A functional neuroimaging study of appetite loss in Alzheimer's disease.

BACKGROUND: Alzheimer's Disease (AD) is frequently associated with changes in appetite. This study investigated the relationship between regional cerebral perfusion and appetite loss in AD. METHODS: 64 patients with possible or probable AD were characterized as being with (n=22) or without (n=44) appetite loss based on the Neuropsychiatric Inventory (NPI) Appetite subscale. 99mTc-ECD SPECT scans were coregistered to a standardized template in Talairach space generating mean ratios of uptake referenced to the cerebellum. Regions of interest (ROIs) included anterior cingulate cortex (ACC), middle mesial temporal cortex (MTC-m), inferior mesial temporal cortex (MTC-i), insula (INS), orbitofrontal cortex (OFC) and thalamus-hypothalamus (THAL). RESULTS: Backward stepwise logistic regression analysis of these ROIs showed hypoperfusion in the L-ACC (p=0.015) and L-OFC (p=0.015), relative sparing of perfusion in the R-ACC (p=0.010), R-OFC (p=0.010) and L-MTC-m (p=0.006), and greater anxiety (p=0.005) independently predicted loss of appetite (chi(2)=22.24, p=0.001, Nagelkerke R(2)=0.41). CONCLUSIONS: Hypoperfusion in the left anterior cingulate and left orbitofrontal cortices, and relative sparing of perfusion in the right anterior cingulate, right orbitofrontal and left middle mesial temporal cortices emerged as predictors of appetite loss in this sample of patients. These findings are consistent with impairments in the extrinsic motivational pathways of eating and impaired reward value of food as components of appetite loss in AD.

A SPECT study of apathy in Alzheimer's disease.

BACKGROUND/AIMS: To assess the association between regional cerebral blood flow (rCBF) and apathy in Alzheimer's Disease (AD). METHODS: SPECT and MRI scans were obtained from 51 nondepressed outpatients meeting criteria for probable AD (age 77.6 +/- 6.6 years; MMSE 22.3 +/- 5.1; 23 apathetic, 28 nonapathetic) and 23 healthy elderly (75.6 +/- 3.8 years) controls. The following regions of interest (ROIs) were compared between apathetic and nonapathetic AD patients and then referenced against aged controls: anterior cingulate, orbitofrontal cortex, middle medial temporal cortex, hippocampus, medial superior temporal cortex, thalamus/hypothalamus and pons. RESULTS: Apathetic and nonapathetic patients had significant differences in rCBF. Relative to nonapathetic AD patients, apathetic AD patients had lower perfusion in 2 ROIs (right orbitofrontal cortex and left anterior cingulate) and higher perfusion in 5 ROIs (right and left hippocampi, left medial superior temporal gyrus, and right and left middle medial temporal cortex). Comparison of rCBF in these 7 ROIs to healthy elderly controls confirmed hypoperfusion in the left anterior cingulate and right orbitofrontal cortex and suggested a relative sparing of perfusion among apathetic AD patients in the remaining 5 ROIs. CONCLUSIONS: In this group of nondepressed patients with AD, apathetic subjects displayed significant perfusion differences compared to nonapathetic subjects.

A metabolic imaging severity rating scale for the assessment of cognitive impairment.

PURPOSE: This study was designed to validate a simple scoring system for evaluating fluorodeoxyglucose (FDG) positron emission tomographic (PET) scans that can be used routinely in patients undergoing the clinical assessment of cognitive impairment. METHODS: The FDG-PET scans of 106 patients with cognitive impairment (65 with Alzheimer disease, 16 with frontal lobe dementia, and 25 atypical cases) were acquired using the PENN-PET scanner 40 minutes after the intravenous administration of 8 mCi FDG. Metabolic activity in various anatomic structures of the brain was scored using the following qualitative scale: 4 = normal; 3 = mildly decreased; 2 = moderately decreased; 1 = severely decreased; and 0 = no activity. Regions of interest were also placed over these regions to obtain a quantitative value. Two distinct scores were obtained. Values for visual and sensorimotor cortices, thalami, basal ganglia, and cerebellum comprised score I. Score II consisted of the values for the frontal, temporal, and parietal cortices. The qualitative metabolic imaging severity rating scale (MISRS) was compared with a quantitative MISRS (obtained from the region-of-interest analysis of the same structures). The MISRS was then compared with the results from the Mini-Mental Status Examination (MMSE) and the Dementia Severity Rating Score (DSRS). RESULTS: In all patients, the qualitative MISRS scores correlated significantly with the quantitative MISRS (r = 0.73, P < 0.0001). In all patients with cognitive impairment, the qualitative and quantitative MISRS scores correlated significantly with the DSRS and the MMSE (P < 0.001). In patients with Alzheimer disease, the qualitative and quantitative MISRS significantly correlated with the DSRS and MMSE. CONCLUSION: A simple and practical rating scale can be used to assess the severity of cognitive impairment in patients with different types of dementing illnesses.

Células ganglionares en transplante cardíaco consideraciones generales / Ganglion cells in cardiac transplantation: generals considerations

A la fecha no hay estudios que relacionen las células ganglionares y la reinervación en los trasnplantes cardíacos. En base a un hallazgo fortuito en autopsia hicimos un análisis teórico en torno a este tópico, utilizando los experimentos que sobre este aspecto han hecho diferentes autores en corazones humanos 1,8,11,19,20,22,25,28, y los experimentos utilizando modelos biológicos en peces 9,10,23,32 que reproducen las condiciones que se generan post transplante cardíaco en los humanos. En el humano se han descrito aislados casos de reinervación funcional post transplante de corazón 19. ¿Será que en estos pacientes se dío el microambiente necesario para que se diera este proceso, aunado a la posible génesis de sustancias regeneradoras de tejido nervioso? Sugerimos la posibilidad (de utilizar sustancias que favorezcan la neuritogénesis y el neurotrofismo (Factor de crecimiento Neural 14,15,18 y/o Transglutaminasa 24 favoreciendo por ende el funcionamiento cardíaco

Rines valcardi, una prueba para la neuropatía autonómica en diabéticos: una revisión / A review of the rines valcardi test by the diabetic autonomic neurophaty

La prueba Rines Valcardi se revisa en este artículo. El estímulo Valsalva se debería eliminar. Sería útil un análisis estadístico de sensibilidad y especificidad con cada uno de los estímulos que componen la prueba. La prueba es útil para pacientes que son llevados a anestesia