Anosognosia is a common symptom of dementia. The aim of this study was to evaluate the contribution of different regions of the brain to anosognosia in Alzheimer's disease (AD) brains using single photon emission computed tomography (SPECT). Forty-two patients with AD were included in this study. After clinical interviews with the patients and their relatives, the patients were divided into two groups: Anosognosia and No-anosognosia. The patients were studied regarding the severity of dementia. They underwent SPECT with HMPAO and regional cerebral blood flow (rCBF) was measured. Regional CBF significantly differed between Anosognosia and No-anosognosia groups in right prefrontal (P < or = 0.02), right inferior parietal (P < or = 0.00), and right (P < or = 0.01) and left (P < or = 0.01) medial temporal cortex. There was a significant correlation between the severity of dementia and rCBF in medial temporal regions. When comparisons were made between mild and moderate stages separately, the 'right inferior parietal region' was the common region which showed hypoperfusion in both anosognosia subgroups. We conclude that anosognosia may be a reflection of functional impairment in right prefrontal, right frontal and especially right inferior parietal regions in AD.
Alzheimer's disease is a progressive irreversible neurodegenerative disorder, characterized by gradual decline of mental faculties including learning capacity, emotional and behavioral alterations, serious decline of motor skills, and dysfunction of the autonomic nervous system with disruption of circadian rhythms. Among the potential modifiable risk factors diabetes and obesity may play a considerable role in the pathogenetic background of the disease. We describe some of the morphological alterations of the hypothalamic nuclei in early cases of Alzheimer's disease, using silver impregnation techniques and electron microscopy. The morphological and morphometric study revealed substantial decrease of the neuronal population, which was particularly marked in the suprachiasmatic, the supraoptic and the paraventricular nuclei of the hypothalamus. The silver staining demonstrated an obvious shortage of the dendritic arborization of neurons, associated with marked spinal pathology and axonal dystrophy. It must be underlined that Alzheimer's pathology, such as neuritic plaques and neurofibrillary degeneration was minimal in hypothalamus in comparison with other areas of the brain. Mitochondrial alterations and fragmentation of Golgi complex were observed by electron microscopy in a substantial number of neurons and astrocytes in the hypothalamic nuclei. The hypothalamic pathology may be related to instability of autonomic regulation which occurs gradually in Alzheimer's disease.
Extrapyramidal symptoms are observed in frontotemporal dementia (FTD). 123I-FP-CIT (DaT scan) single photon emission computed tomography (SPECT) can detect loss of presynaptic dopamine transporters in the striatum. We aimed to evaluate the dopaminergic status of the striatum in patients with FTD using DaT scan. Seven patients (age range 65–76 years), who fulfilled the Neary criteria and in whom the diagnosis of FTD was confirmed by hexamethylpropyleneamine oxime SPECT, were included in the study. The severity of the extrapyramidal symptoms was evaluated by the motor part of the Unified Parkinson’s Disease Rating Scale (UPDRS). SPECT using 123I-FP-CIT was done. A (region – occipital)/occipital ratio was calculated for the striatum, putamen and caudate nucleus. The results were compared with those of the 7 age-matched normal controls. The uptake of the radiotracer in the right and left striatum was reduced to 62% (p = 0.000) and 68% (p = 0.000), respectively, compared to controls. The motor UPDRS score of the patients with FTD showed a negative correlation to the uptake of the radiotracer. The presynaptic dopamine transporter in FTD is impaired, related to the severity of the extrapyramidal symptoms. Since an effective treatment for FTD is still to be established, there is a need for evaluating the efficacy of dopaminergic drugs.
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