The effect of age of onset of PD on risk of dementia

BACKGROUND

Dementia occurs in the majority of patients with Parkinson's disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age.

METHODS

Two community-based studies of PD in New York (n=281) and Rogaland county, Norway (n=227) and two population-based groups of healthy elderly from New York (n=180) and Odense, Denmark (n=2414) were followed prospectively for 3-4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables.

FINDINGS

In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls.

INTERPRETATION

This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD.

Frequency of LRRK2 mutations in early- and late-onset Parkinson disease

OBJECTIVE

To evaluate the frequency of leucine-rich repeat kinase gene (LRRK2) mutations and single nucleotide polymorphisms (SNPs) in early-onset Parkinson disease (EOPD) and late-onset Parkinson disease (LOPD).

METHODS

We genotyped five previously reported LRRK2 mutations (G2019S, L1114L, I1122V, R1441C, and Y1699C) and 17 coding SNPs for haplotype analysis in 504 cases with PD and 314 controls enrolled in the Genetic Epidemiology of PD Study. Cases and controls were recruited without knowledge of family history of PD and cases were oversampled in the < or =50 age at onset (AAO) category.

RESULTS

The LRRK2 G2019S mutation was present in 28 cases with PD (5.6%) and two controls (0.6%) (chi(2) = 13.25; p < 0.01; odds ratio 9.18, 95% CI: 2.17 to 38.8). The mutations L1114L, I1122V, R1441C, and Y1699C were not identified. The frequency of the LRRK2 G2019S mutation was 4.9% in 245 cases with AAO < or =50 years vs 6.2% in 259 cases with AAO >50 (p = 0.56). All cases with PD with the G2019S mutation shared the same disease-associated haplotype. The frequency of the LRRK2 G2019S mutation was higher in the subset of 181 cases reporting four Jewish grandparents (9.9%) than in other cases (3.1%) (p < 0.01). Age-specific penetrance to age 80 was 24% and was similar in Jewish and non-Jewish cases.

CONCLUSIONS

The G2019S mutation is a risk factor in both early- and late-onset Parkinson disease and confirms the previous report of a greater frequency of the G2019S mutation in Jewish than in non-Jewish cases with Parkinson disease.

Association between mild parkinsonian signs and mild cognitive impairment in a community

BACKGROUND

Mild parkinsonian signs (MPS) are associated with prevalent and incident dementia but it is not known whether they are associated with mild cognitive impairment (MCI).

OBJECTIVE

To determine whether MPS and specific MPS (changes in axial function, rigidity, tremor) are associated with MCI in nondemented community-dwelling older people in northern Manhattan, NY.

METHODS

Participants underwent neurologic assessment, including a modified motor portion of the Unified Parkinson Disease Rating Scale. MCI was diagnosed in nondemented participants who had cognitive impairment based on neuropsychological testing and no functional impairment. Participants with MCI were classified as having MCI with memory impairment (MCI+M) vs MCI without memory impairment (MCI-M).

RESULTS

MCI was present in 608 (27.3%) of 2,230 participants, including 255 participants with MCI+M and 353 with MCI-M; 1,622 participants did not have MCI. MPS were present in 369 (16.5%) of 2,230 participants. In a univariate logistic regression model, odds of MCI+M (vs no MCI) were 51% higher in participants with MPS compared to those with no MPS (OR = 1.51, 95% CI = 1.09 to 2.09, p = 0.01). Multivariate models yielded similar results (OR = 1.45, 95% CI = 1.03 to 2.05, p = 0.03). Rigidity was present in a higher proportion of participants with MCI+M compared to participants without MCI.

CONCLUSIONS

Mild parkinsonian signs, especially rigidity, are associated with amnestic mild cognitive impairment. Mild parkinsonian signs and mild cognitive impairment may share similar pathogeneses. Whether this involves Alzheimer-type pathology, Lewy bodies, or vascular changes in the basal ganglia or basal ganglia circuitry deserves further investigation in postmortem studies.

Markers of immune activation and viral load in HIV-associated sensory neuropathy

BACKGROUND

HIV infection is associated with a painful distal sensory polyneuropathy (DSP) that can severely limit the quality of life of affected subjects. The pathogenesis of DSP is unknown, although both HIV proteins and products of immune activation triggered by HIV infection have been implicated.

OBJECTIVE

To assess the association between baseline markers of immune activation and HIV RNA levels (viral load) and time to symptomatic DSP (SDSP).

METHODS

A cohort of 376 subjects, most receiving highly active antiretroviral therapy (HAART), were followed semiannually for up to 48 months. Blood and CSF levels of HIV viral load, monocyte chemotactic protein-1, macrophage colony-stimulating factor (M-CSF), matrix metalloproteinase-2, and tumor necrosis factor-alpha were measured in addition to CD4 lymphocyte cell count.

RESULTS

In subjects without SDSP at baseline (62.5% of the cohort), among the virologic and immunologic markers, only baseline CSF M-CSF levels were associated with time to SDSP (hazard ratio = 2.97, p = 0.05). The Kaplan-Meier estimate of the 1-year incidence of SDSP was 21%, a 15% decrease from that observed in the Dana cohort, a pre-HAART cohort enrolled with the same inclusion/exclusion criteria.

CONCLUSION

Highly active retroviral therapy (HAART) has changed the natural history of HIV-associated symptomatic distal sensory polyneuropathy (SDSP), which may explain, in contrast with studies from the pre-HAART era, the lack of association between SDSP and baseline HIV viral load and CD4 cell count.

Motor signs predict poor outcomes in Alzheimer disease

OBJECTIVE

To examine whether the presence of motor signs has predictive value for important outcomes in Alzheimer disease (AD).

METHODS

A total of 533 patients with AD at early stages (mean Folstein Mini-Mental State Examination [MMSE] 21/30 at entry) were recruited and followed semiannually for up to 13.1 years (mean 3) in five University-based AD centers in the United States and European Union. Four outcomes, assessed every 6 months, were used in Cox models: cognitive endpoint (Columbia Mini-Mental State Examination < or = 20/57 [ approximately MMSE < or = 10/30]), functional endpoint (Blessed Dementia Rating Scale > or = 10), institutionalization equivalent index, and death. Using a standardized portion of the Unified PD Rating Scale (administered every 6 months for a total of 3,149 visit-assessments, average 5.9 per patient), the presence of motor signs, as well as of individual motor sign domains, was examined as time-dependent predictor. The models controlled for cohort, recruitment center, sex, age, education, a comorbidity index, and baseline cognitive and functional performance.

RESULTS

A total of 39% of the patients reached the cognitive, 41% the functional, 54% the institutionalization, and 47% the mortality endpoint. Motor signs were noted for 14% of patients at baseline and for 45% at any evaluation. Their presence was associated with increased risk for cognitive decline (RR, 1.72; 95% CI, 1.24 to 2.38), functional decline (1.80 [1.33 to 2.45]), institutionalization (1.68 [1.26 to 2.25]), and death (1.38 [1.05 to 1.82]). Tremor was associated with increased risk for reaching the cognitive and bradykinesia for reaching the functional endpoints. Postural-gait abnormalities carried increased risk for institutionalization and mortality. Faster rates of motor sign accumulation were associated with increased risk for all outcomes.

CONCLUSIONS

Motor signs predict cognitive and functional decline, institutionalization, and mortality in Alzheimer disease. Different motor sign domains predict different outcomes.

Creatine in Huntington disease is safe, tolerable, bioavailable in brain and reduces serum 8OH2'dG

In a randomized, double-blind, placebo-controlled study in 64 subjects with Huntington disease (HD), 8 g/day of creatine administered for 16 weeks was well tolerated and safe. Serum and brain creatine concentrations increased in the creatine-treated group and returned to baseline after washout. Serum 8-hydroxy-2'-deoxyguanosine (8OH2'dG) levels, an indicator of oxidative injury to DNA, were markedly elevated in HD and reduced by creatine treatment.

Evaluation of HIV RNA and markers of immune activation as predictors of HIV-associated dementia

OBJECTIVE

To evaluate whether baseline levels of plasma and CSF HIV RNA, tumor necrosis factor alpha (TNFalpha), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-2 (MMP-2), or macrophage colony stimulating factor (M-CSF) are predictors of incident HIV-associated dementia (HIVD) in a cohort with advanced HIV infection.

METHODS

A total of 203 nondemented subjects with CD4 lymphocyte counts less than 200/muL, or <300/microL but with cognitive impairment, underwent semiannual neurologic, cognitive, functional, and laboratory assessments. HIVD and minor cognitive motor disorder (MCMD) were defined using American Academy of Neurology criteria. The cumulative incidence of HIVD was estimated using Kaplan-Meier curves. Cox proportional hazards regression models were used to examine the associations between biologic variables and time to HIVD, adjusting for age, sex, years of education, duration of HIV infection, type of antiretroviral use, premorbid IQ score, and presence of MCMD.

RESULTS

After a median follow-up time of 20.7 months, 74 (36%) subjects reached the HIVD endpoint. The dementia was mild in 70% of cases. The cumulative incidence of HIVD was 20% at 1 year and 33% at 2 years. Highly active antiretroviral therapy (HAART) was used by 73% of subjects at baseline. A plasma HIV RNA level was undetectable in 23% of subjects and a CSF HIV RNA level was undetectable in 48% of subjects. In adjusted analyses, neither plasma nor CSF HIV RNA levels (log10) were associated with time to HIVD; log10 levels of plasma TNFalpha (HR 3.07, p = 0.03) and CSF MCP-1 (HR = 3.36, p = 0.06) tended to be associated with time to HIVD.

CONCLUSION

The lack of association between baseline plasma and CSF HIV RNA levels and incident dementia suggests highly active antiretroviral therapy may be affecting CNS viral dynamics, leading to lower HIV RNA levels, and therefore weakening the utility of baseline HIV RNA levels as predictors of HIV-associated dementia.

Motor signs during the course of Alzheimer disease

BACKGROUND

Motor signs (MOSIs) are common in Alzheimer disease (AD) and may be associated with rates of cognitive decline, mortality, and cost of care.

OBJECTIVE

To describe the progression and identify predictors of individual MOSIs in AD.

METHODS

A cohort of 474 patients with AD at early stages was followed semiannually for up to 13.1 years (mean 3.6 years) in five centers in Europe and the United States. MOSIs were rated using a standardized portion of the Unified Parkinson's Disease Rating Scale. Overall, 3,030 visits/assessments of MOSIs (average 6.4/patient) were performed. Prevalence and incidence rates were calculated, and cumulative risk graphs were plotted for individual non-drug-induced MOSI domains. Rates of change over time taking into account potential covariates were also estimated. With use of each MOSI domain as outcome in Cox models, predictors of MOSI incidence were identified.

RESULTS

At least one MOSI was detected in 13% of patients at first examination and in 36% for the last evaluation. Total MOSI score increased at an annual rate of 3% of total possible score. Rates of annual change for speech/facial expression (4%), rigidity (2.45%), posture/gait (3.9%), and bradykinesia (3.75%) were of similar magnitude, and their occurrence increased from first (3 to 6%) to last (22 to 29%) evaluation. Tremor was less frequent throughout the course of the disease (4% at first and 7% at last evaluation) and worsened less (0.75% increase/year).

CONCLUSIONS

Most motor signs occur frequently and progress rapidly in Alzheimer disease. Tremor is an exception in that it occurs less frequently and advances at slower rates.

Pilot association study of the beta-glucocerebrosidase N370S allele and Parkinson's disease in subjects of Jewish ethnicity

Mutations in the beta-glucocerebrosidase gene cause Gaucher's disease, one of the most common lysosomal lipid storage diseases in the Ashkenazi Jewish population. The occurrence of parkinsonism in patients with Type 1 Gaucher's disease has been noted previously. In this pilot study, we evaluated a possible association between Parkinson's disease (PD) and the beta-glucocerebrosidase gene N370S allele (nt.1226 A>G) in 160 Parkinson's disease patients and 92 controls of Jewish ethnicity. We observed a higher frequency of the N370S genotype in PD cases (NS and SS, 10.7%) compared to controls (NS and SS 4.3%); however, the difference was not statistically significant (chi(2) = 3.4, P = 0.2). A total of 17 PD cases carry the N370S allele, including 2 homozygotes and 15 heterozygotes. The N370S allele (nt.1226 A>G) may be associated with PD in patients of Jewish ethnicity and should be examined in a larger study.

Corticobasal syndrome with novel argyrophilic glial inclusions

A 42-year-old, left-handed woman first noted impaired dexterity of the dominant hand, soon followed by dysarthria and cognitive decline. Over a 4-year period, she developed severe left-sided apraxia with eventual neglect of the left arm and progressive extrapyramidal signs. Cognitive testing showed progressive executive, visuospatial, fluency, and naming impairment with relative preservation of memory. Single-photon emission computed tomography demonstrated asymmetric right posterior frontal and superior parietal hypoperfusion. The clinical impression was corticobasal degeneration. At autopsy, severe atrophy was seen in the perirolandic and frontal regions. There was marked neuronal loss and gliosis in the posterior frontal and precentral regions and less severe pathology in prefrontal, temporal, and parietal areas. Mild to moderate gliosis and neuronal loss were also seen in the putamen, globus pallidus, subthalamic, and dentate nuclei. Gallyas silver stain revealed numerous inclusions adjacent to oligodendrocyte nuclei in white and gray matter of affected cortical and subcortical regions. The gracile inclusions were wavy, slender, and stained positively with antibodies to ubiquitin and alphaB-crystallin but not to microtubule-associated proteins (tau, MAP1B, MAP2), tubulin, neurofilaments, glial fibrillary acidic protein, or alpha-synuclein. The argyrophilic inclusions identified in this case are distinct from those previously described in neurodegenerative diseases.

Risk of action tremor in relatives of tremor-dominant and postural instability gait disorder PD

BACKGROUND

Action tremor may be more prevalent in relatives of patients with Parkinson's disease (PD) than in relatives of control subjects. This tremor could represent mild PD or essential tremor. An estimate of the risk of this condition in families of patients with PD is important when studying the genetics of PD.

OBJECTIVE

S: To determine the risk of action tremor in first-degree relatives of probands with tremor-dominant PD (TD-PD) and postural instability gait disorder PD (PIGD-PD) compared with first-degree relatives of control probands.

METHODS

PD and control probands participated in a familial aggregation study of PD. The presence of action tremor in their relatives was ascertained from reports of one or more informants. Relatives who met diagnostic criteria for PD were excluded. Cox proportional hazards models adjusting for gender, education, race, and vital status (dead vs alive) of the relatives were used to assess the relative risk (RR) of action tremor in first-degree relatives of PD probands vs first-degree relatives of control probands.

RESULTS

There were 487 PD probands, 409 control probands, and 5,563 relatives. The risk of action tremor was higher in the relatives of TD-PD probands than in the relatives of control probands (RR = 2.14; 95% CI = 1.53 to 2.98) but not in the relatives of PIGD-PD probands compared with the relatives of control probands (RR = 1.81; 95% CI = 0.66 to 5.02).

CONCLUSION

The risk of action tremor was increased in the relatives of PD probands, particularly when they had TD-PD. Whether the tremor in these relatives represents essential tremor or an isolated manifestation of PD requires further investigation.

Accuracy of family history data on Parkinson's disease

BACKGROUND

Genetic studies of PD frequently rely on family history interviews (FHI), yet the accuracy of data obtained in this way is unclear.

OBJECTIVE

To assess the interinformant reliability and validity of family history information on PD in first-degree relatives of PD cases and controls.

METHODS

A structured FHI was administered to nondemented PD cases and controls and to a second informant (self-report, sibling or child of the subject) for each relative. Interinformant agreement was assessed on four algorithm-derived diagnostic categories of PD: definite, definite or probable, definite, probable or possible ("conservative diagnosis"); or definite, probable, possible, or uncertain ("liberal diagnosis"). The sensitivity and specificity of each diagnostic category were assessed, using as the gold standard diagnoses based on either in-person examination or medical record review.

RESULTS

Five hundred thirty-six families containing 2,225 first-degree relatives were included in the interinformant reliability study. Agreement between informants was excellent for definite or probable PD for all three pairwise comparisons: proband vs self-report (kappa = 0.92), proband vs sibling of subject (kappa = 0.80), and proband vs child of subject (kappa = 0.87). Agreement was also good to excellent for the conservative diagnosis (kappa = 0.66, 0.49, and 0.79). In the validity analysis (141 individuals in 96 families), the conservative diagnosis provided the best combination of sensitivity (95.5%) and specificity (96.2%) for the proband's family history report. No difference was apparent across categories defined by case or control status, relationship to the proband, or gender or age at onset of the proband. However, specificity was lower for deceased relatives than for living relatives.

CONCLUSION

The FHI can be used to obtain reliable and valid family history information on PD in first-degree relatives when a conservative diagnostic algorithm is applied.

Parkin-proven disease: common founders but divergent phenotypes

OBJECTIVE

To compare and contrast clinical and genetic findings in six probands with parkinsonism with a parkin exon 3 438- to 477-bp deletion (Ex3Delta40) to search for evidence of a common founder.

METHOD

Clinical review, parkin gene sequencing, dosage studies, and high-resolution genotype/haplotype analysis were performed.

RESULTS

All subjects had two or more signs consistent with a diagnosis of possible or probable PD with age at onset younger than 45 years (mean +/- SD 29.3 +/- 10.2 years, range 16 to 42 years). Affected individuals were either homozygotes, compound heterozygotes, or Ex3Delta40 carriers with one normal parkin allele. Haplotype analysis revealed both Ex3Delta40 and Ex7 924 C-->T (R275W) mutations originated from common founders, the former most probably of Irish descent. Although three cases had Ex7 924 C-->T (R275W) and Ex3Delta40 mutations, their clinical presentation and mode of inheritance were variable.

CONCLUSION

Parkin mutations on common parkin haplotypes provide testable hypotheses of parkin function in genetically defined parkinsonism.

Inter-rater reliability of a clinical staging of HIV-associated cognitive impairment

OBJECTIVE

To determine the inter-rater reliability of a modification of the Memorial Sloan-Kettering (MSK) Staging for HIV-associated cognitive impairment.

METHODS

Data were abstracted on neurologic, neuropsychological, and functional status on 100 individuals participating at four sites in the Northeast AIDS Dementia (NEAD) Consortium cohort study, a longitudinal study of predictors of cognitive impairment in HIV-infected individuals. Neuropsychological performance was defined 1) based on the neuropsychologist's global impression and 2) solely based on neuropsychological test scores. Raters at each site used the abstracted data to assign an MSK stage to each subject blind to any identifying information. Inter-rater reliability was assessed using kappa statistics. Agreement between computer-generated ratings and site-generated ratings was also assessed.

RESULTS

Kappa statistics for pair-wise agreement among the sites regarding MSK stage ranged from 0.70-0.91, representing good to excellent agreement between sites. Agreement between computer-generated ratings and site-generated ratings was in the good to excellent range (0.62-0.79).

CONCLUSIONS

The authors have modified the MSK rating scale and developed a reliable instrument that can be used in multicenter studies. This instrument will be useful in staging HIV-dementia in future longitudinal studies and will be valuable in increasing accuracy of clinicopathologic studies.

Predictors of nursing home placement in Huntington disease

OBJECTIVE

To determine whether motor, behavioral, or psychiatric symptoms in Huntington disease (HD) predict skilled nursing facility (SNF) placement.

METHODS

Subjects were participants in the Huntington Study Group's Unified Huntington Disease Rating Scale Database (Rochester, NY) between January 1994 and September 1999. Specific motor, psychiatric, and behavioral variables in subjects residing at home and in SNF were analyzed using chi2 and Student's t-tests. For a subset of subjects for whom longitudinal data existed, a Cox proportional hazards model controlling for age, sex, and disease duration was used.

RESULTS

Among 4,809 subjects enrolled, 3,070 had clinically definite HD. Of these, 228 (7.4%) resided in SNF. The SNF residents' average age was 52 years, average disease duration was 8.6 years, and they were predominantly women (63%). The SNF residents had worse motor function (chorea, bradykinesia, gait abnormality, and imbalance, p < 0.0001); were more likely to have obsessions, compulsions, delusions, and auditory hallucinations; and had more aggressive, disruptive (p < 0.0001), and irritable behaviors (p = 0.0012). For 1,559 subjects, longitudinal data existed (average length of follow-up, 1.9 years), and 87 (5%) moved from home to SNF. In the Cox model, bradykinesia (HR 1.965, 95% CI 1.083 to 3.564), impaired gait (HR 3.004, 95% CI 1.353 to 6.668), and impaired tandem walking (HR 2.546, 95% CI 1.460 to 4.439) were predictive of SNF placement.

CONCLUSIONS

Institutionalized patients with HD are more motorically, psychiatrically, and behaviorally impaired than their counterparts living at home. However, motor variables alone predicted institutionalization. Treatment strategies that delay the progression of motor dysfunction in HD may postpone the need for institutionalization.

Heterozygosity for a mutation in the parkin gene leads to later onset Parkinson disease

BACKGROUND

The vast majority of the parkin mutations previously identified have been found in individuals with juvenile or early onset PD. Previous screening of later onset PD cohorts has not identified substantial numbers of parkin mutations.

METHODS

Families with at least two siblings with PD were ascertained to identify genes contributing to PD susceptibility. Screening of the parkin gene, by both quantitative PCR and exon sequencing, was performed in those families with either early onset PD (age onset < or =50 years) or positive lod score with a marker in intron 7 of the parkin gene.

RESULTS

A total of 25 different mutations in the parkin gene were identified in 103 individuals from 47 families. Mutations were found in both parkin alleles in 41 of the individuals, whereas a single mutation in only one of the two parkin alleles was observed in 62 individuals. Thirty-five of the subjects (34%) with a parkin mutation had an age at onset of 60 years or above with 30 of these 35 (86%) having a detectable mutation on only one parkin allele. Few significant clinical differences were observed among the individuals with two, one, or no mutated copies of the parkin gene.

CONCLUSION

Mutations in the parkin gene occur among individuals with PD with an older age at onset (> or =60 years) who have a positive family history of the disease. In addition, the clinical findings of parkin-positive individuals are remarkably similar to those without mutations.

The association of incident dementia with mortality in PD

OBJECTIVE

To evaluate the association of incident dementia with mortality in a cohort of patients with idiopathic PD who were nondemented at baseline evaluation, controlling for extrapyramidal sign (EPS) severity at each study visit.

BACKGROUND

The development of dementia has been associated with reduced survival in PD. Because EPS severity is associated with both dementia and mortality in PD, the association of dementia with mortality may be confounded by disease severity.

METHODS

A cohort of patients with PD was followed annually with neurologic and neuropsychological evaluations. The association of incident dementia and the total Unified PD Rating Scale (UPDRS) motor score with mortality in PD was examined using Cox proportional hazards models with time-dependent covariates. All analyses were adjusted for age at baseline, sex, years of education, ethnicity, and duration of PD.

RESULTS

Of 180 PD patients, 41 (22.8%) died during a mean follow-up period of 3.9 +/- 2.2 years. Among those who died during the study period, 48.8% (20 of 41) became demented during follow-up, as compared to 23.0% (32 of 139) of those who remained alive. Both incident dementia (RR: 2.2, 95% CI: 1.1 to 4.5, p = 0.04) and the total UPDRS motor score at each study visit (RR: 1.04, 95% CI: 1.02 to 1.07, p = 0.001) were associated with mortality in PD when included in the same Cox model.

CONCLUSIONS

Incident dementia has an independent effect on mortality when controlling for EPS severity. The development of dementia is associated with a twofold increased mortality risk in PD.

A randomized clinical trial of CPI-1189 for HIV-associated cognitive-motor impairment

BACKGROUND

CPI-1189 is a compound with antioxidant properties that blocks tumor necrosis factor-alpha (TNFalpha) effects in animal models. It has neuroprotective properties in model systems for HIV-associated neurotoxicity and thus is a candidate for neuroprotective therapy in humans with HIV-associated CNS disease.

OBJECTIVE

To assess the tolerability and safety of CPI-1189 in treating HIV-associated cognitive-motor impairment.

METHODS

Sixty-four subjects with mild to moderate HIV-associated cognitive-motor impairment were randomized to receive either placebo or 50 or 100 mg daily of CPI-1189 in addition to optimal HIV therapy. Subjects were followed prospectively in a double-masked study for 10 weeks. The primary assessment was tolerability and safety of the compound. Secondary objectives examined neuropsychological and functional change associated with this treatment.

RESULTS

The study compound was well tolerated, with 91% of CPI-1189-treated subjects and 76% of placebo-treated subjects completing the trial. Skin rash was seen equally in placebo and active arms, but the only study withdrawals due to skin rash occurred in CPI-1189-treated subjects (n = 2). One subject developed a cataract on drug (100 mg/day). CD4 lymphocyte counts and plasma HIV viral load remained stable in all groups throughout the trial. No significant treatment effects were observed on the change in composite Z-scores for eight neuropsychologic measures (NPZ-8). The Grooved Pegboard Test (nondominant) showed improved performance with CPI-1189 at 100 mg/day (p = 0.01), but no other neuropsychometric or functional measures demonstrated significant improvement.

CONCLUSIONS

CPI-1189 was well tolerated in HIV subjects with cognitive-motor disorder. This study was not powered to conclusively determine efficacy and showed no consistent treatment-associated improvement in cognitive or functional measures.

Relationship between CAG repeat length and late-stage outcomes in Huntington's disease

The relationship between CAG repeat length and age at nursing home (NH) admission and age at percutaneous endoscopic gastrostomy (PEG) was examined in 47 residents of a specialized Huntington's disease long-term care facility who were observed for a median of 3 years (range, 1 to 11 years). CAG repeat length was inversely correlated with time to NH admission and PEG (both p < 0.001), independent of age at onset. CAG repeat length may influence disease progression to late-stage outcomes in addition to age at onset.

Weight loss in early stage of Huntington's disease

BACKGROUND

Huntington's disease (HD) is an autosomal dominant disease with neurologic manifestations. In transgenic mouse models of HD, weight loss is recognized as a feature associated with the disease onset. It is unclear whether a similar pattern occurs in humans.

METHODS

Data from the Huntington Study Group were used to evaluate whether HD is associated with lower body mass index (BMI) at the earliest stage of the disease. There were 361 case subjects in whom HD had been diagnosed with an independence scale rating of 100 (no special care needed), a total functional capacity score of >or=11, and HD duration of <4 years. For each case subject, five sex- and age-matched control subjects were selected from the National Heart, Lung, and Blood Institute Family Heart Study or the Framingham Offspring Study.

RESULTS

Among case subjects, neither disease duration, nor dystonia, nor chorea score was significantly associated with BMI. BMI was significantly lower among case than among control subjects. Among men, age-adjusted BMI (+/-SE) was 25.90 +/- 0.34 kg/m(2) for case subjects with HD and 27.68 +/- 0.16 kg/m(2) for control subjects. Among women, corresponding values were 24.34 +/- 0.43 for case subjects with HD and 26.63 +/- 0.21 kg/m(2) for control subjects.

CONCLUSIONS

At an early stage of the disease, subjects with Huntington's disease had lower body mass index than matched controls from the general population. The cause of weight loss is unknown but the parallel to observations in Huntington's disease transgenic mice suggests that it is a significant hallmark of Huntington's disease gene expression.

Incidence of and risk factors for HIV-associated distal sensory polyneuropathy

OBJECTIVE

To assess the incidence of and risk factors for distal sensory polyneuropathy (DSP) in a cohort of HIV-infected subjects.

METHODS

We followed 272 subjects semiannually for up to 30 months. DSP was diagnosed if subjects had decreased or absent ankle jerks, decreased or absent vibratory perception at the toes, or decreased pinprick or temperature in a stocking distribution. Subjects were further classified at each visit as having asymptomatic DSP (ADSP) (signs only) or symptomatic DSP (SDSP) if, in addition to the neurologic signs, paresthesias or pain was reported.

RESULTS

At baseline, 45% of the subjects did not meet criteria for DSP, 20% met criteria for ADSP, and 35% met criteria for SDSP. Dideoxynucleoside therapy was used by 23% of the patients, and this treatment was independent of their neuropathy status. In longitudinal univariate analyses, history of AIDS diagnoses (hazard ratio [HR] = 1.89; p = 0.02) and lower CD4 cell count (HR = 0.69; p = 0.0006) were risk factors for incident DSP (ADSP or SDSP). However, for incident SDSP only, in addition to history of AIDS diagnoses, mood and neurologic (other than DSP) and functional abnormalities were significant risk factors. Functional abnormalities remained a significant risk factor in a multiple regression analysis. The presence of ADSP and the use of dideoxynucleosides at baseline were not significant risk factors for incident SDSP. The Kaplan-Meier estimate of the 1-year incidence of SDSP was 36%.

CONCLUSION

Subjects with moderate-to-severe immunosuppression from HIV infection commonly have SDSP. However, sex, use of dideoxynucleosides, and presence of ADSP were not significant risk factors for SDSP.

Evaluation of 50 probands with early-onset Parkinson's disease for Parkin mutations

BACKGROUND

Early onset PD has been associated with different mutations in the Parkin gene, including exon deletions and duplications.

METHODS

The authors performed an extensive mutational analysis on 50 probands with onset of PD at younger than 50 years of age. Thirteen probands were ascertained from a registry of familial PD and 37 probands by age at onset at younger than 50 years, blind to family history. Mutational analysis was undertaken on the probands and available family members and included conventional techniques (single strand conformation polymorphism analysis and sequencing) and a newly developed method of quantitative duplex PCR to detect alterations of gene dosage (exon deletions and duplications) in PARKIN:

RESULTS

Using this new technique, the authors detected eight alterations of gene dosage in the probands, whereas 12 mutations were found by conventional methods among the probands and another different mutation in an affected family member. In total, the authors identified compound heterozygous mutations in 14%, heterozygous mutations in 12%, and no Parkin mutation in 74% of the 50 probands. We expanded the occurrence of Parkin mutations to another ethnic group (African-American).

CONCLUSION

The authors systematically screened all 12 Parkin exons by quantitative PCR and conventional methods in 50 probands. Eight mutations were newly reported, 2 of which are localized in exon 1, and 38% of the mutations were gene dosage alterations. These results underline the need to screen all exons and to undertake gene dosage studies. Furthermore, this study reveals a frequency of heterozygous mutation carriers that may signify a unique mode of inheritance and expression of the Parkin gene.

Association between the APOE genotype and psychopathologic symptoms in Alzheimer's disease

BACKGROUND

Psychiatric symptoms occur frequently in the course of AD, are a frequent contributor to institutionalization, predict cognitive decline and death, and often require treatment with psychotropic medications. Previous studies investigating the association between APOE genotype and psychiatric symptomatology in AD have reported contradictory results.

OBJECTIVE

To determine whether APOE genotype predicts incident psychiatric symptomatology in patients with AD.

METHODS

Eighty-seven patients with AD at early stages and no psychiatric history were followed semiannually for up to 9.3 years (mean 5.5 years) for development of delusions, illusions, hallucinations, behavioral symptoms, and depression. Cox proportional hazards models were used to examine the relative risk for incident psychiatric symptomatology (outcome) in relation to APOE genotype (predictor).

RESULTS

The presence of one epsilon4 allele carried a 2.5-fold risk, whereas the presence of two epsilon4 alleles carried a 5.6-fold risk for development of delusions. The associations remained significant even when age, ethnicity, sex, education, duration of disease, and cognitive and functional performance were controlled for. The presence of two epsilon4 alleles was associated with reduced risk for developing hallucinations in the adjusted analysis only. No significant associations were detected between APOE genotype and the incidence of illusions, behavioral symptoms, or depression.

CONCLUSION

The presence of one or more epsilon4 alleles is a significant predictor for the incidence of delusions in the course of AD.

Palliative care for people with late-stage Huntington's disease

Huntington's disease provides a unique model to examine issues of long-term and palliative care for a younger and more mobile population who remain institutionalized longer than other nursing home residents. A lack of community-based alternatives for young families, and the need for highly complex care planning encourage long term care placement mid-way in the disease process. Despite the need for a body of knowledge specific to environmental enrichment and therapeutic strategies for improving quality of life for people in the later stages of Huntington's disease, there is no published data in the neurological or rehabilitation literature. This article reviews the signs and symptoms and offers a multidisciplinary approach to ameliorate problems frequently encountered in caring for this population.