Downstream effects of polypathology on neurodegeneration of medial temporal lobe subregions.

The medial temporal lobe (MTL) is a nidus for neurodegenerative pathologies and therefore an important region in which to study polypathology. We investigated associations between neurodegenerative pathologies and the thickness of different MTL subregions measured using high-resolution post-mortem MRI. Tau, TAR DNA-binding protein 43 (TDP-43), amyloid-ß and α-synuclein pathology were rated on a scale of 0 (absent)-3 (severe) in the hippocampus and entorhinal cortex (ERC) of 58 individuals with and without neurodegenerative diseases (median age 75.0 years, 60.3% male). Thickness measurements in ERC, Brodmann Area (BA) 35 and 36, parahippocampal cortex, subiculum, cornu ammonis (CA)1 and the stratum radiatum lacunosum moleculare (SRLM) were derived from 0.2 × 0.2 × 0.2 mm3 post-mortem MRI scans of excised MTL specimens from the contralateral hemisphere using a semi-automated approach. Spearman's rank correlations were performed between neurodegenerative pathologies and thickness, correcting for age, sex and hemisphere, including all four proteinopathies in the model. We found significant associations of (1) TDP-43 with thickness in all subregions (r = - 0.27 to r = - 0.46), and (2) tau with BA35 (r = - 0.31) and SRLM thickness (r = - 0.33). In amyloid-ß and TDP-43 negative cases, we found strong significant associations of tau with ERC (r = - 0.40), BA35 (r = - 0.55), subiculum (r = - 0.42) and CA1 thickness (r = - 0.47). This unique dataset shows widespread MTL atrophy in relation to TDP-43 pathology and atrophy in regions affected early in Braak stageing and tau pathology. Moreover, the strong association of tau with thickness in early Braak regions in the absence of amyloid-ß suggests a role of Primary Age-Related Tauopathy in neurodegeneration.

Anatomical segmentation of the human medial prefrontal cortex.

The medial prefrontal areas 32, 24, 14, and 25 (mPFC) form part of the limbic memory system, but little is known about their functional specialization in humans. To add anatomical precision to structural and functional magnetic resonance imaging (MRI) data, we aimed to identify these mPFC subareas in histological preparations of human brain tissue, determine sulci most consistently related with mPFC areal boundaries, and use these sulci to delineate mPFC areas in MRIs. To achieve this, we obtained three-dimensional MRI data from 11 ex vivo hemispheres and processed them for cyto- and myelo-architectonic analysis. The architectonic boundaries of mPFC areas were identified in histology and cortical surface length and volumes were measured. Unfolded maps of histologically determined boundaries were generated to identify the association of mPFC areal boundaries with sulci across cases. This analysis showed that cingulate and superior rostral were the sulci most consistently related to mPFC areal boundaries. Based on presence/absence and anastomosis between such sulci, 6 sulci patterns in the 11 hemispheres were found. A further analysis of 102 hemispheres of in vivo MRI scans (N = 51 males, mean ± SD 24.1 ± 3.1 years of age) showed similar sulci patterns, which allowed us to delineate the mFPC areas in them. The volumes of mPFC areas across histological, ex vivo and in vivo MRI delineations were comparable and probabilistic maps generated from the MRIs of the102 hemispheres. Probabilistic maps of mPFC areas were registered to MNI space and are available for regional analysis of functional magnetic resonance imaging data.

Anatomical pathways for auditory memory II: information from rostral superior temporal gyrus to dorsolateral temporal pole and medial temporal cortex.

Auditory recognition memory in non-human primates differs from recognition memory in other sensory systems. Monkeys learn the rule for visual and tactile delayed matching-to-sample within a few sessions, and then show one-trial recognition memory lasting 10-20 min. In contrast, monkeys require hundreds of sessions to master the rule for auditory recognition, and then show retention lasting no longer than 30-40 s. Moreover, unlike the severe effects of rhinal lesions on visual memory, such lesions have no effect on the monkeys' auditory memory performance. The anatomical pathways for auditory memory may differ from those in vision. Long-term visual recognition memory requires anatomical connections from the visual association area TE with areas 35 and 36 of the perirhinal cortex (PRC). We examined whether there is a similar anatomical route for auditory processing, or that poor auditory recognition memory may reflect the lack of such a pathway. Our hypothesis is that an auditory pathway for recognition memory originates in the higher order processing areas of the rostral superior temporal gyrus (rSTG), and then connects via the dorsolateral temporal pole to access the rhinal cortex of the medial temporal lobe. To test this, we placed retrograde (3% FB and 2% DY) and anterograde (10% BDA 10,000 mW) tracer injections in rSTG and the dorsolateral area 38 DL of the temporal pole. Results showed that area 38DL receives dense projections from auditory association areas Ts1, TAa, TPO of the rSTG, from the rostral parabelt and, to a lesser extent, from areas Ts2-3 and PGa. In turn, area 38DL projects densely to area 35 of PRC, entorhinal cortex (EC), and to areas TH/TF of the posterior parahippocampal cortex. Significantly, this projection avoids most of area 36r/c of PRC. This anatomical arrangement may contribute to our understanding of the poor auditory memory of rhesus monkeys.

Síndrome de aorta media / Mid-aortic syndrome: case studies from a paediatric nephrology department

Introducción: El síndrome de aorta media (SAM) (o su término anglosajón, mid aortic syndrome) describe el estrechamiento segmentario de la aorta abdominal y ramas que de ella derivan. Un alto porcentaje involucrará a las arterias renales, siendo la hipertensión arterial (HTA) la manifestación clínica cardinal. Objetivo: Revisión de los casos diagnosticados de SAM del Servicio de Nefrología Pediátrica del Hospital Vall d’Hebron. Materiales y métodos: Estudio retrospectivo de 5 pacientes entre 8 días y 12 años. Se analiza debut, exploraciones diagnósticas, actitud terapéutica y evolución. Resultados: La hipertensión fue el motivo de estudio común. En 2 de los 5 casos se asoció a insuficiencia renal. El diagnóstico definitivo se alcanzo por arteriografía y angio-RM, observándose en todos los casos afectación de las arterias renales (en 3 casos unilateral). El tratamiento fue conservador en 3 casos, 1 caso requirió tratamiento quirúrgico y otro fallece a los 7 meses. Conclusiones: El SAM, aunque poco frecuente, constituye una causa importante de HTA en la infancia. La técnica diagnóstica de elección es la arteriografía. Es importante descartarla posible afectación cerebral ya que condiciona el pronóstico vital. La hipertensión es de difícil manejo médico. Son indicaciones de tratamiento quirúrgico HTA refractaria a tratamiento médico, claudicación intermitente, angina intestinal y compromiso renal por hipoperfusión. De lo contario, se optará siempre por tratamiento médico ya que la lesión es progresiva durante la infancia y tiende a estabilizarse en la pubertad (AU)

Introduction: Mid-aortic syndrome (MAS) describes a narrowing segment of the abdominal aorta and the branches arising from there. This narrowing frequently involves the renal arteries, with the only clinical sign being arterial hypertension. Objective: To review the cases of MAS diagnosed in the Paediatric Nephrology Department of the Vall D’Hebron Hospital (Barcelona). Methods and materials: A retrospective study was conducted on 5 patients aged from 8 days to 12 years old. We analysed the onset, diagnostic examinations, treatment and outcome. Results: Hypertension was the common reason behind the study. In two of the five cases, it was associated with renal failure. The definitive diagnostic was made using angiography and angio-MR, observing, in all the cases, that the renal arteries were affected (in 3 cases unilateral). The treatment was by medication in 3 cases, 1 required surgery and 1 died at 7 months. Conclusions: MAS, although uncommon, is a very important cause of AHT in infancy. Angiography is the only technique to diagnose it. It is important to rule out cerebral involvement, which could lead to a fatal outcome. Hypertension is very difficult to control through medication. Surgery is required only when the hypertension is not controllable through medication, when there is intermittent claudication, intestinal angina, and renal hypoperfusion. Ideally, it is better to opt for medication as treatment, as the narrowing is progressive up to the end of puberty, after which, the narrowing stabilizes (AU)

[Mid-aortic syndrome: case studies from a paediatric nephrology department]. / Síndrome de aorta media.

INTRODUCTION: Mid-aortic syndrome (MAS) describes a narrowing segment of the abdominal aorta and the branches arising from there. This narrowing frequently involves the renal arteries, with the only clinical sign being arterial hypertension. OBJECTIVE: To review the cases of MAS diagnosed in the Paediatric Nephrology Department of the Vall D'Hebron Hospital (Barcelona). METHODS AND MATERIALS: A retrospective study was conducted on 5 patients aged from 8 days to 12 years old. We analysed the onset, diagnostic examinations, treatment and outcome. RESULTS: Hypertension was the common reason behind the study. In two of the five cases, it was associated with renal failure. The definitive diagnostic was made using angiography and angio-MR, observing, in all the cases, that the renal arteries were affected (in 3 cases unilateral). The treatment was by medication in 3 cases, 1 required surgery and 1 died at 7 months. CONCLUSIONS: MAS, although uncommon, is a very important cause of AHT in infancy. Angiography is the only technique to diagnose it. It is important to rule out cerebral involvement, which could lead to a fatal outcome. Hypertension is very difficult to control through medication. Surgery is required only when the hypertension is not controllable through medication, when there is intermittent claudication, intestinal angina, and renal hypoperfusion. Ideally, it is better to opt for medication as treatment, as the narrowing is progressive up to the end of puberty, after which, the narrowing stabilises.