Neuroanatomy of the Functional Aging Brain
José León-Carrión, Margaret J. Giannini in Behavioral Neurology in the Elderly, 2001
In the transmission of information within the brain and between the central nervous system (CNS) and the periphery, myelin plays an important role related to velocity and reliability. Normally, when a demyelinating disease appears, neurobehavioral and cognitive deficits can be observed. Normal cognitive development requires normal myelination of the pathways of the CNS. One of the most frequent and easily observed abnormalities in MRI images is the well-known white matter hyperintensities (WMH) or leukoaraiosis (see Figure 4.1). A study by Salonen et al.6 found that signal intensity of the white matter increased concomitantly with widening of the cerebrospinal fluid spaces while basal ganglia remained stable. High-signal foci in white matter increased in number and size after the age of 50, and the periventricular high-signal foci were constant after the age of 65. They suggest that their visual impression of a decrease in signal intensity of the central gray matter with age seems to be mistaken. Pathological processes should be suspected if periventricular foci are found in middle-aged or young subjects.
Neuroanatomy: Age-related changes
Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor in Essentials of Geriatric Neuroanesthesia, 2019
White matter loss starts at a later stage in the aging brain but is more rapid than gray matter loss, and ultimately exceeds it (16). Myelin breakdown is an aspect of healthy aging, and this breakdown contributes to the loss of white matter volume in the elderly. White matter changes play a causal role in cognitive performance in aging, including mental speed, episodic memory function, executive and flexible cognition, and nonverbal problem solving. Thirty percent of subjects older than 60 years of age demonstrate white matter hyperintensities in the periventricular and subcortical regions on MR studies, and these lesions tend to increase with age (17). These white matter lesions, or leukoaraiosis, occur as a result of atrophic perivascular demyelination secondary to vascular insufficiency in the aged. The presence of white matter hyperintensities has been correlated with signs of cognitive decline (18,19). It has also been shown in recent studies to be a predictor of stroke (20). The identifiable risk factors for these lesions include diabetes, hypertension, decreased respiratory function, high cholesterol, and female gender (21).
The Neuropathology of Alzheimer’s Disease
Zaven S. Khachaturian, Teresa S. Radebaugh in Alzheimer’s Disease, 2019
Leukoaraiosis is a term used to describe the diffuse periventricular white matter alterations found on computerized tomography scan and magnetic resonance imaging in patients with AD and in intellectually normal elderly individuals. It has been suggested that these changes are ischemic in nature, resulting from hypoperfusion in the distal zone of penetrating blood vessels. Microscopically these zones show pallor, mild myelin loss, gliosis, ependymal breakdown, and hyalinization, fibrosis, and luminal narrowing of arterioles. The importance of these lesions in cognitive function is not known, especially in regard to vascular dementia, AD, and mixed forms of dementia.
Magnetic resonance imaging changes in Asian people living with HIV
Published in Infectious Diseases, 2021
Yusuke Yoshino, Ichiro Koga, Takatoshi Kitazawa, Hiroshi Oba, Shigeru Furui, Hiroshi Matsuda, Yasuo Ota
Imaging assessments of the elderly often reveals leukoaraiosis, which have been previously considered a benign accompaniment of aging. Leukoaraiosis is a radiological term used to describe WMHs observed as bright white appearances on T2 MRI scans. However, recent studies have reported a strong correlation of leukoaraiosis with ischaemic stroke, unfavourable course of acute ischaemic stroke, worse long-term outcomes, and cognitive disturbances [20]. Currently, leukoaraiosis is considered a cerebral small vessel disease. We found a significantly higher prevalence of leukoaraiosis in the PLWH than in the controls at younger ages. Watson et al. reported that PLWH aged > 60 years had a significantly higher WMH burden [10]. Another recent study reported that middle-aged (aged ≤ 45 years) male PLWH had a higher WMH burden, which was correlated with cognitive deficits, cardiovascular risk factors, and duration of suppressed CD4-positive T-lymphocyte counts [9]. This indicates that leukoaraiosis could be more prevalent in PLWH of all age groups than in HIV-negative individuals. Moreover, the early emergence of WMH could result in the occurrence of HAND, and WMHs could be a predictive marker of HAND. However, we did not observe a significant correlation of leukoaraiosis with the two neurocognitive scales used in this study. There is a need for long-term prospective observational studies to further assess these hypotheses.
Cotard's Syndrome Triggered by Fear in a Patient with Intellectual Disability: Causal or Casual Link?
Published in Issues in Mental Health Nursing, 2018
Fabrizio Sottile, Rosaria De Luca, Lilla Bonanno, Giuseppina Finzi, Carmela Casella, Rocco Salvatore Calabrò
A 46-year-old man came to our observation because his sister found him in a confusional state. The patient was affected by an idiopathic moderate mental retardation; he was mostly independent in performing the basic daily life activities, but lived with his sister. He attended a mental health outpatient clinic, and had a quite normal social life. About 2 months before his admission, the patient witnessed a theft attempt that caused an abnormal “state of fear.” Indeed, after about 2 weeks from the event, he started refusing food as he considered himself dead. His illness further progressed in a month and he developed muteness, total refusal to eat, and fecal and urinary incontinence. Subsequently, the patient was hospitalized in our Neurology Unit. At admission, general conditions showed a general state of malnutrition (hematochemical tests showed hemoglobin of 11 g/dL and hypoalbuminemia). At neurological examination, the patient had sad affect, mutism, rigidity in all the four limbs, and negativism; disperception was also evidenced. Magnetic resonance imaging examination revealed a mild to moderate leukoaraiosis. When general clinical conditions improved, the patient underwent a specific neuropsychological assessment. In particular, at the Wechsler Adult Intelligence Scale (WAIS), evaluating the intelligence quotient (IQ), he reported a score of 55; at the post-traumatic stress disorder (PTSD) his total score was 18 (indicating the absence of such disorder), whereas the Visual-Analogue Test for Anosognosia (VATam) score was 31 (demonstrating the presence of severe anosognosia).
Prevalence and Nature of Structural Brain Abnormalities in Batterers: A Magnetic Resonance Imaging Study
Published in International Journal of Forensic Mental Health, 2019
Natalia Bueso-Izquierdo, Juan Verdejo-Román, José Pablo Martínez-Barbero, Miguel Ángel Pérez-Rosillo, Miguel Pérez-García, Natalia Hidalgo-Ruzzante, Stephen D. Hart
White matter lesions consistent with leukoaraiosis were observed in 8 participants: 6 batterers and 2 other offenders. White matter punctuate lesions are a common finding in neuroimaging studies, and they are commonly cataloged as “nonspecific” in radiology reports. In young patients, the most important task for the radiologist is to rule out multiple sclerosis as the underlying cause; as noted previously, MAGNIMS criteria were used to rule out multiple sclerosis in our subjects. White matter punctuate lesions may be also related to normal ageing, cardiovascular risk factors, or migraine (Osborn, Alder, & Mitchell, 1991). We categorized white matter lesions were according to ARWMC classification, which is based on number and location of lesions, cognitive decline, and cardiovascular risk factors. In 10 of the 11 cases, participants had very few and isolated lesions, consistent with Grade 1 of the ARWMC classification. Grade 1 may be a normal finding in healthy people; it is usually subclinical and does not need to be included in radiology reports.
Related Knowledge Centers
- White Matter
- Lateral Ventricles
- Magnetic Resonance Imaging
- Hyperintensity
- CT Scan
- Radiodensity
- Hypertension
- Diabetes
- Hyperhomocysteinemia
- Binswanger'S Disease