Kindling, regarded as an animal model of temporal lobe epilepsy, consists in gradually developing progressive limbic motor seizures due to repeated subthreshold electrical stimulation of certain brain regions or administration of proconvulsive chemical substances in subthreshold doses. It is a particularly interesting model, which can be used to study subsequent changes in animal behaviour, reflecting emotional disturbances observed among patients with epilepsy. The paper presents a review of various animal models of epilepsy used in the research into the mechanisms of seizures and action of antiepileptic drugs. Moreover, among major pathogenic mechanisms involved in the epileptic disorder the role of the glutamate or GABA system, and the function of Y neuropeptide or adenosine are discussed, with the emphasis on the phenomenon of the so-called long-term synaptic augmentation (LTP). The effect of kindling on animal behaviour was described (in rats) in order to better understand the nature of epilepsy-related disorders, including psychiatric disturbances in patients suffering from epilepsy.
The aim of the paper is to review the effect of gonadal and adrenal hormones on seizures in different physiological stages in lifetime of women with epilepsy. Studies in a variety of animal models of epilepsy support clinical observations that estradiol is generally proconvulsant, while progesterone is anticonvulsant. Women with epilepsy are more likely to experience abnormalities in their menstrual cycle length. Significantly abnormal cycles affect 18% of women with epilepsy. Irregular cycles may be a consequence of anovulatory menstrual cycles and/or luteal phase defficiency. Anovulatory cycles were reported to affect over 30% of menstrual cycles in a group of women with localization-related epilepsy of mesial temporal lobe origin. Irregular menstrual cycles and anovulation may also occur in association with polycystic ovaries. Although the frequency of polycystic ovaries occurrence in healthy women has not been established, several reports suggest that women with epilepsy are more likely to develop multiple ovarian cysts and to present a clinical picture similar to that of the polycystic ovary syndrome. In women with catamenial epilepsy the onset of seizures is often associated with menarche. In a small number of women the first ever seizure occurs during pregnancy. The effect of menopause on epilepsy is an area that has received scant attention. Pilot data suggest that synthetic hormone replacement therapy may be associated with an increase in the seizure frequency in menopausal women with epilepsy. Reproductive dysfunction has an important effect on the patients' overall health and quality of life.
Any epileptic seizure, through affecting the autonomous system, may result in cardiac arrhythmia. In turn, arrhythmia by producing hemodynamic disturbances in the cardiovascular system may lead to a loss of consciousness with convulsions due to a prolonged insufficient oxygen supply to the brain. Cases of sudden death are more frequent among those suffering from epilepsy than in the general population. The risk of sudden death is to a large extent due to cardiac arrhythmias of which bradycardia is the most dangerous although not the most frequent variety. The best protection against sudden death is the heart pacemaker grafting, supported by pharmacotherapy with antiepileptic drugs. The most useful techniques in the differential diagnosis of epilepsy, cardiac arrhythmia and their interrelations are simultaneous 24-hour ECG and EEG monitoring, as well as video EEG.
Dissociative disorders (formerly known as hysterical) are clinical events unrelated to any physiologic dysfunction, but resembling symptoms of an organic disease. Due to their rich symptomatology all over the world dissociative disorders are the cause of many unnecessary hospital admissions, medical examinations and even surgical interventions involving considerable and needless expenses. Patients suffering from such personality disorders are usually incorrectly diagnosed and treated symptomatically only. In view of insufficient diagnostic criteria and a lack of effective management strategies physicians see their role with this group of patients primarily as limited to the exclusion of a serious organic disease. The problem becomes even more complicated in cases of dissociative disorders concurrent with a real organic disease. Epileptic patients with psychogenic pseudoepileptic seizures are an example of this dual condition. Results of a study using MMPI suggest that the presence of these two types of seizures is reflected in an elevation of anxiety factors in the personality profile. Research findings indicate that to reduce the development of dissociative disorders the treatment should be focused on amelioration of anxiety and depression, which might lead to an increased satisfaction of these patients and to their more efficient coping with daily life problems.
The relationship between the sleep apnoea syndrome (SAS) and cerebrovascular diseases has been widely investigated in recent years. The incidence of SAS was found to be higher in stroke patients than in the general population. The effect of various factors on the prevalence, type and severity of SAS was assessed in stroke patients (including their BMI, age, sex, concomitant diseases, localization of stroke focus, type of stroke, severity of neurological motor deficit, etc.). The role of SAS in the pathogenesis of cerebrovascular diseases remains still unclear. In the literature a number of factors are reported that may directly or indirectly increase the risk of stroke in SAS patients, such as e.g. elevated intracranial pressure, decreased cerebral blood flow, alterations of blood pressure associated with sleep apnoea, sustained hypertension, cardiac arrhythmias, increased platelet aggregation, decreased fibrynolytic activity, accelerated atherosclerosis, raised hematocrit levels, excessive sympathetic activity. SAS is considered to be not only a risk factor for cerebral infarction, but also, in some cases, a consequence of stroke. Either central or obstructive apneas may appear after stroke. Since SAS adversely affects rehabilitation and recovery of stroke patients, screening for SAS should be a routine practice in every stroke unit. Moreover, appropriate treatment and preventive measures may also contribute to a decrease in these patients' mortality rates and their more effective rehabilitation.
The nature of dynamic mutations, their presumable underlying mechanism, as well as their role in the pathogenesis of Huntington's disease are presented in the paper. Amplification of selected trinucleotide sequences, the anticipation phenomenon, and genome imprinting theory are discussed in more detail.
The term "juvenile parkinsonism" has been known for over l 00 years. In the majority of cases it is a heterogeneous syndrome. Only the autosomal recessive juvenile parkinsonism was confirmed to be a relatively separate syndrome connected with a mutation in the parkine gene. The early onset (before age 20), dystonic movements, positive response to L-dopa, and early dopainduced dyskinesia are the main phenotypic features of the syndrome. The absence of Lewy's bodies is the main pathological difference between the autosomal recessive juvenile parkinsonism and Parkinson's disease. Recent studies show that parkine mutations are connected not only with autosomal recessive parkinsonism, but may be also found in typical cases of Parkinson's disease with Lewy's body pathology. The diagnosis of juvenile parkinsonism demands its differentiation with many other diseases that may appear in adolescence with such main symptoms as rigidity, tremor and dystonia. In the differential diagnosis first and foremost the L-dopa responsive dystonia and secondary symptomatic parkinsonism should be taken into account.
Hereditary motor and sensory neuropathy t. I (HMSN t. I) is a disease inherited in an autosomal dominant way. Three gene loci have been identified so far, in chromosomes 17, l, and 10. A significant cause of the HMSN are abnormalities within the peripheral myelin protein 22 (PMP 22).The disease develops slowly in I-III decades of life. The polyneuropathic syndrome discovered in physical examination, frequently with such symptoms as feet deformity, EMG-confirmed chronic denervation process in the upper and lower limbs, and characteristic neuropathological changes (primary myelin degeneration with segmental myelin sheath thickening), as well as an analysis of pedigree and genetic material should lead to the diagnosis of HMSN t. I. The diagnosed HMSN requires that rehabilitation should be started immediately.
The aim of this paper is to present toxic effects of aluminium on the nervous system. This metal belongs to environmental factors that may play a crucial role in the pathogenesis Alzheimer's disease (AD). The molecular mechanism of AD may consist in P-amyloid accumulation in the presence of aluminium, leading consequently to neurodegeneration. P-amyloid causes an abnormally high concentration of Ca²+ ions in neurons resulting in neurodegenerative changes. The cholinergic system, and especially hippocampus and cortex are known to be particularly affected in AD. The amount of Aluminium absorbed from food and drugs in the gastrointestinal tract, transported into and accumulated in the brain is crucial for human health. The daily consumption of aluminium ranges from l0 to 40 mg. A small amount of Aluminium (approximately less than l%) is absorbed from food via the gastrointestinal pathway. A relatively small proportion of this dose gets through the blood-brain barrier and enters the brain. However, the ability of the brain to eliminate aluminium is limited and therefore, Aluminium accumulates in the brain in an age-dependent manner. Some epidemiological studies show a relationship between concentration of aluminium in the drinking water and Alzheimer's disease.