested that surgical intervention for arachnoid cyst improved psychotic symptoms.2 Therefore, endoscopic fenestration of the cyst was performed. The delusions and hallucinations improved postoperatively, and the patient was discharged. The delusions of persecution, however, later increased. MRI using time–spatial labeling inversion pulse showed inadequate flow of cerebrospinal fluid through the fenestra. Hence, another craniotomy was performed. Fenestra closure caused by arachnoid regeneration was found during this procedure. After partial removal of the cyst wall, the delusions remitted partially. The amplitude of P300 and MMN in the frontocentral region increased after each surgery. In contrast, MMN amplitude in the bilateral mastoid region showed no change. There was no difference between the basic rhythm and amplitudes of EEG before and after surgery. This patient provided written, informed consent. In some reports, left temporal arachnoid cysts were found to be associated with schizophrenia-like symptoms.2 Recent studies have demonstrated volume loss in the left superior temporal gyrus in schizophrenia.3 The temporal lobe is regarded as an important region for P300 and MMN, the amplitudes of which are reduced in schizophrenia and the other psychoses. This is one of the reproducible abnormal biological findings in schizophrenia. Therefore, small P300 and MMN amplitude, schizophrenia-like psychotic symptoms, and left temporal lobe volume loss are closely related.3 In the present case, the compressed and/or defective development of the temporal lobe due to the arachnoid cyst probably caused the low P300 and MMN amplitudes. If low ERP were of organic origin, the amplitudes would improve.