The brainstem has an ectodermal origin and is composed of 4 parts: the diencephalon, mesencephalon, pons, and medulla oblongata. It serves as the connection between the cerebral hemispheres with the ...medulla and the cerebellum and is responsible for basic vital functions, such as breathing, heartbeat blood pressure, control of consciousness, and sleep. The brainstem contains both white and gray matter. The gray matter of the brainstem (neuronal cell bodies) is found in clumps and clusters throughout the brainstem to form the cranial nerve nuclei, the reticular formation, and pontine nuclei. The white matter consists of fiber tracts (axons of neuronal cells) passing down from the cerebral cortex—important for voluntary motor function—and up from peripheral nerves and the spinal cord—where somatosensory pathways travel—to the highest parts of the brain. The internal structure of brainstem, although complex, presents a systematical arrangement and is organized in 3 laminae (tectum, tegmentum, and basis), which extend its entire length. The motor pathway runs down through the basis, which is located at the most anterior part. The cranial nerve nuclei are settled into the middle layer (the tegmentum), just in front of the 4th ventricle and are placed, from medial to lateral, on the basis of their function: somatic motor, visceral motor, visceral sensory, and somatic sensory. All the somatosensory tracts run upward to the thalamus crossing the tegmentum in front of the cranial nerve nuclei. The tectum, formed by the quadrigeminal plate and the medullary velum, contains no cranial nuclei, no tracts and no reticular formation. The knowledge of precise anatomical localization of a lesion affecting the brainstem is crucial in neurological diagnosis and, on this basis, is essential to be familiar with the location of the mayor tracts and nuclei appropriately. Nowadays, current magnetic resonance imaging techniques, although still macroscopic, allow the fine internal structure of the brainstem to be viewed directly and make it possible to locate the main intrinsic structures that justify the symptoms of the patient. In this article we discuss the anatomy of the brainstem and highlight the features and landmarks that are important in interpreting magnetic resonance imaging.
Letter From the Guest Editors Ángeles Fernández-Gil, M; Palacios Bote, Ramón
Seminars in ultrasound, CT, and MRI,
04/2013, Letnik:
34, Številka:
2
Journal Article
Summary
Background
Mutations in the GCK gene lead to different forms of glucokinase (GCK)‐disease, activating mutations cause hyperinsulinaemic hypoglycaemia while inactivating mutations cause ...monogenic diabetes. Hyperinsulinism (HI) is a heterogeneous condition with a significant genetic component. The major causes are channelopathies, the other forms are rare and being caused by mutations in genes such as GCK.
Objective
To describe the clinical and genetic presentation of four families with activating GCK mutations, and to explore the pathogenicity of the novel mutation identified through functional studies.
Results
Four cases of HI with mutations in GCK were identified. These include one novel mutation (p.Trp99Cys). Functional analysis of the purified mutant fusion protein glutathione‐S‐transferase (GST)‐GCK‐p.Trp99Cys demonstrated that p.Trp99Cys is an activating mutation as it induces a higher affinity for glucose and increases the relative activity index more than 11 times. Moreover, the thermal stability of the mutant protein was similar to that of its wild type. All patients were responsive to diazoxide treatment. One of the mutations arose de novo, and two were dominantly inherited, although only one of them from an HI affected parent. The age of presentation in our cases varied widely from the neonatal period to adulthood.
Conclusion
The clinical phenotype of the GCK activating mutation carriers was heterogeneous, the severity of symptoms and age at presentation varied markedly between affected individuals, even within the same family. The novel activating GCK mutation (p.Trp99Cys) has a strong activating effect in vitro although it has been identified in one case of a milder and late‐onset form of HI.
Tuberous sclerosis, also called Bourneville Pringle disease, is a phakomatosis with potential dermal, nerve, kidney and lung damage. It is characterized by the development of benign proliferations in ...many organs, which result in different clinical manifestations. It is associated with the mutation of two genes: TSC1 (hamartin) and TSC2 (tuberin), with the change in the functionality of the complex target of rapamycin (mTOR). MTOR activation signal has been recently described in systemic lupus erythematosus (SLE) and its inhibition could be beneficial in patients with lupus nephritis. We report the case of a patient who began with clinical manifestations of tuberous sclerosis complex (TSC) 30 years after the onset of SLE with severe renal disease (tipe IV nephritis) who improved after treatment with iv pulses of cyclophosphamide. We found only two similar cases in the literature, and hence considered the coexistence of these two entities of great interest.
The term hippocampal sclerosis was originally used to describe a shrunken and hardened hippocampus, which histologically displayed neuronal loss and glial proliferation. These alterations are mainly ...located in the hilus of the dentate gyrus and in the CA1 and CA3 pyramidal cell layers but all hippocampal regions may show neuronal cell loss to varying degrees. A number of morphologic and cytochemical findings are associated with mesial temporal sclerosis, especially within the dentate gyrus. These changes include selective loss of inhibitory interneurons, abnormal sprouting of axons, reorganization of neural transmitter receptors, alterations in second messenger systems, and hyperexcitability of the granule cells. Extrahippocampal pathology is also found at other temporal lobe structures. Frequent extrahippocampal pathology affects the amygdala, first seen with neuronal cell loss and gliosis in the laterobasal complex. Surgical removal of this epileptogenic area can be curative or provide significant reduction in seizure frequency in the majority of individuals. Magnetic resonance imaging (MRI) is highly sensitive in detecting and locating mesial temporal sclerosis when a correct MRI temporal lobe protocol is used. The most important MRI findings, atrophy and abnormal T2 signal, allow us to detect mesial temporal sclerosis in the majority of the cases. Secondary MRI findings help in the diagnosis and lateralization of mesial temporal sclerosis in patients with subtle primary findings and in cases of bilateral hippocampal abnormalities. The development of advanced magnetic resonance (MR) techniques, such as functional MR, diffusion, or transference of magnetization, will lead to greater understanding of this pathology and will improve our diagnostic capacity.
Letter from the Guest Editors Fernández-Gil, M. Ángeles, MD; Bote, Ramón Palacios, MD
Seminars in ultrasound, CT, and MRI,
06/2010, Letnik:
31, Številka:
3
Journal Article
Macroanatomy and Microanatomy of the Temporal Lobe DeFelipe, Javier, PhD; Fernández-Gil, M. Ángeles, MD; Kastanauskaite, Asta, PhD ...
Seminars in ultrasound, CT, and MRI,
12/2007, Letnik:
28, Številka:
6
Journal Article
Recenzirano
Because of its different functions and organization, the temporal lobe may be divided into lateral and medial parts. This separation may be useful for teaching purposes, since the medial temporal ...lobe needs a separated and a more precise study because of its complex structure and because it is the substrate where some specific types of epilepsy originate. The use of certain magnetic resonance imaging (MRI) sequences and protocols has improved the diagnosis of some particular epilepsies, but this technical benefit must be accompanied by the accurate knowledge of the anatomy of the temporal lobe. With this purpose we have prepared this article, which highlights the ultastructural and macroanatomy of the temporal lobe seen on MRI.
This work examines the possible behaviour of Neanderthal groups at the Cueva Des-Cubierta (central Spain) via the analysis of the latter's archaeological assemblage. Alongside evidence of Mousterian ...lithic industry, Level 3 of the cave infill was found to contain an assemblage of mammalian bone remains dominated by the crania of large ungulates, some associated with small hearths. The scarcity of post-cranial elements, teeth, mandibles and maxillae, along with evidence of anthropogenic modification of the crania (cut and percussion marks), indicates that the carcasses of the corresponding animals were initially processed outside the cave, and the crania were later brought inside. A second round of processing then took place, possibly related to the removal of the brain. The continued presence of crania throughout Level 3 indicates that this behaviour was recurrent during this level's formation. This behaviour seems to have no subsistence-related purpose but to be more symbolic in its intent.
Letter from the Guest Editors Palacios Bote, Ramón, MD; Fernández-Gil, M. Ángeles, MD
Seminars in ultrasound, CT, and MRI,
02/2008, Letnik:
29, Številka:
1
Journal Article
