Biomedical subjects
Andrew J Lees
Publications and source records attributed to Andrew J Lees.
Health-related quality of life in patients with progressive supranuclear palsy.
We assessed health-related quality of life (QoL) of patients with progressive supranuclear palsy (PSP), identified the most important QoL issues in patients with this disorder, and assessed the usefulness of existing QoL measures in patients with PSP. Twenty-seven patients in all stages of PSP and their carers underwent a semistructured in-depth interview on the impact of PSP and a neurological examination. They were also asked to complete existing measures of QoL and depression. An item-pool of issues relevant to QoL of patients with PSP was created from the patient and carer interviews. Carers and patients largely agreed on issues relevant for patients' QoL but more carers than patients considered symptoms of frontal lobe dysfunction as problematic for the patients. There was no association of QoL with age and gender, as assessed in interviews and on two QoL instruments. QoL deteriorated with increasing disease duration and severity and greater cognitive impairment and was associated with worse depression scores. While the generic SF-36 was not found to be useful to assess QoL in PSP, feasibility and validity for the PDQ-39 and the EQ-5D were acceptable in this study. However, additional issues relevant to patients with PSP that were not addressed in these instruments included visual disturbances, dysarthria, dysphagia, muddled thinking, confusion, and apathy. The generic EQ-5D and the Parkinson's disease-specific PDQ-39 are useful instruments to assess QoL in patients with PSP. However, they lack questions on important aspects of QoL in PSP that were reported by patients and carers in semistructured interviews. The item pool created in these interviews provides the basis for the development of disease-specific QoL instruments for patients with PSP.
CSF and serum immune parameters in Sydenham's chorea: evidence of an autoimmune syndrome?
Previous investigations have suggested that Sydenham's chorea (SC) may be an autoantibody mediated disorder. We examined this autoimmune hypothesis by measuring Th1 (IFN-gamma, IL-12) and Th2 (IL-4, IL-10) cytokines, oligoclonal bands (OCB) and anti-basal ganglia antibodies (ABGA). CSF IL-4 was elevated in 31% of acute SC and 50% of persistent SC. CSF IL-10 was also elevated in 31% of acute SC but 0% of persistent SC. CSF IFN-gamma was undetectable in all patients. Serums IL-4, IL-10 and IL-12 were elevated in acute compared to persistent SC. OCB were found in 46% of acute SC, ABGA were in 93% of acute SC and 50% of persistent SC was of IgG(1) and IgG(3) subclass. These findings support an autoantibody pathogenesis.
Compulsive use of dopamine replacement therapy in Parkinson's disease: reward systems gone awry?
Dopamine replacement therapy (DRT) is the most effective treatment for Parkinson's disease (PD); it provides substantial benefit for most patients, extends independence, and increases survival. A few patients with PD, however, take increasing quantities of medication far beyond those required to treat their motor disabilities. These patients demand rapid drug escalation and continue to request more DRT despite the emergence of increasingly severe drug-induced motor complications and harmful behavioural consequences. In this article we detail the features of compulsive DRT-seeking and intake in PD, in relation to theories of compulsive drug use.
Alzheimer's associated variant ubiquitin causes inhibition of the 26S proteasome and chaperone expression.
Intracellular protein inclusions in Alzheimer's disease and progressive supranuclear palsy contain UBB+1, a variant ubiquitin. UBB+1 is able block the 26S proteasome in cell lines. Proteasome inhibition by drug action has previously been shown to induce a heat-shock response and render protection against stress. We investigated UBB+1 by developing a stable, conditional expression model in SH-SY5Y human neuroblastoma cells. Induction of UBB+1 expression caused proteasome inhibition as was confirmed by reduced ability to process misfolded canavanyl proteins, accumulation of GFPu, a proteasome substrate, and reduced cleavage of a fluorogenic substrate. We show that expression of UBB+1 induces expression of heat-shock proteins. This priming of the chaperone system in these cells promotes a subsequent resistance to tert-butyl hydroperoxide-mediated oxidative stress. We conclude that although UBB+1-expressing cells have a compromised ubiquitin-proteasome system, they are protected against oxidative stress conditions.
Parkin disease: a phenotypic study of a large case series.
Mutations in the parkin gene, PARK2, are a common cause of parkinsonism in familial as well as isolated cases with an age of onset <40 years and should be considered in the diagnostic work up of young-onset parkinsonism. We report a detailed clinical evaluation of a personal series of 24 patients with mutations in the parkin gene. The clinical presentation of most cases was broadly comparable to that of previous descriptions of autosomal recessive early-onset or juvenile parkinsonism and young-onset Parkinson's disease and also had similarities with phenotypes of dopa-responsive dystonia. However, our only case with consanguineous parents had an age of onset of 54 years. We report three new phenotypes at presentation: cervical dystonia; autonomic dysfunction and peripheral neuropathy; and pure exercise-induced dystonia. We emphasize a number of clinical features that can be seen in parkin disease: focal dystonia; early instability; freezing; festination or retropulsion; concurrent autonomic failure; dramatic response to anticholinergics; early or atypical L-dopa-induced dyskinesias; exquisite sensitivity to small doses of L-dopa; and recurrent psychosis, even taking L-dopa alone. We also report behavioural disorder prior to the onset of parkinsonism. Some relatives carrying a single parkin mutation without extrapyramidal symptoms or signs also had psychiatric symptoms that might be related to their carrier status.
[(123)I]-FP-CIT-SPECT in the early diagnosis of PD presenting as exercise-induced dystonia.
Isolated foot dystonia following exercise is a rare manifestation of early PD. It may precede the onset of parkinsonism by years and can be clinically indistinguishable from familial exercise-induced dystonia. The authors present a patient with dystonic claudication where dopamine transporter SPECT using (123)I-FP-CIT allowed early diagnosis of PD and enabled effective symptomatic treatment with a dopamine agonist.
The tau locus is not significantly associated with pathologically confirmed sporadic Parkinson's disease.
Mutations of the tau gene in frontotemporal dementia with parkinsonism and genetic association of the tau locus with progressive supranuclear palsy and corticobasal degeneration directly implicate the tau gene in the aetiology of these tauopathies. Three studies have also shown an association of the tau locus with clinically diagnosed Parkinson's disease. Noting the significant incidence of clinical misdiagnosis of Parkinson's disease, we investigated this tau gene association in a series of 157 pathologically confirmed cases of brain stem Lewy body Parkinson's disease by analysing their tau haplotype status. Although H1H1 homozygotes are elevated in the Parkinson's disease cases (63.1%) compared to controls (56.1%) this difference is not significant (P=0.22). These results indicate that any association must either be weak (with an odds ratio of less than 2) or that previous positive associations were due to contamination of clinically diagnosed cases with other diagnostic clinico-pathological entities such as neurofibrillary tangle Parkinson's syndrome.
The slow axonal transport of the microtubule-associated protein tau and the transport rates of different isoforms and mutants in cultured neurons.
We demonstrate that the microtubule-associated protein tau, in the form of enhanced green fluorescent protein (EGFP) tau, is transported along axons of neurons in culture in the slow component of axonal transport with a speed comparable with that previously measured in vivo. It was demonstrated that the EGFP tag has no effect on transport characteristics, and the methodology enables slow transport rates of individual tau isoforms and tau mutants to be measured. We also expressed EGFP-tagged tau isoforms containing either three or four C-terminal repeats and zero or two N-terminal inserts in cultured neurons. No significant differences were found in the average rate of slow transport of the wild-type tau isoforms, suggesting that the exon 10 C-terminal repeat or the N-terminal inserts do not contain regions that play a significant regulatory role in axonal transport. Similarly, we found that missense mutations in tau have no noticeable effect on the rate of transport; hence their ability to cause neurodegeneration is by another mechanism other than that affecting the overall slow axonal transport of tau.
Reporting clinical trials: full access to all of the data.
Explore the source record for details and available documents.
Bilaterally coherent tremor resembling enhanced physiological tremor: report of three cases.
The contribution of the central nervous system to tremor pathogenesis is unclear. Poor side-to-side coherence in physiological, essential, and parkinsonian tremors suggests distinct bilateral generators. By contrast, significant bilateral coherence demonstrated in orthostatic tremor and in enhanced physiological tremor (EPT) in patients with persistent mirror movements favours single or closely linked bilateral oscillators. We describe three patients (aged 21-37 years) who developed unusual bilateral postural and kinetic tremors at 6-13 Hz resembling EPT. The tremor involved all limbs, and in two cases the face or jaw, in the absence of other significant neurological features. Significant side-to-side coherence was demonstrated in each case using cross-correlation of electromyographic recordings from homologous muscle pairs. We postulate that these unusual tremors originate from a single brainstem source or from bilateral oscillators closely linked at or below this level.
Reporting clinical trials: full access to all the data.
Explore the source record for details and available documents.
Adult-onset tic disorders.
We report on 8 patients with adult-onset motor tics and vocalisations. Three had compulsive tendencies in childhood and 3 had a family history of tics or obsessive-compulsive behaviour. In comparison with DSM-classified, younger-onset Gilles de la Tourette syndrome, adult-onset tic disorders are more often associated with severe symptoms, greater social morbidity, a potential trigger event, increased sensitivity, and poorer response to neuroleptic medication.
EMG-EMG coherence in writer's cramp.
We investigated the extent to which oscillatory drives to muscle, believed to arise mainly from the motor cortex, are exaggerated and/or fail to react normally to peripheral stimulation in writer's cramp. We used the coherence between active forearm flexor and intrinsic hand muscles as our index of such drives before and after digital nerve stimulation of the dominant hand. The results in 8 patients with writer's cramp were compared with those in eight age- and sex-matched healthy subjects. We found no significant difference in either the strength of intermuscular coherence or its modulation by cutaneous stimulation between patients and healthy subjects during voluntary flexion of the wrist and extension-abduction of the fingers. Therefore, we were unable to provide evidence for a pervasive disturbance of oscillatory cortical motor outflow in writer's cramp.
Apomorphine monotherapy in the treatment of refractory motor complications of Parkinson's disease: long-term follow-up study of 64 patients.
Continuous subcutaneous infusion of apomorphine is now increasingly recognized as an effective treatment for refractory off periods and peak-dose dyskinesias in Parkinson's disease. We have reviewed our experience with apomorphine infusions, after a strategy decision in 1995 based on emerging preclinical data, to treat all patients with steady-state plasma levels of apomorphine throughout the waking day, minimizing additional pulsatile stimulation either by oral dopaminergic medication or bolus parenteral injections of apomorphine. Sixty-four patients have been treated with apomorphine pumps and 45 of these successfully converted to monotherapy, managing to discontinue all other forms of dopaminergic stimulation during the daytime treatment period with apomorphine. Patients were followed up for a mean of 33.8 months (range, 4-108 months) and clinical data analyzed retrospectively. The mean maintenance dose of apomorphine was 98 mg per 24 hours (monotherapy group: 103 mg/24 hours; polytherapy group: 93 mg/24 hours), which did not significantly increase at final follow-up. There was a mean maximum dyskinesia reduction of 64% (S.D. = 20) in the monotherapy group, compared to 30% (S.D. = 33) in those continuing on polytherapy (P < 0.001), despite a maintained increase in on time (monotherapy group: 55%, P < 0.005; polytherapy group: 50%, P = 0.05). Fifteen patients failed to successfully convert to monotherapy but benefited nonetheless, and only 3 failed apomorphine infusional therapy altogether. Reasons for failure were mixed, including difficulty with compliance and adverse effects such as daytime somnolence, skin complications, and painful dystonias. There was a significantly higher success rate in patients able to manage the treatment either independently or with the help of their caregiver. These results confirm that subcutaneous apomorphine monotherapy can reset peak-dose dyskinesia threshold in levodopa-treated patients and further reduce off-period disability after all available forms of oral medication, including long-acting dopamine agonists, have been tried.
Reporting clinical trials: full access to all the data.
Explore the source record for details and available documents.
Treatment of Parkinson's disease: levodopa as the first choice.
The introduction of levodopa in the 1960s revolutionised the treatment of Parkinson's disease (PD), and it continues to be the most effective symptomatic therapy. The vast majority of PD patients who start treatment with L-dopa experience good to excellent functional benefit. In vitro studies with high doses of L-dopa and absent glia had shown that it may be neurotoxic, but other tissue culture studies show L-dopa to be neuroprotective. Most studies in animal models and clinico-pathological and mortality studies in humans failed to show evidence in favour of accelerated dopaminergic neuronal loss with long-term L-dopa therapy.L-dopa continues to be beneficial throughout the course of PD, although as the disease progresses, escape of some symptoms from adequate control may occur and refractory disabilities such as impaired balance, dysarthria, cognitive decline and hallucinations may emerge. Treatment of advanced PD may also be complicated by the emergence of motor fluctuations and dyskinesias. Studies in animal models and in humans show that these motor complications are not specific to a particular dopaminergic agent, but that they are related both to the extent of the striatal lesion and to the mode of application of dopaminergic agents: Pulsatile administration of L-dopa and of the dopamine agonist apomorphine causes more motor complications than continuous striatal dopaminergic receptor stimulation, and continuous administration can alleviate existing dyskinesias and fluctuations. Several controlled studies comparing levodopa and dopamine agonists as initial treatment have attempted to answer the question whether delaying L-dopa therapy can reduce the occurrence of motor complications. Three medium-term (3-5 years) and one 10-year study showed less dyskinesia in the first five years of treatment in patients who had started therapy with a dopamine agonist. However, these studies also consistently showed that levodopa provided better functional improvement in the first years of treatment. Ten-year follow-up data in patients randomised to L-dopa or bromocriptine also showed a slightly lower incidence of motor complications in the bromocriptine arm. However, this difference was not significant for the clinically relevant moderate and severe forms of dyskinesias and fluctuations, and was achieved at the expense of significantly worse disability scores during the first years of therapy. Furthermore, the relative impact of motor disability and dyskinesias on patients' quality of life remains to be established. Concordance is essential in the optimum treatment of PD and patients should be informed of the various therapeutic options available. Treatment should respect individual patients' needs and take into account their particular functional disabilities and specific handicaps. Low-dose L-dopa therapy (up to 400 mg/day), however, remains the most effective initial treatment of choice for the majority of patients.
Progressive supranuclear palsy and its relation to pacific foci of the parkinsonism-dementia complex and Guadeloupean parkinsonism.
Steele, Richardson and Olszweski in 1964 described a distinctive clinical and pathological entity they called progressive supranuclear palsy (PSP). Now on Guadeloupe in the Carribbean French West Indies, Caparros-Lefebvre is identifying many patients with similar clinical and histological features. Others have a clinical syndrome of atypical parkinsonism that resembles the parkinsonism-dementia complex (PDC) of Guam and the Kii peninsula of Japan (PDC). But in those Pacific foci the histology is different and the abnormal tau is of Alzheimer's type rather than the PSP type of Guadeloupe. In both locales, neurotoxins of local foods are implicated in etiology. Future studies will confirm if Guadeloupean parkinsonism is truly a geographic focus of PSP, and if dietary factors account for both.