TATU

We present a brain map of the areas supplied by various arteries in the brainstem, cerebellum and cerebral hemispheres. Arterial territories are depicted in a form that is directly applicable to neuroimaging slices in clinical practice. The arterial territories are outlined based on an extensive overview of anatomical studies of cerebral blood supply. For arterial territories of the hemispheres, we present the variability of the cortical territories of the three main cerebral arteries and define the minimal and maximal cortical supply areas.

The hippocampus is a temporal brain structure belonging to the limbic lobe and is fundamentally involved in memory processing, learning, and emotions. It consists of two allocortex laminae: the gyrus dentatus and the cornu ammonis, one rolled up inside the other, creating a bulge in the temporal horn of the lateral ventricle. Arterial vascularization of the hippocampus is dependent on the collateral branches of the posterior cerebral artery and the anterior choroidal artery, forming the network of superficial hippocampal arteries that in turn lead to deep intrahippocampal arteries. Venous vascularization is provided by the intrahippocampal veins, which drain into the superficial hippocampal veins. Knowledge of anatomical organization and vascularization of the hippocampus is essential to understanding its dysfunctions and its appearance on MRI.

This chapter is aimed at highlighting the recent findings concerning physiopathology, diagnosis, and management of conversion, factitious disorder, and malingering. Conversion disorder is the unintentional production of neurological symptom, whereas malingering and factitious disorder represent the voluntary production of symptoms with internal or external incentives. They have a close history and this has been frequently confounded. Practitioners are often confronted to medically unexplained symptoms; they represent almost 30% of neurologist's consultation. The first challenge is to detect them, and recent studies have confirmed the importance of "positive" clinical bedside signs based on incoherence and discordance, such as the Hoover's sign for the diagnosis of conversion disorder. Functional neuroimaging has allowed a better understanding of the pathophysiology, and highlighted abnormal cerebral activation patterns in conversion disorder in relation to motor, emotional, and limbic networks, different from feigners. This supports the theory evoked by Charcot of a "psychodynamic lesion," which is also reflected by the new term introduced in the DSM-5: functional neurological disorder. Multidisciplinary therapy is recommended with behavioral cognitive therapy, antidepressant to treat frequent comorbid anxiety or depression, and physiotherapy. Factitious disorder and malingering should be clearly delineated from conversion disorder. Factitious disorder should be considered as a mental illness and more research on its physiopathology and treatment is needed, when malingering is a non-medical condition encountered in medico-legal cases.