Clinical Neuroscience - 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

[Connections between anatomical structures of the brain and cognitive functions]

SZENDI István, KISS Marianna, VÖRÖS Erika, CSERNAY László, JANKA Zoltán

[

The aim of neuropsychiatry is the analysis of neurocognitive abnormalities in mentol disorders and the multiple use of the results. lts objectives are: 1 . identification of useful cognitive subprocesses that are testable with the neuroimaging and electrophysiological methods examining not only the nosological illness categories any more, but rather the mentol symptoms or dimensions; 2. outlining of consistent phenotypes for molecular and epidemiologic genetics by determining the correlation between clinical features and neurocognitive markers; 3. creating testable (controllable both for animal studies and computing methods) syndromatological and nosological models as well as etiological and therapeutic theories. The anatomically defined brain regions that are important in cognition are multifunctional. The networks providing neural implementation of cognitive functions participate in the farming of several network systems simultaneously. The networks are sparsely distributed, and the centres of these network systems are relatively specialized for the specific behavioral components of their main neuropsychological dimensions. ln the course of examinations of the specific cognitive functions we can determine subnetworks related to the function, but we cannot define whether these are the dedicated subnetworks or we just found a relationship with one of the overlapping configurations of distributed networks. Change of research paradigm from function-based to component-based can help to resolve this ambiguity. ln the article we present the possibilities of parallel application of structural MR and cognitive neuropsychological tesis. By using these methods we can grasp the connection of function and structure at the cytoarchitectonic level.]

HUN 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

[Tracing the acute changes of the blood-brain barrier with MR after closed head injury ]

BARZÓ Pál, CZIGNER Andrea, MARMAROU Anthony, FATOUROS Panos, CORWIN Frank, DUNBAR Jana

[The objective of this study was to determine the early time course of blood-brain barrier (BBB) changes in diffuse closed head injury using T1 -weighted MR imaging following intravenous administration of the MR contrast agent Gd-DTPA. The maximum signal intensity enhancement was used to calculate the difference in BBB disruption.A new impact-acceleration model was used to induce closed head injury. Forty-five adult Sprague-Dawley rats were separated into four groups: Group I, sham operated (four animals), Graup II (HH) hypoxia and hypotension for 30 minutes (four animals), Group III (T) trauma only (23 animals), and Group IV (THH) trauma coupled with hypoxia & hypotension ( 14 animals).ln the trauma-induced animals the signal intensity increased dramatically immediately after impact. By 15 minutes, permeability decreased exponentially and by 30 minutes, it was equal to that of control animals. When trauma was coupled with secondary insult, the signal intensity enhancement was lower after the trauma, consistent with reduced blood pressure and blood flow. However, the signal intensity increased dramatically on reperfusion and was equal to that of control by 60 minutes after the combined insult. ln conclusion, the authors suggest that closed head injury is associated with a rapid and transient BBB opening thai begins at the time of the trauma and lasts no more than 30 minutes. lt has also been shown thai addition of posttraumatic secondary insult - hypoxia and hypotension - prolongs the time of BBB breakdown after closed head injury. The authors further conclude that MR imaging is an excellent technique to follow the evolution of trauma-induced BBB damage noninvasively from as early as a few minutes up to hours or even longer after the trauma occurs.]

HUN 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

[Contribution of vasogenic and cellular edema to traumatic brain swelling measured by diffusion-weighted imaging ]

BARZÓ Pál, CZIGNER Andrea, MARMAROU Anthony, FATOUROS Panos, CORWIN Frank, KOJI Hayasaki

[The contribution of brain edema to brain swelling ín cases of traumatic brain injury remains a critical problem. We believe that complex neurotoxic events followed by cellular edema are the major contributor to brain swelling. The objective of this study was to quantify temporary changes ín brain water content and document the type of edema occurring during the stages of edema development following closed head injury. A new impact acceleration model was used to induce dosed head injury. Adult Sprague-Dawley rats were separated into two groups: sham (n=8), trauma (n=42). The measurement of brain water content was based on values of tissue longitudinal relaxation time (T₁), whereas the differentiation of edema formation was based on the measurements of the random, microscopic, translational motion of water protons which provides a diffusion-weighted image by MRI. Diffusionweighted images were obtained sequentially (every minute) up to one hour post injury. T₁ images and diffusion-weighted image were performed at the end of the first hour post injury and on days 1, 3, 7, 14, 28, 42 in both trauma control groups. ln trauma animals, we found a significant increase in apparent diffusion constant ( 10±5%) as well as the brain water content (0.7±0.3%) during the first 60 minutes post injury, indicating an increase in the volume of the extracellular fluid. This was followed by a continuing decrease ( 10±3%) of the apparent diffusion constant beginning at 45-60 minutes post injury reaching a minimum at days 7-14. Since the water content of the brain continued to increase during the next 24 hours ( 1 ±0.3%), it is suggested that the decreased apparent diffusion constant indicated cellular edema formation. ln condusion the closed head injury is associated with a biphasic pathophysiological response. The vasogenic and cytotoxic forms of edema is time-dependent and reflects a complex sequence of vascular and cellular events.]

HUN 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

[Placebo effect among drug-resistent epileptic patients participating in drug studies]

RAJNA Péter, VERES Judit, SZIRMAI Rita

[lntroduction - The judgment on the use and importance of placebo agents, placebo effect and placebo trealmenl has nol yet been uniform in medicine.
Aim of the study - l. To observe and clarify the coexisting placebo effect of active biological (pharmacological) trealment. 2. To establish the prevalence ratio of placebo effect occurring in H-III multicenter studies of new epileptic drugs.
Population and methods - Between 1994-1998 the Epilepsy Center of the Department of Psychiatry and Psychotherapy of Semmelweis University participated in 5 randomized, conlrolled, H-III multicenter double-blind studies where the inclusion and exclusion criteria were practically identical. Altogether, 53 patients completed the studies and the results were analysed in a form of melaanalysis.
Results - General favourite response lo study procedures was 68% in the placebo controlled studies and 72% in the comparative ones. Response ratio in the summarized placebo group was more than 25%. ln 22 patients, a transitory (mainly initial) positive response occurred, which is - taking the known pharmacokinetical and pharmacodynamical evenls into account - can also be viewed as an initial placebo response. We did no! find any difference between palienls according to their demographic or epileptological characteristics or their physical and psychic status in relation to their placebo-responder or nonresponder abilities. Patients suffering from milder forms of epilepsy (within the established prolocol range), showed closer dependency to their doctors and were more sensitive towards the emotional and psychic problems of their illness.
Conclusions - The placebo effect can not be excluded during the course of active pharmacotherapy. Transitory or initial drug effects might be of special concern regarding the lack of efficacy. Further studies are necessary lo find the biological and psychological characteristics of the placeboresponder person, to define the exact and volunlary application of placebo agents and lo conslrucl the prolocols for these special trealment forms.]

HUN 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

[Assessment of cerebral hemodynamics in healthy and preeclamptic pregnant women using transcranial doppler sonography ]

FÜLESDI Béla, ZATIK János, ARANYOSI János, MOLNÁR Csilla, JORGOS Settakis, TÓTH Zoltán

[lntroduction - Previous studies already reported on altered cerebral hemodynamics in pregnants suffering from preeclampsya. The aim of the present work was to compare cerebral vasoreactivity of women with preeclampsia and with complication-free pregnancies.

Subjects and methods - 28 preeclamptic and 24 healthy pregnants were studied using DWL-7 transcranial Doppler sonography. Blood flow velocities and pulsatility indices of the middle cerebral arteries were registered at rest, during roll over test, after 30 seconds of breath holding as well as 60 seconds after voluntary hyperventilation. During statistical analysis, the absolute values of the blood flow velocity parameters and the percentual change of the blood flow velocities after administering the vasoreactivity stimulus were taken into account.

Results - Resting cerebral blood flow velocities were higher among preeclamptic, as compared to healthy pregnants (preeclampsia: 82.1 ± 13.7 cm/ s, healthy: 66.2± 10.3 cm/s, p<0.001 ). During roll over test, systemic blood pressure significantly increased, while middle cerebral artery velocities decreased in both groups. During breath holding middle cerebral artery velocities increased similarly in both groups. Hyperventilation resulted in a lesser decrease of the blood flow velocities in the preeclamptic group.

Conclusions - Middle cerebral artery blood flow velocties are increased in preeclamtic pregnant women. Although cerebral vasoreactivity to hyperventilation stimulus is altered in preeclampsia, our results on roll over test suggest a maintained cerebral autoregulation in this patient group. The pathophysiological background of cerebral hemodynamical changes in preeclampsia has to be clarified in further studies.]

HUN 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

[Dental care of patients with epilepsy - a guide for medical personnel involved in the care of epileptic patients]

KÁROLYHÁZI Katalin, KIVOVICS Péter, LINNINGER Mercedes, NEMES Katalin, ARÁNYI Zsuzsanna

[Patients with epilepsy seem to have a poorer dental condition compared to the healthy population, the cause of which is complex. All efforts should be token to provide equal dental care to epileptic patients, however certain factors of their disease must be token into account. Among these, most important is the type of seizures, with special emphasis on the involvement of the masticatory apparatus and on possible oral cavity injuries and aspiration. ln addition, seizure frequency, mentol state and compliance of the patient plays significant role as well. Based on these factors patients with epilepsy were grouped into four classes, according to their dental manageability. Special aspects of dental care in these four classes are discussed in comparison with the care of healthy patients. The planning of the dental prosthesis, as with healthy patients, was done according to the Fábián-Fejérdy classification.]

HUN 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

[Late onset form of ornithine transcarbamylase deficiency with fatal outcome]

LIPTAI Zoltán, GYARMATI Éva, KULCSÁR Andrea, CENNI Bruno, FAGGYAS Attila

[Ornithine transcarbamylase deficiency is the most common disorder of the urea cycle. Aport from its neonatal form there is a less known late onset type with behavioural disturbances, episodic vomiting and encephalopathy. Authors describe the case of a 14-year-old girl whose case history has been unremarkable apart from meat protein avoidance since the age of 4 to 5 years. One year prior to present hospitalization she had been investigated due to headaches and dizziness, but no positive findings were found. She was hospitalized again for fluctuating signs of confusion, agressive behaviour, somnolence and slurred speech. EEG showed marked slowing, cranial CT, MRI and cerebrospinal fluid results were norma!. The only consequent laboratory abnormality was the elevated serum ammonia level. Disturbance in consciousness progressed, repeated seizures occured and the patient died of herniation of the cerebellar tonsils on the 9 th hospital day. The clinical course reminded of a urea cycle disorder. Blood and urine samples sent far laboratory analysis after the child's death revealed excessive orotic aciduria and a diminished serum citrulline levei. DNA analysis from dried blood spots has shown a known Ala209Val mutation on exon 6 of OTC (ornithine transcarbamylase) gene. The same mutation could not be found in the healthy 17-year-old sister. The authors briefly describe the appropriate diagnostic approach of the disorder and emphasize the role of metabolite screening in making diagnosis as early as possible. Therapeutic possibilities are also mentioned that may help most of similar patients to survive or even avoid hyperammonaemic episodes.]

HUN 2001;54(11-12)

Clinical Neuroscience

NOVEMBER 01, 2001

The role of the blood-brain barrier in the pathogenesis of neonatal and ischaemic brain injuries: investigations using animal models

NÉMETH László

ln the central nervous system (CNS) of vertebrates intravascular and interstitial spaces are separated by a highly specialised endothelial lining, which is the morphological basis of the blood-brain barrier (BBB).

ENG 2001;54(11-12)