New Insight into the Mechanism of Mannitol Effects on Cerebrospinal Fluid Pressure Decrease and Craniospinal Fluid Redistribution.

Intracranial hypertension, which often follows a severe brain injury, is usually treated with intravenous (i.v.) application of hyperosmolar solutions. The mechanism of intracranial cerebrospinal fluid (CSF) pressure decrease after such a treatment is still unclear. The aim of this article was to try to explain the mechanism of CSF pressure reduction after i.v. hyperosmolar mannitol bolus in regard to the changes in CSF volume. Two types of experiments were done on anesthetized cats before and after hyperosmolar mannitol application: ventriculo-cisternal perfusion at different perfusion rates, simultaneously measuring the perfusate outflow volume, and CSF pressure recording in the lateral ventricle before and during artificial CSF infusion. Mannitol application in the first group of cats significantly reduced collected prefusate volume during ventriculo-cisternal perfusion, and in the second group it prevented CSF pressure increase caused by artificial CSF infusion. Our results strongly suggest that the mechanism of hyperosmolar mannitol action after its i.v. application is based on osmotic fluid retrieval from interstitial and cerebrospinal compartments into the microvessels. This shift, without significant volume change inside the cranium, causes a predominant decrease of CSF volume in the spinal part of the system, which in turn leads to lowering of the CSF pressure. Spinal CSF volume decrease is enabled by the extensibility of the spinal dura, this way providing the possibility for CSF volume redistribution inside the CSF system, together with CSF pressure decrease. This mechanism of mannitol action is in accordance with the new hypothesis of CSF physiology.

Position and role of forensic psychiatry in integrative psychiatry.

The integrative approach to psychiatry has gained more importance in recent years. Is it justified or not, does it improve theory or practice, those are only some of the questions to which we are looking for answers, but in this paper we shall underline the necessity of enrolling forensic psychiatry into integrative, modern psychiatry. The reason and the motive for that integration is the fact that nowadays the content and the activities of contemporary forensic psychiatrists are totally reduced to executing the tasks given by courts. It is therefore entirely right to say that current forensic psychiatry finds itself in the passive role of executing orders of the court. Our aim is to point out how important it is that forensic psychiatry becomes an interdisciplinary profession in interaction with psychiatry but also with other medical branches just as with judiciary, educational institutions, moral-ethical institutions and religious institutions in producing preventive programmes and by participating in individual decision making process likewise. Our primary goal is to present the status and the position of contemporary forensic psychiatry and to specify the necessary improvements and its place in integrative psychiatry. It should be better, more meaningful and more ethical, both for the individual and the society in total. We want forensic psychiatry to include a protective and therapeutic role for each individual forensic examinee, i.e. a person who has already been in forensic examination and for whom one evaluates mental competence because of a mental disorder. We also want it to get a far larger and more active general role in society in terms of preventing criminal acts among the mentally ill and in society in total.

Alterations in brain activation in posttraumatic stress disorder patients with severe hyperarousal symptoms and impulsive aggressiveness.

OBJECTIVE: We wanted to assess possible alterations in brain activation in PTSD patients with severe hyperarousal symptoms and impulsive aggressiveness. METHOD: 25 Croatian War (1991-1995) veterans with combat-related PTSD with severe hyperarousal symptoms and impulsive aggressiveness were assessed for possible alterations in cerebral blood flow in single photon emission computed tomography brain scans. RESULTS: Increased regional cerebral blood flow in projection area of nucleus accumbens was found in 13 of 25 subjects, and for all in the dominant brain hemisphere. DISCUSSION: We believe that at least some of PTSD symptoms, and especially the impulsive aggression, can be associated with increased regional cerebral blood flow in the projection area of nucleus accumbens.

[Diagnostic and therapeutic guidelines for posttraumatic stress disorders]. / Dijagnosticke i terapijske smjernice za posttraumatski stresni poremecaj.

Posttraumatic stress disorder (PTSD) presents an important medical and social problem in the Republic of Croatia with prevalence of 10-30% depending on the population. On the basis of our 8-year clinical experience in treating PTSD and detailed analysis of related literature a special team of the Department of Psychological Medicine, Zagreb University Hospital, compiled the proposed guidelines for diagnostics and treatment of PTSD. The established guidelines are independently developed, clinically proven at our Clinic and in terms of custom made procedure world wide unique. Their essential feature is psychoanalytic comprehension and approach to etiopathogenesis of PTSD, although it also applies to other psychotherapeutic techniques (cognitive-behavioral, relaxation, existential). The diagnostic model is based upon structured clinical interview (DSM-IV, ICD-10), but it also complies with the principles of psychotherapeutic interview. Therapeutic interventions as proposed are divided according to therapeutic goal into symptomatic and etiological.

Elimination of phenolsulfonphthalein from the cerebrospinal fluid via capillaries in central nervous system in cats by active transport.

It was recently proposed that organic anions, such as cerebral acidic metabolites and phenolsulfonphthalein (PSP), are eliminated from cerebrospinal fluid (CSF) by diffusion into the central nervous system (CNS) and further by active transport into capillaries. To test this hypothesis, PSP was injected into cisternal CSF and its distribution into various parts of the CNS was measured 1 and 3 h later in control cats and those pretreated with probenecid, which blocks active transport of organic anions into capillaries. PSP in tissue shows an intensive pink color when exposed to 1 N NaOH. Planimetric analysis of color pictures of coronal CNS slices showed that at the first hour, diffusion and distribution of PSP into the CNS in both groups of animals was similar, while at the third hour, a great reduction of PSP distribution in the CNS in control and only a slight reduction in probenecid pretreated cats was observed. The results support the hypothesis that active transport across the capillary wall in the CNS is the main avenue for elimination of cerebral acidic metabolites from both CSF and CNS and in such a way that central homeostasis is maintained.