Biomedical subjects

C R Jack

Publications and source records attributed to C R Jack.

At least 37 records · Page 2Linked to original sources

PubMed2000

Regional metabolic patterns in mild cognitive impairment and Alzheimer's disease: A 1H MRS study.

BACKGROUND: Mild cognitive impairment (MCI) is a recently described transitional clinical state between normal aging and AD. Assuming that amnestic MCI patients had pathologic changes corresponding to an early phase and probable AD patients to a later phase of the disease progression, the authors could approximate the temporal course of proton MR spectroscopic (1H MRS) alterations in AD with a cross-sectional sampling scheme. METHODS: The authors compared 1H MRS findings in the superior temporal lobe, posterior cingulate gyri, and medial occipital lobe in 21 patients with MCI, 21 patients with probable AD, and 63 elderly controls. These areas are known to be involved at different neurofibrillary pathologic stages of AD. RESULTS: The N-acetylaspartate (NAA)/creatine (Cr) ratios were significantly lower in AD patients compared to both MCI and normal control subjects in the left superior temporal and the posterior cingulate volumes of interest (VOI) and there were no between-group differences in the medial occipital VOI. Myoinositol (MI)/Cr ratios measured from the posterior cingulate VOI were significantly higher in both MCI and AD patients than controls. The choline (Cho)/Cr ratios measured from the posterior cingulate VOI were higher in AD patients compared to both MCI and control subjects. CONCLUSION: These findings suggest that the initial 1H MRS change in the pathologic progression of AD is an increase in MI/Cr. A decrease in NAA/Cr and an increase in Cho/Cr develop later in the disease course.

Aged↗

PubMed2000

Usefulness of MRI measures of entorhinal cortex versus hippocampus in AD.

OBJECTIVE: MRI-based measurements of hippocampal atrophy are a sensitive indicator of the early pathologic degeneration of the medial temporal lobe in AD. However, AD pathology appears first in the transentorhinal/entorhinal cortex, not the hippocampus. The authors tested the hypothesis that MRI-based measurements of the entorhinal cortex are more sensitive than measurements of hippocampal volume in discriminating among three clinical groups; controls, patients with a mild cognitive impairment (MCI), and patients with mild probable AD. METHODS: The authors studied 30 controls, 30 patients with MCI, and 30 patients with AD who were matched among clinical groups on age, gender, and education. All underwent a standardized MRI protocol from which the authors made measurements of hippocampal volume, entorhinal cortex volume, and the cumulative length of the medial border of the entorhinal cortex. RESULTS: Pairwise intergroup differences (p < 0.01) were found for all MRI measurements with the exception of the cumulative length of the entorhinal cortex, which did not differentiate controls from MCI patients. Whereas the hippocampal and entorhinal cortex volume measurements provided slightly better intergroup discrimination than the entorhinal distance measurement, overall differences in discriminating ability among the three MRI measurements were minor. CONCLUSIONS: Despite the theoretical rationale for the superiority of entorhinal measurements in early AD, the authors found MRI measurements of the hippocampus and entorhinal cortex were approximately equivalent at intergroup discrimination. Measurements of the hippocampus may be preferable because MRI depiction of the boundaries of the entorhinal cortex can be obscured by anatomic ambiguity, image artifact, or both.

Aged↗

PubMed2000

Memory and MRI-based hippocampal volumes in aging and AD.

OBJECTIVE: To demonstrate structural-functional relationships between MRI-based volumetric measurements of medial temporal lobe structures and cognitive function. BACKGROUND: Previous work has documented the ability of MRI-based measurements of the hippocampus to discriminate between age-matched control subjects and patients with very mild AD. Relatively less is known about the correlation between medial temporal lobe structures and cognitive functions. METHOD: We evaluated structural-functional relationships among the hippocampal formation, parahippocampal gyrus, and amygdala, and measures of memory, language, and general cognitive performance in 220 probable AD patients and normal control subjects. Standardized instruments of memory and general cognitive function were used to assess subjects enrolled in a longitudinal study of aging and dementia. RESULTS: The volume of the hippocampal formation predicted performance on most acquisition and recall measures across the spectrum of normal aging and AD. If the groups were segregated, most of the expected associations between medial temporal lobe structures and memory measures were observed in the AD patients. CONCLUSION: MRI-based hippocampal volumetry accurately depicts the structural-functional relationships between memory loss and hippocampal damage across the spectrum from normal aging to dementia.

Aged↗

PubMed2000

Prospective multiaxial motion correction for fMRI.

Corruption of the image time series due to interimage head motion limits the clinical utility of functional MRI. This paper presents a method for real-time prospective correction of rotation and translation in all six degrees of rigid body motion. By incorporating an orbital navigator (ONAV) echo for each of the sagittal, axial, and coronal planes into the fMRI pulse sequence, rotation and translation can be measured and the spatial orientation of the image acquisition sequence that follows can be corrected prospectively in as little as 160 msec. Testing of the method using a computerized motion phantom capable of performing complex multiaxial motion showed subdegree rotational and submillimeter translational accuracy over a range of +/-8 degrees and +/-8 mm of motion. In vivo images demonstrate correction of simultaneous through-plane and in-plane motion and improved detection of fMRI activation in the presence of head motion.

Artifacts↗

PubMed2000

Factors predictive of the outcome of frontal lobe epilepsy surgery.

PURPOSE: To identify factors that predict the outcome in seizure control after frontal lobe epilepsy surgery (FLES). FLES is the second most frequent type of epilepsy surgery, but the results are generally not as good as those after anterior temporal lobectomy. METHODS: Our cohort consisted of 68 consecutive patients whose first epilepsy surgery involving the frontal lobe occurred between 1987 and 1994. Clinical history and results of imaging and electroencephalographic studies were reviewed in detail. Excellent outcome was defined as being seizure free or having only nondisabling seizures at last follow up. RESULTS: Forty of the 68 patients (58.8%) had an excellent outcome; none of the patients with a history of childhood febrile seizures had an excellent outcome, whereas outcome was excellent in 63% of those without that history (p </= 0.01). The other significant presurgical factor was the presence of a potentially epileptogenic lesion in the frontal lobe on neuroimaging (excellent outcome in 72% when present versus 41% when absent, p </= 0.001). The only significant postsurgical factor was early postoperative seizure control in the first year (excellent outcome in 96% with early control versus 25% without, p </= 0.01). CONCLUSIONS: History of childhood febrile seizures is a poor prognostic factor in FLES patients. It may suggest that the structural basis of all or some of the patients' intractable seizures is mesial temporal sclerosis. On the other hand, neuroimaging detection of a potentially epileptogenic frontal lobe lesion and early postoperative seizure control are associated with subsequent excellent outcome.

Adult↗

PubMed2000

Significance of cerebellar atrophy in intractable temporal lobe epilepsy: a quantitative MRI study.

PURPOSE: To determine the incidence of cerebellar atrophy (CA) in patients with intractable temporal lobe epilepsy, whether any clinical factors are significantly associated with CA, whether CA is unilateral or asymmetric and whether this feature has any relationship to the side of epileptogenicity, and whether the presence of CA is related to epilepsy surgery outcome. METHODS: We developed a magnetic resonance imaging method of measuring the presurgical volumes of the cerebellar hemispheres of 185 patients who underwent temporal lobectomy for intractable epilepsy and of 80 control subjects. In addition, cerebellar volumes were normalized to the total brain volumes. CA was determined as being present when the measured volume was smaller than two standard deviations from the mean value found in control subjects. RESULTS: Both absolute and normalized cerebellar volumes were found to be significantly reduced in the epilepsy patients compared with the control subjects. Without normalization of the cerebellar volumes, CA was present in 25.9% of the epilepsy patients; with normalization, it was present in only 16.2%. The atrophy was symmetric between the cerebellar hemispheres, and there was no significant difference in volume between the hemisphere ipsilateral and the hemisphere contralateral to the side of the temporal lobectomy. The duration of epilepsy was significantly longer and the age at onset of epilepsy was younger in patients with CA than in those without CA. The presence of CA was not associated with the outcome of temporal lobectomy. CONCLUSIONS: CA is symmetric and common in patients with intractable temporal lobe epilepsy. However, the results suggest that the atrophy in one third of patients with CA also proportionately affects the cerebral hemispheres. The duration of epilepsy and the age at onset of epilepsy are associated with the occurrence of CA. Seizure control after temporal lobectomy is not influenced by the presence of CA.

Adult↗

PubMed1999

Prediction of AD with MRI-based hippocampal volume in mild cognitive impairment.

OBJECTIVE: To test the hypothesis that MRI-based measurements of hippocampal volume are related to the risk of future conversion to Alzheimer's disease (AD) in older patients with a mild cognitive impairment (MCI). BACKGROUND: Patients who develop AD pass through a transitional state, which can be characterized as MCI. In some patients, however, MCI is a more benign condition, which may not progress to AD or may do so slowly. PATIENTS: Eighty consecutive patients who met criteria for the diagnosis of MCI were recruited from the Mayo Clinic Alzheimer's Disease Center/Alzheimer's Disease Patient Registry. METHODS: At entry into the study, each patient received an MRI examination of the head, from which the volumes of both hippocampi were measured. Patients were followed longitudinally with approximately annual clinical/cognitive assessments. The primary endpoint was the crossover of individual MCI patients to the clinical diagnosis of AD during longitudinal clinical follow-up. RESULTS: During the period of longitudinal observation, which averaged 32.6 months, 27 of the 80 MCI patients became demented. Hippocampal atrophy at baseline was associated with crossover from MCI to AD (relative risk [RR], 0.69, p = 0.015). When hippocampal volume was entered into bivariate models-using age, postmenopausal estrogen replacement, standard neuropsychological tests, apolipoprotein E (APOE) genotype, history of ischemic heart disease, and hypertension-the RRs were not substantially different from that found univariately, and the associations between hippocampal volume and crossover remained significant. CONCLUSION: In older patients with MCI, hippocampal atrophy determined by premorbid MRI-based volume measurements is predictive of subsequent conversion to AD.

Aged↗

PubMed1999

Subtraction SPECT co-registered to MRI improves postictal SPECT localization of seizure foci.

OBJECTIVE: To determine whether the detection of focal hypoperfusion by subtraction SPECT co-registered to MRI (SISCOM) improves the sensitivity and specificity of postictal SPECT in intractable partial epilepsy. BACKGROUND: Postictal SPECT injections are easier to perform than are ictal injections, but the images are more difficult to interpret and have been reported to have lower sensitivity and specificity. METHODS: Thirty-five consecutive intractable partial epilepsy patients who had postictal SPECT studies were evaluated. The following sets of SPECT images were separately interpreted by three blinded reviewers and classified as either localizing to 1 of 16 possible sites in the brain or as nonlocalizing: unsubtracted postictal and interictal images for conventional side-by-side comparison, SISCOM images of hyperperfusion, SISCOM images of hypoperfusion, and both sets of SISCOM hyperperfusion and hypoperfusion images (combined SISCOM evaluation). RESULTS: Significantly higher proportions of the hyperperfusion SISCOM images (65.7%), the hypoperfusion SISCOM images (74.3%), and the combined SISCOM evaluation (82.9%) were localizing than were the conventional method of side-by-side comparison of unsubtracted images (31.4%; p < 0.0001). Concordance with the discharge diagnosis was higher for the combined SISCOM evaluation than it was for either the hyperperfusion or the hypoperfusion SISCOM images alone (both p < 0.05). For the hypoperfusion SISCOM and the combined SISCOM evaluations, concordance of the localization with the site of epilepsy surgery was associated with a greater probability of an excellent outcome than were nonconcordant/nonlocalizing images (both p < 0.05). CONCLUSION: The use of SISCOM to detect focal cerebral hypoperfusion, in addition to focal hyperperfusion, improves the sensitivity and specificity of postictal SPECT in intractable partial epilepsy.

Adolescent↗

PubMed1999

Comparative study of 99mTc-ECD and 99mTc-HMPAO for peri-ictal SPECT: qualitative and quantitative analysis.

OBJECTIVES: Most studies that clinically validated peri-ictal SPECT in intractable partial epilepsy had used technetium-99m-hexamethylpropylene amine oxime (99mTc-HMPAO or 99mTc-exametazime) as the radiopharmaceutical. Because of some theoretical advantages, technetium-99m-ethyl cysteinate diethylester (99mTc-ECD or 99mTc-bicisate) is increasingly being used instead. This study compares unstabilised 99Tc-HMPAO and 99mTc-ECD in the performance of peri-ictal SPECT in partial epilepsy. METHODS: The injection timing and localisation rates in 49 consecutive patients with partial epilepsy who had peri-ictal injections with unstabilised 99mTc-HMPAO were compared with 49 consecutive patients who had peri-ictal injections with 99mTc-ECD. Quantitative cortical/subcortical and cortical/extracerebral uptake ratios were also compared. Subtraction SPECT coregistered to MRI (SISCOM) was performed in patients whose interictal SPECTS were available. RESULTS: In the 99mTc-ECD patients, the latency from seizure commencement to injection was shorter (median 34 v 80 seconds, p<0.0001) and there was a lower rate of postictal injections (16.3% v 57.1%, p<0.0001). The cortical/extracerebral and cortical/subcortical uptake ratios were greater in the 99mTc-ECD images (median 5.0 v 3.6, and 2.5 v 2.2 respectively; both p<0.005), but the relative peri-ictal increase in uptake in the cortical focus did not differ significantly (median 37.0% v 37.0%; p>0.05). Blinded review of the SISCOM images were localising in a higher proportion of the 99mTc-ECD patients (40/45 (88.9%) v 25/37 (67.6%), p<0.05), and had a better concordance with EEG, MRI, and with the discharge diagnosis. CONCLUSION: 99mTc-ECD compares favourably with unstabilised 99mTc-HMPAO as a radiopharmaceutical for peri-ictal SPECT studies. Its use results in earlier injections and less frequent postictal injections than unstabilised 99mTc-HMPAO, thereby enhancing the sensitivity and the specificity of peri-ictal SPECT for the localisation of intractable partial epilepsy.

Adolescent↗

PubMed1999

Progressive hippocampal atrophy in chronic intractable temporal lobe epilepsy.

We report on a 28-year-old man with long-standing intractable complex partial and secondary generalized seizures, whose magnetic resonance imaging scans 4 years apart documented progressive decrease in the left hippocampal volume. Left anterior temporal lobectomy with amygdalohippocampectomy rendered the patient seizure free at 12 months' follow-up. The findings demonstrate that patients with uncontrolled temporal lobe seizures may develop progressive atrophy of the hippocampus, in the absence of status epilepticus.

Adult↗

PubMed1999

Assessment of functional MR imaging in neurosurgical planning.

BACKGROUND AND PURPOSE: Presurgical sensorimotor mapping with functional MR imaging is gaining acceptance in clinical practice; however, to our knowledge, its therapeutic efficacy has not been assessed in a sizable group of patients. Our goal was to identify how preoperative sensorimotor functional studies were used to guide the treatment of neuro-oncologic and epilepsy surgery patients. METHODS: We retrospectively reviewed the medical records of 46 patients who had undergone preoperative sensorimotor functional MR imaging to document how often and in what ways the imaging studies had influenced their management. Clinical management decisions were grouped into three categories: for assessing the feasibility of surgical resection, for surgical planning, and for selecting patients for invasive functional mapping procedures. RESULTS: Functional MR imaging studies successfully identified the functional central sulcus ipsilateral to the abnormality in 32 of the 46 patients, and these 32 patients are the focus of this report. In epilepsy surgery candidates, the functional MR imaging results were used to determine in part the feasibility of a proposed surgical resection in 70% of patients, to aid in surgical planning in 43%, and to select patients for invasive surgical functional mapping in 52%. In tumor patients, the functional MR imaging results were used to determine in part the feasibility of surgical resection in 55%, to aid in surgical planning in 22%, and to select patients for invasive surgical functional mapping in 78%. Overall, functional MR imaging studies were used in one or more of the three clinical decision-making categories in 89% of tumor patients and 91% of epilepsy surgery patients. CONCLUSION: Preoperative functional MR imaging is useful to clinicians at three key stages in the preoperative clinical management paradigm of a substantial percentage of patients who are being considered for resective tumor or epilepsy surgery.

Adolescent↗

PubMed1998

Hippocampal atrophy and apolipoprotein E genotype are independently associated with Alzheimer's disease.

A variety of anatomic and functional neuroimaging findings are associated with Alzheimer's disease (AD). One of the strongest imaging associations identified is between AD and hippocampal atrophy. The epsilon4 allele of the apolipoprotein E (ApoE) gene increases the risk of developing AD and lowers the mean age of onset of the disease. The purpose of this study was to assess the association between hippocampal volume and ApoE polymorphisms in elderly control subjects and in patients with probable AD. We performed magnetic resonance imaging-based volume measurements of the hippocampus in 125 cognitively normal elderly controls and 62 patients with probable AD. ApoE genotyping was performed by using standard methods. Hippocampal volumes were significantly smaller in AD cases than in control subjects. Hippocampal volumes did not differ significantly within either clinical group on the basis of ApoE genotype. Both the epsilon4 allele of ApoE and hippocampal atrophy were significantly but independently associated with AD.

Aged↗

PubMed1998

A prospective approach to correct for inter-image head rotation in fMRI.

Global head motion occurring between successive image acquisitions during a functional MRI time series can corrupt the signal of physiologic brain activation, potentially invalidating interpretation of the final activation map from that particular fMRI time series. By approximating the head as a rigid body, multiaxial global head motion can be decomposed into orthogonal linear and rotational components. This paper describes a method using orbital navigator echoes to provide prospective correction for both through-plane and in-plane inter-image head rotation in functional MRI. The dynamic detection and correction of rotation can be performed in <100 ms. Phantom experiments demonstrate accurate correction of rotational motion over a range of +/-0.36 degrees to +/-12 degrees. Imaging studies in volunteers document the feasibility of real-time prospective correction of rotational motion in vivo. Using a modified receiver operating characteristic method, motion-corrected functional MRI sensorimotor studies incorporating deliberate head rotations are shown to be superior to functional MRI time series acquired under similar conditions but without motion correction.

Artifacts↗

PubMed1998

Subtraction ictal SPET co-registered to MRI in partial epilepsy: description and technical validation of the method with phantom and patient studies.

Computer-aided subtraction of the co-registered and normalized interictal from the ictal single photon emission tomography (SPET) scan, followed by co-registration to the magnetic resonance image, may improve the utility of ictal SPET in the localization of partial epilepsy. This paper describes and technically validates our method. The SPET to SPET co-registration was tested using six sequential 99Tc(m) brain phantom SPET images of different known positions (15 matches). The registration error was determined by multiplying the calculated match transformation matrix by the inverse of the known transformation matrix. The 'worst case' co-registration error was less that one voxel diameter in all cases (median 3.2 mm, range 1.2-4.8 mm). For interictal to ictal SPET registrations in 10 consecutive intractable partial epilepsy patients, a similar root mean square distance (RMSD) between corresponding points on the matched scans was found as for the phantom studies (median 2.2 vs 2.6 mm). The appropriateness of our normalization was studied by comparing the pixel intensity distributions between the matched scans, and by analysing the subtraction pixel intensity distribution. The pixel intensity distribution for both the normalized phantom, and paired normalized patient studies, were closely matched to each other except for the extreme values, which in clinical situations likely represent regions of ictal activation or depression. The subtraction image intensity distributions were symmetrically centred on zero for all values up to at least within the 5th to 95th centile range, confirming good normalization for the 'non-activated' pixels. Also, a linear relationship was demonstrated between the measured pixel intensity on the phantom scans and the true changes in 99Tc(m) activity based on its decay constant. The results of this study demonstrate that our method produces accurate SPET to SPET co-registration, and appropriate SPET normalization, thereby allowing a valid ictal subtraction image to be derived.

Brain↗

PubMed1998

Effects of a stereotactic headframe assembly on proton magnetic resonance spectroscopy.

The effects of a magnetic resonance-compatible stereotactic headframe assembly on single voxel proton magnetic resonance spectroscopy (MRS) were investigated. Multiple stimulated echo acquisition mode (STEAM) spectra were obtained within a commercially available brain metabolite phantom placed within the headframe assembly (Leksell, Model G). All acquisition parameters were kept constant, except voxel location. Maximal distortion occurred for voxels acquired in the immediate vicinity of a headframe fixation pin, manifested by spectral broadening, changes in peak area and height and distortion of the baseline, rendering these acquisitions nondiagnostic. The range of this interaction was short, and a voxel acquired with nearest edge located 2.0 cm or greater from the fixation pin tip produced NAA/Cr, Cho/Cr and mI/Cr ratios differing by less than 7.5% from a spectrum obtained at the phantom center. The feasibility of performing single voxel MRS with a stereotactic headframe in place is demonstrated.

Brain Mapping↗

PubMed1998

Subtraction ictal SPECT co-registered to MRI improves clinical usefulness of SPECT in localizing the surgical seizure focus.

Traditional side-by-side visual interpretation of ictal and interictal single-photon emission computed tomography (SPECT) scans can be difficult in identifying the surgical focus, particularly in patients with extratemporal or otherwise unlocalized intractable epilepsy. Computer-aided subtraction ictal SPECT co-registered to MRI (SISCOM) may improve the clinical usefulness of SPECT in localizing the surgical seizure focus. We studied 51 consecutive intractable partial epilepsy patients who had interictal and ictal scans. The SPECT studies were blindly reviewed and classified as either localizing to 1 of 16 sites in the brain or as nonlocalizing. SISCOM images were localizing in 45 of 51 (88.2%) compared with 20 of 51 (39.2%) for traditional side-by-side inspection of ictal and interictal SPECT images (p < 0.0001). Inter-rater agreement for two independent reviewers was better for SISCOM (84.3% versus 41.2%, kappa = 0.83 versus 0.26; p < 0.0001). Concordance of seizure localization with the more established tests was also higher for SISCOM. Late injection of the radiotracer (> 45 seconds), but not secondary generalization of the seizure, was associated with a falsely localizing or nonlocalizing SISCOM. Epilepsy surgery patients whose SISCOM localization was concordant with a falsely localizing or nonlocalizing SISCOM. Epilepsy surgery patients whose SISCOM localization was concordant with the surgical site were more likely to have excellent outcome than patients with nonconcordant or nonlocalizing findings (62.5% [10/16] versus 20% [2/10]; p < 0.05). On the other hand, seizure localization by the traditional method of SPECT inspection had no significant association with postsurgical outcome. We conclude that SISCOM improves the sensitivity and the specificity of SPECT in localizing the seizure focus for epilepsy surgery. Concordance between SISCOM localization and site of surgery is predictive of postsurgical improvement in seizure outcome.

Brain↗

PubMed1998

Predictors of outcome of anterior temporal lobectomy for intractable epilepsy: a multivariate study.

OBJECTIVE: To identify presurgical and postsurgical factors that are independently predictive of the outcome of anterior temporal lobectomy (ATL) for intractable epilepsy. BACKGROUND: There have been reports of prognostic factors in epilepsy surgery, but little is known about factors that independently predict outcome of ATL. METHODS: We studied 175 consecutive ATL patients who had at least 2 years of postsurgical follow-up. Significant factors on univariate analyses were subjected to stepwise logistic regression analysis. RESULTS: On univariate analyses, two presurgical conditions were significantly associated with excellent seizure control at last follow-up: (1) unilateral hippocampal formation atrophy as detected on MRI and (2) all scalp interictal epileptiform discharges concordant with the location of ictal onset (p < 0.05). Three postsurgical factors that occurred during the first year were associated with excellent seizure outcome: the absence of interictal epileptiform discharges at 3 months, complete seizure control, and having only nondisabling seizures for those who did not become seizure free. Logistic regression analysis revealed the following to be independently predictive of excellent seizure control: MRI-detected unilateral hippocampal formation atrophy, concordant interictal epileptiform discharges, complete seizure control during the first postsurgical year, and having only nondisabling seizures during the first postsurgical year for those who did not become seizure free. CONCLUSIONS: Presurgical identification of unilateral hippocampal formation atrophy, or of interictal epileptiform discharges that are all concordant with the location of ictal onset, predict excellent outcome of ATL. However, the probability of excellent outcome is highest (94%) when both factors are present.

Adolescent↗

PubMed1998

Rate of medial temporal lobe atrophy in typical aging and Alzheimer's disease.

OBJECTIVES: To determine the annual rates of volumetric change of the hippocampus and temporal horn in cognitively normal elderly control subjects and individually matched patients with AD, and to test the hypothesis that these rates were different. BACKGROUND: Cross-sectional studies consistently reveal cerebral atrophy in elderly nondemented subjects compared with healthy young adults, and greater atrophy in patients with AD relative to elderly control subjects. However, rates of atrophy are estimated most accurately by performing serial measurements in the same individuals. METHODS: MRI-based volumetric measurements of the hippocampi and temporal horns were performed in 24 cognitively normal subjects aged 70 to 89 years who were individually matched with respect to gender and age with 24 patients with AD. Each subject underwent an MRI protocol twice, separated by 12 months or more. RESULTS: The mean annual rate of hippocampal volume loss among control subjects was -1.55+/-1.38% and the temporal horns increased in volume by 6.15+/-7.69% per year. These rates were significantly greater among AD patients: hippocampus, -3.98+/-1.92% per year, p < 0.001; temporal horn, 14.16+/-8.47% per year, p = 0.002. CONCLUSION: A statistically significant yearly decline in hippocampal volume and an increase in temporal horn volume was identified in elderly control subjects who represent typical aging individuals. These rates were approximately 2.5 times greater in patients with AD than in individually age- and gender-matched control subjects.

Aged↗