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Biomedical subjects

A J Lees

Publications and source records attributed to A J Lees.

At least 127 records · Page 7Linked to original sources

Apolipoprotein E e4 allele frequency in patients with multiple system atrophy.

The glial cytoplasmic inclusion provides a histological hallmark for multiple system atrophy, a group of neurodegenerative disorders including: striatonigral degeneration, olivopontocerebellar atrophy, and Shy-Drager syndrome. Apolipoprotein E (APOE) genotype was determined by the polymerase chain reaction and restriction digestion of DNA extracted from frozen brain tissue from 22 patients (64.9 +/- 2.2 years) with clinically and neuropathologically verified multiple system atrophy (MSA). In addition, brain tissue from 36 age- and sex-matched patients who died with Alzheimer's disease (68.8 +/- 1.6 years) and 66 neurologically and psychiatrically normal subjects (66.6 +/- 1.8 years) was genotyped. The APOE e4 allele frequency in the Alzheimer's disease subjects was significantly increased (0.44, P < 0.001), as has been reported previously. The APOE e4 allele frequency of the MSA cases (0.11) was not significantly different from that of the control subjects (0.12). These data indicate that the APOE e4 allele is not a risk factor for multiple system atrophy.

Aged↗

Dopaminergic function in familial Parkinson's disease: a clinical and 18F-dopa positron emission tomography study.

There is increasing evidence for familial aggregation in Parkinson's disease (PD). It is possible that some asymptomatic relatives of PD patients have subclinical nigral Lewy body pathology and their identification could help determine the true prevalence of the disease. We used 18F-dopa positron emission tomography to investigate nigrostriatal dopaminergic terminal function in asymptomatic members of 7 unrelated kindreds in which at least 2 members had parkinsonism. Eight (25%) of the 32 asymptomatic relatives showed abnormal putamen 18F-dopa uptake (2.5 standard deviations below the normal mean). When discriminant function analysis was applied, all of these 8 subjects plus another 3 were classified with high probability as having PD. On neurological examination, 5 of the 32 relatives scanned had an isolated mild postural tremor and 2 of these 5 had reduced putamen uptake. Our findings provide further support for a role of inheritance in the etiology of PD and suggest that the penetrance for nigrostriatal dopaminergic dysfunction in familial clusters of PD is higher than the prevalence of clinical parkinsonism reported in epidemiological surveys.

Adult↗

Torticollis due to disinhibition of the vestibulo-collic reflex in a patient with Steele-Richardson-Olszewski syndrome.

A patient with the clinical picture of Steele-Richardson-Olszewski syndrome and an unusual intermittent neck twisting is reported. He had virtually no voluntary ocular movements and only very slow, low-amplitude voluntary head movements. However, in response to optokinetic or vestibular stimulation, he developed full eye deviations in the direction of the slow phase of the expected nystagmus. No quick phases were observed, and the deviation outlasted the duration of the vestibular stimuli because of defective saccades. The head also turned fully during these stimuli, quicker than on attempted voluntary movements, and remained deviated similarly to the eyes. This suggests that the neck deviations in this patient were due to a disinhibited vestibulo-collic reflex and a disturbed head position resetting mechanism. Neck electromyographic responses in response to whole-body rotation indicated that the vestibulocollic reflex responsible for the torticollis in this patient had a short latency of approximately 30 ms.

Amygdala↗

Proton magnetic resonance spectroscopy in Steele-Richardson-Olszewski syndrome.

Proton magnetic resonance spectroscopy, localized to the lentiform nucleus, was carried out in nine patients with a clinical diagnosis of Steele-Richardson-Olszewski syndrome (SRO) and in eight healthy age-matched controls. Three of the nine SRO patients had a so-called "eye of the tiger sign" with high signal in the globus pallidus surrounded by a ring of low signal on T2 weighted magnetic resonance imaging previously only reported in Hallervorden-Spatz disease. One of these patients had pathologically proven SRO at postmortem. The SRO group showed a significant reduction in the median concentration from N-acetyl groups (median, 6.87 mM; range, 4.92-10.59 mM; p < 0.015) compared with the control group (median, 9.85 mM; range, 9.26-11.0 mM). The N-acetylaspartate concentration was significantly reduced in seven of the nine patients studied. The reduction of the N-acetylaspartate-creatine ratio from the lentiform nucleus in the SRO group may reflect neuronal loss, occurring predominantly in the globus pallidus. Proton magnetic resonance spectroscopy may be a useful, noninvasive technique to help differentiate the various parkinsonian syndromes.

Adult↗

Cerebellar axial postural tremor.

Three cases are presented with a predominantly axial postural tremor, without visible palatal tremor. Tremor varied in frequency between 3 and 10 Hz, often jumping from one frequency to another in this band. All three patients had evidence of cerebellar pathology. Cases 1 and 2 developed tremor in the setting of a late-onset cerebellar degeneration and after excision of a right cerebellar haemangioblastoma, respectively. Etiology was unclear in Case 3. Nevertheless, this patient had a cerebellar dysarthria. The tremor was similar to that sometimes seen in conjunction with palatal tremor, and EMG studies in Case 3 demonstrated a subclinical modulation of palatal muscle activity simultaneous with the truncal tremor. It is suggested that an axial postural tremor may be due to pathology of the cerebellum and its outflow pathways, despite the absence of clinically apparent palatal tremor.

Adult↗

Parkinsonism associated with acute intracranial hematomas: an [18F]dopa positron-emission tomography study.

We present the case of a 36-year-old woman with a right temporal hematoma and an overlying subdural hematoma following rupture of a right middle cerebral artery aneurysm. Three weeks after recovering consciousness, she developed a levodopa-responsive parkinsonian syndrome involving the right limbs. A year after the vascular event, she reported subjective improvement in her parkinsonism, which has remained stable since. 18F-dopa positron-emission tomography showed a marked reduction of uptake in the left putamen, raising the possibility that the intracranial hemorrhage unmasked latent Parkinson's disease. To the best of our knowledge, this is the first case of parkinsonism associated with spontaneous acute intracerebral and subdural hematomas.

Acute Disease↗

Oxidative DNA damage in the parkinsonian brain: an apparent selective increase in 8-hydroxyguanine levels in substantia nigra.

Oxidative damage has been implicated in the pathology of Parkinson's disease (PD), e.g., rises in the level of the DNA damage product, 8-hydroxy-2'-deoxyguanosine, have been reported. However, many other products result from oxidative DNA damage, and the pattern of products can be diagnostic of the oxidizing species. Gas chromatography/mass spectrometry was used to examine products of oxidation and deamination of all four DNA bases in control and PD brains. Products were detected in all brain regions examined, both normal and PD. Analysis showed that levels of 8-hydroxyguanine (8-OHG) tended to be elevated and levels of 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FAPy guanine) tended to be decreased in PD. The most striking difference was a rise in 8-OHG in PD substantia nigra (p = 0.0002); rises in other base oxidation/deamination products were not evident, showing that elevation in 8-OHG is unlikely to be due to peroxynitrite (ONOO-) or hydroxyl radicals (OH.), or to be a prooxidant effect of treatment with L-Dopa. However, some or all of the rise in 8-OHG could be due to a change in 8-OHG/FAPy guanine ratios rather than to an increase in total oxidative guanine damage.

Aged↗

A generalised increase in protein carbonyls in the brain in Parkinson's but not incidental Lewy body disease.

The degeneration of neurones in Parkinson's disease (PD) may involve oxidative stress. Previously, increased lipid peroxidation and oxidative DNA damage have been reported in parkinsonian substantia nigra. In the present study the protein carbonyl assay was used to assess oxidative protein damage in postmortem brain tissue from patients with PD and age-matched controls. In brain areas associated with PD, such as substantia nigra, caudate nucleus, and putamen, there was a significant increase in carbonyl levels. However, increased carbonyl levels were also found in areas of the brain not thought to be affected in PD. This perhaps suggests that protein carbonyl formation is related to therapy with L-DOPA, which can exert prooxidant properties in vitro. Consistent with this possibility, brain regions from individuals with incidental Lewy body disease (putative presymptomatic PD) showed no rise in carbonyls in any brain areas. Our data show that either oxidative protein damage occurs widely but late in PD brain, and/or that L-DOPA treatment contributes to protein oxidation.

Adult↗

Apraxia in Parkinson's disease, progressive supranuclear palsy, multiple system atrophy and neuroleptic-induced parkinsonism.

We studied 45 non-demented patients with Parkinson's disease (PD), 12 with progressive supranuclear palsy (PSP), 10 with multiple system atrophy (MSA) and 12 with neuroleptic-induced parkinsonism (NIP) for the presence of apraxia. Our aim was to determine whether a standard comprehensive assessment of different praxic functions would demonstrate specific types of errors not attributable to bradykinesia, rigidity, tremor or any other abnormal elementary motor deficit. PD patients on chronic levodopa treatment were examined in the 'on' and 'off' (treatment) states. Based on apraxia assessment scores, bilateral ideomotor apraxia for transitive movements was found in eight (75%) and 12 (27%) of PSP and PD patients, respectively. Ideomotor apraxia was mainly characterized by spatial errors (i.e., external and internal configuration, body-part-as-object and trajectory). Four PSP but no PD patients exhibited ideomotor apraxia for intransitive movements. PSP as well as PD patients with ideomotor apraxia also had difficulties in imitating hand and finger postures, but none of them failed on pantomime comprehension and pantomime recognition/discrimination. Some PSP patients exhibited, in addition, a limbkinetic type of apraxia and a minority of them displayed deficits on tasks involving multiple steps. Neither MSA nor NIP patients showed any disturbance of praxic functions. There were no differences in age, disease duration, Mini Mental State Examination (MMSE), Unified Parkinson's disease Rating Scale and Hoehn-Yahr scores between apraxic and non-apraxic PD patients, and ideomotor apraxia scores were similar in the 'on' and 'off' states. A correlation was found between ideomotor apraxia scores in PD patients and deficits in frontal lobe-related neuropsychological tasks such as the Tower of Hanoi, verbal fluency and the Trail Making Test. Furthermore, PD patients with apraxia showed higher Hamilton depression scores than non-apraxic PD patients. In PSP patients, ideomotor apraxia scores correlated significantly with cognitive deficit as measured with MMSE. The presence or absence of cortical involvement, and its severity and distribution might determine the presence and type of apraxia in PD and PSP. Apraxia in these conditions would therefore reflect combined cortico-striatal dysfunction.

Adult↗

Autonomic effects of selegiline: possible cardiovascular toxicity in Parkinson's disease.

OBJECTIVES: The United Kingdom Parkinson's Disease Research Group (UKPDRG) trial found an increased mortality in patients with Parkinson's disease randomised to receive selegiline (10 mg/day) and levodopa compared with those taking levodopa alone. Unwanted effects of selegiline on cardiovascular regulation have been investigated as a potential cause for the unexpected mortality finding of the UKPDRG trial. METHODS: The cardiovascular responses to a range of physiological stimuli, including standing and head up tilt, were studied in patients with Parkinson's disease receiving levodopa alone and a matched group on levodopa and selegiline. RESULTS: Head up tilt caused selective and often severe orthostatic hypotension in nine of 16 patients taking selegiline and levodopa, but was without effect on nine patients receiving levodopa alone. Two patients taking selegiline lost consciousness with unrecordable blood pressures and a further four had severe symptomatic hypotension. The normal protective rises in heart rate and plasma noradrenaline were impaired. The abnormal response to head up tilt was reversed by discontinuation of selegiline. Drug withdrawal caused a pronounced deterioration in motor function in 13 of the 16 patients taking selegiline. CONCLUSION: Therapy with selegiline and levodopa in combination may be associated with severe orthostatic hypotension not attributable to levodopa alone. Selegiline also has pronounced symptomatic motor effects in advanced Parkinson's disease. The possibilities that these cardiovascular and motor findings might be due either to non-selective inhibition of monoamine oxidase or to amphetamine and met-amphetamine are discussed.

Aged↗

Dopaminergic function in patients with posttraumatic parkinsonism: an 18F-dopa PET study.

Posttraumatic encephalopathy (PTE) is characterized by a combination of upper motor neuron, basal ganglia, cerebellar, and psychiatric disturbances. A "striatal" variant, with predominant posttraumatic parkinsonism (PTP), is uncommon and may be difficult to distinguish from idiopathic Parkinson's disease (PD). We report the clinical characteristics of six patients clinically presumed to have PTP who were investigated with 18F-dopa PET. We compared their findings with those of age-matched controls and a group of idiopathic PD patients without a history of head trauma. The PTP patients showed a uniform 40% reduction (p < 0.0001) of mean 18F-dopa uptake in caudate and putamen compared with controls. Their mean putamen uptake was significantly higher than that seen in the PD group (p < 0.004) while mean caudate uptake was lower. The PTP mean caudate:putamen Ki ratio (0.97) was similar to that of controls (1.10) but significantly lower than that of the PD group (1.90) (p < 0.0001). These results suggest that although PTP may appear clinically similar to PD, 18F-dopa PET may help to differentiate it in vivo by demonstrating uniform nigrostriatal involvement as opposed to relative sparing of caudate function. These data also provide support for the view that delayed neurologic sequelae may follow cumulative head trauma.

Aged↗

In vivo studies on striatal dopamine D1 and D2 site binding in L-dopa-treated Parkinson's disease patients with and without dyskinesias.

Dyskinesias are usually seen in Parkinson's disease (PD) patients after several years of L-dopa therapy. Their presence has been attributed to supersensitivity of striatal D1 and D2 receptors. We have used PET to assess striatal D2 receptor binding in untreated PD patients and striatal D1 and D2 binding in L-dopa-treated PD patients. Untreated patients showed a 14% increase in mean D2 receptor binding in the putamen contralateral to the more affected limbs (p < 0.02). Treated patients were segregated into subgroups according to the presence or absence of dyskinesias. There were no differences in mean caudate and putamen D1 and D2 binding between dyskinetic and nondyskinetic patients, matched for duration of clinical disease. Both dyskinetic and nondyskinetic PD subgroups showed a similar 16% reduction of mean caudate D2 binding (p < 0.01) with normal D2 binding in putamen. Mean caudate and putamen D1 binding potentials of both subgroups were reduced by 10% compared with those of controls, though this trend did not reach significance. Putamen D1 binding, however, showed a negative correlation with duration and L-dopa treatment (p < 0.03). These findings suggest that, while exposure of PD patients to L-dopa may be associated with reductions in caudate D2 and caudate and putamen D1 receptor, dyskinesias are unlikely to result from alterations in striatal dopamine receptor binding.

Adult↗

The relationship between dementia and direct involvement of the hippocampus and amygdala in Parkinson's disease.

Severe dementia affects 10 to 20% of all patients with Parkinson's disease (PD) and is particularly common in those aged 65 years and over. In a clinicopathologic study, we correlated Mini-Mental State Examination scores and DSM-III dementia ratings with the density of Lewy bodies, Lewy neurites, neurofibrillary tangles, neuritic plaques, gliosis, and neurons in the hippocampus and amygdala of 27 PD patients without Alzheimer's disease changes. Cortical Lewy body densities were examined in the anterior cingulate gyrus. The degree of cognitive impairment was correlated with the density of Lewy neurites in the CA2 hippocampal field, raising the possibility that disruption of the connection between the dentate gyrus, entorhinal cortex, septal nuclei, and hypothalamus and the CA1 field contributes to dementia in PD.

Aged↗

Trauma and Parkinson disease.

The relationship between physical trauma and Parkinson's disease is reviewed. Post-traumatic Parkinson's syndrome may occur following cumulative head trauma in contact sports and exceptionally rarely after single severe closed head injury. It remains uncertain, however, whether physical injury should be considered one aetiological factor in the pathogenesis of Parkinson's disease.

Athletic Injuries↗