Lower Homovanillic Acid Levels Research Articles

DNAJC6 Mutations Disrupt Dopamine Homeostasis in Juvenile Parkinsonism-Dystonia.

BackgroundJuvenile forms of parkinsonism are rare conditions with onset of bradykinesia, tremor and rigidity before the age of 21 years. These atypical presentations commonly have a genetic aetiology, highlighting important insights into underlying pathophysiology. Genetic defects may affect key proteins of the endocytic pathway and clathrin‐mediated endocytosis (CME), as in DNAJC6‐related juvenile parkinsonism.ObjectiveTo report on a new patient cohort with juvenile‐onset DNAJC6 parkinsonism‐dystonia and determine the functional consequences on auxilin and dopamine homeostasis.MethodsTwenty‐five children with juvenile parkinsonism were identified from a research cohort of patients with undiagnosed pediatric movement disorders. Molecular genetic investigations included autozygosity mapping studies and whole‐exome sequencing. Patient fibroblasts and CSF were analyzed for auxilin, cyclin G–associated kinase and synaptic proteins.ResultsWe identified 6 patients harboring previously unreported, homozygous nonsense DNAJC6 mutations. All presented with neurodevelopmental delay in infancy, progressive parkinsonism, and neurological regression in childhood. 123I‐FP‐CIT SPECT (DaTScan) was performed in 3 patients and demonstrated reduced or absent tracer uptake in the basal ganglia. CSF neurotransmitter analysis revealed an isolated reduction of homovanillic acid. Auxilin levels were significantly reduced in both patient fibroblasts and CSF. Cyclin G–associated kinase levels in CSF were significantly increased, whereas a number of presynaptic dopaminergic proteins were reduced.ConclusionsDNAJC6 is an emerging cause of recessive juvenile parkinsonism‐dystonia. DNAJC6 encodes the cochaperone protein auxilin, involved in CME of synaptic vesicles. The observed dopamine dyshomeostasis in patients is likely to be multifactorial, secondary to auxilin deficiency and/or neurodegeneration. Increased patient CSF cyclin G–associated kinase, in tandem with reduced auxilin levels, suggests a possible compensatory role of cyclin G–associated kinase, as observed in the auxilin knockout mouse. DNAJC6 parkinsonism‐dystonia should be considered as a differential diagnosis for pediatric neurotransmitter disorders associated with low homovanillic acid levels. Future research in elucidating disease pathogenesis will aid the development of better treatments for this pharmacoresistant disorder. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Levodopa-Carbidopa Intestinal Gel in a Pediatric Parkinsonism-plus Syndrome.

In Parkinson's disease, levodopa-carbidopa intestinal gel (LCIG) is indicated in control of motor fluctuations, dyskinesias1 and non-motor symptoms. We here report the first case of LCIG pediatric use. Our patient presented with upper limb tremor at 6 months and subsequently with axial hypotonia, dysphagia and generalized dystonia. He did not achieve the milestones in psychomotor development: he could not stand, walk, nor manipulate objects; verbal production was never acquired. At 14 months, brain magnetic resonance was normal and cerebrospinal fluid examination showed low levels of homovanillic acid, neopterin and biopterin. This article is protected by copyright. All rights reserved.

Middle-range exploratory activity in adult rats suggests higher resilience to chronic social defeat.

Stressful life events play an important role in the aetiology of human mood disorders and are frequently modelled by chronic social defeat (SD) in rodents. Exploratory phenotype in rats is a stable trait that is likely related to inter-individual differences in reactivity to stress. The aim of the study was to confirm that low levels of exploratory activity (LE) are, in rodents, a risk factor for passive stress coping, and to clarify the role of medium (ME) and high (HE) exploratory disposition in the sensitivity to SD. We examined the effect of SD on male Wistar rats with LE, ME, and HE activity levels as measured in the exploration box. After SD, the rats were evaluated in social preference, elevated zero maze, and open-field tests. Brain tissue levels of monoamines were measured by high-performance liquid chromatography. Rats submitted to SD exhibited lower weight gain, higher sucrose consumption, showed larger stress-induced hyperthermia, lower levels of homovanillic acid in the frontal cortex, and higher levels of noradrenaline in the amygdala and hippocampus. Open-field, elevated zero maze, and social preference tests revealed the interaction between stress and phenotype, as only LE-rats were further inhibited by SD. ME-rats exhibited the least reactivity to stress in terms of changes in body weight, stress-induced hyperthermia, and sucrose intake. Both low and high novelty-related activity, especially the former, are associated with elevated sensitivity to social stress. This study shows that both tails of a behavioural dimension can produce stress-related vulnerability.

Clinical and genetic studies in a family with a novel mutation in the sepiapterin reductase gene

Sepiapterin reductase deficiency is a rare, but treatable inherited disorder of tetrahydrobiopterin and neurotransmitter metabolism. This disorder is most probably underdiagnosed. To date, only 44 cases have been described in the literature. We present the clinical and genetic investigations in a family with a complex movement disorder. We examined two affected sisters and three healthy family members. The cerebrospinal fluid was analyzed for neurotransmitter and pterins, and the sepiapterin reductase gene (SPR) was sequenced. The sisters had a complex movement disorders with dystonia and diurnal fluctuations. Both had oculogyric crises, and the older sister also hypersomnia. Both sisters had raised prolactin levels twice above the reference level. One sister had a dramatic response to levodopa, the other responded, but developed dyskinesia despite low doses. Both patients improved dramatically over time with levodopa (2.3 and 1.5 mg/kg/day). Very low levels of homovanillic acid and 5-hydroxyindoleacetic acid and increased levels of sepiapterin and dihydrobiopterin were measured in the cerebrospinal fluid before treatment. DNA analyses revealed a novel homozygous mutation in exon 2 in the SPR gene, c.364A>G/p.(Tyr123Cys), located in a highly conserved region in the gene. Both parents and the healthy sister were carriers for the same mutation. A new homozygous mutation in the SPR gene was found in two sisters with dopa-responsive dystonia. This important and treatable neurotransmitter disorder must be considered in patients with a complex movement disorder with diurnal fluctuations with or without intellectual impairment. Patients with these symptoms should undergo levodopa trial, cerebrospinal fluid investigations, and genetic analyses.

Mitochondrial diseases mimicking neurotransmitter defects

Objectives Mitochondrial disorders are clinically heterogeneous. We aimed to describe 5 patients who presented with a clinical picture suggestive of primary neurotransmitter defects but who finally fulfilled diagnostic criteria for mitochondrial disease. Methods We report detailed clinical features, brain magnetic resonance findings and biochemical studies, including cerebrospinal fluid (CSF) biogenic amine and pterin measurements, respiratory chain enzyme activity, and molecular studies. Results The 5 patients had a very early onset age (from 1 day to 3 months) and a severe clinical course. They all showed a clinical picture suggestive of infantile hypokinetic-rigid syndrome (hypokinesia, hypomimia, slowness of reactions, tremor), other abnormal movements (myoclonus, dystonia), axial hypotonia, limb hypertonia, feeding difficulties, and psychomotor delay. Abnormal CSF findings among the 4 patients without treatment included low levels of homovanillic acid (HVA) in 3 patients, with associated low 5-hydroxyindoleacetic acid (5-HIAA) concentrations in two of them. Absent or mild and transitory improvement was observed after treatment with l-dopa. A diagnosis of mitochondrial disorder was finally made due to the appearance of hyperlactacidemia, diverse respiratory chain defects, and multisystemic involvement. Conclusions Secondary neurotransmitter disturbances may occur in mitochondrial diseases. Differential diagnosis of hypokinetic-rigid syndrome presenting in infancy could also include paediatric mitochondrial disorders.

A functional polymorphism in the MAOA gene promoter (MAOA-LPR) predicts central dopamine function and body mass index

Variation in brain monoaminergic activity is heritable and modulates risk of alcoholism and other addictions, as well as food intake and energy expenditure. Monoamine oxidase A deaminates the monoamine neurotransmitters serotonin, dopamine (DA), and noradrenaline. The monoamine oxidase A (MAOA) gene (Xp11.5) contains a length polymorphism in its promoter region (MAOA-LPR) that putatively affects transcriptional efficiency. Our goals were to test (1) whether MAOA-LPR contributes to interindividual variation in monoamine activity, assessed using levels of cerebrospinal fluid (CSF) monoamine metabolites; and (2) whether MAOA-LPR genotype influences alcoholism and/or body mass index (BMI). Male, unrelated criminal alcoholics (N=278) and controls (N=227) were collected from a homogeneous Finnish source population. CSF concentration of 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) were available from 208 participants. Single allele, hemizygous genotypes were grouped according to inferred effect of the MAOA alleles on transcriptional activity. MAOA-LPR genotypes had a significant effect on CSF HVA concentration (P=0.01) but explained only 3% of the total variance. There was a detectable but nonsignificant genotype effect on 5-HIAA and no effects on MHPG. Specifically, the genotype conferring high MAOA activity was associated with lower HVA levels in both alcoholics and controls, a finding that persisted after accounting for the potential confounds of alcoholism, BMI, height, and smoking. MAOA-LPR genotype predicted BMI (P<0.005), with the high-activity genotype being associated with lower BMI. MAOA-LPR genotypes were not associated with alcoholism or related psychiatric phenotypes in this data set. Our results suggest that MAOA-LPR allelic variation modulates DA turnover in the CNS, but does so in a manner contrary to our prior expectation that alleles conferring high activity would predict higher HVA levels in CSF. Our results are consistent with an emerging literature that suggests greater complexity in how variation in MAOA expression alters monoaminergic function. Finally, our work suggests that MAOA may be involved in the regulation of BMI. Independent samples are necessary to confirm this preliminary finding.

Sepiapterin reductase deficiency an autosomal recessive DOPA-responsive dystonia

The diagnosis of a 14-year-old girl with a new homoallelic mutation in the sepiapterin reductase (SR) gene is reported. Initially she presented at the age of 2 with hypotonia and mild cognitive developmental delay, and was diagnosed as having mild methylmalonic aciduria, which was recently identified as methylmalonylCoA racemase deficiency, a new defect in valine-isoleucine metabolism. After a 12-year progression of her neurologic condition, which had made her wheelchair-bound at the age of 6, dystonia with diurnal variation had become apparent. At the age of 14 this finding led to rapid diagnosis of SR deficiency. The diagnostic approach with CSF neurotransmitter and pterins analysis and combined phenylalanine/BH 4 loading test, and finally measurement of sepiapterin in CSF is illustrative for the diagnosis of SR deficiency. As in all other patients with this new defect, very low levels of homovanillic acid and 5-hydroxyindoleacetic acid and high levels of biopterin and sepiapterin in the CSF are the diagnostic hallmark. The girl improved dramatically on treatment with l-DOPA and 5-hydroxytryptophan. The initial diagnosis of methylmalonic aciduria may afterwards be considered to have not significantly contributed to her clinical condition and only has led to a long delay of the clinically relevant diagnosis of SR deficiency. Although the clinical condition of this recently recognized autosomal recessive defect in pterin metabolism is complex and many symptoms can occur in variable severity and time of onset, dystonia with diurnal variation is a characteristic finding, as shown in nearly all patients described so far. The rapid and favourable response on treatment with l-DOPA warrants the classification of SR deficiency as another autosomal recessive type of DOPA-responsive dystonia (DRD). This classification is important to improve the awareness of clinicians that more than one metabolic defect can underlie the phenotype of a DOPA-responsive dystonic disorder and that dystonia should always trigger a rapid diagnosis of the underlying neurotransmitter synthesis defect, in view of the excellent treatability of a DRD.

Sex hormones and biogenic amine turnover of sex offenders in relation to their temperament and character dimensions

Relationships between Cloninger's temperament and character dimensions and plasma sex hormone levels and biogenic amine turnover were studied in male prison inmates convicted of rape ( n=61) or child molestation ( n=24) and normal male controls ( n=25). The participants completed the Temperament and Character Inventory (TCI), which includes the temperament dimensions Novelty Seeking, Harm Avoidance, Reward Dependence and Persistence as well as the character dimensions Self-Directedness, Cooperativeness and Self-Transcendence. Plasma levels of testosterone, dihydrotestosterone, sex hormone binding globulin, luteinizing hormone (LH) and follicle-stimulating hormone were estimated in plasma samples and 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) in urine samples. Both sex offender groups had higher Novelty, Seeking and lower Reward Dependence, Self-Directedness and Cooperativeness scores compared with the controls. Plasma levels of testosterone and dihydrotestosterone were significantly higher in rapists than in controls. Novelty Seeking scores were positively correlated with LH levels in rapists, and with testosterone levels in child molesters. Harm Avoidance scores were negatively correlated with 5-HIAA levels in rapists and with HVA levels in child molesters. In rapists, the calculated free androgen index showed a negative correlation with 5-HIAA. For the sex offender sample as a whole, the subgroup with high testosterone levels had higher Harm Avoidance scores, the subgroup with low HVA levels had lower Cooperativeness scores, and the subgroups with high 5HIAA or MHPG levels had lower Persistence scores. The results indicate that Novelty Seeking behavior in the group of rapists is associated with a hyperactive hypothalamic-pituitry-gonadal axis. In addition, low serotonin turnover and low dopamine turnover seem to be associated with a passive-avoidant behavioral style in rapists and child molesters, respectively.

Neurochemical analysis of brain monoamines after l-histidine and chlorpheniramine administration in goldfish

This study investigated the effects of chlorpheniramine (CPA) and l-histidine (LH) administration on catecholaminergic levels in goldfish brain using neurochemical analysis. Fifty-eight animals were used. After 20 min of i.p. administration of the drugs or saline the animals were decapitated, and the telencephalon and the diencephalon were dissected. We also measured catecholamines in a non-injected (NI) group. Results showed lower homovanillic acid (HVA) levels after treatment with 100 mg/kg of LH when compared to saline and 5-hydroxyindoleacetic acid levels were lower in the saline group when compared to the NI group. In the diencephalon the NI group and animals treated with CPA at 4.0 and 8.0 mg/kg had lower HVA levels. Results suggest that LH had an inhibitory effect on dopaminergic activity and an anxiolytic-like effect for CPA results is suggested.

Reduced cerebrospinal HVA concentrations and HVA/5-HIAA ratios in suicide attempters: Monoamine metabolites in 120 suicide attempters and 47 controls

Dysfunctions of central monoaminergic systems are important elements of the leading biological hypotheses of suicide and depression. The purpose of the present paper was to study the levels and the relationships between the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA), the dopamine metabolite homovanillic acid (HVA) and the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) in the cerebrospinal fluid (CSF) in 120 hospitalised suicide attempters and 47 controls (healthy volunteers or patients admitted for minor surgery). The suicide attempters showed significantly lower HVA levels (174±82 vs. 216±96 nmol/L, P=0.004), HVA/5HIAA ratios (1.6±0.5 vs. 2.1±0.6, P=0.0001) and HVA/MHPG ratios (4.2±2.1 vs. 4.8±1.7, P=0.02) than the controls. The correlations between the monoamine metabolites were markedly lower in patients than in controls. CSF 5-HIAA showed no significant differences between patients and controls (107±40 vs. 108±51 nmol/L) or between violent and non-violent attempters (112±58 vs. 105±33 nmol/L). The monoamine metabolites showed no significant differences between survivors and patients who subsequently completed suicide, or between suicide attempters subgrouped by psychiatric diagnoses. The results suggest that low HVA levels and altered relationships between the monoamine metabolites are associated with suicidal behaviour.

Rapid-onset dystonia-parkinsonism: Linkage to chromosome 19q13

Rapid-onset dystonia-parkinsonism (RPD) is an autosomal dominant movement disorder characterized by sudden onset of persistent dystonia and parkinsonism, generally during adolescence or early adulthood. Symptoms evolve over hours or days, and generally stabilize within a few weeks, with slow or no progression. Other features include little or no response to L-dopa, and low levels of homovanillic acid in the central nervous system. Neuroimaging studies indicate no degeneration of dopaminergic nerve terminals in RDP, suggesting that this disorder results from a functional deficit, as in dystonia, rather than neuronal loss, as in Parkinson's disease. We studied 81 members of two midwestern US families with RDP, 16 of whom exhibited classic features of RDP. We found significant evidence for linkage in these two families to markers on chromosome 19q13, with the highest multipoint LOD score at D19S198 (z = 5.77 at theta = 0.0). The flanking markers D19S587 and D19S900 define a candidate region of approximately 8 cM. Although RDP itself is a rare condition, it is important because it has clinical and biochemical similarities to both Parkinson's disease and dystonia. Identification of the genetic defect in RDP holds promise for understanding the underlying disease processes of both of these more common diseases.

Plasma homovanillic acid and prolactin in systemic lupus erythematosus.

Prolactin (PRL) is an important immunoregulator and might have a role in the pathogenesis of systemic lupus erythematosus (SLE). The regulation of pituitary prolactin secretion is complex and involves a negative feedback process in the hypothalamus, in which dopamine plays the principal role. However, the main source of serum prolactin in lupus patients is still not clearly established. Since homovanillic acid (HVA), the principal metabolite of dopamine (DA), is removed from the brain into the blood, it would indirectly reflect DA metabolism. It is assumed that the turnover of a neurotransmitter can be determined through an analysis of its metabolites. The objective of this study was to analyse plasma samples from SLE patients to see if there were any alterations in neurally functioning DA through its principal metabolite, HVA. We also measured the levels of PRL and compared HVA and PRL with the clinical activity of the disease. Twenty-four SLE patients and fifteen healthy controls were studied. The investigation was done over a period of 3 months. The results of this study show significantly low levels of HVA in lupus patients compared to controls (P < 0.0001). This corresponds to a decrease in dopamine turnover. Hyperprolactinemia was observed in nine patients, and the average level of prolactin in lupus patients was higher than in healthy controls (P < 0.001). For the duration of the study, a significant percentage of variation was observed in the levels of HVA in the clinically active patients (P < 0.05) compared to inactive patients. When PRL was compared in these groups, throughout the study, no significant percentage of variation was observed. The relationship between HVA and PRL in healthy controls was r = 0.47, P = 0.08, and in patients was r = 0.04, P = 0.84. It is suggested that there is a probable association between plasma levels of HVA and PRL in the healthy controls and not in the SLE patients.

Dopa-Responsive Dystonia, Tyrosine Hydroxylase Deficiency and Aromatic L-Amino Acid Decarboxylase Deficiency: Multifaceted Diseases That Can Masquerade as Cerebral Palsy • 1874

Diagnosis of dopa-responsive dystonia (DRD) due to GTP cyclohydrolase I(GTPCH) deficiency (autosomal dominant), tyrosine hydroxylase (TH) deficiency(autosomal recessive) or aromatic L-amino acid decarboxylase (AADC) deficiency(autosomal recessive) is difficult as symptoms are often non-specific. We have established a series of tests which, either in isolation, or in combination allow identification of these disorders. Measurement of biogenic amine neurotransmitter metabolites in cerebrospinal fluid (CSF) shows low levels of homovanillic acid (HVA - dopamine metabolite) in all three conditions. GTPCH deficiency is distinguished by decreased levels of tetrahydrobiopterin and its precursor, neopterin, and AADC deficiency by high levels of 3-O-methyldopa(3OMD). Low levels of HVA, with normal pterins and 3OMD in the absence of brain lesions is highly suggestive of TH deficiency. Diagnosis is also possible in the absence of CSF. 3OMD concentrations are highly elevated in plasma and urine in AADC deficiency. Confirmation of the diagnosis is accomplished by assay of AADC activity in plasma. Evidence for TH deficiency can be obtained by a finding of reduced concentrations of plasma catecholamines, but final confirmation requires DNA mutation analysis as tissues are not readily available for TH enzyme assay. Due to a secondary inhibition of phenylalanine metabolism, DRD can be diagnosed by measurement of phenylalanine and tyrosine in plasma after an oral phenylalanine load. This battery of tests has to date identified 6 cases of AADC deficiency, 4 cases of TH deficiency, and 4 cases of DRD. Of these, 8 had been described as having cerebral palsy (CP) prior to our diagnosis. As CP is normally considered an untreatable disorder, it is important that patients with CP of unknown etiology be tested, as symptoms in DRD and the TH and AADC deficiencies often respond dramatically to treatment with either levodopa, or a mixture of dopamine agonists and monoamine oxidase inhibitors.

Auditory sensory gating, hippocampal volume, and catecholamine metabolism in schizophrenics and their siblings

Schizophrenia may result from the concentrated action of several pathophysiological factors. This pilot study compared the distribution of measurements of three such putative factors in 11 schizophrenics and their siblings: a neurophysiological deficit in auditory sensory gating, diminished hippocampal volume, and increased catecholamine metabolism. Abnormal auditory sensory gating was found in all schizophrenics in the 11 families studied and in 8 of their 20 siblings. Compared with the schizophrenics, the clinically unaffected siblings with abnormal auditory gating had larger hippocampal volume. There was no similar difference for the siblings with normal gating. The siblings with abnormal auditory gating also had lower homovanillic acid levels than the other siblings. The data suggest that a familial neuronal deficit, identified by diminished sensory gating, may be a necessary, but not sufficient factor in the pathogenesis of schizophrenia. Individuals with this deficit are generally clinically unaffected, except for schizophrenics, who also have other abnormalities, such as diminished hippocampal volume and increased catecholamine metabolism.

Marked reduction in indexes of dopamine metabolism among patients with depression who attempt suicide.

Cerebrospinal fluid studies have reported that low concentrations of the dopamine metabolite homovanillic acid are associated with suicidal behavior in depression. Although only a small proportion of homovanillic acid in the urine derives from the brain, we decided to examine 24-hour urinary outputs of homovanillic acid in relation to suicidal behavior in depression. Patients with depression who had attempted suicide had significantly smaller urinary outputs of homovanillic acid, dihydroxyphenylacetic acid, and total body output of dopamine (sum dopamine) than did patients with depression who had not attempted suicide. Patients with depression who reattempted suicide during 5-year follow-up had significantly smaller urinary outputs of homovanillic acid and sum dopamine than did patients who did not reattempt suicide, patients who never attempted suicide, and normal control subjects, and had significantly smaller outputs of dihydroxyphenylacetic acid than patients who never attempted suicide or control subjects. These data suggest that urinary outputs of homovanillic acid may be peripheral correlates of suicidality in depression. These data add to data on the low levels of homovanillic acid in cerebrospinal fluid in suggesting that diminished dopaminergic neurotransmission may play a part in suicidal behavior in depression.

Treatment of Heredo-Degenerative Ataxias with Amantadine Hydrochloride

Amantadine hydrochloride (AH) was administered (200 mg/day) for more than three months to 17 patients with Friedreich's ataxia (FA) and to 12 patients with olivopontocerebellar atrophies (OPCA) in an open clinical trial. Reaction time (RT) and movement time (MT) with the right and left hand were measured before and after treatment. A striking improvement on both RT and MT was observed in the OPCA group (on seven out of eight measures), whereas in the FA patients improvement was seen only in two out of four MT measures with no improvement in RT. Both groups had low levels of homovanillic acid (HVA) in their cerebrospinal fluid before treatment, relative to their controls. However, improvement with AH was not related to HVA levels.

Regional effects of ceruletide, a cholecystokinin-8 analog, on the striatal monoaminergic systems in food-deprived mice

To clarify the pharmacological mechanism by which ceruletide affects involuntary movements, we used 20-h food-deprived mice to examine the acute effects of ceruletide (600 μg/kg, i.p.) on the histochemistry of striatal dopaminergic and serotonergic systems. The latter was unchanged but a reduction in catecholamine fluorescence was seen which was restricted to the ventrolateral (VL) portion of the striatum. Biochemical assays also indicated decreased levels of dopamine (DA) and its metabolites in this restricted region of the striatum with little or no change in noradrenaline, serotonin or their metabolites. In all regions examined, except the dorsomedial part of the mid-striatum, the ration of dopamine metabolites to dopamine was higher in the ceruletide-treated group than in controls, suggesting increased DA release. Further pharmacological experiments showed that, compared to results in mice receiving only ceruletide: the ceruletide-induced decreases in DA and dihydroxyphenylacetic acid (DOPAC) in VL were less after α-methyl- p-tyrosine treatment; ceruletide caused no significant decrease in either DA or DOPAC after pargyline pretreatment, although the low levels of homovanillic acid (HVA) were still further significantly reduced; and the ceruletide-induced decrease of DA was reduced, that of DOPAC was abolished and that of HVA enhanced by nomifensine pretreatment. These results suggested that ceruletide might induce a more rapid degradation of DA in VL and increased efflux of HVA through the blood-brain barrier. This evidence suggests that ceruletide has a regionally specific effect on the striatal dopaminergic system which may relate to the amelioration of involuntary movements.

Characteristics of psychotic inpatients with high or low HVA levels at admission.

The purpose of this study was to examine the clinical profiles of psychotic patients whose fasting levels of plasma free homovanillic acid (HVA) were elevated on the day after admission to the hospital. These 85 subjects with nonorganic psychoses had been previously studied with respect to their response to neuroleptic treatment. They were divided into two groups on the basis of a median split of their pretreatment plasma HVA levels, and the two groups were compared on a number of clinical and demographic variables ascertained during their hospital stay. Fasting levels of plasma free HVA and 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured by gas chromatography-mass spectrometry. The high-HVA group tended to show a better prognostic profile than the low-HVA group; however, the only significant difference between groups was in the greater use of psychotogenic drugs by low-HVA males. Fourteen additional psychotic patients with distinctly elevated HVA levels and normal MHPG values were also diagnostically heterogeneous. The results suggest that psychotic patients with different diagnoses who have relatively high levels of plasma free HVA before treatment will show a favorable early response to neuroleptic drugs. There may be neurobiological processes linking some patients across the clinical spectrum of the psychotic disorders.

Dominantly inherited apathy, central hypoventilation, and Parkinson's syndrome

We describe 2 new patients from a family in which 10 persons in 3 successive generations had a dominant neuropsychiatric disorder characterized by apathy, central hypoventilation, and parkinsonism. Neuropathologically, both patients showed severe neuronal loss and reactive gliosis in the substantia nigra. Neurochemical studies showed a marked depletion of dopamine in substantia nigra, putamen, and caudate nucleus, as well as reduction in serotonin content in the substantia nigra. Glutamate contents were low in frontal cortex and thalamus, and gamma-aminobutyric acid (GABA) contents were low in thalamus and substantia nigra of both patients. In addition, phosphoethanolamine contents were reduced in all brain regions of both patients, especially in the substantia nigra. One patient with severe symptoms had low levels of homovanillic acid, 5-hydroxyindoleacetic acid, and GABA in his CSF repeatedly for 3 years before death (aged 58), while the 2nd patient died (aged 51) of an unrelated cause before developing any symptoms of the familial disorder. Because brain deficiencies of multiple neurotransmitters appear to be involved, this disorder is unlikely to respond to treatment; however, neurochemical studies of CSF may make presymptomatic diagnosis feasible.

CSF monoamine metabolites in dementia of the Alzheimer type and controls: Evidence for lower levels of homovanillic acid and 5‐hydroxyindoleacetic acid in patients

AbstractThe monoamine metabolites 5‐hydroxyindoleacetic acid (5‐HIAA) and homovanillic acid (HVA) in lumbar cerebrospinal fluid (CSF) were measured in 15 patients with dementia of the Alzheimer type (DAT) and 48 controls by means of a sensitive liquid chromotagraphic method. Relative to a large group of control subjects, the mean CSF 5‐HIAA and HVA levels in patients with DAT appeared to be significantly lower. This finding appeared to be sex‐related, in that the decrease in CSF monoamine metabolite levels could be attributed predominantly to male patients. A statistically significant relationship was found between 5‐HIAA and HVA in both patients and controls. Linear regression analysis revealed a statistically significant positive relationship between age and CSF HVA in female controls only. No relationship was found between 5‐HIAA and age either in patients or in controls. It is concluded that CSF 5‐HIAA and HVA levels are decreased in male patients with DAT, probably signalling a sex‐related change in serotonin and probably dopamine functioning in the central nervous system.