Favorable change of lipid profile after carbamazepine withdrawal

OBJECTIVE

Patients treated with carbamazepine (CBZ) have increased serum levels of total cholesterol (TC), high-density lipoproteins (HDL), and low-density lipoproteins (LDL). We aimed to investigate whether these changes of serum lipids are reversible after CBZ withdrawal.

MATERIAL AND METHODS

We used a prospective, randomized double-blinded design. A total of 160 patients who had been seizure free on anti-epileptic drug monotherapy for more than 2 years were included and randomized to withdrawal or not. The intervention was completed by 150 (80 females, 53%) patients. Serum samples from before and 4 months after completed withdrawal or no withdrawal were obtained from 130 patients (63 females, 48%). Of these, 84 were treated with CBZ, 28 with valproate, nine with phenytoin, four with phenobarbital, and five with lamotrigine. Of the patients who had been treated with CBZ, 47 were randomized to the withdrawal group, and 37 were randomized to the non-withdrawal group.

RESULTS

Among the CBZ-treated patients, a significant decrease in serum levels of TC, LDL, and apolipoprotein B (ApoB) were found in the withdrawal group compared with the non-withdrawal group. Mean differences in change were as follows: TC 0.68 mmol/l (P = 0.005, CL - 1.15 to -0.21); LDL - 0.67 mmol/l (P = 0.001, CL - 1.03 to -0.29); ApoB - 0.13 g/l (P = 0.02, CL - 0.23 to -0.03). No significant changes in HDL, apolipoprotein A, and C-reactive protein were detected.

CONCLUSION

Our results indicate that CBZ may have unfavorable effects on serum levels of TC, LDL, and ApoB. However, these changes seem to be reversible even after years of treatment.

The Norwegian Brain Council ('Hjernerådet')--united efforts are necessary!

There is a strong tradition of neuroscience in Norway, and Norwegian neurologists have been actively involved in developing partnerships between all those who recognize the importance of the brain and of brain diseases. It was therefore unsurprising that Norwegian neurologists took the initiative in establishing the Norwegian Brain Council (NBC). NBC was founded in 2007 and now comprises 27 organizations and institutions. It includes all those who work with brain research and brain diseases in Norway, as well as all relevant user organizations. Industries and businesses that are related to brain disease may be partners, but do not have full membership. The main mission of NBC is to provide information about the brain and brain diseases for both lay people and public authorities, including politicians, and to promote better treatment for patients with brain diseases and more research in neuroscience. The council has firm ties to the European Brain Council (EBC). NBC plans to follow the initiative taken by EBC in organizing a 'Month of the Brain' in 2013 and a 'Year of the Brain' in 2014. These initiatives could provide an impetus for greater focus on brain diseases, which is essential in order to meet the considerable challenges that are posed by brain diseases in the years to come.

Repeated neuropsychological assessment in well-controlled epilepsy

BACKGROUND

The majority of patients with epilepsy are seizure-free, and repeated neuropsychological assessment may be highly relevant in this group. However, previous studies have not addressed the possible influence of important clinical variables on repeated neuropsychological assessment in this population.

METHODS

Using data from a large antiepileptic drug (AED) withdrawal study, we calculated the neuropsychological practice effects for 139 seizure-free patients with epilepsy and analysed the influence of different epilepsy-related factors on improvement that were observable 7 months after the initial neuropsychological assessment.

RESULTS

A clear and significant improvement in neuropsychological test performance was found for all the tests employed, regardless of AED withdrawal. Furthermore, patients characterized by evidence of brain pathology, such as known cerebral aetiology, pathological MRI and pathological EEG, showed less practice effects than patients not characterized by these variables. The differences were primarily evident for measures of verbal learning and memory.

CONCLUSION

The data obtained from this study suggest that the development of general norms for change in the particular patient population, as well as specific norms for change related to important clinical variables, might be necessary to be able to determine whether genuine neuropsychological changes have occurred in individual patients in this group.

Haematological side effects of antiepileptic drug treatment in patients with epilepsy

OBJECTIVES

Little is known about the haematological side effects of the newer antiepileptic drugs (AEDs), but recent case reports have raised concerns regarding the possibility of altered thrombocyte counts or function in some patients during levetiracetam (LEV) treatment. The aim of our study was to investigate haematological changes in patients treated with the newer AEDs, LEV and lamotrigine (LTG), compared with the older AEDs, valproate (VPA) and carbamazepine (CBZ).

METHODS

This cross-sectional study included 251 patients with epilepsy of both genders, aged 18-45 years, using AED monotherapy: 52 patients on LEV (31 men, 21 women), 80 on LTG (37 men, 43 women), 90 on CBZ (61 men, 29 women), 29 on VPA (15 men, 14 women), and 79 healthy controls (36 men, 43 women). Haemoglobin (Hb), white blood cells (WBC) and platelet (thrombocyte) counts were estimated. The subjects were recruited from hospitals in south-eastern Norway and Innsbruck, Austria.

RESULTS

Significantly lower platelet counts were recorded in both men and women on LEV monotherapy. In the LEV group, platelets were 14% lower (40.68 × 10(9) /l lower) than in the control group. There was no difference according to sex or age of the patients. Only minor changes in haematological parameters were observed for the other drugs investigated.

CONCLUSIONS

Both men and women treated with LEV monotherapy have lower blood platelet counts than healthy controls, with no difference in Hb or WBC. Haematological changes observed with the other AEDs were minor.

Partnership and cooperation is necessary to improve and expand neurology

BACKGROUND

Brain disorders have a large impact on society, representing one third of the total burden of disease. Neurology is more than before divided into fields of highly specialized branches.

OBJECTIVE

To assess the need for co-operation in neuromedicine to achieve optimal results for patient treatment, diagnosis and care.

DISCUSSION

Co-operation regarding patients with disorders in the brain and nervous system should involve medical specialists, general practitioners, other professionals, patients and carers. Optimal co-operation represents both an institutional and personal challenge. The principle of joint action between several subspecialists should also have consequences for educational systems and requirements. Formalised co-operation is well established in medical research, and principles for good practice in neuroscience have relevance also for clinical medicine. How to organise the optimal treatment is therefore not only a challenge for neurologists, but also for the total health system within hospitals and in society.

CONCLUSION

Open-handedness and a willingness to co-operate should be a hallmark for neurologists.

Gender differences in risk-taking behaviour in youth with epilepsy: a Norwegian population-based study

OBJECTIVES

It is well known that behavioural problems and psychiatric disorders occur with greater prevalence in children and adolescents with epilepsy. Youth with epilepsy (YWE) may also be more susceptible to risk-taking behaviour, but this has seldom been studied. The aim of this study was to explore risk-taking behaviour in YWE.

MATERIAL AND METHODS

In this study, 19,995 young people (age range: 13-19 years) participated and completed an extensive questionnaire, including The Strengths and Difficulties Questionnaire self-report. A variable, risk-taking behaviour, was identified, including daily consumption of alcohol, substance abuse or having committed a criminal offence such as being in a fight with a weapon, committing a burglary or using threats to obtain money.

RESULTS

Two hundred and forty-seven youths reported currently having, or having had, epilepsy (lifetime prevalence: 1.2%). Of these, 8.3% reported daily alcohol consumption (1.0% in controls; P<0.001), 12.4% had tried illegal substances (5.5% of controls; P<0.001), and 19.7% had committed criminal offences (8.5% in controls; P<0.001). A gender difference was found: girls with epilepsy did not exhibit risk-taking behaviour more frequently than controls, but having epilepsy was a risk factor for such behaviour in boys (OR: 3.2).

CONCLUSION

Boys with epilepsy exhibit risk-taking behaviour more frequently than controls. Other risk factors for this behaviour were living with a single parent, low family income and psychiatric symptoms. This behavioural association should be addressed as it probably contributes to the negative social outcomes that frequently occur in the adult epilepsy population.

Improvement in verbal memory after withdrawal of carbamazepine and valproate in patients with well-controlled epilepsy: a randomized, double-blind study

BACKGROUND

For most major antiepileptic drugs, neuropsychological side effects have been reported. Healthy volunteer studies have found that both carbamazepine and valproate impair aspects of verbal memory.

OBJECTIVE

The aim of this study was to assess the effects of carbamazepine and valproate on verbal memory, in a well-controlled epilepsy population.

METHODS

This was carried out with a randomized, double-blind and placebo-controlled study of anticonvulsant withdrawal in patients receiving monotherapy.

RESULTS

In the carbamazepine group (n=92), withdrawal significantly improved recall after 30 min (P=0.03). In the valproate group (n=32), withdrawal significantly improved performance of immediate word span (P=0.04).

CONCLUSIONS

Withdrawal was randomized to placebo, but the choice of medication was not randomized to placebo. This means that the shown differences in neuropsychological outcome cannot with full certainty be attributed to either antiepileptic drug. The improvement of memory, after both carbamazepine and valproate withdrawal, was slight, and the impact on daily life function is uncertain.

Cardiovascular risk factors in epilepsy patients taking levetiracetam, carbamazepine or lamotrigine

OBJECTIVES

The aim of the study was to investigate risk factors for cardiovascular disease in patients with epilepsy using the new antiepileptic drug levetiracetam (LEV), compared with patients taking carbamazepine (CBZ) or lamotrigine (LTG).

METHODS

Two hundred and twelve patients and 80 controls (age: 18-45 years) of both genders were included. The patients had been treated with either LEV (n = 52), CBZ (n = 87) or LTG (n = 73) monotherapy for at least 6 months. Total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were measured. Smoking, drinking habits and physical activity were recorded and body mass index (BMI) was calculated.

RESULTS

Neither LEV nor LTG altered TC, LDL or HDL. Both men and women using CBZ had higher TC, HDL and LDL than controls. LDL/HDL and TC/HDL ratios were unchanged. Women on CBZ and LTG had a greater BMI when compared with the control group. Patients with epilepsy recorded less physical activity and lower alcohol use than the controls.

CONCLUSIONS

Neither LEV nor LTG affected blood lipid levels, while patients treated with CBZ have higher cholesterol, HDL and LDL than controls. The patients were less physically active, and women on CBZ and LTG had higher BMI.

Cost of disorders of the brain in Norway

BACKGROUND

Little is known about the cost of neurological disorders in Norway.

OBJECTIVES

To estimate the cost of disorders of the brain, including the main psychiatric, neurological and neurosurgical conditions in Norway.

METHODS

Most of the data are extrapolations from a large European cost study that collected the best available epidemiological and health economical evidence for the year 2004. Some epidemiological data are available from Norway, but very little on costs.

RESULTS

Brain disorders seemed to affect 1.5 million Norwegians in 2004, and the total cost amounted to 5.8 billion Euros. The most prevalent disorders are anxiety disorders and migraine, and the most costly are affective disorders, addiction and dementia. Migraine is the most costly of the purely neurological conditions, followed by stroke, epilepsy and Parkinson's disease. The indirect costs account for more than half of the total costs.

DISCUSSION

Although the different brain disorders are very dissimilar in appearance, from health economic and public health perspectives, it is relevant to view them as a whole, since many of them share important pathophysiological mechanisms. This means that new insights into one disorder can have relevance for many other disorders.

CONCLUSION

As a result of the high impact on individuals and society, more resources should be allocated to treatment and research into brain disorders.

Phenotypic characteristics of temporal lobe epilepsy: the impact of hippocampal sclerosis

OBJECTIVES

Whether mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) is a condition with a unique biological background that can be delineated from other TLE, is unresolved. Here we performed a comparative analysis of two TLE patient cohorts - one cohort with HS and one without HS - in order to identify phenotypic characteristics specifically associated with MTLE-HS.

METHODS

Epidemiological data and clinical and diagnostic features were compared between patients with MTLE-HS and TLE patients without HS. When appropriate, data were compared with healthy controls.

RESULTS

Fifty-six (26%) patients were diagnosed with MTLE-HS and 162 (74%) with other TLE. Age at epilepsy onset was lower in patients with MTLE-HS (P = 0.003) than in TLE patients without HS. Incidence of simple partial seizures was higher in the MTLE-HS group (P = 0.006), as were complex partial seizures (P = 0.001), ictal psychiatric symptoms (P = 0.015), and autonomic symptoms (P < 0.001). Interictal psychiatric symptoms, including depression, were less frequent in MTLE-HS (P = 0.043). MTLE-HS patients had a higher incidence of childhood febrile seizures (FS; P = 0.043) than TLE patients without HS. In contrast, the former group had the lower frequency of first-grade family members with childhood FS (P = 0.019).

CONCLUSIONS

We identified phenotypic characteristics that distinguish MTLE-HS from other types of TLE. These characteristics will be important in diagnostics, treatment, and determination of prognosis, and provide a basis for future phenotype-genotype studies.

Norwegian neurology: present status and future trends

Diseases of the nervous system constitute a major cause of morbidity and mortality. The chronic nature of many neurological diseases demands long-term follow-up and good communicative skills. Financial conditions and compensation is closely linked to modern health care and may limit the availability of new therapeutic options. An ageing population and modern lifestyle represent challenges for neurology in the future. The participation in public debate and strategic planning of health services are crucial to improve neurological services on a national and global level. Our focus should be the promotion of special needs of patients with neurological disease.

Antiepileptic monotherapy significantly impairs normative scores on common tests of executive functions

BACKGROUND

Understanding how antiepileptic (AED) monotherapy influences normative test scores is of importance in the clinic for correct interpretation of neuropsychological profiles. Previous studies have primarily reported minor influence on neuropsychological raw scores, and the clinical relevance of these findings is unclear.

AIM OF THE STUDY

To obtain a clinical valid answer to this question, we analysed changes in T-scores after AED withdrawal in a large group of well-controlled epilepsy patients, for tests previously shown to be sensitive to AED withdrawal.

METHODS

We report outcomes on measures of choice reaction time from the California Computerized Assessment Package, on the Controlled Oral Word Association Test and on the Stroop Color-Word Interference Test.

RESULTS

Significantly improved T-scores were revealed after AED withdrawal on five of the six tests of executive functions with mean improvement of 5 T-scores. Comparable results were achieved in the subgroup taking carbamazepine, with a mean improvement of 6.2 T-scores.

CONCLUSION

The present results suggest that T-scores for computerized tests of choice reaction time and tests of verbal fluency and response inhibition may be significantly impaired as a consequence of AED monotherapy, and that careful interpretation of these scores is required in diagnostic assessment of patients receiving AED monotherapy.

White matter lesion severity is associated with reduced cognitive performances in patients with normal CSF Abeta42 levels

OBJECTIVE

To identify possible associations between white matter lesions (WML) and cognition in patients with memory complaints, stratified in groups with normal and low cerebrospinal fluid (CSF) Abeta42 values.

MATERIAL AND METHODS

215 consecutive patients with subjective memory complaints were retrospectively included. Patients were stratified into two groups with normal (n = 127) or low (n = 88) CSF Abeta42 levels (cut-off is 450 ng/l). Cognitive scores from the Mini-Mental State Examination (MMSE) and the Neurobehavioral Cognitive Status Examination (Cognistat) were used as continuous dependent variables in linear regression. WML load was used as a continuous independent variable and was scored with a visual rating scale. The regression model was corrected for possible confounding factors.

RESULTS

WML were significantly associated with MMSE and all Cognistat subscores except language (repetition and naming) and attention in patients with normal CSF Abeta42 levels. No significant associations were observed in patients with low CSF Abeta42.

CONCLUSIONS

WML were associated with affection of multiple cognitive domains, including delayed recall and executive functions, in patients with normal CSF Abeta42 levels. The lack of such associations for patients with low CSF Abeta42 (i.e. with evidence for amyloid deposition), suggests that amyloid pathology may obscure cognitive effects of WML.

Multimodal imaging in mild cognitive impairment: Metabolism, morphometry and diffusion of the temporal-parietal memory network

This study compared sensitivity of FDG-PET, MR morphometry, and diffusion tensor imaging (DTI) derived fractional anisotropy (FA) measures to diagnosis and memory function in mild cognitive impairment (MCI). Patients (n=44) and normal controls (NC, n=22) underwent FDG-PET and MRI scanning yielding measures of metabolism, morphometry and FA in nine temporal and parietal areas affected by Alzheimer's disease and involved in the episodic memory network. Patients also underwent memory testing (RAVLT). Logistic regression analysis yielded 100% diagnostic accuracy when all methods and ROIs were combined, but none of the variables then served as unique predictors. Within separate ROIs, diagnostic accuracy for the methods combined ranged from 65.6% (parahippocampal gyrus) to 73.4 (inferior parietal cortex). Morphometry predicted diagnostic group for most ROIs. PET and FA did not uniquely predict group, but a trend was seen for the precuneus metabolism. For the MCI group, stepwise regression analyses predicting memory scores were performed with the same methods and ROIs. Hippocampal volume and FA of the retrosplenial WM predicted learning, and hippocampal metabolism and parahippocampal cortical thickness predicted 5 minute recall. No variable predicted 30 minute recall independently of learning. In conclusion, higher diagnostic accuracy was achieved when multiple methods and ROIs were combined, but morphometry showed superior diagnostic sensitivity. Metabolism, morphometry and FA all uniquely explained memory performance, making a multi-modal approach superior. Memory variation in MCI is likely related to conversion risk, and the results indicate potential for improved predictive power by the use of multimodal imaging.

Morphometric changes in the episodic memory network and tau pathologic features correlate with memory performance in patients with mild cognitive impairment

BACKGROUND AND PURPOSE

Mild cognitive impairment (MCI) may affect several cognitive domains, including attention and reasoning, but is often first characterized by memory deficits. The purpose of this study was to ask these 2 questions: 1) Can levels of CSF tau proteins and amyloid beta 42 peptide explain thinning of the cerebral cortex in patients with MCI? 2) How are brain morphometry, CSF biomarkers, and apolipoprotein E (APOE) allelic variation related to episodic memory function in MCI?

MATERIALS AND METHODS

Hippocampal volume and cortical thickness were estimated by MR imaging and compared for patients with MCI (n = 18) and healthy controls (n = 18). In addition, regions of interest (ROIs) were selected in areas where the MCI group had atrophy and which overlapped with the episodic memory network (temporal, entorhinal, inferior parietal, precuneus/posterior cingulate, and frontal). Relationships among morphometry, CSF biomarkers, APOE, and memory were tested. The analyses were repeated with an independent sample of patients with MCI (n = 19).

RESULTS

Patients with MCI and pathologic CSF values had hippocampal atrophy. However, both patients with pathologic and patients with nonpathologic CSF had a thinner cortex outside the hippocampal area. CSF pathology was related to hippocampal volume, whereas relationships with cortical thickness were found mainly in one of the samples. Morphometry correlated robustly with memory performance across MCI samples, whereas less stable results were found for tau protein.

CONCLUSION

The differences in hippocampal volume between the MCI and the healthy control groups were only found in patients with pathologic CSF biomarkers, whereas differences in cortical thickness were also found for patients without such pathologic features. Morphometry in areas in the episodic memory network was robustly correlated with memory performance. It is speculated that atrophy in these areas may be associated with the memory problems seen in MCI.

A retrospective view on research in neuroscience in Norway

This brief historical review on neuroscience in Norway shows a comparatively high research activity with many important results. The Norwegian zoologist Fridtjof Nansen, who later became a famous Arctic explorer, was the first to formulate the neuron doctrine. 'The Oslo School of Neuroanatomy' contributed enormously to the understanding of the detailed anatomy and chemistry of the central nervous system. Norwegian neurophysiologists made important findings from studies of hippocampus including the inhibitory basket cell, the LTP phenomenon and the 'hippocampal-slice-technique'. In clinical neuroscience the description of Refsum's disease and studies of myasthenia gravis and multiple sclerosis have been of particular importance. Two of 13 centres of excellence in Norway selected in 2003 were from neuroscience, and The Norwegian Research Council has its own programme for neuroscience. The Norwegian Neurological Association arranges annual meetings to promote interest in neurological research.

G protein beta3 subunit C825T polymorphism modifies the presentation of temporal lobe epilepsy

PURPOSE

Experimental studies suggest a role of G protein-mediated signaling pathways in epileptogenesis. A genetic variation affecting the G protein subunit Gbeta3 denoted the C825T polymorphism has been reported to increase the signaling efficiency through G(i) proteins and to modify responses to certain drugs. The C825T polymorphism has also been associated with several diseases including hypertension, diabetes type II, obesity, and major depressive disorder. In this study, we have explored whether the G protein polymorphism C825T is associated with or influences temporal lobe epilepsy (TLE).

METHODS

The study included 227 TLE patients, 186 controls, and 106 family members of TLE patients. DNA was extracted from blood samples and typing of the polymorphism was performed. Case record forms were analyzed for all the homozygote TLE patients and homozygote controls, i.e., carrying the TT genotype as well as for 28 matched TLE patients (16 females, 12 males) without the polymorphism (CC genotype).

RESULTS

Typing of the C825T polymorphism showed that 6.0% of the TLE patients, 7.0% of the controls, and 7.5% of the family members were homozygote for the polymorphism; i.e., carrying the TT genotype. TLE patients carrying the TT genotype had higher severity score on eight out of nine predefined parameters compared with the TLE patients without polymorphism, i.e., carrying CC genotype. TT genotype TLE patients also had increased body mass index, body weight, and waist circumference compared with the TLE patients carrying the CC genotype. There was no increased frequency of hypertension or diabetes.

CONCLUSIONS

There was no increased frequency of TLE between the carriers of the TT genotype compared with the healthy controls and/or family members without epilepsy. However, the TLE patients with the TT genotype showed tendencies of a more severe disease phenotype.

Changes in autonomic cardiac control in patients with epilepsy after discontinuation of antiepileptic drugs: a randomized controlled withdrawal study

The aim of this study was to assess cardiac autonomic control in patients with epilepsy before and after withdrawal of antiepileptic drugs (AEDs). The study was prospective, randomized and double blinded. Spectral analysis of heart rate variability (HRV) in 24 h ECG-registration before and after withdrawal of AEDs was used to assess autonomic cardiac control. The assessment of HRV with spectral analysis was based on sinus rhythm and normal heart beats [normal to normal beat (NN)]. Thirty-nine patients had 24 h rhythms free from any ectopic beats both before and after intervention, and were included in the analysis. Significant differences were found in the withdrawal group: filtered RR intervals for all 5 min segments of the analysis; percentage of differences between adjacent filtered RR intervals that are greater than 50 ms for the whole analysis; very low frequency power; low frequency power and high frequency power. The results demonstrate that slow withdrawal of AEDs in seizure-free patients with epilepsy on drug mono-therapy resulted in an increase in both parasympathetic and sympathetic functions, indicative of increased power amongst patients following cessation of AED treatment. As low HRV has been associated with increased mortality in patients with other diseases, this increased HRV may be beneficial.

Valproate is an effective, well-tolerated drug for treatment of status epilepticus/serial attacks in adults

OBJECTIVE

Status epilepticus (SE) and serial attacks (SA) represent neurological emergencies, and mortality rate for SE/SA is high, ranging from 3% to 25%, depending on cause and co-morbidity. As SE/SA become more refractory to treatment over time, rapid, appropriate treatment is extremely important. Here, we report a prospective registration of the effect of intravenous (IV) valproate (VPA) on SE/SA in a group of Norwegian patients.

PATIENTS AND METHODS

Forty-one adult patients (18 males, 23 females) were included in the study. All had previously been unsuccessfully treated with diazepam. For 19, the main SE/SA seizure type was generalized tonic-clonic, while 16 had complex-partial seizures. Six had seizures that were difficult to classify. The treatment protocol recommended 25 mg/kg of VPA loading dose over 30 min, followed by continuous infusion of 100 mg/h for at least 24 h, then per oral administration. If seizures persisted after the loading dose, general anaesthesia (barbiturates/propofol/midazolam) was administered.

RESULTS

No serious side effects were reported. In 76% of the cases (31 of 41), SE/SA stopped and anaesthesia was not required. Of the patients treated within 3 h, only 5% needed anaesthesia, whereas of those treated after 3-24 h, 38% needed anaesthesia. Of those who waited for more than 24 h before treatment, 60% required anaesthesia. Furthermore, 60% of the patients who needed anaesthesia were given loading doses below 2100 mg.

CONCLUSIONS

VPA seems to be a safe, effective treatment of SE/SA, but efficacy is dependent on time lapse between symptoms and VPA treatment, and administration of a sufficiently high loading dose.

Diaschisis after thalamic stroke: a comparison of metabolic and structural changes in a patient with amnesic syndrome

INTRODUCTION

We present a patient with a left anteromedial thalamic lesion with an amnesic syndrome. The patient underwent neuropsychological testing, cerebrospinal fluid (CSF) analyses, magnetic resonance imaging (MRI) [T2, flair, and diffusion tensor imaging (DTI)] and [18F]-2-fluoro-deoxy-d-glucose positron emission tomography (FDG-PET) to assess indirect effects of thalamic lesions on cortical function.

CASE REPORT

A 67-year-old right-handed woman was admitted to a university-based memory unit because of memory and concentration problems. Neuropsychological testing revealed dysfunction of episodic memory, semantic memory and working memory. General intellectual function and attention capacity were preserved. MRI revealed an anteromedial thalamic lesion in the left hemisphere. FDG-PET showed decreased uptake in the frontal, parietal and temporal lobes of the left hemisphere. Regions of interest (ROI) in white matter were selected and left and right hemispheres were compared. Fractional anisotropy (FA) in ROI representing thalamo-cortical connections were decreased in the left hemisphere when compared with the right.

CONCLUSION

The results show the importance of a network that include the anterior and dorsomedian nuclei, which influence the activity in areas of the cortex responsible for memory processes. The imaging findings suggest that areas of cortical diaschisis after thalamic infarction correspond to areas affected by thalamo-cortical fibre loss as measured with FA.

Lamotrigine in idiopathic epilepsy - increased risk of cardiac death?

OBJECTIVES

Lamotrigine (LTG) has recently been shown to inhibit the cardiac rapid delayed rectifier potassium ion current (Ikr). Ikr-blocking drugs may increase the risk of cardiac arrhythmia and sudden unexpected death. With this background, it may be of importance that in our outpatient clinic between August 1, 1995 and August 1, 2005 we registered four consecutive cases of sudden unexpected death in epilepsy (SUDEP) in non-hospitalized patients that were all being treated with LTG in monotherapy. Here we describe and discuss these cases, the relevant literature, and the reasons to question whether these events were as a result of coincidence alone.

METHODS

All the cases were collected consecutively at the outpatient clinic, Department of Neurology, Stavanger University Hospital, Norway. Clinical and pathological data were obtained and the relevant literature reviewed.

RESULTS

All were females with idiopathic epilepsy.

CONCLUSIONS

A systematic study is needed to reveal whether LTG may increase the risk of SUDEP in certain groups of patients.

Antiepileptic drugs alter reproductive endocrine hormones in men with epilepsy

Disturbances of reproductive endocrine hormones are more often found in men with epilepsy than in the general population. There is an ongoing debate whether this can be attributed to chronic use of antiepileptic drugs or to the epilepsy itself. The aim of the present study was to evaluate the degree of endocrine disturbances in men with epilepsy compared with healthy controls, and to investigate whether there was a drug-specific effect of valproate (VPA) or carbamazepine (CBZ). Men with epilepsy, 20-40 years old, having used either VPA (n = 16) or CBZ (n = 19) as monotherapy for >2 years were included and compared with age-matched controls. Men with epilepsy (VPA + CBZ) had significantly lower FSH values and higher C-peptide values compared with controls. Regarding possible drug-specific effects, the VPA treated patients had significantly higher dehydroepiandrosterone (DHEAS) levels and lower FSH and LH concentrations compared with the controls, whereas there were no differences in testosterone, testosterone/sexhormone-binding globulin (SHBG) ratio or androstenedione levels. Men on VPA also had significantly lower free carnitine/total carnitine, which may have implications for sperm motility, and also higher insulin and C-peptide concentrations. The CBZ treated patients had significantly lower testosterone/SHBG ratio than the controls. Compared with the CBZ treated patients, men on VPA had significantly higher DHEAS concentrations and lower levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) as well as a lower free carnitine/total carnitine ratio. A marked age dependency was found in all three groups regarding several of the endocrine hormones. In conclusion, drug-specific endocrine effects of VPA and CBZ were found in men with epilepsy. Long-term VPA treatment leads to significant changes in DHEAS, FSH, LH, insulin, C-peptide and carnitine ratio. Long-term CBZ treatment leads to significant lower testosterone/SHBG ratio. A strict age matching were found to be of importance in the evaluation of endocrine function in men.

Alterations in semen parameters in men with epilepsy treated with valproate or carbamazepine monotherapy

Men with epilepsy are known to have reduced fertility. Whether this is drug-induced or a result of the epilepsy itself is still under debate. Few studies have been carried out on semen from men with epilepsy. The aim of the present study was first to investigate possible drug-specific effects of long-term treatment with either valproate or carbamazepine on semen quality and testicular size, and secondly to see whether the results in epilepsy patients differed from healthy fertile males. Men with epilepsy, 20-40 years old, having used either valproate (n = 16) or carbamazepine (n = 20) for >2 years, were included. The semen data of healthy fertile men without epilepsy in the same age group (n = 90) were used as controls. The semen was examined according to WHO (1999). No significant differences in semen quality were seen between men receiving either valproate or carbamazepine. However, semen from the valproate-treated, as opposed to the carbamazepine-treated, differed from controls with regard to tail abnormalities. Absolute testicular size was not significantly different between the two treatment groups. However, after correcting for changes in body mass index (BMI), the testicular size/BMI ratio was lower in the valproate-treated patients. The valproate-treated patients gained significantly more weight than the carbamazepine-treated patients after start of current medication. No differences between the patient groups were found in terms of libido/potency or number of pregnancies fathered. When comparing all epilepsy patients with healthy fertile males, there was a significant reduction in the percentage of rapidly progressive motile sperms in the semen from epileptic patients. The semen from men with epilepsy also showed significant differences from the controls regarding neck and head abnormalities of the spermatozoa.

Incidence and predictors for post-stroke epilepsy. A prospective controlled trial. The Akershus stroke study

The aim of the study was to assess the incidence and identify predictors for post-stroke epilepsy (PSE), in particular the possible influence of treatment in a stroke unit (SU). Patients with PSE were identified between 4 weeks and 1 year after the stroke. Different parameters were studied as possible predictors. Twelve patients (2.5%) developed PSE during 12 months. Four of the patients (33%) were treated in an SU and eight of the patients (67%) were treated in general medical wards (GMWs) (P=0.50). Mean age in those with PSE was 75 and 76 in those without (P=0.57). Four out of 363 patients (1.1%) with minor stroke [Scandinavian Stroke Scale (SSS)-score >30] developed PSE. Seven out of 104 patients (6.3%) with severe stroke developed PSE (P=0.004). In the multivariate analysis SSS-score scores below 30 was a significant predictor for incidence of PSE (odds ratio=6.1, P=0.003). At 12 months the incidence of PSE was 2.5%. SSS-score below 30 was a significant predictor for PSE, whilst age and treatment in SU versus GMW were not.

Morphological changes in the testis after long-term valproate treatment in male Wistar rats

Uncertainty exists about the effect of antiepileptic drugs on gonadal function. In females, long-term valproate treatment has been shown to induce endocrine disturbances and an increased number of ovarian cysts. The aim of the present study was to investigate whether valproate can also induce morphological changes in the testis of male animals. In addition, possible morphological changes in the liver, heart, lungs, lymphatic nodes, pancreas, kidney or brain were studied. The carcinogenic implications were evaluated by the measurement of p53. Male Wistar rats were fed perorally with valproate mixture 200 mg kg(-1)(n= 15) or 400 mg kg(-1)(n= 20), or control solution (n= 15) twice daily for 90 days. Serum concentrations measured 4-6 hours after the last dose were 105 and 404 micromol l(-1)in low- and high-dose valproate treated animals respectively. There was a highly significant, 51% decrease (P< 0.001) in testicular weight in the high-dose treated valproate rats with no changes in the other groups. There was widespread testicular atrophy with histologically verified spermatogenic arrest in 15/20 of the high-dose valproate treated animals. No changes in the testis were seen in the low-dose valproate treated rats, nor in the control rats. There were no morphological changes in the other investigated organs. None of the groups showed over-expression of p53. In conclusion, a dose-dependent effect of chronic valproate treatment was found on testicular morphology in rats. Caution must be taken before these results can be applied to humans.

Altered ovarian function and cardiovascular risk factors in valproate-treated women

PURPOSE

Polycystic ovaries and menstrual disturbances seem to be common among women taking valproate for epilepsy. The purpose of the present study was to assess the frequency of valproate-related metabolic and endocrine disorders in different groups of women with epilepsy.

SUBJECTS AND METHODS

Seventy-two women with epilepsy and 52 control subjects from centers in three European countries (Finland, Norway, and the Netherlands) participated in the study. Thirty-seven of the women with epilepsy were taking valproate monotherapy and 35 carbamazepine monotherapy.

RESULTS

The frequency of polycystic ovaries or hyperandrogenism, or both, among valproate-treated women with epilepsy was 70% (26 of 37) compared with 19% (10 of 52) among control subjects (P <0.001). They were found in 79% (11 of 14) of obese and 65% (15 of 23) of lean women on valproate, and in 20% (7 of 35) of carbamazepine-treated women. The obese valproate-treated women with polycystic ovaries or hyperandrogenism, or both, had hyperinsulinemia and associated unfavorable changes in serum lipid levels consistent with insulin resistance.

CONCLUSIONS

Polycystic ovaries and related hyperandrogenism are frequently encountered in both obese and lean women taking valproate for epilepsy. The use of valproate is associated with risk factors for cardiovascular disease in obese women.

Up-regulation of hippocampal glutamate transport during chronic treatment with sodium valproate

Excessive glutamatergic neurotransmission has been implicated in some neurodegenerative disorders. It would be of value to know whether glutamate transport, which terminates the glutamate signal, can be up-regulated pharmacologically. Here we show that chronic treatment of rats with the anti-epileptic drug sodium valproate (200 mg or 400 mg/kg bodyweight, twice per day for 90 days) leads to a dose-dependent increase in hippocampal glutamate uptake capacity as measured by uptake of [(3)H]glutamate into proteoliposomes. The level of glutamate transporters EAAT1 and EAAT2 in hippocampus also increased dose-dependently. No effect of sodium valproate on glutamate transport was seen in frontal or parietal cortices or in cerebellum. The hippocampal levels of glial fibrillary acidic protein and glutamine synthetase were unaffected by valproate treatment, whereas the levels of synapsin I and phosphate-activated glutaminase were reduced by valproate treatment, suggesting that the increase in glutamate transporters was not caused by astrocytosis or increased synaptogenesis. A direct effect of sodium valproate on the glutamate transporters could be excluded. The results show that hippocampal glutamate transport is an accessible target for pharmacological intervention and that sodium valproate may have a role in the treatment of excitotoxic states in the hippocampus.

Chronic lamotrigine treatment increases rat hippocampal GABA shunt activity and elevates cerebral taurine levels

The mechanism of action of the antiepileptic drug lamotrigine has previously been investigated only in acute experiments and is thought to involve inhibition of voltage-dependent sodium channels. However, lamotrigine is effective against more forms of epilepsies than other antiepileptic drugs that also inhibit sodium channels. We investigated whether chronic lamotrigine treatment may affect cerebral amino acid levels. Rats received lamotrigine, 10 mg/kg/day, for 90 days. The hippocampal level of GABA increased 25%, and the activities of glutamate decarboxylase and succinic semialdehyde/GABA transaminase increased 12 and 21% (p< 0.05), respectively, indicating increased GABA turnover. The uptake of GABA and glutamate into proteoliposomes remained unaltered. The level of taurine increased 27% in the hippocampus and 16% in the frontal and parietal cortices. The activities of hexokinase and alpha-ketoglutarate dehydrogenase, remained at control values. Serum lamotrigine was 41.7+/-1.5 microM (mean+/-S.E.M.), which is within the range seen in epileptic patients. Acute experiments with 5, 20 or 100 mg lamotrigine/kg, caused no changes in brain amino acid levels. The results suggest that chronic lamotrigine treatment increases GABAergic activity in the hippocampus. The cerebral increase in taurine, which has neuromodulatory properties, may contribute to the antiepileptic effect of lamotrigine.

Valproate, but not lamotrigine, induces ovarian morphological changes in Wistar rats

Valproate (VPA) medication is associated with development of polycystic ovaries, menstrual disorders and hormonal changes in women with epilepsy. We sought to determine if changes in the ovaries also occurred in an animal model without epilepsy, and whether this effect could be related to a carcinogenic effect expressed by overexpression of p53. A potentially alternative antiepileptic drug, lamotrigine (LTG), was evaluated simultaneously. To this end, female Wistar rats were fed perorally with VPA 400 mg/kg/day (n = 15), VPA 600 mg/kg/day (n = 20), LTG 10 mg/kg/day (n = 15) or control solution (n = 15) for 90-95 days. There was a significant, dose-dependent increase in the number of follicular cysts, reduction in the number of corpora lutea and reduction of ovarian weight in the VPA group. No ovarian pathology was observed in the LTG group. In neither of the groups were morphological changes seen in other organs, nor was there any overexpression of the tumor suppressor gene p53 found. An alternative antiepileptic drug, LTG, showed no ovarian pathology, and there were no light microscopic changes in other organs, or evidence of pathologic p53 overexpression in the LTG-treated animals.

Failure to confirm neurotoxic impairment using cerebral magnetic resonance imaging on solvent-exposed workers

OBJECTIVES

The study aimed at assessing signs of nervous system impairment by cerebral magnetic resonance imaging (MRI) among workers with a history of long-term exposure to mixtures of organic solvents.

METHODS

Thirty-six workers (mean age 44.1 years) with at least 10 (mean 23.9) years of occupational exposure to solvents and pair-matched referents with no former solvent exposure went through a blind, random-order investigation of cerebral MRI, performed with a 1.5-tesla scanner.

RESULTS

Linear measurements of the MRI tomograms showed a slight tendency toward wider ventricles and broader cortical sulci in the reference group. Visual evaluation of the MRI by 2 experienced neuroradiologists showed no significant difference between the groups; however, there was substantial interobserver variability.

CONCLUSIONS

The MRI findings of this study do not support the hypothesis that long-term low-level occupational exposure to organic solvents results in the development of brain atrophy, or specific MRI signal changes in the region of the basal ganglia and thalami.

Predictors for recurrence of epileptic seizures in a general epilepsy population

The aim of our study was to identify predictors for recurrence of epileptic seizures in a large county hospital population. We identified 956 patients (18-67 years) with ICD 9 code 345 as primary diagnosis, seen at the Central Hospital of Akershus over 7 years (1987-1994). The diagnosis of epilepsy was confirmed for 696 of the patients. These were divided into two groups: (1) no seizures during the previous year (n = 485) and (2) seizures during the previous year (n = 184). To identify predictors for recurrence of seizures, we used neurologic deficit, number of AEDs used, CT-scan findings, EEG findings, aetiology, gender, age below and above 50 years and comorbidity as independent variables in a logistic regression model. In a univariate analysis, the strongest predictors for recurrence of seizures were: age above 50 years (OR = 5.2;P < 0.0001), known aetiology (OR = 1.4;P = 0.04) and use of two or more AEDs (OR = 5. 7;P < 0.0001). In the multivariate analysis age, more than 50 years (OR = 1.7;P = 0.0216) and use of two or more AEDs (OR = 5.6;P < 0.0001) were the only predictors for recurrence of epileptic seizures.

Long-term valproate treatment induces changes in ovarian morphology and serum sex steroid hormone levels in female Wistar rats

Long-term valproate treatment is associated with polycystic ovaries and endocrine disorders in women with epilepsy. The mechanisms responsible for these effects are unknown, but both the epilepsy itself and the drug per se may be of importance. The aim of this study was to investigate possible effects of the drug on gonadal structure and function in animals with no epileptic disorders. Three groups, each of 15 female Wistar rats, were fed perorally with a valproate mixture (50 mg / kg or 200 mg / kg) or control solution once daily for 90 days, giving mean valproate concentrations within the normal human range. A significant, 20% increase in ovary weight was found in both low- (P = 0.027) and high- (P < 0.001) dose animals together with a significantly increased number of ovarian follicular cysts. Mean serum testosterone concentration was significantly reduced in both low- and high-dose animals. There was a non-significant trend towards reduced estrogen levels, while progesterone levels were unchanged. Even if the hormonal changes are somewhat different from those in humans, the findings demonstrate that changes in gonadal structure and endocrine function also occur in intact animals indicating a drug-specific effect. Our findings encourages further studies using animal models to elucidate possible mechanisms involved in the endocrine side-effects of antiepileptic drugs.

Cerebral artery blood velocity in normal subjects during acute decreases in barometric pressure

To investigate the effect of acute changes in barometric pressure on regional cerebral perfusion we studied the middle cerebral artery (MCA) blood velocity in five healthy male volunteers by means of a low-pressure chamber. The MCA blood velocity, arterial blood and respiratory gases were measured at the barometric pressures of 1, 0.8, 0.65, and 0.5 atmospheres. The observed blood velocity (Vo) showed no systematic changes. Decreases in barometric pressure induced hypoxia and hypocapnia. When normalizing the MCA blood velocity (Vn) to a standard P(CO2) (5.3 kPa), thereby correcting for the hypoxic induced hypocapnia, we obtained an inverse relationship between cerebral artery blood velocity and arterial blood oxygen content (CaO2). The oxygen supply to the brain, estimated as the product of Vo and CaO2, decreased with lowering of the barometric pressure. However, the product of Vn and CaO2 remained constant. This suggests the existence of a regulatory mechanism attempting to maintain a constant oxygen supply to the brain during acute changes in CaO2, if the hyperventilation induced decrease in PCO2 can be omitted. In the artificial situation of a low pressure chamber, our findings are quite similar to those obtained at sea level. This indicates that the underlying mechanisms of control of cerebral blood flow do not change during acute exposure to altitude.

Focal retrograde amnesia associated with vascular headache

We report the case of a 42-year-old man with repeated attacks of headache associated with retrograde amnesia. Neuropsychological tests before and after the major episode of amnesia showed mild neuropsychological deficits but with spared anterograde memory and learning functions. The amnesia was dense for a period of 15-20 years and included people and events (public and private). There was also a suggestion of amnesia for learned skills. Neurologically he had mild clinical signs and focal EEG-abnormalities in the left fronto-temporal region, but CT, MRI, and SPECT showed no abnormality. Five years after the onset of amnesia there was no recovery of the retrograde memory deficit, but a PET (glucose) scan was normal and neuropsychological testing showed no deficits. An association with migraine has been reported for some non-classical amnesias, but this is the first case of selective retrograde amnesia in a patient with headache as a primary neurological diagnosis.

Cyclosporin A and brain excitability studied in vitro

PURPOSE

Seizures are frequently observed after organ transplantations. This has been attributed to a direct effect of cyclosporin A (CsA) on the brain, although other mechanisms may also be of importance. The aim of this study was to investigate possible acute and direct effects of CsA on neuronal excitability.

METHODS

Female rat hippocampal slices were perfused with CsA solutions containing 400 (n = 4), 1,000 (n = 4), 2,000 (n = 6), 8,000 (n = 8) microg/L CsA or control (n = 8) for 30 min, or penicillin, 2,000 IE/ml (n = 7). Actual concentrations of CsA were measured in the perfusate drawn from the slice chamber. To study CsA accumulation in the slices, uptake of radioactive CsA was measured in 12 living and 11 dead slices.

RESULTS

Despite a significant accumulation of CsA in the living neuronal slices, no effects were observed on prevolley, field excitatory postsynaptic potential (fEPSP), or population spike amplitude. Penicillin, however, led to epileptiform activity within 10 min in all cases. Concentrations of CsA in the perfusate from the slice chamber were about half the calculated levels, demonstrating that the slices had been exposed to actual CsA concentrations in the range of approximately 200-4,000 microg/L CsA.

CONCLUSIONS

Our results demonstrate a lack of acute effects of CsA on neuronal excitability within clinically relevant concentrations despite an active accumulation of the drug in the slices. Long-term effects on brain tissue, indirect metabolic effects, or synergistic effects may be responsible for the neurotoxicity of the drug.

[Neuropsychiatric symptoms and findings in systemic lupus erythematosus ]

Systemic lupus erythematosus (SLE) frequently involves the central nervous system. The clinical presentation is highly variable and heterogeneous. The involvement of the central nervous system is often reflected in minor or major neuropsychiatric symptoms. We describe three cases of this neuropsychiatric lupus erythematosus. A variety of laboratory tests are essential in order to establish the correct diagnosis of neuropsychiatric SLE. We discuss the usefulness of magnetic resonance imaging in both a diagnostic setting and as a tool for improving the understanding of the pathogenesis of neuropsychiatric SLE.

[Epilepsy]

Epilepsy is a common neurological disorder which affects about 30,000 persons in Norway. 10% of the population may have experienced a single seizure, most of them occurring as a febrile seizure in childhood. Specialists in neurology and pediatrics are responsible for the diagnostic procedures and treatment. However, most doctors will see patients with seizures. This must be recognized as a symptom with many causes, rather than as a specific kind of disease. The author briefly reviews diagnosis, classification and treatment, with special emphasis on aspects which may be of importance for the general practitioner.

Acute effects of 17 beta-estradiol on brain excitability studied in vitro and in vivo

The acute effects of 17 beta-estradiol on brain excitability were studied in vitro and in vivo utilizing rat hippocampal slices and a cat cerveau isolé preparation. The hippocampal slices were perfused with 17 beta-estradiol (10(-7)-10(-10) M) for 30 min. No effects were observed on synaptic activation and inhibition and on the response to iontophoretically applied GABA in intact and ovariectomized female rats (n = 43). In males (n = 32), however, a small (12%) but significant increase in population spike amplitude was observed after 30 min exposure to 10(-9) M 17 beta-estradiol. Higher and lower concentrations were ineffective. In vivo, no acute effects of 17 beta-estradiol on focal epileptic seizure thresholds, evoked potentials, or augmenting response were observed in the visual cortex of non-estrous female cats (n = 11; median dose 1 micrograms/kg, range 0.5 microgram/kg-10 mg/kg).

Neuropsychological findings in a non-clinical sample of workers exposed to solvents

The risk of long-term damage to the CNS after exposure to mixed solvents in work environments is controversial. Thirty-six workers were studied who had been exposed to organic solvents for more than 10 years (mean 24.5 years) in a working environment. The workers and unexposed controls were studied with a battery of neuropsychological and cognitive tests. Significant group differences were observed for the Wechsler adult intelligence scale (WAIS) digit span and symbol digit substitution, and on paired associate learning and continuous word recognition. The results suggest that long-term work-related exposure to organic solvents may have chronic toxic effects.

The progesterone metabolite 5 alpha-pregnan-3 alpha-ol-20-one reduces K(+)-induced GABA and glutamate release from identified nerve terminals in rat hippocampus: a semiquantitative immunocytochemical study

5 alpha-Pregnan-3 alpha ol-20-one (3 alpha-OH-DHP) reduced the depolarization-induced loss of GABA and, to a lesser extent, the glutamate-like immunoreactivities from nerve terminals in the in vitro hippocampal slice. Phenobarbital (PB) had similar effects. These results suggest that 3 alpha-OH-DHP affects presynaptic transmitter release, possibly in a barbiturate-like manner.

[Driver's licence and seizures]

The authors consider various types of seizures and their medico-legal consequences in connection with motor vehicle driving. Epilepsy, syncope, transitory ischemic attacks, migraine, electrolyte disturbances, hypoglycaemia, hypersomnia, and alcohol-induced fits are discussed in brief. The authors also discuss risk of recurrence, the seizure-free interval before driving can be resumed, and possible mitigating factors.

[Driver's licenses and medicine. A review of legal requirements and practice]

There are health requirements for acquiring and renewing a driver's license. Physicians are legally obliged to inform the local health authorities when a patient no longer meets these health requirements. This paper describes the current Norwegian legislation, formalities of administration, and practice of traffic medicine. Visual acuity, field of vision, seizures, heart disease, diabetes mellitus, abuse of alcohol and drugs, psychiatric disorders, aging and dysfunction of the locomotor system are discussed in brief.

Comparison of 5 alpha-pregnan-3 alpha-ol-20-one and phenobarbital on cortical synaptic activation and inhibition studied in vitro

The effects of 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha-OH-DHP) and phenobarbital (PB) on synaptic excitation and inhibition in rat hippocampal slices in vitro were compared. Stimulations were made orthodromically and antidromically while we recorded extracellularly from the dendritic and the somatic layer of the CA1 region. Perfusion with 5 micrograms/ml of 3 alpha-OH-DHP for 30 min significantly increased the recurrent inhibition evoked by antidromic stimulation. The effect was most pronounced at short interstimulus intervals. The duration of the recurrent inhibition also was prolonged. There was no effect on the conditioned population spike after orthodromic paired-pulse stimulation. Furthermore, no effect was observed on the amplitude of the orthodromic fiber volley, the rate of increase in the field excitatory postsynaptic potential (EPSP) and the latency and amplitude of the CA1 population spike. Qualitative and quantitative similar findings were observed during perfusion with PB 0.1 mg/ml, (i.e., a concentration 20 times higher than that of 3 alpha-OH-DHP). Higher concentrations of PB also affected synaptic excitation. The findings suggest a similar effect of 3 alpha-OH-DHP and PB on recurrent GABA-ergic inhibition; however, 3 alpha-OH-DHP appears to be much more potent.

[Botulinum toxin treatment of spastic torticollis]

Botulinum toxin A was administered to 19 patients with spasmodic torticollis. A significant decrease of abnormal head and neck movements was recorded, and all the patients who suffered pain reported relief. Side effects were minor and transient. The results of this study indicate that botulinum toxin is an effective means of treating torticollis.

Regional cerebral blood flow after long-term exposure to carbon disulfide

Sixteen former rayon viscose workers were investigated four years after the exposure to carbon disulfide was discontinued. Median age was 58 years (range 43-65 years), median exposure time was 17 years (range 10-35 years). Encephalopathy was diagnosed in altogether 14 workers. To further explore pathophysiological mechanisms, cerebrovascular investigations were employed. Doppler ultrasound examination of the precerebral vessels in 15 workers showed a slight stenosis of the left internal carotid artery in one. Regional cerebral blood flow investigation (rCBF) with single photon emission computerized tomography (SPECT) with Xenon-133 gas was performed in 14. There was no significant difference from a control group. Regional side-to-side asymmetries beyond reference limits were demonstrated in eight workers. The abnormalities were modest, but may indicate a tendency toward focal blood flow disturbances in workers with long-term exposure to carbon disulfide.