Motor difficulties from childhood to midlife: A 40-year cohort study

BACKGROUND

There are few studies of the persistence of childhood motor difficulties (MD) into adulthood.

AIMS

To investigate the association of childhood MD with motor skills and body mass index (BMI) in midlife.

METHODS AND PROCEDURES

We studied 324 adults aged 40 from a cohort born in 1971-1974. At age 9, they had undergone the Test of Motor Impairment, used to classify them into groups: childhood MD (cMD), borderline cMD (bcMD), or no cMD. At age 40, participants comprised 23 with cMD, 47 with bcMD, and 254 with no cMD. Participants completed motor tests of balance, manual dexterity, and visuomotor speed, followed by recording of their BMI.

OUTCOMES AND RESULTS

At age 40, the cMD group performed worse than the no-cMD group on all motor tests (p < .001-.008). The bcMD group had slower visuomotor speed than the no-cMD group (p = .025). The groups differed in BMI (p = .002). Having cMD was associated with obesity in midlife (p < .001). After adjusting for sex, childhood socioeconomic status, and BMI at age 9, both cMD and bcMD were associated with obesity in midlife (p = .015).

CONCLUSIONS AND IMPLICATIONS

Childhood MD are associated with poor motor skills, overweight, and obesity in midlife. This emphasises the importance of early intervention and follow-up when a child exhibits MD.

WHAT THIS PAPER ADDS

This prospective longitudinal study presents novel evidence that individuals with a history of comprehensively and objectively assessed childhood motor difficulties (MD) have worse motor skills and a higher risk of obesity in midlife than do those with no childhood MD. There is a growing literature on adults with developmental coordination disorder or a history of MD. There is, however, a scarcity of longitudinal studies of childhood MD that continue beyond early adulthood, into midlife. In a systematic search, we could identify only one longitudinal study of objectively measured childhood MD with a reassessment of motor skills in those same participants in adulthood, and no study with a reassessment after age 20. Furthermore, longitudinal studies of the association of comprehensively and objectively assessed childhood MD with BMI in midlife have been lacking.

The shared ancestry between the C9orf72 hexanucleotide repeat expansion and intermediate-length alleles using haplotype sharing trees and HAPTK

The C9orf72 hexanucleotide repeat expansion (HRE) is a common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The inheritance is autosomal dominant, but a high proportion of subjects with the mutation are simplex cases. One possible explanation is de novo expansions of unstable intermediate-length alleles (IAs). Using haplotype sharing trees (HSTs) with the haplotype analysis tool kit (HAPTK), we derived majority-based ancestral haplotypes of HRE samples and discovered that IAs containing ≥18-20 repeats share large haplotypes in common with the HRE. Using HSTs of HRE and IA samples, we demonstrate that the longer IA haplotypes are largely indistinguishable from HRE haplotypes and that several ≥18-20 IA haplotypes share over 5 Mb (>600 markers) haplotypes in common with the HRE haplotypes. These analysis tools allow physical understanding of the haplotype blocks shared with the majority-based ancestral haplotype. Our results demonstrate that the haplotypes with longer IAs belong to the same pool of haplotypes as the HRE and suggest that longer IAs represent potential premutation alleles.

C9orf72 hexanucleotide repeat allele tagging SNPs: Associations with ALS risk and longevity

C9orf72 hexanucleotide repeat expansion is a common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The C9orf72 locus may harbor residual risk outside the hexanucleotide repeat expansion, but the evidence is conflicting. Here, we first compared 683 unrelated amyotrophic lateral sclerosis cases and 3,196 controls with Finnish ancestry to find best single nucleotide polymorphisms that tag the C9orf72 hexanucleotide repeat expansion and intermediate-length alleles. Rs2814707 was the best tagging single nucleotide polymorphisms for intermediate-length alleles with ≥7 repeats (p = 5 × 10^-307) and rs139185008 for the hexanucleotide repeat expansion (p = 7 × 10^-114) as well as alleles with ≥20 repeats. rs139185008*C associated with amyotrophic lateral sclerosis after removing cases with the hexanucleotide repeat expansion, especially in the subpopulation homozygous for the rs2814707*T (p = 0.0002, OR = 5.06), which supports the concept of residual amyotrophic lateral sclerosis risk at the C9orf72 haplotypes other than the hexanucleotide repeat expansion. We then leveraged Finnish biobank data to test the effects of rs2814707*T and rs139185008*C on longevity after removing individuals with amyotrophic lateral sclerosis / frontotemporal dementia diagnoses. In the discovery cohort (n = 230,006), the frequency of rs139185008*C heterozygotes decreased significantly with age in the comparisons between 50 and 80 years vs. >80 years (p = 0.0005) and <50 years vs. >80 years (p = 0.0001). The findings were similar but less significant in a smaller replication cohort (2-sided p = 0.037 in 50-80 years vs. >80 years and 0.061 in <50 years vs. >80 years). Analysis of the allele frequencies in 5-year bins demonstrated that the decrease of rs139185008*C started after the age of 70 years. The hexanucleotide repeat expansion tagging single nucleotide polymorphisms decreasing frequency with age suggests its' association with age-related diseases probably also outside amyotrophic lateral sclerosis / frontotemporal dementia.

No Clinically Relevant Memory Effects in Perinatal Hyperglycemia and Hypoglycemia: A 40-Year Follow-Up of a Small Cohort

Maternal diabetes mellitus in pregnancy is associated with impairments in memory functions of the offspring in childhood and adolescence but has not been studied in adulthood. The association of perinatal hypoglycemia with memory has not been studied in adulthood either. The combined sequelae of these two risk factors have not been directly compared. We studied general cognitive ability and memory functions in a prospective follow-up of a cohort born in 1971 to 1974. The sample included participants exposed to prenatal hyperglycemia (n = 24), perinatal hypoglycemia (n = 19), or both (n = 7). It also included controls with no early risks (n = 82). We assessed the participants' Intelligence quotient (IQ), working memory, and immediate and delayed recall of both verbal and visual material at the age of 40. We did not find significant differences in IQ or the memory tests between the groups. We did identify an interaction (p = 0.03) of the early risk with the type of digit span task: compared to the controls, the participants exposed to perinatal hypoglycemia had a larger difference between the forward digit span, a measure of attention, and the backward digit span, a measure of working memory processing (p = 0.022). The interaction remained significant when birth weight was controlled for (p = 0.026). Thus, in this small cohort, prenatal hyperglycemia, perinatal hypoglycemia, and their combination appeared relatively benign disorders. The association of these conditions with neurocognitive impairments in adulthood remains unconfirmed. The significance of the working memory difference needs to be verified with a larger sample.

Mortality in individuals with childhood ADHD or subthreshold symptoms - a prospective perinatal risk cohort study over 40 years

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is associated with negative life outcomes and recent studies have linked it to increased mortality. These studies have examined nationwide registers or clinic-referred samples and mostly included participants up until the age of 30. No studies have investigated mortality associated with subthreshold levels of ADHD symptoms. Our aim was to analyze mortality in a perinatal risk cohort of 46-year-old adults with childhood ADHD (cADHD) and milder childhood attention problems (including hyperactivity and inattention; cAP) compared with a group with similar birth risks but no or low levels of childhood ADHD symptoms (Non-cAP). Causes of death obtained from a national register were examined.

METHODS

Mortality was analyzed with Cox proportional hazard models for all-cause mortality, cause-specific mortality (natural and unnatural causes), and age-specific mortality (under and over age 30). All models were adjusted with gender. The total n in the study was 839 (cADHD n = 115; cAP n = 216; Non-cAP n = 508).

RESULTS

By the age of 46, 11 (9.6%) deaths occurred in the cADHD group, 7 (3.2%) in the cAP group, and 20 (3.9%) in the Non-cAP group. The cADHD group had the highest mortality risk (adjusted hazard ratio = 2.15; 95% CI 1.02, 4.54). Mortality was not elevated in the cAP group (adjusted hazard ratio = 0.72; 95% CI .30, 1.72). Mortality in the cADHD group was mainly attributed to unnatural causes of death (adjusted hazard ratio = 2.82; 95% CI 1.12, 7.12). The mortality risk in the cADHD group was sixfold before age 30 (adjusted hazard ratio = 6.20; 95% CI 1.78, 21.57).

CONCLUSIONS

Childhood ADHD was associated with a twofold risk of premature death by the age of 46 in this prospective longitudinal cohort study. Our results corroborate previous findings and the morbidity of ADHD. Subthreshold levels of childhood ADHD symptoms were not linked to increased mortality. Our results suggest that mortality risk is higher in young than middle adulthood. Future studies should examine mortality associated with ADHD in different ages in adulthood to identify those in greatest risk of premature death.

ALS in Finland

Background and Objectives

To analyze the frequencies of major genetic variants and the clinical features in Finnish patients with amyotrophic lateral sclerosis (ALS) with or without the C9orf72 hexanucleotide repeat expansion.

Methods

A cohort of patients with motor neuron disease was recruited between 1993 and 2020 at the Helsinki University Hospital and 2 second-degree outpatient clinics in Helsinki. Finnish ancestry patients with ALS fulfilled the diagnosis according to the revised El Escorial criteria and the Awaji-criteria. Two categories of familial ALS (FALS) were used. A patient was defined FALS-A if at least 1 first- or second-degree family member had ALS, and FALS-NP, if family members had additional neurologic or psychiatric endophenotypes.

Results

Of the 815 patients, 25% had FALS-A and 45% FALS-NP. C9orf72 expansion (C9pos) was found in 256 (31%) of all patients, in 58% of FALS-A category, in 48% of FALS-NP category, and in 23 or 17% of sporadic cases using the FALS-A or FALS-NP definition. C9pos or SOD1 p.D91A homozygosity was found in 328 (40%) of the 815 patients. We compared demographic and clinical characteristics between C9pos and patients with unknown cause of ALS (Unk). We found that the age at onset was significantly earlier and survival markedly shorter in the C9pos vs Unk patients with ALS. The shortest survival was found in bulbar-onset male C9pos patients, whereas the longest survival was found in Unk limb-onset males. Older age at onset associated consistently with shorter survival in C9pos and Unk patients in both limb-onset and bulbar-onset groups. There were no significant differences in the frequencies of bulbar-onset and limb-onset patients in C9pos and Unk groups. ALS-frontotemporal dementia (FTD) was more common in C9pos (17%) than in Unk (4%) patients, and of all patients with ALS-FTD, 70% were C9pos.

Discussion

These results provide further evidence for the short survival of C9orf72-associated ALS. A prominent role of the C9orf72 and SOD1 variants was found in the Finnish population. An unusually high frequency of C9pos was also found among patients with sporadic ALS. The enrichment of these 2 variants likely contributes to the high incidence of ALS in Finland.

Carriership of two copies of C9orf72 hexanucleotide repeat intermediate-length alleles is a risk factor for ALS in the Finnish population

The hexanucleotide repeat expansion in intron 1 of the C9orf72 gene causes amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. In addition to the effects of the pathogenic expansion, a role of intermediate-length alleles has been suggested in ALS, corticobasal degeneration and Parkinson’s disease. Due to the rarity of intermediate-length alleles with over 20 repeats and the geographical variability in their frequency, large studies that account for population stratification are needed to elucidate their effects. To this aim, we used repeat-primed PCR and confirmatory PCR assays to determine the C9orf72 repeat allele lengths in 705 ALS patients and 3958 controls from Finland. After exclusion of expansion carriers (25.5% of the ALS patients and 0.2% of the controls), we compared the frequency of intermediate-length allele carriers of 525 ALS cases and 3950 controls using several intermediate-length allele thresholds (7–45, 17–45, 21–45, 24–45 and 24–30). The carriership of an intermediate-length allele did not associate with ALS (Fisher’s test, all p ≥ 0.15) nor was there any association with survival (p ≥ 0.33), when we divided our control group into three age groups (18–65, 66–84 and 85–105 years). Carriership of two intermediate-length alleles was associated with ALS, when the longer allele was ≥ 17 repeats (p = 0.002, OR 5.32 95% CI 2.02–14.05) or ≥ 21 repeats (p = 0.00016, OR 15.21 95% CI 3.79–61.0). Our results show that intermediate-length alleles are a risk factor of ALS when present in both alleles, whereas carrying just one intermediate-length allele was not associated with ALS or survival.

ADHD and subthreshold symptoms in childhood and life outcomes at 40 years in a prospective birth-risk cohort

We investigated ADHD symptoms and life outcomes in adulthood and their association with childhood ADHD and subthreshold symptoms in a prospectively followed cohort with perinatal risks. We identified participants with childhood ADHD (cADHD, n = 37), subthreshold symptoms defined as attention problems (cAP, n = 64), and no ADHD or cAP (Non-cAP, n = 217). We compared the groups and a control group with no perinatal risks (n = 64) on self-reported ADHD symptoms, executive dysfunction, and life outcomes in adulthood. At age 40, 21.6% of the cADHD, 6.3% of the cAP, 6.0% of the Non-cAP group, and 1.6% of the controls reached a screener cutoff for possible ADHD. The cADHD group had lower educational level, more ADHD symptoms and executive dysfunction, and higher rates of drug use than the other groups. Childhood ADHD associated with perinatal risks persists into midlife whereas childhood subthreshold ADHD symptoms in this cohort were not associated with negative outcomes in adulthood.

A Prospective 30-Year Follow-Up of ADHD Associated With Perinatal Risks

OBJECTIVE

Longitudinal follow-up of ADHD suggests a poorer outcome in those affected. Studies extending to 30 years however are rare. We investigated the adult outcome of ADHD associated with perinatal risks (PRs), treated non-pharmacologically.

METHOD

A study group of 122 participants (86 men, 36 women) with PR-associated ADHD was followed-up from birth and compared with a control group also prospectively studied.

RESULTS

The study group showed more cognitive, motor perception, and learning impairments as well as psychiatric problems at ages 5, 9, and 16. At age 30, the study group reported less education, more involuntary job dismissals and more alcohol abuse. Self-reported ADHD symptoms were still prevalent in adulthood.

CONCLUSION

ADHD symptoms persist and impair the long-term educational, occupational, and psychiatric outcome. ADHD in participants with PR appears to follow a course seen in studies of unselected ADHD.

Adult with Middle Interhemispheric Variant of Holoprosencephaly: Neuropsychological, Clinical, and Radiological Findings

OBJECTIVE

The middle interhemispheric variant of holoprosencephaly (MIHV) is a mild, rare variant of holoprosencephaly. Only a few cases of children with MIHV have been reported. Here we report in detail an adult case.

METHOD

The patient is a female in her 30s. The patient underwent an extensive neuropsychological examination, a neurological examination and a magnetic resonance imaging.

RESULTS

Neuroradiologically, the patient had a typical finding of MIHV, with the absence of the central corpus callosum and union of posterior frontal and anterior parietal gyri. In neuropsychological examination, the patient had average or above average performance in verbal comprehension, naming, reading and writing, and below average performance in perceptual reasoning, visuospatial abilities, processing speed and memory. Also difficulties in mathematical abilities, psychomotor skills, and executive functions were found. No gross neurological involvement was noted. She was diagnosed with atypical depression, post-traumatic stress disorder and a dissociative disorder in early adulthood. Despite cognitive deficits, she was able to achieve a tertiary level education.

CONCLUSIONS

This is the first adult case of MIHV described in detail. Our case emphasizes the possibility of a missed diagnosis of marked brain malformations in patients with craniofacial abnormalities. More cases and prospective follow-up studies are needed to understand the evolvement of both neuropsychological and psychiatric symptoms in these patients.

Attrition in a 30-year follow-up of a perinatal birth risk cohort: factors change with age

Background. Attrition is a major cause of potential bias in longitudinal studies and clinical trials. Attrition rate above 20% raises concern of the reliability of the results. Few studies have looked at the factors behind attrition in follow-ups spanning decades. Methods. We analyzed attrition and associated factors of a 30-year follow-up cohort of subjects who were born with perinatal risks for neurodevelopmental disorders. Attrition rates were calculated at different stages of follow-up and differences between responders and non-responders were tested. To find combinations of variables influencing attrition and investigate their relative importance at birth, 5, 9, 16 and 30 years of follow-up we used the random forest classification. Results. Initial loss of potential participants was 13%. Attrition was 16% at five, 24% at nine, 35% at 16 and 46% at 30 years. The only group difference that emerged between responders and non-responders was in socioeconomic status (SES). The variables identified by random forest classification analysis were classified into Birth related, Development related and SES related. Variables from all these categories contributed to attrition, but SES related variables were less important than birth and development associated variables. Classification accuracy ranged between 0.74 and 0.96 depending on age. Discussion. Lower SES is linked to attrition in many studies. Our results point to the importance of the growth and development related factors in a longitudinal study. Parents' decisions to participate depend on the characteristics of the child. The same association was also seen when the child, now grown up, decided to participate at 30 years. In addition, birth related medical variables are associated with the attrition still at the age of 30. Our results using a data mining approach suggest that attrition in longitudinal studies is influenced by complex interactions of a multitude of variables, which are not necessarily evident using other multivariate techniques.

Adult neurobehavioral outcome of hyperbilirubinemia in full term neonates-a 30 year prospective follow-up study

Background. Neonatal hyperbilirubinemia (HB) may cause severe neurological damage, but serious consequences are effectively controlled by phototherapy and blood exchange transfusion. HB is still a serious health problem in economically compromised parts of the world. The long term outcome has been regarded favorable based on epidemiological data, but has not been confirmed in prospective follow-up studies extending to adulthood.

Methods. We studied the long term consequences of HB in a prospective birth cohort of 128 HB cases and 82 controls. The cases are part of a neonatal at-risk cohort (n = 1196) that has been followed up to 30 years of age. HB cases were newborns ≥ 2500 g birth weight and ≥ 37 weeks of gestation who had bilirubin concentrations > 340 µmol/l or required blood exchange transfusion. Subjects with HB were divided into subgroups based on the presence (affected HB) or absence (unaffected HB) of diagnosed neurobehavioral disorders in childhood, and compared with healthy controls. Subjects were seen at discharge, 5, 9 and 16 years of life and parent’s and teacher’s assessments were recorded. At 30 years they filled a questionnaire about academic and occupational achievement, life satisfaction, somatic and psychiatric symptoms including a ADHD self-rating score. Cognitive functioning was tested using ITPA, WISC, and reading and writing tests at 9 years of life.

Results. Compared to controls, the odds for a child with HB having neurobehavioral symptoms at 9 years was elevated (OR = 4.68). Forty-five per cent of the HB group were affected by cognitive abnormalities in childhood and continued to experience problems in adulthood. This was apparent in academic achievement (p < 0.0001) and the ability to complete secondary (p < 0.0001) and tertiary (p < 0.004) education. Also, the subgroup of affected HB reported persisting cognitive complaints e.g., problems with reading, writing and mathematics. Childhood symptoms of hyperactivity/impulsivity (p < 0.0001) and inattention (p < 0.02) were more common in HB groups, but in adulthood the symptoms were equal. The affected HB had lower scores in parameters reflecting life satisfaction, less controlled drinking, but not increased substance abuse.

Discussion. Our results indicate that neonatal HB has negative consequences in adult age. A prospectively collected cohort with strict inclusion criteria enables to control most of the bias factors involved with retrospective data. The control and HB groups were remarkably similar at birth in terms of medical data, and the growth environment of the children, as well as the parents’ social groups, education, size of family, type of housing at birth and at 9 years of age. Our findings bear resemblance to disorders of the fronto-striatal network, and also symptoms of the ADHD spectrum were frequent in the HB group suggesting a link of HB to other neurodevelopmental disorders.

The Perinatal Adverse events and Special Trends in Cognitive Trajectory (PLASTICITY) - pre-protocol for a prospective longitudinal follow-up cohort study

Prospective follow-up studies on long term effects of pre- and perinatal adverse conditions in adulthood are rare. We will continue to follow the prospective cohort of initially 1196 subjects with predefined at-delivery risk factors out of 22,359 consecutive deliveries during 1971-74 at a single maternity hospital. The risk cohort and 93 controls have been followed up with a comprehensive clinical program at 5, 9, and 16 years of age and by questionnaire at the age of 30 years. Major medical events known to affect the development and growth of the brain, or cognitive functions and personality have been documented. Here we present a pre-protocol for the project, which we will call PLASTICITY, whose aim is to follow consenting subjects and controls into mid-adulthood and beyond, and to explore how the neonatal risk factors modulate neurodevelopmental and neurodegenerative processes such as learning disabilities, ADHD, aging, early onset mild cognitive impairment and even dementia. Our first focus is on the neurological and cognitive outcomes at age 40 years, using detailed neurological, neuropsychological, neuroimaging, genetic, blood chemistry and registry based methods. Results will be expected to offer information on the risk of neurological, psychiatric, metabolic and other medical consequences as well as the need for health and social services at the brink of middle age, when new degenerative phenomena are known to emerge. The evaluation at age 40 years will serve as a baseline for later aging studies. We welcome all comments and suggestions, which we will apply in finalizing details and inviting collaboration.

Neuropsychological sequelae of acute-onset sporadic viral encephalitis

Acute encephalitis is an inflammation of the brain parenchyma. In the USA, by estimation, 20,000 cases occur every year. A variety of cognitive deficits may persist after the acute stage, and they are often the sole cause of disability. Recent literature demonstrates the heterogeneity of both amnestic disorders and the outcome following encephalitis. Herpes simplex virus is the most commonly recognised single aetiology of sporadic encephalitis and it may be the cause of the most severe symptoms. Antiviral medication, however, seems to have improved the cognitive outcome when compared to the historical, untreated cases. The cognitive sequelae following herpes simplex virus encephalitis (HSVE) are best known and most commonly described, e.g., in textbooks, but they do not represent the typical symptomatology of encephalitis in general. Much less is unfortunately known about other types of encephalitis, those that account perhaps up to 80% of all cases, where both mild and severe defects have been observed. This article summarises the current knowledge.

How useful is [123I]beta-CIT SPECT in clinical practice?

OBJECTIVE

To assess the accuracy and clinical usefulness of [(123)I]beta-CIT (2beta-carbomethoxy-3beta-(4-iodophenyl)tropane) SPECT in the differential diagnosis of Parkinson's disease.

SUBJECTS

185 consecutive patients with symptoms of movement disorder were studied. The diagnoses were Parkinson's disease (92), essential tremor (16), vascular parkinsonism (15), various Parkinson plus syndromes (P+) (12), dementia with Lewy bodies (DLB) (5), dystonia (5), drug induced movement disorder (12), and other diagnoses (8). A reference group (psychogenic parkinsonism) comprised 20 subjects with complaints suggesting extrapyramidal disease but with no unequivocal signs on clinical examination and no abnormalities on brain imaging.

RESULTS

beta-CIT uptake was significantly lower in the whole striatum as well as separately in the putamen and in the caudate nucleus in Parkinson's disease than in the reference group or in drug induced movement disorder, essential tremor, or dystonia. The uptake of beta-CIT in the vascular parkinsonism group was heterogeneous and mean beta-CIT uptake fell between the reference group and the Parkinson's disease group. In the P+ and DLB groups the striatal uptake ratios overlapped those of the Parkinson's disease group.

CONCLUSIONS

[(123)I]beta-CIT SPECT may not be as useful a tool in the clinical differential diagnosis of Parkinson's disease as was previously believed, but it was 100% sensitive and specific for the diagnosis in younger patients (age <55 years). In older patients (age >55 years) specificity was substantially lower (68.5%). This differential specificity reflected the different distribution of differential diagnostic disorders (P+, DLB, vascular parkinsonism) in the older and younger age groups.

Assessment of a DJ-1 (PARK7) polymorphism in Finnish PD

Mutations in DJ-1 are a cause of autosomal recessive parkinsonism. Polymorphism of genes implicated in hereditary forms of parkinsonism may be a predisposing factor in sporadic Parkinson's disease (PD). The authors analyzed whether a polymorphism (g.168_185del) within exon 1 of DJ-1 contributes to the risk of sporadic PD in a Finnish case-control series. This gene does not play a major role in the genetic predisposition to PD in this population.

Apolipoprotein E (APOE), PARKIN and catechol-O-methyltransferase (COMT) genes and susceptibility to sporadic Parkinson's disease in Finland

Recent studies have demonstrated that genetic factors modify susceptibility to sporadic Parkinson's disease (PD). So far the results of candidate gene studies have been conflicting. It has been suggested that polymorphisms in apolipoprotein E (APOE), PARKIN and catechol-O-methyltransferase (COMT) genes might increase the risk of PD. We studied 147 Finnish non-demented patients with sporadic PD and 137 controls. APOE epsilon allele and genotype frequencies in PD patients did not differ significantly from controls. Three single nucleotide polymorphisms of the PARKIN gene and an intronic and an exonic (Val158Met) polymorphism of the COMT gene were studied. None of these polymorphisms showed association with PD in our series. In contrast to reports in oriental populations, our results do not support a major role of APOE, PARKIN and COMT polymorphisms in PD susceptibility in the Finnish population.

Release of soluble ICAM-5, a neuronal adhesion molecule, in acute encephalitis

BACKGROUND

Intercellular adhesion molecule (ICAM)-5 (telencephalin) is an adhesion molecule in telencephalic neurons of the mammalian brain that binds to the leukocyte integrin CD11a/CD18. The authors observed that human cerebral neurons also expressed ICAM-5 and that ICAM-5--mediated neuron--leukocyte binding in cultured hippocampal neurons. This led the authors to examine ICAM-5 expression during clinical CNS inflammation.

METHODS

The authors found, by immunoblotting, a 115-kDa soluble form of ICAM-5 (sICAM-5) cleaved from the membrane-bound (130 kDa) ICAM-5, and established an ELISA assay to measure it. CSF samples of patients with acute encephalitis and MS were studied.

RESULTS

sICAM-5 was increased in encephalitis (320 plus minus 107 ng/mL; n = 25), as compared with patients with MS (128 plus minus 10 ng/mL; n = 16) and control subjects without CNS disease (137 plus minus 6 ng/mL; n = 42) (p < 0.001). The concentration of sICAM-5 correlated with the performance in the immediate recall task (p = 0.013) and with the leukocyte count in the CSF (p = 0.02), especially in cases caused by herpes simplex virus (HSV) (r = 0.94; p = 0.002).

CONCLUSIONS

sICAM-5 is cleaved from CNS into CSF during acute encephalitis, and it may mediate leukocyte--neuron interactions. sICAM-5 release from cerebral neurons may actively regulate immune responses and leukocyte adhesion during microbial neuroinvasion in humans during encephalitis.

Cognitive outcome in acute sporadic encephalitis

Acute encephalitis is an inflammation of the brain parenchyma. In the United States, 20,000 cases occur yearly. A variety of cognitive deficits, often the sole cause of disability, may persist after the acute stage. Still, infectious diseases tend to be covered only briefly in neuropsychological handbooks. Recent literature demonstrates the heterogeneity of both amnestic disorders and the outcome following encephalitides. Herpes Simplex virus (HSV), the most common single etiology of sporadic encephalitis, usually causes the most severe symptoms. Modern antiviral medication, however, seems to improve the cognitive outcome. Much less is known about non-HSV encephalitides, where both mild and severe defects have been observed. This article summarizes the current knowledge and also calls upon a more active neuropsychological research in the area.

Is EEG useful in assessing patients with acute encephalitis treated with acyclovir?

EEG has been used widely in diagnosing encephalitis, as it demonstrates rather typical abnormalities, especially in herpes simplex virus encephalitis (HSVE). We analysed 204 EEG recordings from 98 consecutive acyclovir-treated patients with acute encephalitis between 1984 and 1994. Periodic complexes (PC) in the acute phase predicted poor outcome (Kendall tau 0.40, P < 0.001). However, unlike in many other diseases, e.g. stroke and intracerebral haemorrhage, the diffuse slowing of the background activity at acute phase did not predict outcome (Kendall tau -0.6, P = 0.35). At follow-up, the emergence of diffuse slow background activity was significantly associated with a less favourable outcome (Kendall tau 0.33, P = 0.0016). Among clinical variables, only epileptic seizures early during the course of the disease correlated significantly with outcome. EEG does have value as a prognostic indicator in acute encephalitides, but it seems that diffuse slowing of background activity or irritative features acutely are not as important as previously thought, based on the experiences of the pre-acyclovir era.

Does glutamate mediate brain damage in acute encephalitis?

Cerebrospinal fluid (CSF) amino acid neurotransmitter concentrations in 23 patients with acute encephalitis were compared with those in patients with acute brain infarction, multiple sclerosis and controls. The concentration of glutamate was significantly higher in encephalitis (5.2+/-6.7 micromol/l) and stroke patients (9.6+/-14.2 micromol/l) than in MS patients (1.6+/-0.9 micromol/l) and controls (1.7+/-0.8 micromol/l; p < 0.001). The concentration of glycine was significantly higher in encephalitis (11.0+/-4.7 micromol/l) than in stroke (7.6+/-3.2 micromol/l) and MS patients (6.3+/-2.1 micromol/l) or controls (5.6+/-1.8 micromol/l; p < 0.002). Taurine levels were significantly lower in encephalitis patients than in the other groups (p = 0.04). The correlation of high glutamate levels with poor outcome was almost significant (Kendall tau 0.63, p = 0.06). Our observations suggest that exicitotoxic neurotransmission may play an important role in the series of events that lead to neuronal damage in encephalitis.

Neuromagnetic sequelae of herpes simplex encephalitis

Spontaneous cortical activity and auditory evoked responses were recorded with a whole-scalp 122-channel neuromagnetometer from 4 patients after left-hemisphere dominant herpes simplex encephalitis and associated memory disorders. Spontaneous activity of one patient contained periodic sharp waves over the left hemisphere; the background activity was attenuated. The sources of periodic sharp waves clustered close to the sources of auditory evoked fields in the temporal lobe. In controls, dominant rhythmic activity over the parieto-occipital region had spectral maximum at 10.6 +/- 0.6 Hz; in patients the dominant rhythmic activity peaked at 8.6 +/- 1.8 Hz. The suppression of the parieto-occipital activity in eyes-open versus eyes-closed condition was smaller in patients than in controls. The patients' peak spectral frequency was correlated with neuropsychological tests reflecting deficient attentional capacity. The observed changes probably reflect decreased subcortical control of the cortical electric activity.

Duration of transient amnesia correlates with cognitive outcome in acute encephalitis

Temporary periods of amnesia are encountered in acute encephalitides. We investigated the association between transient encephalitic amnesia (TENA) and outcome in 60 patients. Twenty-six patients had TENA lasting < or = 1 day (short TENA), 17 had TENA lasting 2-7 days, and 17 had TENA for > 7 days (long TENA). The long TENA group had more neuropsychological impairment, larger brain lesions, and more difficulty in daily activities than the short TENA group. The findings were not explained by the number of epileptic seizures, delay of acyclovir medication, or the aetiology of encephalitis. TENA is a useful new clinical tool in predicting the outcome of acute encephalitis and selecting patients who are in need of detailed neuropsychological evaluation.

Cognitive recovery instead of decline after acute encephalitis: a prospective follow up study

OBJECTIVE

Follow up of cognitive sequelae of acute encephalitis and estimation of the frequency of persisting dementia.

METHODS

Out of a series of 45 consecutive patients with acute encephalitis prospectively studied in 1990-95, 40 were screened for difficulty in everyday life using the Blessed dementia scale (BDS) 3.7 (1.4), mean (SD), years after onset. Eight patients had had herpes simplex encephalitis (HSVE), 16 some other identified aetiology, and in 21 the aetiology was unknown. All, except two patients with a nonherpetic encephalitis, were treated with acyclovir. All patients with disability in BDS (12/40), were invited to a neuropsychological reassessment, and the results of this assessment were compared with those of a similar assessment done after the acute stage. At follow up one patient could not complete the tests due to intractable epilepsy.

RESULTS

In six of 11 cases the symptoms causing disability were mainly psychiatric. Five patients (two with HSVE) had a pronounced memory impairment together with other cognitive deficits, indicating dementia (frequency of 12.8%). In eight of the 11 testable cases cognitive performance had improved over the years, in two cases a decline was found and one patient with severe deficits showed no change. Intractable epilepsy was found in four of 12 cases.

CONCLUSION

Cognitive decline had taken place already at the acute stage, and further deterioration was uncommon. Considerable improvement occurred in most patients during follow up. Also in patients with HSVE treated with acyclovir the cognitive recovery was substantial and of a magnitude not expected based on previous literature. Intractable epilepsy contributed to the cognitive deterioration in some cases. Affective disorders also had a surprisingly important role for the long term outcome.

Unilateral hyperfusion in brain-perfusion SPECT predicts poor prognosis in acute encephalitis

We studied 88 patients with acute encephalitis using hexamethylpropyleneamine oxime and single photon emission computed tomography (SPECT). All patients had been initially treated with intravenous acyclovir. The etiology could be disclosed in 37 patients (42%), which included 15 patients with herpes simplex encephalitis, 7 with varicella-zoster encephalitis, and 29 with other encephalitides (Mycoplasma, adenovirus, influenza, rotavirus, rubella, Epstein-Barr, arbovirus, syphilis, and tuberculosis). Unilateral hyperperfusion in SPECT was an independent predictor of poor prognosis, whereas neither clinical outcome variables, such as seizures, state of consciousness, and focal neurologic findings, nor CSF or EEG findings were not. Focal unilateral hyperperfusion is an indicator of severe inflammation of the brain tissue and predicts a poor outcome as assessed in terms of activities of daily living after recovery.

Subcortical type cognitive impairment in herpes zoster encephalitis

Nine immunocompetent patients with acute herpes zoster encephalitis (HZE) were studied with the help of neurological investigations. All patients were treated with acyclovir. Neuropsychological performance was compared with that of a group of 16 healthy controls. Computed tomography of the head showed infarct-like hypodense lesions in two patients, involving the internal capsule in one case and the temporoparietal cortex and white matter in another. Hypoperfusion shown by single photon emission computed tomography, mostly involving the frontal areas bilaterally, was seen in six of the seven patients examined. Hyperperfusion as seen in herpes simplex encephalitis was not encountered. One patient remained mildly demented, but all the other patients recovered relatively well. Neuropsychological examination after acyclovir treatment showed a decline in memory and speed of cognitive processes, without circumscribed neuropsychological deficits. Six of the nine patients showed behavioural disinhibition, and mood changes were also observed. Memory impairment in HZE was not as global or as severe as is described after encephalitis due to herpes simplex virus. In HZE both the brain perfusion pattern and the neuropsychological test profile showed features compatible with subcortical dysfunction.

Brain perfusion SPECT abnormalities in neuronal ceroid lipofuscinoses

Brain perfusion was studied with the Tc-99m-HMPAO SPECT method in 19 INCL patients, 21 JNCL patients and 5 patients with Jansky-Bielschowsky variant disease (JBVD). The typical SPECT findings at an early stage of INCL were bilateral anterior frontal, posterior temporoparietal and occipital hypoperfusion, whereas reduction in cerebellar perfusion appeared later. However, perfusion of basal ganglia and thalami, although atrophic on MRI, was usually well preserved up to the terminal stage. All JNCL patients except one had at least one hypoperfused area. Mild hypoperfusion was usually located in the parietal and occipital lobes and cerebellum, whereas more severe hypoperfusion was observed in the temporal lobes. In JNCL, SPECT revealed lesions not detected on CT. All JBVD patients had supra- and infratentorial hypoperfusion, which was usually bilateral. This study shows that although in NCLs brain hypoperfusion can appear prior to structural abnormalities seen on MRI or CT, such abnormalities are not always associated with significant hypoperfusion.

Cognitive impairment after acute encephalitis: comparison of herpes simplex and other aetiologies

OBJECTIVE

To compare the cognitive defects after acute acyclovir treated herpes simplex encephalitis with those after other types of acute encephalitis.

METHODS

Seventy seven consecutive patients between 1985 and 1995 and 29 normal controls were studied. Of the 77 patients without concomitant neurological conditions, 17 had herpes simplex, one virus encephalitis (HSVE group), 27 had some other identified aetiology (non-HSVE group), and in 33 patients the cause was unknown. Acyclovir treatment was started less than four days after the first mental symptoms in 12 of 17 patients with HSVE. A thorough neuropsychological assessment was carried out about one month after the onset.

RESULTS

The HSVE group had deficits in verbal memory, verbal-semantic functions, and visuoperceptual functions more often than the non-HSVE group. The risk for cognitive defects was twofold to four-fold in the patients with HSVE compared with the non-HSVE patients. Two (12%) of the patients with HSVE and 12 (44%) of the non-HSVE patients were cognitively intact. Six patients with HSVE (46%) and 17 (89%) non-HSVE patients later returned to work. The lesions on CT or MRI were bilateral only in one patient with HSVE. The defects in the three patients with adenovirus infection were severe and resembled the amnesia after HSVE. Cognitive impairment, not previously reported, was found in encephalitis after rotavirus infection and epidemic nephropathy.

CONCLUSION

The recovery in the HSVE group was better than expected based on the medical literature. On the other hand there were surprisingly severe cognitive defects in encephalitis after other viruses. With early acyclovir treatment patients with the least severe HSVE were equivalent to those with non-HSV encephalitis with good outcome whereas those with the most severe non-HSV encephalitis were equivalent to those with HSVE with poor outcome.

Amnesia in acute herpetic and nonherpetic encephalitis

OBJECTIVES

To evaluate how often global amnesia syndrome is encountered as a sequel of herpes simplex virus type 1 encephalitis (HSVE) and in other types of acute encephalitides, and to evaluate whether there are qualitative differences in amnesia caused by different encephalitides.

SUBJECTS

Forty-five consecutive patients with encephalitis (mean age, 40.8 years) studied prospectively within a 5-year period, 8 of whom had HSVE. There were 24 normal controls.

MEASURES

Neuropsychological assessment and memory evaluation after the acute stage of encephalitis, as well as at follow-up after 27.7 +/- 18.6 months.

RESULTS

Three patients (6%), including 1 with HSVE, had persistent anterc grade and retrograde memory defects, typical features of global amnesia. Twelve patients had anterograde amnesia in the first assessment. No statistically significant differences in the memory measures were found between the HSVE (n = 4) and the non-HSVE (n = 8) groups. Some patients had predominantly semantic difficulty, some had a "frontal-type" memory disorder, and in some patients rapid forgetting was the prominent feature.

CONCLUSIONS

The frequency of amnesia can reliably be evaluated only in consecutive series of patients. Previous literature, mainly case reports, may give the impression that global amnesia is a common consequence of encephalitis. Our findings do not support that view. Furthermore, there are clear differences in the quality of the memory impairment between cases of acute encephalitides. Our findings suggest that amnesia as a consequence of encephalitis, even HSVE, should not be considered a uniform phenomenon.

Brain perfusion SPECT in juvenile neuronal ceroid lipofuscinosis

The juvenile neuronal ceroid-lipofuscinosis (JNCL) is a recessively inherited progressive encephalopathy. We studied 21 JNCL patients with a duration of illness of 1 to 17 years by 99mTc-HM-PAO single photon emission computed tomography (SPECT) and correlated the findings with clinical parameters. All patients had at least one hypoperfused brain area, the median number of such areas was 5 per patient. Parietally, occipitally, and in the cerebellar lobes hypoperfusion was usually mild whereas it was temporally more severe. Right parietal hypoperfusion correlated to neurological dysfunction.

Registration and display of brain SPECT and MRI using external markers

Accurate anatomical localisation of abnormalities observed in brain perfusion single-photon emission computed tomography (SPECT) is difficult, but can be improved by correlating data from SPECT and other tomographic imaging modalities. For this purpose we have developed software to register, analyse and display 99mTc-hexamethylpropyleneamine oxime SPECT and 1.0 T MRI of the brain. For registration of SPECT and MRI data external skin markers containing 99mTc (220 kBq) in 50 microliters of coconut butter were used. The software is coded in the C programming language, and the X Window system and the OSF/Motif standards are used for graphics and definition of the user interface. The registration algorithm follows a noniterative least-squares method using singular value decomposition of a 3 x 3 covariance matrix. After registration, the image slices of both data sets are shown at identical tomographic levels. The registration error in phantom studies was on average 4 mm. In the two-dimensional display mode the orthogonal cross-sections of the data sets are displayed side by side. In the three-dimensional mode MRI data are displayed as a surface-shaded 3 D reconstruction and SPECT data as cut planes. The usefulness of this method is demonstrated in patients with cerebral infarcts, brain tumour, herpes simplex encephalitis and epilepsy.

Hyperfixation of 99mTc-HMPAO and hypofixation of 123I-iomazenil in acute herpes encephalitis

We studied two patients with herpes encephalitis (HSE) by [99mTc]HMPAO and [123I]iomazenil single photon emission computed tomography. Increased uptake of HMPAO was seen for up to 63 days in the HSE affected brain area. Iomazenil binds to benzodiazepine receptors and can measure neurone loss. Decreased iomazenil uptake was observed a few days after onset, at a time when hyperfixation of HMPAO occurred. Because in HSE neurone loss occurs simultaneously with hyperfixation of HMPAO, it is unlikely that this hyperfixation is caused by increased neuronal activity, as in epilepsy. This suggests that the hyperfixation of HMPAO in HSE occurs in glia and is sustained by inflammation-related hypermetabolism and acidity. The early neurone loss in HSE stresses the importance of immediate antiviral treatment.

Isolated retrograde amnesia for autobiographical material associated with acute left temporal lobe encephalitis

Retrograde amnesia for autobiographical material in the absence of anterograde amnesia or other memory disturbances was found in a patient with acute viral encephalitis. Memory loss showed a temporal gradient, but new learning was spared. Both brain perfusion imaging with 99mTc-HMPAO SPECT, and EEG localized the lesion in the left temporal lobe while CT and MRI were normal. This observation supports the anatomical differentiation between the different memory functions. The uncommon combination of isolated retrograde amnesia without other neuropsychological findings may raise the doubt of psychogenic aetiology, which in this case was refuted.

Dopamine D2-receptors in human narcolepsy: a SPECT study with 123I-IBZM

Increased dopamine D2 receptor binding in basal ganglia has been reported in human narcolepsy. These studies have been based on post-mortem material of 8 patients, most of them also medicated for narcolepsy. We studied six narcoleptics without stimulant or anticataplectic medication. The patients had an unambiguous history of cataplexy, and they were also studied polygraphically. Single photon emission computed tomography (SPECT) imaging was performed. The D2 receptor density was determined by using 123I-iodobenzamide (IBZM). The control subjects were 8 unmedicated Parkinson patients with one-sided (hemiparkinsonian) clinical symptoms. The D2 receptor density in them is known to be normal or somewhat increased compared to healthy normals. The striatum/frontal D2 activity ratio was 1.331 +/- 0.084 (with phantom study correction 2.101 +/- 0.300) in the narcoleptic patients, and in the parkinsonian controls 1.321 +/- 0.052 (2.067 +/- 0.185) for the asymptomatic side and 1.335 +/- 0.025 (2.117 +/- 0.090) for the symptomatic side (i.e. contralateral to the side with the clinical extrapyramidal signs). There was no statistical difference between the groups or between the symptomatic and asymptomatic side in the Parkinson patients. Thus, our results differ from the earlier post-mortem studies.

Validation of quantitative brain dopamine D2 receptor imaging with a conventional single-head SPET camera

Phantom measurements were performed with a conventional single-head single-photon emission tomography (SPET) camera in order to validate the relevance of the basal ganglia/frontal cortex iodine-123 iodobenzamide (IBZM) uptake ratios measured in patients. Inside a cylindrical phantom (diameter 22 cm), two cylinders with a diameter of 3.3 cm were inserted. The activity concentrations of the cylinders ranged from 6.0 to 22.6 kBq/ml and the cylinder/background activity ratios varied from 1.4 to 3.8. From reconstructed SPET images the cylinder/background activity ratios were calculated using three different regions of interest (ROIs). A linear relationship between the measured activity ratio and the true activity ratio was obtained. In patient studies, basal ganglia/frontal cortex IBZM uptake ratios determined from the reconstructed slices using attenuation correction prior to reconstruction were 1.30 +/- 0.03 in idiopathic Parkinson's disease (n = 9), 1.33 +/- 0.09 in infantile and juvenile neuronal ceroid lipofuscinosis (n = 7) and 1.34 +/- 0.05 in narcolepsy (n = 8). Patients with Huntington's disease had significantly lower ratios (1.09 +/- 0.04, n = 5). The corrected basal ganglia/frontal cortex ratios, determined using linear regression, were about 80% higher. The use of dural-window scatter correction increased the measured ratios by about 10%. Although comprehensive correction methods can further improve the resolution in SPET images, the resolution of the SPET system used by us (1.5-2 cm) will determine what is achievable in basal ganglia D2 receptor imaging.

Brain perfusion SPECT in children with frequent fits

We studied 14 children with frequent fits using 99mTc-HM-PAO single photon emission computed tomography (SPECT). There were 11 patients with partial secondary generalized epilepsy (PSGE) and 3 with Lennox-Gastaut syndrome (LGS). The typical regional cerebral blood flow (rCBF) finding in PSGE was a single area of abnormally low perfused cortex, and that in LGS, multiple hypoperfused areas. Clinically, the LGS patients were more severely affected. SPECT was more sensitive in detecting abnormalities than EEG, CT or MRI. Extensive impairment of rCBF may thus indicate unfavourable development of intellectual performance and poor seizure control.

Interictal brain 99Tc-HM-PAO SPECT hypoperfusion in patients with unstable partial epilepsy and normal CT

Brain perfusion was studied interictally with 99mTc-HM-PAO SPECT in 47 adult patients with partial epilepsy and normal brain CT. Epilepsy was classified as secondarily generalized in 24 patients, as complex partial in 17 patients and as simple partial in 6 patients. In 24 patients good seizure control was not achieved as these patients had a median number of 78 seizures during the preceding month, while in the rest of the patients seizure control was relatively good (less than 6 seizures during preceding month). Local brain hypoperfusion was observed in 41 or 87% of the patients. Hypoperfusion was located close to the EEG foci in 76% and equally often with temporal and frontal foci. Hypoperfusion and the EEG focus were located on the same side in 83%. Hypoperfusion was more frequent in secondarily generalized epilepsy and simple partial epilepsy than in complex partial epilepsy. Left-sided hypoperfusion was especially associated with complex partial epilepsy. It is likely that the significant epileptogenic brain area was revealed in patients with SPECT focus and EEG focus in the same brain area. In one of our patients MRI showed a small temporal lesion which on successful removal was identified as a low-grade oligodendroglioma. Abnormalities of regional brain uptake of HM-PAO demonstrated by SPECT in patients with partial epilepsy and normal brain CT give further information about pathophysiology in partial epilepsy; this may be of use both for selecting appropriate therapy and in presurgical localization of foci.

Jansky-Bielschowsky variant disease: CT, MRI, and SPECT findings

Six patients with a variant type of Jansky-Bielschowsky (JBVD) disease were examined using 3 different imaging methods. Five of the patients underwent computed tomography, 4 magnetic resonance imaging, and 5 single photon emission computed tomography. All patients had brain atrophy that was most severe in the cerebellum. Magnetic resonance imaging demonstrated the parenchymal abnormalities well; all patients had hyperintense periventricular white matter, especially around the bodies and atria of the lateral ventricles, and a significant decrease in signal intensity in the thalami and/or putamina. Single photon emission computed tomography disclosed hypoperfusion of the cerebellum in all patients. Neuroimaging examinations are valuable in the diagnosis of JBVD. It may be difficult to divide patients with neuronal ceroid-lipofuscinosis disorders into clinical subtypes in the early stage of the disease. Magnetic resonance imaging, especially when combined with a typical clinical pattern, makes the diagnosis of JBVD highly likely. Radiologic examinations of the brain may also prove important in following the progression, as well as in investigating the pathophysiology, of the disease.

MRI of the brain, EEG sleep spindles and SPECT in the early diagnosis of infantile neuronal ceroid lipofuscinosis

Two patients with infantile neuronal ceroid lipofuscinosis are presented whose clinical diagnosis was based on the typical clinical picture, together with absent sleep spindles and MRI findings (hypointense thalami and hyperintense periventricular white matter) as early as 18 months in one girl. In addition to a flat cortical SEP, these abnormalities appeared earlier than the typical ERG and VEP findings used previously for clinical diagnosis of this condition. MRI of the other patient showed the same changes and EEG sleep spindles were absent by two years.

99Tcm-HMPAO SPECT in suspected dementia

To evaluate the usefulness of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) in suspected dementia we studied 160 consecutively imaged elderly patients from our hospital's memory disorder clinic. The diagnosis was based on clinical data, laboratory tests, neuropsychological examination, computed tomography (CT) and EEG. The patients were divided into six diagnostic categories: Alzheimer's disease (AD), multi-infarct dementia (MID), frontal lobe-type dementia (FTD), vascular encephalopathy not fulfilling the criteria of dementia, specific organic conditions, and psychiatric disorders. SPECT images were assessed without knowing the clinical diagnosis, and divided into AD pattern, FTD pattern, MID pattern, abnormal but unclassifiable, and normal. Twenty-three of 36 patients with clinical AD, 25/33 patients with clinical MID, and 2/5 patients with clinical TFD had compatible SPECT patterns. SPECT distinguished AD from MID in the majority (80%) of cases. In patients with depression or anxiety SPECT was abnormal in 16/21 cases, suggesting that SPECT may give early clues to the presence of an underlying organic disease in such elderly patients. Thus, SPECT with 99Tcm-HMPAO seems to be useful in the diagnosis of suspected dementia.

Regional cerebral blood flow after human cardiac arrest. A hexamethylpropyleneamine oxime single photon emission computed tomographic study

We studied 30 patients 24 hours after out-of-hospital cardiac arrest and 13 age-matched normal controls with the use of technetium Tc 99m-hexamethylpropyleneamine oxime single photon emission computed tomography. All patients were followed up for 12 months or until death. Frontal hypoperfusion (anteroposterior perfusion ratio, less than 0.90) was observed in 23 patients (77%). In eight patients who remained comatose and died, the total size of perfusion defects was larger (38% +/- 20%) than in the 21 patients who recovered consciousness (24% +/- 14%), but the anteroposterior ratio was similar in both of these patient groups (0.83 +/- 0.09) and significantly lower than in the controls (0.96 +/- 0.03). During follow-up, both the anteroposterior perfusion ratio and the relative defect size improved, but frontal hypoperfusion was still observed in seven of 13 patients. After cardiac arrest, regional cerebral blood flow is characterized by frontal hypoperfusion that tends to improve over time but that persists in most patients.