The brain in older persons with and without dementia: findings on MR, PET, and SPECT images

Evaluation of imaging indicators in differentiating idiopathic normal pressure hydrocephalus from Alzheimer's disease

BACKGROUND

There are currently many imaging indicators for idiopathic normal pressure hydrocephalus (iNPH). However, their diagnostic performance has not been well compared, especially in differentiating iNPH from Alzheimer's disease (AD). This study aimed to evaluate the diagnostic performance of these imaging indicators in differentiating iNPH from AD.

METHODS

We retrospectively collected patients with iNPH from the West China Hospital between June 2016 and December 2023. Age-sex-matched patients with AD and healthy controls (HCs) are included as controls (ChiCTR2300070078, March 2023). Twelve imaging indicators were evaluated on MRI, including disproportionately enlarged subarachnoid space hydrocephalus (DESH), Evans' index (EI), callosal angle, z-EI, temporal horn, dilated Sylvian fissure, focal sulcal dilation, tight high convexity, deep white matter hyperintensities, periventricular hyperintensities, DESH scale, and Simplified Radscale. We analyzed the receiver operating characteristic curves and calculated the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy.

RESULTS

A total of 46 patients with iNPH (mean age: 73.1 ± 6.5; 35 males), 46 patients with AD (mean age: 73.0 ± 6.6; 35 males), and 46 HCs (mean age: 73.0 ± 5.9; 35 males) were included. The largest area under the receiver operating characteristic curve (AUC) was found in EI (0.93; 95 % CI: 0.89-0.98) and z-EI (0.93; 95 % CI: 0.87-0.98). DESH scale ≥ 6 had the highest specificity (93 %, 43/46).

CONCLUSION

EI and z-EI had the best diagnostic performance in differentiating iNPH from AD. The DESH scale could assist in diagnosing iNPH due to its high specificity.

Prediction of brain age using quantitative parameters of synthetic magnetic resonance imaging

Objective

Brain tissue changes dynamically during aging. The purpose of this study was to use synthetic magnetic resonance imaging (syMRI) to evaluate the changes in relaxation values in different brain regions during brain aging and to construct a brain age prediction model.

Materials and methods

Quantitative MRI was performed on 1,000 healthy people (≥ 18 years old) from September 2020 to October 2021. T1, T2 and proton density (PD) values were simultaneously measured in 17 regions of interest (the cerebellar hemispheric cortex, pons, amygdala, hippocampal head, hippocampal tail, temporal lobe, occipital lobe, frontal lobe, caudate nucleus, lentiform nucleus, dorsal thalamus, centrum semiovale, parietal lobe, precentral gyrus, postcentral gyrus, substantia nigra, and red nucleus). The relationship between the relaxation values and age was investigated. In addition, we analyzed the relationship between brain tissue values and sex. Finally, the participants were divided into two age groups: < 60 years old and ≥ 60 years old. Logistic regression analysis was carried out on the two groups of data. According to the weight of related factors, a brain age prediction model was established and verified.

Results

We obtained the specific reference value range of different brain regions of individuals in different age groups and found that there were differences in relaxation values in brain tissue between different sexes in the same age group. Moreover, the relaxation values of most brain regions in males were slightly higher than those in females. In the study of age and brain relaxation, it was found that brain relaxation values were correlated with age. The T1 values of the centrum semiovale increased with age, the PD values of the centrum semiovale increased with age, while the T2 values of the caudate nucleus and lentiform nucleus decreased with age. Seven brain age prediction models were constructed with high sensitivity and specificity, among which the combined T1, T2 and PD values showed the best prediction efficiency. In the training set, the area under the curve (AUC), specificity and sensitivity were 0.959 [95% confidence interval (CI): 0.945–0.974], 91.51% and 89.36%, respectively. In the test cohort, the above indicators were 0.916 (95% CI: 0.882–0.951), 89.24% and 80.33%, respectively.

Conclusion

Our study provides specific reference ranges of T1, T2, and PD values in different brain regions from healthy adults of different ages. In addition, there are differences in brain relaxation values in some brain regions between different sexes, which help to provide new ideas for brain diseases that differ according to sex. The brain age model based on synthetic MRI is helpful to determine brain age.

Distinct volumetric features of cerebrospinal fluid distribution in idiopathic normal-pressure hydrocephalus and Alzheimer's disease

Objective

The aims of the study were to measure the cerebrospinal fluid (CSF) volumes in the lateral ventricle, high-convexity subarachnoid space, and Sylvian fissure region in patients with idiopathic normal-pressure hydrocephalus (INPH) and Alzheimer’s disease (AD), and to evaluate differences in these volumes between INPH and AD groups and healthy controls.

Methods

Forty-nine INPH patients, 59 AD patients, and 26 healthy controls were imaged with automated three-dimensional volumetric MRI.

Results

INPH patients had larger lateral ventricles and CSF spaces of the Sylvian fissure region and smaller high-convexity subarachnoid spaces than other groups, and AD patients had larger lateral ventricles and CSF spaces of the Sylvian fissure region than the control group. The INPH group showed a negative correlation between lateral ventricle and high-convexity subarachnoid space volumes, while the AD group showed a positive correlation between lateral ventricle volume and volume for CSF spaces of the Sylvian fissure region. The ratio of lateral ventricle to high-convexity subarachnoid space volumes yielded an area under the curve of 0.990, differentiating INPH from AD.

Conclusions

Associations between CSF volumes suggest that there might be different mechanisms between INPH and AD to explain their respective lateral ventricular dilations. The ratio of lateral ventricle to high-convexity subarachnoid space volumes distinguishes INPH from AD with good diagnostic sensitivity and specificity. We propose to refer to this ratio as the VOSS (ventricle over subarachnoid space) index.

Deep learning-based brain age prediction in normal aging and dementia

Brain aging is accompanied by patterns of functional and structural change. Alzheimer's disease (AD), a representative neurodegenerative disease, has been linked to accelerated brain aging. Here, we developed a deep learning-based brain age prediction model using a large collection of fluorodeoxyglucose positron emission tomography and structural magnetic resonance imaging and tested how the brain age gap relates to degenerative syndromes including mild cognitive impairment, AD, frontotemporal dementia and Lewy body dementia. Occlusion analysis, performed to facilitate the interpretation of the model, revealed that the model learns an age- and modality-specific pattern of brain aging. The elevated brain age gap was highly correlated with cognitive impairment and the AD biomarker. The higher gap also showed a longitudinal predictive nature across clinical categories, including cognitively unimpaired individuals who converted to a clinical stage. However, regions generating brain age gaps were different for each diagnostic group of which the AD continuum showed similar patterns to normal aging.

The capability of detecting small vessels beyond the conventional MRI sensitivity using iron-based contrast agent enhanced susceptibility weighted imaging

Imaging brain microvasculature is important in cerebrovascular diseases. However, there is still a lack of non-invasive, non-radiation, and whole-body imaging techniques to investigate them. The aim of this study is to develop an ultra-small superparamagnetic iron oxide (USPIO) enhanced susceptibility weighted imaging (SWI) method for imaging micro-vasculature in both animal (~10 μm in rat) and human brain. We hypothesized that the USPIO-SWI technique could improve the detection sensitivity of the diameter of small subpixel vessels 10-fold compared with conventional MRI methods. Computer simulations were first performed with a double-cylinder digital model to investigate the theoretical basis for this hypothesis. The theoretical results were verified using in vitro phantom studies and in vivo rat MRI studies (n = 6) with corresponding ex vivo histological examinations. Additionally, in vivo human studies (n = 3) were carried out to demonstrate the translational power of the USPIO-SWI method. By directly comparing the small vessel diameters of an in vivo rat using USPIO-SWI with the small vessel diameters of the corresponding histological slide using laser scanning confocal microscopy, 13.3-fold and 19.9-fold increases in SWI apparent diameter were obtained with 5.6 mg Fe/kg and 16.8 mg Fe/kg ferumoxytol, respectively. The USPIO-SWI method exhibited its excellent ability to detect small vessels down to about 10 μm diameter in rat brain. The in vivo human study unveiled hidden arterioles and venules and demonstrated its potential in clinical practice. Theoretical modeling simulations and in vitro phantom studies also confirmed a more than 10-fold increase in the USPIO-SWI apparent diameter compared with the actual small vessel diameter size. It is feasible to use SWI blooming effects induced by USPIO to detect small vessels (down to 10 μm in diameter for rat brain), well beyond the spatial resolution limit of conventional MRI methods. The USPIO-SWI method demonstrates higher potential in cerebrovascular disease investigations.

Quantitative MRI of Perivascular Spaces at 3T for Early Diagnosis of Mild Cognitive Impairment

BACKGROUND AND PURPOSE

The limitations inherent in the current methods of diagnosing mild cognitive impairment have constrained the use of early therapeutic interventions to delay the progression of mild cognitive impairment to dementia. This study evaluated whether quantifying enlarged perivascular spaces observed on MR imaging can help differentiate those with mild cognitive impairment from cognitively healthy controls and, thus, have an application in the diagnosis of mild cognitive impairment.

MATERIALS AND METHODS

We automated the identification of enlarged perivascular spaces in brain MR Images using a custom quantitative program designed with Matlab. We then quantified the densities of enlarged perivascular spaces for patients with mild cognitive impairment (n = 14) and age-matched cognitively healthy controls (n = 15) and compared them to determine whether the density of enlarged perivascular spaces can serve as an imaging surrogate for mild cognitive impairment diagnosis.

RESULTS

Quantified as a percentage of volume fraction (v/v%), densities of enlarged perivascular spaces were calculated to be 2.82 ± 0.40 v/v% for controls and 4.17 ± 0.57 v/v% for the mild cognitive impairment group in the subcortical brain (P < .001), and 2.74 ± 0.57 v/v% for the controls and 3.90 ± 0.62 v/v% for the mild cognitive impairment cohort in the basal ganglia (P < .001). Maximum intensity projections exhibited a visually conspicuous difference in the distributions of enlarged perivascular spaces for a patient with mild cognitive impairment and a control patient. By means of receiver operating characteristic curve analysis, we determined the sensitivity and specificity of using enlarged perivascular spaces as a differentiating biomarker between mild cognitive impairment and controls to be 92.86% and 93.33%, respectively.

CONCLUSIONS

The density of enlarged perivascular spaces was found to be significantly higher in those with mild cognitive impairment compared with age-matched healthy control subjects. The density of enlarged perivascular spaces, therefore, may be a useful imaging biomarker for the diagnosis of mild cognitive impairment.

Infliximab administration reduces neuronal apoptosis on the optic pathways in a rabbit hydrocephalus model: a preliminary report

OBJECT

This study was designed to explore the effects of infliximab on the optic pathway in kaolin induced hydrocephalus rabbit model.

METHODS

After injection of kaolin to the cisterna magna of 12 New Zealand rabbits for induction of hydrocephalus, animals were divided into 2 groups and received either infliximab or normal saline. The intracranial pressure measurement was performed 2 times; firstly, before kaolin injection and secondly, before decapitation to ensure that the rabbits had hydrocephalus. After 2 weeks, animals were decapitated.

RESULTS

Apoptotic cells in the lateral geniculate body, optic radiation, and optic disc were counted with TUNEL method. Apoptotic cell counts of the lateral geniculate body and the optic radiation were showed statistically significant difference between the infliximab group and the control group.

CONCLUSIONS

This study suggests that infliximab may have a neuroprotective effect through its anti-apoptotic property on hydrocephalus induced optic pathways injury.

Whole-brain atrophy in multiple sclerosis measured by two segmentation processes from various MRI sequences

Recent MRI and pathologic studies have drawn attention to the destructive nature of the multiple sclerosis (MS) disease process, including the early occurrence of axonal and neuronal loss, leading to macroscopic brain and spinal cord atrophy. Measurement of brain atrophy from MRI has emerged as a potential outcome measure and marker of disease severity in MS and neurodegenerative diseases such as Alzheimer's. However, the optimal method for quantifying atrophy has not been established, including the choice of pulse sequence and segmentation algorithm employed. Using two different MRI scanners to ensure generalizability of results, we compared the reproducibility of four pulse sequences and two analysis methods (fully automated [FA] and semi-automated [SA]) when obtaining brain parenchymal fraction (BPF), a normalized measure of whole-brain atrophy, in patients with MS (n=13) and normal controls (n=2). In order to ensure the validity of our fully automated analysis technique, we also used it to evaluate the atrophy rate over nine months in 57 MS patients from the placebo arm of a clinical trial. All pulse sequences were capable of yielding reproducibility of around 1% coefficient of variation (CoV) or better. The best reproducibility was obtained using 2D multi-slice sequences (conventional spin echo [SE] and fluid-attenuated inversion recovery [FLAIR]), with fully automated analysis. Fully automated analysis of the longitudinal data (conventional spin echo) showed an atrophy rate of -0.5% change in BPF per year, in line with previous findings from a similar cohort of patients. In conclusion, BPF measurement is affected by both pulse sequence and segmentation method. Automated measurement has high reproducibility especially when 2D sequences are used. Semi-automated measurement may have increased accuracy, but with a decreased efficiency and reliability.

Normal pressure hydrocephalus triggers intrathecal production of TNF-alpha

Normal pressure hydrocephalus (NPH) is associated with periventricular white matter lesions and demyelination. The aim of the present study was to examine the cerebrospinal fluid (CSF) levels of tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine mediating myelin damage, in patients with NPH. TNF-alpha levels were analyzed by ELISA and measured before and after shunt operation in 35 patients with NPH. The levels of this cytokine were related to the symptomatology and to magnetic resonance imaging (MRI) verified white matter lesions. They were also related to intrathecal levels of sulfatide, a marker for white matter degradation and to levels of neurofilament, a marker for neuronal degeneration. The preoperative levels of TNF-alpha were increased in the CSF of NPH patients compared to controls, and correlated to the levels of sulfatide. The intrathecal TNF-alpha levels were higher in NPH patients with impairment of wakefulness than in those without this symptom. The preoperative TNF-alpha levels were significantly correlated to the improvement of psychometrical test scores, and of wakefulness and to the overall improvement of the patients following shunt operation. Importantly, shunt operation led to complete disappearance of intrathecal TNF-alpha. We conclude that NPH is correlated with intrathecal TNF-alpha production being reversed following shunt operation in parallel with the clinical improvement. The positive correlation between preoperative TNF-alpha and sulfatide levels in the CSF suggest that intrathecal TNF-alpha may contribute to the damage of the white matter known to occur in patients with NPH.

MR signal intensity of gray matter/white matter contrast and intracranial fat: effects of age and sex

Signal intensity (SI) values of gray- and white-matter brain regions of interest (ROIs) were obtained from T(2)- and proton density-weighted magnetic resonance (MR) images of 58 normal subjects aged 22-82 years (31 females, 52.3+/-18.8 years; 27 males, 54.1+/-18.1 years). Sampled ROIs included the caudate, putamen, thalamus, orbitofrontal gyrus, gyrus rectus, uncus, frontal white matter, anterior and posterior corpus callosum, cranial-cervical junction fat, and retroorbital fat. Effects of age and sex on SI were examined using repeated-measures analysis of covariance. For both T(2)- and proton density-weighted acquisitions, a significant inverse relationship between age and SI was observed for the ratio of all summed gray-matter ROIs divided by summed white-matter ROIs. This relationship was additionally observed for ratios of both subcortical gray/white matter and cortical gray/white matter. Females compared with males had significantly lower cortical gray/white matter ratios on T(2)-weighted scans. Differences in SI were observed between cranial-cervical junction fat and retroorbital fat on both acquisitions, with females showing significantly higher values for cranial-cervical junction fat and males showing higher values for retroorbital fat. Implications for brain morphometry, the use of fat as a reference standard, and other issues in neuroimaging are discussed.

Dementing disorders: volumetric measurement of cerebrospinal fluid to distinguish normal from pathologic findings -- feasibility study

The authors describe a magnetic resonance (MR) imaging technique to quantify the severity and distribution of cerebral atrophy by using automated volumetric analysis of the distribution of cerebrospinal fluid. The MR imaging technique demonstrated high diagnostic sensitivity and specificity in a group of healthy subjects and patients with dementing diseases. The authors conclude that this approach provides valuable clinical information that is complementary to information acquired with standard diagnostic practices.

Movement disorders and normal aging

As the population continues to age, it has become increasingly important for clinicians to recognize the clinical characteristics of normal aging. Impaired mobility is one of the most frequent effects of normal aging, and this necessitates a specific understanding of the effects of normal aging on the motor system. This article reviews the physiological basis and clinical manifestations of normal aging as related to movement disorders. The impact of normal aging on major hypokinetic and hyperkinetic movement disorders is also discussed.

Other Parkinson syndromes

The etiology of parkinsonism is varied. Symptomatic parkinsonism is seen in the setting of genetic disorders, infectious processes, structural lesions, and as a result of concomitant medications. A thorough history and good examination will differentiate PD from the diverse group of conditions that can mimic it.

CSF sulfatide distinguishes between normal pressure hydrocephalus and subcortical arteriosclerotic encephalopathy

OBJECTIVES

To examine the CSF concentrations of molecules reflecting demyelination, neuronal and axonal degeneration, gliosis, monoaminergic neuronal function, and aminergic and peptidergic neurotransmission in a large series of patients with normal pressure hydrocephalus (NPH) or subcortical arteriosclerotic encephalopathy (SAE), to elucidate pathogenic, diagnostic, and prognostic features.

METHODS

CSF concentrations of glycosphingolipid (sulfatide), proteins (neurofilament triplet protein (NFL), glial fibrillary acidic protein (GFAP)), neuropeptides (vasoactive intestinal peptide (VIP), 4-aminobutyric acid (GABA)), and monoamines (homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA), 4-hydroxy-3-methoxyphenylglycol (HMPG)) were analysed in 43 patients with NPH and 19 patients with SAE. The diagnoses of NPH and SAE were based on strict criteria and patients with NPH were subsequently operated on. Twelve clinical variables, psychometric tests measuring perceptual speed, accuracy, learning, and memory and a psychiatric evaluation were performed in all patients and before and after a shunt operation in patients with NPH.

RESULTS

The CSF sulfatide concentration was markedly increased in patients with SAE (mean 766, range 300-3800 nmol/l) compared with patients with NPH (mean 206, range 50-400 nmol/l) (p<0.001). 5-HIAA, GABA, and VIP in CSF were higher in patients with SAE than in patients with NPH. The patients with NPH with cerebrovascular aetiology had higher sulfatide concentrations and a poorer outcome after shunt surgery than patients with NPH with other aetiologies.

CONCLUSIONS

The pathogenesis of the white matter changes in NPH and SAE is different and ischaemic white matter changes can be a part of the NPH state. The markedly increased CSF sulfatide concentrations in patients with SAE indicate ongoing demyelination as an important pathophysiological feature of SAE. The CSF sulfatide concentration distinguished between patients with SAE and those with NPH with a sensitivity of 74% and a specificity of 94%, making it an important diagnostic marker.

MRI temporal lobe volume measures and neuropsychologic function in Alzheimer's disease

The authors performed quantitation of the temporal lobes using magnetic resonance imaging in 20 patients with mild-to-moderate Alzheimer's disease, 20 age-matched aged control subjects, and 26 healthy young volunteers. Compared to young subjects, aged controls showed volume reductions in amygdala (17%, p = 0.02), hippocampus (15%, p = 0.0001) and temporal lobe (22%, p = 0.0001). Compared to aged controls, Alzheimer's subjects showed further volume reductions in amygdala (33%, p = 0.0001) and hippocampus (20%, p = 0.006) but not temporal lobe (7%, p = 0.15). In Alzheimer's subjects, left temporal lobe volume correlated strongly with the Mini Mental State (MMSE) score (adjusted r2 = 0.46, p = 0.0006) whereas right amygdala volume correlated inversely with the noncognitive ADAS score (adjusted r2 = 0.46, p = 0.0006). The authors conclude that significant volume changes occur in the temporal lobe in aging and in Alzheimer's disease, with the greatest percentage reductions in the amygdala in Alzheimer's disease. Temporal neocortical atrophy and temporal limbic atrophy might be associated with different patterns of performance and behavior in Alzheimer's patients.

Magnetic resonance imaging of anatomic and vascular characteristics in a canine model of human aging

Dogs exhibit both neuroanatomical and cognitive changes as a function of age that parallel those seen in aging humans. This study describes in vivo changes in neuroanatomical and cerebrovascular characteristics of the canine brain as a function of age in a group of dogs ranging from 4 to 15 years old. Dynamic contrast-enhanced magnetic resonance imaging (MRI) was used to measure the kinetics of contrast agents in the brain. Measures of vascular volume and blood-brain barrier (BBB) permeability were derived from a pharmacokinetic analysis. Cortical atrophy and ventricular enlargement were characteristic features of the aged canine brain. Vascular volume did not vary as a function of age and BBB permeability exhibited a nonsignificant increasing trend with age. However, BBB dysfunction was detected in one middle-aged dog that in addition to having unusually large ventricles, demonstrated an early onset of diffuse senile plaques at postmortem. These findings indicate that BBB dysfunction detected by magnetic resonance imaging may be useful for predicting and potentially diagnosing early pathological conditions.

Flow void of cerebrospinal fluid in idiopathic normal pressure hydrocephalus of the elderly: can it predict outcome after shunting?

OBJECTIVE

We investigate the predictive value of cerebrospinal fluid (CSF) flow void on outcome after shunting in a prospective series of patients with idiopathic normal pressure hydrocephalus (NPH).

METHODS

The degree and extension of CSF flow void were examined on T2-weighted magnetic resonance imaging scans of 37 elderly patients with idiopathic NPH who underwent subsequent shunting. The degree of flow void was assessed in comparison with the signal of large cerebral arteries. The extension was evaluated via the calculation of sum scores for the occurrence of flow void in different locations of the ventricular system. Those parameters were not considered in the decision to perform shunting. CSF flow void in the aqueduct and the adjacent third and fourth ventricles of the 37 patients with idiopathic NPH was compared with that of 37 age-matched control patients. CSF flow void scores in patients with idiopathic NPH were investigated for correlations between postoperative outcome scores and ventricular width indices.

RESULTS

No difference was found between the occurrence of aqueductal CSF flow void in patients with idiopathic NPH and the control group. A significant difference, however, was noted for the extension of the CSF flow void, which was greater in the NPH group. Postoperative improvement was found in 33 of 37 patients with idiopathic NPH at a mean follow-up of 15.6 months. Only small, statistically not significant correlations were found between CSF flow void and postoperative outcome. Flow void sum scores, however, correlated significantly with ventricular width indices.

CONCLUSION

The degree and extension of CSF flow void on T2-weighted magnetic resonance imaging scans have little predictive value for outcome after shunting in patients with idiopathic NPH. The greater extension of the CSF flow void in patients with NPH is most likely related to increased ventricular width. It is not useful to consider CSF flow void findings on conventional magnetic resonance imaging scans in making the decision to offer shunting in patients with idiopathic NPH.

Magnetic resonance imaging of Alzheimer's disease

1. Although dementia is caused by a heterogeneous group of diseases and pathologic states, Alzheimer's disease is the largest cause, estimated to account for 50 to 75% of all dementias. 2. Unfortunately, confirmation of Alzheimer's disease (AD) requires postmortem histologic confirmation; clinical diagnosis prior to death remains one of exclusion. 3. A large number of structural and volumetric MRI studies have noted anatomic and structural changes accompanying AD, including variable degrees of general cortical atrophy. 4. A classic feature reported by many MRI studies is hippocampal and temporal lobe atrophy. 5. White matter hyperintensities on MRI are common, especially in late onset AD although their significance is still controversial. 6. This article reviews the contribution of magnetic resonance to imaging the neuropathologic changes of AD, discussing both advantages and limitations, and summarizing the major findings.

Quantitative computed tomography and magnetic resonance imaging in aging and Alzheimer's disease. A review

In recent aging research, quantitative techniques have been used to overcome limitations of qualitative interpretation of magnetic resonance and computed tomographic imaging. The purpose of this review is to summarize imaging results emphasizing quantitative studies using these two modalities in human aging. Magnetic resonance spectroscopy is viewed as an extension of imaging, and results of in vivo spectroscopic studies are included. Because Alzheimer's disease (AD) is closely related to aging, a discussion of quantitative imaging techniques that may distinguish normal elderly from patients with AD is included.

An Italian kindred with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Vascular dementia is usually sporadic and associated with definite risk factors. Several cases also occur in a familial fashion, and may affect middle-aged or even younger subjects. Recently, an autosomal dominant inheritance was demonstrated in two unrelated French families, the members of which were affected by stroke-like episodes culminating in progressive dementia. Genetic linkage analysis assigned the disease locus to chromosome 19q12. We report an additional kindred of Italian origin in which at least 16 subjects presented leukoencephalopathic alterations. Recurrent strokes, psychiatric disturbances, dementia, and in 2 members, tetraplegia and pseudobulbar palsy were the hallmarks of this syndrome. Notably, 5 asymptomatic individuals had neuroradiological signs of leukoencephalopathy. Pathological examination of 1 subject revealed a widespread vasculopathy of the perforating arterioles, characterized by deposition of eosinophilic-congophilic material that did not immunostain with antibodies against prion protein, beta-amyloid, cystatin C, transthyretin, or heat-shock protein 70 and was similar to that described in the French families. Based on the maximum lod score, the most likely location for the disease locus was also mapped to chromosome 19q12, and found to coincide with the CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) locus. The present results confirm the existence of a nosologically distinct, autosomal dominant cerebrovascular disease, presenting with recurrent subcortical ischemic strokes independent of vascular risk factors.