Inborn errors of metabolism and motor disturbances in children

Motor disturbances are very common in paediatric neurology. Often families can be reassured that these are just variants of normal development. However, abnormal movements can also be the hallmark of severe brain dysfunction of different and complex origins. This review concentrates on motor disturbances as frequent and important symptoms of inborn errors of metabolism. A structured diagnostic approach is developed taking into account age-dependent physiological developments and pathophysiological responses of gross and fine motor functions. A series of investigations are presented with the primary aim of early diagnosis of treatable conditions. The correct recognition and differentiation of movement disorders (ataxia, rigid akinetic syndrome (Fparkinsonism_), dystonia, athetosis, tremor,and others), spasticity, and neuromuscular disorders, requires profound neurological expertise. A high level of suspicion and close interaction between paediatric neurologists and specialists in inborn errors of metabolism are indispensable to effectively and timely identify patients in whom motor disturbances are the presenting and/or main symptom of an inborn error.

Secondary abnormalities of neurotransmitters in infants with neurological disorders

Neurotransmitters are essential in young children for differentiation and neuronal growth of the developing nervous system. We aimed to identify possible factors related to secondary neurotransmitter abnormalities in pediatric patients with neurological disorders. We analyzed cerebrospinal fluid (CSF) and biogenic amine metabolites in 56 infants (33 males, 23 females; mean age 5.8mo [SD 4.1mo] range 1d-1y) with neurological disorders whose aetiology was initially unknown. Patients were classified into three clinical phenotypes: epileptic encephalopathy, severe motor impairment, and non-specific manifestations. All patients showed normal results for screening of inborn errors of metabolism. We report clinical, neuroimaging, and follow-up data. Among the patients studied, 10 had low homovanillic acid (HVA) levels and in four patients, 5-hydroxyindoleacetic acid (5-HIAA) was also reduced. Patients with neonatal onset had significantly lower levels of HVA than a comparison group. HVA deficiency was also associated with severe motor impairment and the final diagnosis related to neurodegenerative disorders. 5-HIAA values tended to be decreased in patients with brain cortical atrophy. The possibility of treating patients with L-Dopa and 5-hydroxytryptophan, in order to improve their neurological function and maturation, may be considered.

Palatal tremor in childhood: clinical and therapeutic considerations

Palatal tremor (PT) is a rhythmic movement of the soft palate that often causes an ear click. PT can be symptomatic (SPT) or essential (EPT). The symptomatic form usually occurs in adults and the essential form mainly occurs in children. Several different treatments for EPT in children appear in the literature with variable reported efficacy. This report details four paediatric patients with EPT (three males, one female; mean age 6y 4mo [SD 6mo]; age at onset 6-7y) treated with piracetam (2-oxo-1-pyrrolidine acetamide). Piracetam was used to treat EPT because of its antimyoclonic properties. All children showed a good response to doses of 100 to 300mg/kg/day. EPT relapsed on withdrawal of piracetam and remitted on reintroduction. Piracetam's effect on EPT was sustained. It is concluded that piracetam is an effective drug for the treatment of EPT in children.

[Inborn errors of neurotransmitters in neuropaediatrics]

AIMS

The aim of this work is to describe the clinical, biochemical and genetic characteristics of neurotransmitter diseases at the paediatric age, together with possible forms of treatment. We also sought to determine the diagnostic methodology of these disorders (collection and analysis of samples).

DEVELOPMENT

These diseases essentially consist of a deficit of biogenic amines and alterations in GABA metabolism (gamma-aminobutyric acid). Disorders affecting the neurotransmission of biogenic amines often present in the form of hypokinesia, trunk hypotonia with increased limb tone, oculogyric crises, ptosis, faulty temperature regulation or abnormal movements. Defects in GABA metabolism give rise to epileptic encephalopathies and unspecific mental retardation, sometimes associated to signs of cerebellar dysfunction, convulsions and alterations in neuroimaging studies. Overall incidence of these diseases is low but they are unquestionably under-diagnosed, since they cannot be detected by conventional studies in plasma and urine, and require extraction and directed analysis of cerebrospinal fluid (CSF) for their detection. Additionally, the CSF study must be carried out in specific standardised conditions. Segawa's disease, or dopa-responsive dystonia, responds extremely well to therapy, whereas the other entities respond in varying ways to the different therapeutic alternatives.

CONCLUSIONS

It is important for the paediatrician to know about these entities as a group of treatable neurometabolic diseases. Moreover, their detection would allow prenatal diagnosis in the vast majority of cases.

[Movement disorders of functional origin (psychogenic) in children]

PATIENTS AND METHODS

Sixteen cases of functional (psychogenic) pediatric movement disorders (PMD) have been analyzed. They represents 2.4% of a PMD personal series (age of onset less than 18).

RESULTS

Apart from a case, age of onset was older than 10 years. 81% (13/16 cases) were females. Tremor (68%) was the predominant abnormal movement followed by mioclonus. These facts are according with the scarce studies reported of functional PMD. We emphasize the diagnostic difficulties of this kind of conditions.

CONCLUSIONS

Diagnostic clues are age of onset older than 10 years, female gender, clinical inconsistency of the movement, increasing or decreasing of the movements with attention to the movements or distraction, normality of the exams including neurophysiological studies. However in some cases a follow-up is necessary to confirm the diagnosis.

Electrophysiological approach to the study of essential tremor in children and adolescents

Surface electromyography and accelerometry provide essential information on the neurophysiological characteristics of essential tremor. There are many reports on neurophysiological features in adult-onset essential tremor, but to our knowledge there have been no similar investigations of essential tremor in children. We conducted a neurophysiological study of nine children, six males and three females, with definite essential tremor. They were subdivided into two groups according to age: a 'children's group', consisting of four patients aged from 7 to 12 years, and an 'adolescent group', consisting of five patients aged from 14 to 16 years. Finger tremor as opposed to hand tremor was studied. In children the mean tremor frequency was 5.3 Hz (SD 0.5) with arms extended, which increased to 8.2 Hz (SD 1.5) when we added a mass of 300 g. In adolescents the mean tremor frequency was 9.0 Hz (SD 1.4) with arms extended, and 7.2 Hz (SD 1.8) with added mass. We discuss several hypotheses to find an explanation for these results.

[Stereotypic movements]

Stereotypic movements are repetitive patterns of movement with certain peculiar features that make them especially interesting. Their physiopathology and their relationship with the neurobehavioural disorders they are frequently associated with are unknown. In this paper our aim is to offer a simple analysis of their dominant characteristics, their differentiation from other processes and a hypothesis of the properties of stereotypic movements, which could all set the foundations for research work into their physiopathology.

[Comorbid disorders associated with tics]

INTRODUCTION

Tics are the most frequent abnormal movements in children. This is one reason for their importance. Another reason is their relationship to fascinating disturbances of human behaviour such as compulsion and obsessions. Several 'behavioural disorders', mainly attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD), are more frequent in patients with tics than in the general population. These associated disorders (named 'comorbid') are probably of more consequence than the tics. Relationship between tics and comorbid disorders is not well known. This review considers data, consequences, hypothesis and management of comorbid disorders associated to tics.

DEVELOPMENT

From the personal series of children with tics, data of comorbid disorders associated to tics was analysed. Of 340 cases of tics, 132 (39%) cases have ADHD, 135 (40%) cases have OCD, obsessive compulsive symptoms (OCS) or obsessive-compulsive behaviour (OCB). 68 (20%) cases have both ADHD and OCD. Considering only Tourette cases (219) the figures are only slight higher: ADHD (42%), OCD (45%) and ADHD plus OCD (24%) suggesting that all the spectrum of tics has a common basis.

CONCLUSIONS

Familial studies shows that 44 percent of the patients with tics have a positive familial history of tics and 30 percent positive familial history of obsessive compulsive signs. The data of the literature on the tics and comorbid disorders relationship is also revised.

Autosomal dominant Emery-Dreifuss muscular dystrophy: a new family with late diagnosis

Emery-Dreifuss muscular dystrophy is characterized by the clinical triad of early onset contractures of elbows, Achilles tendons and spine, wasting and weakness with a predominantly humero-peroneal distribution and life-threatening cardiac conduction defects and/or cardiomyopathy. Two main types of inheritance have been described: the X-linked form is caused by mutations in the STA gene on locus Xq28 and the gene for the autosomal dominant form (LMNA gene) has been localized on chromosome 1q11-q23. Recently, mutations in this LMNA gene have been also found to be responsible for the less frequent autosomal recessive form of the disease. Although all forms share a similar clinical presentation, some differences appear to exist between them as has been described recently in a large number of patients. We present the first documented Spanish family genetically confirmed to have autosomal dominant Emery-Dreifuss muscular dystrophy. Clinical, pathological and genetic data are described. We emphasize the difficulties in diagnosis, especially in sporadic cases or young patients in whom the clinical picture is not completely established.

[Frequency of movement disorders in children]

We analyze the main clinical characteristics of a series of 800 patients seen by us, who had movement disorders which had started during childhood. The results are compared with those movement disorders of adult onset reported in the literature.

Glutaryl-CoA dehydrogenase deficiency in Spain: evidence of two groups of patients, genetically, and biochemically distinct

Glutaryl-CoA dehydrogenase (GCDH) deficiency causes glutaric aciduria type I (GA I), an inborn error of metabolism that is characterized clinically by dystonia and dyskinesia and pathologically by neural degeneration of the caudate and putamen. Studies of metabolite excretion allowed us to categorize 43 GA I Spanish patients into two groups: group 1 (26 patients), those presenting with high excretion of both glutarate and 3-hydroxyglutarate, and group 2 (17 patients), those who might not be detected by routine urine organic acid analysis because glutarate might be normal and 3-hydroxyglutarate only slightly higher than controls. Single-strand conformation polymorphism (SSCP) screening and sequence analysis of the 11 exons and the corresponding intron boundaries of the GCDH gene allowed us to identify 13 novel and 10 previously described mutations. The most frequent mutations in group 1 were A293T and R402W with an allele frequency of 30% and 28%, respectively. These two mutations were also found in group 2, but always in heterozygosity, in particular in combination with mutations V400M or R227P. Interestingly, mutations V400M and R227P were only found in group 2, and at least one of these mutations was found in 11 of 15 unrelated alleles, accounting together for 53% of the mutant alleles in group 2. Therefore, it seems clear that two genetically and biochemically distinct groups of patients exist. The severity of the clinical phenotype seems to be closely linked to the development of encephalopathic crises rather than to residual enzyme activity or genotype. Comparison of GCDH protein with other acyl-CoA dehydrogenases (whose x-ray crystal structure has been determined) reveals that most of the mutations identified in GCDH protein seem to affect folding and tetramerization, as has been described for a number of mutations affecting mitochondrial beta-oxidation acyl-CoA dehydrogenases.

[Practical considerations regarding the diagnosis and treatment of disorders of movement in childhood]

OBJECTIVE

Disorders of movement in children frequently cause difficulties with both the semiology and the diagnostic approach.

DEVELOPMENT

Based on our experience, we analyze useful strategies to overcome these difficulties and consider the clinical semiology, use of complementary tests and therapeutic approach.

CONCLUSION

Correct clinical identification is the essential basis for differential diagnosis and therapeutic management of the disorders of movement.

Inhibition of human immunodeficiency virus type (HIV-1) replication by some diversely functionalized spirocyclopropyl derivatives

Inhibition of HIV-1 replication by differently substituted spirocyclopropyl compounds has been evaluated. Compound 21 showed a moderate activity (EC50 ranging from 2.3 to 5.8 micrograms/ml) against different HIV-1 strains (IIIB, RF, NDK, and an AZT-resistant strain) in different cell lines (MT-4 and C-8166 cells), while it was cytotoxic at 77.7 micrograms/ml, resulting in a selectivity index of 34. This compound was inactive against HIV-2 (ROD) and SIV (MAC251). From "time-of-addition" experiments compound 21, like AZT, appeared to inhibit HIV-1 at the reverse transcriptase step.

[Various practical considerations in the management of movement disorders in children]

Disorders of movement in children often cause semiological and diagnostic difficulties to the paediatricians concerned. Based on personal experience, the author analyzes aspects which are particularly useful in overcoming these problems. Epidemiology, rules for history taking, indications as to the interpretation of clinical signs and use of complementary studies are considered.

[Rett's syndrome in the Spanish population]

INTRODUCTION AND OBJECTIVE

Rett syndrome was described in 1966 and became known through the English medical literature in 1983. There are typical and atypical forms. The objective of this study was to record the cases diagnosed in Spain and discover their clinical characteristics in order to describe its phenotype and geographical distribution.

PATIENTS AND METHODS

We know of 207 cases and have obtained the records of 168 of these patients. A protocol and data collection programme has been developed giving the criteria for inclusion, and data which support or exclude this. Data collection was by post and the data for identification were the date of birth and the initials of the name and two surnames. With these variables, double-registering of patients was almost impossible. A statistical study with descriptive analysis and a study of continuous and alternating variables was immediately done.

RESULTS AND CONCLUSION

The results gave the main characteristics, the differences between typical and atypical cases and a comparative study of variables. It has given clinical data which may be useful for prognosis of the condition in the future.

[Moyamoya disease. A cause of vascular occlusion in childhood]

OBJECTIVE

The objective of this study was to review the cases of Moya-Moya diagnosed in our center.

PATIENTS AND METHODS

We reviewed the Moya-Moya cases diagnosed from 1979 to 1997. We evaluated the following elements: age of clinical onset, sex, clinical features, complementary examinations, neuroimage, treatment and follow-up.

RESULTS

Six patients were diagnosed. The first case appeared in 1979 and the last in 1997. These included four boys and 2 girls, with ages between 5 months and 14 years. The initial clinical feature in all six cases was acute hemiparesis, noting that in one case this was preceded by homolateral seizures. Neuroimaging revealed ischaemic infarction areas in brain CT or MNR. The diagnosis was based on angiography, where in four cases there appeared bilateral occlusion of the internal carotid, or of the anterior or middle cerebral arteries and in the other two there was a unilateral occlusion of the interior carotid and middle cerebral arteries. Regarding etiology, in four patients the dysfunction was due to either fibromuscular dysplasia of the carotid, neurofibromatosis, cranial trauma or to Down's syndrome. In the other two cases no other primary cause was found.

CONCLUSIONS

Acute stroke is an infrequent disease of pediatric age patients, however it is necessary to do a thorough angiography study to rule out the Moya-Moya like vascular anomalies.

"In vitro" effect of some 5-hydroxy-indolalkylamine derivatives on monoamine uptake system

Three different indolalkylamine derivatives (FA 102, FA 69, FA 70) having in common an -OH group at 5 position of the indole ring and differing in the presence of a methyl group at the N or the acetylenic group of the side chain, have been synthesized and assayed as monoamine oxidase-A (MAO-A) [E.C.1.4.3.4] inhibitors. They were effective inhibitors with, in some cases, similar potencies to clorgyline. "In vitro" experiments were performed on rat brain synaptosomes to investigate whether these MAO-A inhibitors had any effect on noradrenaline (NA), dopamine (DA) and 5-hydroxytryptamine (5-HT) transport systems in different rat brain regions. The effect of these drugs were compared with those of clorgyline and 1-deprenyl. FA 102, FA 69, FA 70 behaved as inhibitors of 3H-monoamine uptake with similar rank of order of potency for amine uptake inhibition: 5-HT > DA > NA. The IC50 values for FA 102, FA 69, FA 70, respectively, were: 17 microM, 60 microM, 18 microM for 5HT uptake in cortex and 37 microM, 55 microM and 20 microM in hippocampus; 70 microM, 385 microM for NA uptake in cortex and 315 microM, 255 microM and 600 microM in hypothalamus; 270 microM, 160 microM, 40 microM for DA uptake in striatum. 1-Deprenyl was a very poor inhibitor of monoamine uptake, whereas clorgyline behaved similarly to these indolalkylamine derivatives. Comparing these results with the IC50 values of citalopram, nisoxetine and GBR12909, specific and selective inhibitors of 5-HT, NA and DA transport systems respectively, indicated that these indolalkylamine derivatives interact more strongly with the 5HT uptake system.

[The Ohtahara's syndrome: a special form of age-dependent epilepsy]

The aim of this report is to review the clinical and the outcome data in four patients with Ohtahara syndrome at Sant Joan de Déu Hospital, Barcelona, following the same clinical and electroencephalografic criteria reported by the author. The etiology of this syndrome is unknown and plurifactorial. Investigation studies were negative except for the EEG and neuroimaging. MRI was performed in two children, and pachigyria was observed in one and mycropoligyria in the other. There were no response to cofactors, phenobarbital, vigabatrine and valproate. Therefore two patients underwent treatment with ACTH with no response in one and good response in the other. Two patients died at 2 and 6 months; other one was transferred to another center at 6 months-old and was lost at follow-up. The fourth patient, fourteen-month-old, is free of seizures with improvement of EEG register with important development retardation. We conclude that Ohtahara syndrome is a severe neonatal epilepsy with poor neurologic outcome; MRI detects often brain malformations as cortical dysplasia and a therapeutic trial of ACTH is indicated because the possibility of control of the seizures.

[Ataxia telangiectasia: review of 13 new cases]

We report the review of 13 patients who were diagnosed of ataxia telangiectasia before 6 years of age. All of them manifested cerebelous ataxia, oculocutaneus telangiectasias (11), sinopulmonary infections (9), dystonia (9), oculomotor apraxia (9) and Burkitt linfoma (1). We analyse the most common presentation of the disease in early stages and the complementary studies performed. The prompt diagnosis allow us a better control of infections, malignant process and finally the possibility of genetic counseling.

Kinetic behaviour of some acetylenic indolalkylamine derivatives and their corresponding parent amines

Different methoxy indolalkylamines based on a common structure, and differing in the side chain attached at the 2 position of the indole ring were studied as MAO A inhibitors. Some are acetylenic derivatives and consequently might behave as "suicide" MAO inhibitors (FA 42, FA 43, FA 45). The rest of compounds are the corresponding parent amines and they might behave as MAO substrates (FA 51, FA 52, FA 53, FA 54). The kinetic behaviour of the parent amines as MAO A and MAO B inhibitors and substrates was determined. In case of acetylenic derivatives, kinetic constants defining the non-covalent adduct formation and the covalent adduct formation were also calculated for the mechanism-based inhibition. These parameters will allow us to establish the correlation with structural features that predetermine one compound to be a good MAO substrate or a good MAO A and MAO B inhibitor.

Kinetics of the reversible tight-binding inhibition of pig liver catechol-O-methyltransferase by [2-(3,4-dihydroxy-2- nitrophenyl)vinyl]phenyl ketone

The inactivation of partially purified pig liver catechol-O-methyltransferase (COMT) by [2-(3,4-dihydroxy-2-nitrophenyl)vinyl]phenylketone has been studied. The results demonstrated that COMT is inhibited in a reversible tight-binding fashion with an apparent Ki of 0.2 microM. IC50 values were determined at different concentrations of both substrates of the enzymatic reaction, pyrocatechol and S-adenosyl-L-methionine (AdoMet). The plot of IC50 versus pyrocatechol concentration gave a straight line, suggesting competitive inhibition. However the nitrocatechol derivative showed an uncompetitive inhibition pattern when measured as a function of AdoMet concentration.

Acetylenic and allenic derivatives of 2-(5-methoxy-1-methylindolyl)alkylamines as selective inhibitors of MAO-A and MAO-B

A new series of thirty derivatives of 2-(5-methoxy-1-methylindolyl)alkylamines has been synthesized and the compounds assayed as inhibitors of MAO-A and MAO-B from bovine brain mitochondria. IC50 values for both isoenzymes were determined using tyramine as a common substrate. Structure-activity and selectivity relationships are discussed.

[Severe and mild forms of nemaline myopathy: a report of three cases]

Three new cases of two different forms of congenital nemaline myopathy are reported. Two of them represent a severe neonatal form. These cases were presented as a floppy infant syndrome. Although neither of them needed intensive care, they had feeding difficulties and one needed a feeding-tube for a period of time. Both of the patients showed a very severe motor delay and neither could manage to walk independently. During their lives, they suffered from repeated pneumonias, which was the cause of death in both cases before the age of two years. The mild congenital type represents a more benign form. Although hypotonic and weak, the patient managed to walk independently before two years of age. The weakness was spread all over, but was focused in the face, extensors of the neck and axial muscles. At 9 years of age, the patient has not experienced any respiratory trouble. The CK (creatine kinase) test were normal in all patients, but the EMG (electromyogram) showed different electromyographic patterns. The rods were in subsarcolemic positions, cytoplasmic positions or in both positions.

Inhibition of catechol-O-methyltransferase by 1-vinyl derivatives of nitrocatechols and nitroguaiacols. Kinetics of the irreversible inhibition by 3-(3-hydroxy-4-methoxy-5-nitro benzylidene)-2,4-pentanedione

It is well known that activated alkene derivatives react with thiol groups according to a Michael's addition reaction. On the basis of the presence of at least one thiol group essential for the activity of catechol-O-methyltransferase (COMT), several 1-vinyl derivatives of nitrocatechol and nitroguaiacol were synthesized and tested as potential irreversible active site-directed inhibitors of COMT. All the synthesized products were potent inhibitors of partially purified pig liver COMT. However, the inhibition was reversible in most cases, with the exception of 3-(3-hydroxy-4-methoxy-5-nitrobenzylidene)-2,4-pentanedione (compound 2) which inhibited COMT in an irreversible manner. When the inhibition of COMT was measured as a function of the length of time of pre-incubation with 2, biphasic kinetics were observed, suggesting the modification of at least two thiol groups which are essential for COMT activity. The analysis of the two parts of the inhibition curve as a function of the inhibitor concentration showed that compound 2 modified the more reactive group in a non-specific manner, while it behaved as an active site-directed inhibitor on the second slow-reacting thiol group. Importantly, a saturating concentration of S-adenosyl-L-methionine (AdoMet) in the pre-incubation mixture gave pseudo-first order kinetics, suggesting total protection of one thiol group. Magnesium ions had no effect on the protection of COMT by AdoMet. In the presence of 3,5-dinitrocatechol (DNC) slight protection of COMT was observed; when the inactivation of both groups was analysed independently, protection of the specifically modified group was detected, while the reaction with the other group was faster in the presence of DNC. When both AdoMet and DNC were present, inactivation of COMT by 2 was not observed, suggesting that both reacting groups are located at or near the active site.

Dihydroxynitrobenzaldehydes and hydroxymethoxynitrobenzaldehydes: synthesis and biological activity as catechol-O-methyltransferase inhibitors

A series of nitro derivatives of dihydroxy- and hydroxymethoxybenzaldehyde was synthesized and tested as potential inhibitors of partially purified pig liver catechol-O-methyltransferase (COMT). All the dihydroxynitrobenzaldehydes prepared were potent inhibitors of COMT, but only one hydroxymethoxynitrobenzaldehyde (3-hydroxy-4-methoxy-5-nitrobenzaldehyde) showed activity as a COMT inhibitor. Although previously reported data showed that the presence of electron-withdrawing substituents at position 5 seemed to be very important for activity as COMT inhibitor, our results suggest that the requirement necessary to enhance the activity of the dihydroxyni-trobenzaldehyde derivatives toward COMT is the presence of the nitro group in a position ortho with respect to one hydroxyl group. The assayed compounds showed a reversible inhibition of COMT, which was mixed for all the dihydroxynitro derivatives but noncompetitive for 3-hydroxy-4-methoxy-5-nitrobenzaldehyde when pyrocatechol was the variable substrate and uncompetitive in all the inhibitors with respect to S-adenosyl-L-methionine.

The kinetics of monoamine oxidase inhibition by three 2-indolylmethylamine derivatives

The inhibition of bovine brain mitochondrial MAO-A and MAO-B by three acetylenic and non-acetylenic derivatives of 2-indolylmethylamine, chosen among more than 100 new compounds, were studied. The non-acetylenic derivative N-methyl-2(5-hydroxy-1-methylindolyl)methylamine (1) was a weak non-selective inhibitor which was shown to act in a reversible and competitive manner towards the deamination of tyramine. The two acetylenic derivatives N-methyl-N-(2-propynyl)-2-(5-benzyloxy-1-methylindolyl)methylamine (2) and N-methyl-N-(2-propynyl)-2-(5-hydroxy-1-methylindolyl)methylamine (3) were potent MAO inhibitors, one of them non-selective (compound 2) and the other MAO-A selective inhibitor (compound 3). Both of them were irreversible and competitive inhibitors, compound 2 towards the deamination of tyramine and compound 3 towards the deamination of serotonin and beta-phenylethylamine. A mechanism for the inhibition of the enzyme by both irreversible inhibitors is proposed and the inhibition parameters are determined.

Inhibition of catechol-O-methyltransferase by N-(3,4-dihydroxyphenyl) maleimide

Catechol-O-methyltransferase (COMT) is inhibited rapidly and irreversibly by N-(3,4-dihydroxyphenyl) maleimide. S-adenosylmethionine (AdoMet) and magnesium ions protect the enzyme from inactivation by this compound, but no protection is observed by the catechol substrate. However, the corresponding succinimide analogue shows a reversible inhibition of COMT, which is competitive with pyrocatecholphthalein and non-competitive with AdoMet. Amino-group reagents also inhibit COMT and this inhibition is protected by AdoMet, suggesting that sulphydryl and amino groups essential for activity are located in an AdoMet-binding site on COMT. The maleimide derivative may be considered to be an active-site directed inhibitor.

Selective thromboxane synthetase inhibitors and antihypertensive agents. New derivatives of 4-hydrazino-5H-pyridazino[4,5-b]indole, 4-hydrazinopyridazino[4,5-a]indole, and related compounds

A series of new derivatives of 4-hydrazino-5H-pyridazino[4,5-b]indole (5) and 4-hydrazinopyridazino[4,5-a]indole (12) have been synthesized to investigate their activities as selective thromboxane synthetase inhibitors as well as antihypertensive agents. Several of the prepared compounds were found to be selective thromboxane synthetase inhibitors, in concordance with the Gorman model. The most potent were 8-(benzyloxy)-3,4-dihydro-4-oxo-5H-pyridazino[4,5-b]indole (3c) and 8-methoxy-4-hydrazino-5H-pyridazino[4,5-b]indole (5). This last compound did not inhibit prostacyclin formation and showed an antihypertensive activity similar to that of hydralazine. The acute toxicity in mice for 5a . HCl is about 2.2 times less than that for hydralazine.

Primary degeneration of the granular layer of the cerebellum (Norman type). A Golgi study

Purkinje cells, impregnated with the rapid Golgi method, in a patient with primary degeneration of the granular layer showed abnormal orientation of the perikaryon and dendrites, reduction in size of the dendritic arbor, absence of spiny branchlets, and large numbers of stubby spines and hypertrophic spines on secondary dendritic branches; stubby spines and thorn-like formations were seldom observed on the primary dendrites and perikaryon of some Purkinje cells. These findings are similar to those described in the cerebellum of the homozygous weaver mutant mouse and in the cerebella of experimentally induced agranular phenocopies, thus suggesting that similar plastic changes occur in human and animal Purkinje cells as a result of the absence of parallel fibres input in early developmental stages. In addition, Purkinje cells in this patient showed club-shaped deformities in the distal region of primary dendrites, which were filled with radially oriented, short dendrites covered with stubby spines and hypertrophic spines. These latter structures appear to be fully impregnated asteroid bodies observed in paraffin sections.

[Herpetic encephalitis in children. Study of 9 cases]

Here we review nine cases of children with herpetic encephalitis (EH) admitted to the "San Juan de Dios" Hospital in Barcelona from 1976 to 1983. Of particular significance is the average age of 3,2 years, initial respiratory symptoms, fever and seizures in the majority of the cases. The EEG showed in every case short focal periodic activity from the 3rd to the 8th day of the illness, with normal CT-scan in 5 patients from the 5th to the 9th day. All the patients showed deterioration in the course of the illness, with serious sequels or death. We support an early herpetic encephalitis diagnosis and its treatment (ARA-A or Acyclovir) based on the clinical symptoms, the characteristic EEG, and a normal initial CT-scan. Antibodies levels and evolution will confirm or deny the diagnosis, without the need for a cerebral biopsy.

[Late infantile form of Pompe's disease. Deficiency of alpha-1,4-glucosidase (acid maltase)]

Four patients with late infantile form of Pompe's disease, acid maltase deficiency, are presented. In three of them an autosomical recessive genetical transmission was demonstrated. Signs of neuromuscular involvement were present in all of our patients before four years of age. All cases had elevated muscle and liver enzymes. Echocardiographic studies revealed a septal hypertrophy in three patients. Presence of myotonic discharges on EMG examination suggested the diagnosis in three cases. Pathological and biochemical studies of two siblings, one of them aged 14 months, without clinical findings, demonstrated that the enzyme in late infantile form of acid maltase deficiency is missing from birth. Clinical and pathological muscular involvement of case number 4, in front of normal amounts of acid maltase in this muscle, must alert clinicians to perform enzymatic studies in various tissues in order to confirm diagnosis and better understand biochemical basis of the disease.

Familial agenesis of the corpus callosum with hypothermia and apneic spells

Two siblings, a boy and a girl, with agenesis of the corpus callosum, apneic spells, attacks of apnea, cyanosis and spontaneous hypothermia, are reported about. Both children died after a few months of life. Postmortem examination revealed a severe spongiosis of the white matter in addition to the agenesis of the corpus callosum and septum pellucidum, in both cases.

[Intracranial arachnoid cysts in children. Review of 34 cases]

Clinical, radiological, and therapeutical aspects of 34 cases of childhood intracranial arachnoid cysts are reviewed. Two thirds (23) were located supratentorially, the remaining 11 had an infratentorial localization. Of the first group 15 were situated at the sylvian region, 6 were hemispherical and 2 suprasellar. Clinical manifestations were present before 6 months of age in 68% of all the cases. Macrocephaly and focal seizures were the most common clinical findings. Skull X-Ray examination was helpful only when cysts were located at sylvian region. CT Brain Scan was positive in all cases (32) in which it was performed, dynamic studies with Metrizamide were necessary in 6 cases and arteriography in 4 cases to definitively prove the diagnosis. Surgical approach (removal of cysts or cyst/ventriculo-peritoneal shunting) was undertaken in 20 cases, with unequal results. Authors comment on possible etiopathogenic factors, indications for use of dynamic studies with Metrizamide and rational guide for surgical therapy on these patients.

[Hereditary neuropathies in childhood. Study of 31 patients]

Authors present the results of prospective clinical and electrophysiological study on 31 children diagnosed of inherited sensory-motor neuropathy. Patients were grouped according to their electrophysiological findings and their mode of inheritance, which was ascertained in all the cases by clinical and electrophysiological study of their parents. The large number of patients, felt into a group with identical characteristics of type I, HSMN of Dick and Lambert. A second group of patients, with a wide range of clinical manifestations, in some cases suggestive of type III HSMN, showed a sporadic mode of inheritance and evidence of demyelination on electrical studies. The third group of patients, which were classified as type II HSMN, showed again, a wide range of clinical manifestations, with some patients severely involved, and thus, casting some doubt on the benign prognosis of this type of neuropathy claimed by some authors.