Microsurgical considerations of the anterior spinal and the anterior-ventral spinal arteries.

BACKGROUND: There are few data describing the microanatomy of the anterior-ventral spinal (AVSA) and anterior spinal arteries (ASA) and discussing their clinical and surgical implications. We describe the anatomical features of this arterial complex, and highlight their use when planning and performing surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum. METHOD: The microsurgical anatomy and branching pattern of the AVSA and the ASA from fifty human cadaver brain stems is described using a surgical microscope. RESULTS: We found one anterior-ventral spinal artery at each side in 30 of the brain stems (60%). The ASA was a direct branch emerging from the left vertebral artery (VA) in 15 (30%), from the right VA in 4 (8%), and from the basilar artery (BA) in one brain stem (2%). The previously described as "typical pattern" of the junction of the AVS arteries from both sides, was observed only in 9 brain stems (18%). The anterior communicating spinal artery (ACoSA) was observed in 15 brain stems (30%). Also multiple ACoS arteries were described in one brain stem. Both, the AVSA and the ASA were observed to send long circumferential branches that supplied irrigation to the olive in 42 (84%) brain stems. CONCLUSIONS: This anatomical study gives important information for a better understanding of the clinical picture of ischemic lesions of the brain stem, such as the medial medullary syndrome, and highlights the remarkable role of the AVSA and ASA as anatomical landmarks during the surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum.

[Non-surgical potentially reversible dementias]. / Demencias potencialmente reversibles no quirúrgicas.

AIMS: In this study, we review dementias that are potentially reversible. The paper summarises the causes that essentially require management by medical means, while causes of a surgical nature will be dealt with in a second article. These papers attempt to avoid mistaken diagnoses and labels in patients with a high potential to improve their cognitive disorder and to guide us towards a more suitable management. DEVELOPMENT: Dementia is a public health problem, mainly in countries with long life expectancy. It has an incidence of 3-11% in patients over the age of 65, and 20-50% in those over 85 years old. Most of them (50-70%) have Alzheimer-type dementia, followed by the vascular type (20%); there is a smaller percentage of cases of the so-called subcortical dementias and also those secondary to medical and/or surgical conditions that suggest potential reversibility. These latter cases are not easy to recognise and their incidence, depending on the series, ranges from 0 to 37%. Once they have been diagnosed, it is still difficult to state whether they will in fact turn out to be reversible. Their most common causes, such as deficiencies, metabolic disorders, chronic diseases, toxins, and so on, must be detected as early as possible, which can be done by means of clinical observation and use of the laboratory. CONCLUSIONS: Although the potential to improve in patients with a diagnosis of reversible dementia is still subject to discussion, this brief review guides us in the search for their causes and their management, since late detection and management are very likely to be the cause of a poor progression.