Biomedical subjects
A J Lees
Publications and source records attributed to A J Lees.
Striatal D2 receptor status in patients with Parkinson's disease, striatonigral degeneration, and progressive supranuclear palsy, measured with 11C-raclopride and positron emission tomography.
Equilibrium striatal: cerebellar 11C-raclopride (RAC) uptake ratios reflect the density of striatal dopamine D2 binding sites. Using positron emission tomographic scanning we have measured striatal RAC uptake in 6 untreated patients with Parkinson's disease (PD), 5 chronically treated patients with PD and a fluctuating response to L-dopa, 10 patients with striatonigral degeneration (SND), and 9 patients with progressive supranuclear palsy (PSP). Regional cerebral blood flow was determined also, with C15O2. Mean striatal: cerebellar RAC uptake was not significantly different from normal in untreated patients with PD, though 2 of these 6 patients showed significantly increased putamen tracer binding. Mean caudate and putamen: cerebellar RAC uptake ratios of the group with PD and a fluctuating response to L-dopa were significantly reduced by 30% and 18%, respectively. The patients with SND had lesser, but significant, 10% and 11% decreases in mean caudate and putamen: cerebellar RAC uptake ratios, respectively, whereas patients with PSP showed 24% and 9% reductions in caudate and putamen: cerebellar RAC binding. Striatal and frontal blood flow were significantly reduced in patients with PSP, but not in patients with PD or SND. In conclusion, striatal D2 binding potential is normal or raised in untreated patients with PD, but reduced in patients with PD and a fluctuating response to L-dopa. Patients with SND and PSP show a decrease in striatal RAC binding, but to a lesser extent than patients with PD and a fluctuating response to treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Alpha-tocopherol levels in brain are not altered in Parkinson's disease.
alpha-Tocopherol (vitamin E) levels in normal brain were lower in the cerebellum than in the cerebral cortex or basal ganglia. There was no difference in alpha-tocopherol levels in the cerebellum, basal ganglia, or cerebral cortex between control subjects and patients with Parkinson's disease.
The identification of presymptomatic parkinsonism: clinical and [18F]dopa positron emission tomography studies in an Irish kindred.
An Irish kindred is described in which 5 of 10 siblings in the fourth or fifth decade of life developed an akinetic-rigid syndrome clinically indistinguishable from idiopathic Lewy body Parkinson's disease. Four of these patients were scanned by positron emission tomography (PET) with [18F]dopa after clinical diagnosis and in all, a profound impairment of tracer uptake into the striatum was recorded. The fifth patient was initially scanned at a time when he was asymptomatic and normal by clinical examination. His scan showed impaired tracer uptake, indicating a subclinical defect in the presynaptic nigrostriatal system. Within months of his scan, he too developed subtle symptoms and signs of parkinsonism although there was little further clinical progression or change in his PET scan over the following year. A clinically normal sibling was also scanned and found to have subclinical impairment of [18F]dopa uptake in the putamen. The 19-year-old daughter of an affected sibling had a mild postural tremor but no other symptoms or signs. The [18F]dopa uptake in her putamen fell at the borderline between normal and parkinsonian values. This study confirms that PET can identify preclinical parkinsonism in at-risk subjects. The finding of abnormalities in several clinically unaffected family members suggests that family studies based on clinical assessment alone may miss a significant number of subclinically affected individuals, leading to an underestimate of any genetic component to Parkinson's disease.
Impaired activation of the supplementary motor area in Parkinson's disease is reversed when akinesia is treated with apomorphine.
Using positron emission tomography (PET) we previously showed that activation of the putamen, supplementary motor area, and cingulate cortex is impaired in patients with Parkinson's disease (PD) when they are off treatment and perform volitional motor tasks. Evidence suggests that these areas are involved in the generation of internally cued movements in normal subjects. We have now studied the effect of the dopamine agonist apomorphine on cerebral activation when used to treat the akinesia of PD. Regional cerebral blood flow was measured using C15O2 PET in PD patients at rest and when performing paced joystick movements with the right hand in one of four freely chosen directions. All patients used apomorphine regularly, and were studied before treatment, while still "off" but receiving a subcutaneous apomorphine infusion, and when switched "on" with apomorphine. Significant increases in regional cerebral blood flow were determined using statistical parametric mapping. Under resting conditions apomorphine had no effect on focal or global cerebral blood flow. Seven patients with PD performed the motor task adequately in the "off" and "on" states. This group of subjects demonstrated impaired activation of the supplementary motor area and contralateral putamen in the "off" state. Activation of the supplementary motor area significantly improved when the akinesia was reversed with apomorphine. We conclude that the concomitant improvement of supplementary motor area activation and motor function in apomorphine-treated patients with PD provides further evidence for the role of this structure in generating motor programs.
When did Ray Kennedy's Parkinson's disease begin?
Ray Kennedy's Parkinson's disease probably began during his distinguished career as a professional soccer player at least 10 years before the first unequivocal physical signs and 14 years before the diagnosis was finally made, when he was 35-years old. Early prodromal symptoms included intermittent subtle disturbances of movement and posture affecting the right arm and leg, mild facial immobility, episodes of profound malaise and lack of energy, inner feelings of tremulousness, excessive unprovoked bouts of perspiration, and accompanying feelings of heat. Abnormalities of movement in the right arm can be seen in video footage of soccer games up to 8 years before his disability came to medical attention. Many of his premorbid personality traits are characteristic of those believed to be associated with the subsequent development of the malady. At least in some patients with Parkinson's disease, the search for instigating aetiological factors should focus 10-20 years before the cardinal signs can be recognised with certainty.
Temporary deterioration in parkinsonian signs after modest alcohol intake.
Explore the source record for details and available documents.
Diffuse Lewy body disease presenting with supranuclear gaze palsy, parkinsonism, and dementia: a case report.
A 67-year-old man with a family history of parkinsonism had visual complaints due to difficulty in convergence, which was followed 2 years later by development of bradykinesia and rigidity. The diagnosis of Steele-Richardson-Olszewski syndrome was made on the basis of a supranuclear gaze palsy, bradykinesia, rigidity, and poor response to levodopa. However, subsequent neuropathological examination revealed diffuse Lewy body disease with no evidence of neurofibrillary tangles involving either subcortical or brain stem structures.
Treatment of cervical dystonia hand spasms and laryngeal dystonia with botulinum toxin.
One hundred and twenty-six patients with different forms of focal dystonia (89 with cervical dystonia, 12 with hand cramps and 25 with laryngeal dystonia) were treated with localised injections of botulinum toxin. Mean doses per muscle were 200 mouse units (m.u.) for treating cervical dystonia, 40-120 m.u. for forearm muscles in writers' cramp and 3.7 m.u. for the thyroarytenoid muscle in laryngeal dystonia. Responder rates have been above 80% in all patient groups and beneficial effects could be reproduced over follow-up periods of up to 4 years. The commonest side-effects were dysphagia after treatment of spasmodic torticollis, weakness of neighbouring muscles after injections for hand cramps and breathiness and hypophonia following laryngeal injections. All these were transient and generally well tolerated. It is concluded that botulinum toxin injections are a safe and effective treatment in all three types of focal dystonia.
Cardiovascular reflexes in Parkinson's disease: effect of domperidone and apomorphine.
Cardiovascular reflexes were evaluated in 18 patients with idiopathic Parkinson's disease who had a Hoehn & Yahr score of III-IV. The effect of apomorphine and domperidone on blood pressure, heart rate, R-R interval variation, and the Valsalva ratio were studied. Autonomic dysfunction was not found in the patients and there were no differences between subgroups of patients on different treatments. Apomorphine altered cardiovascular reflexes to a greater degree in patients who received the drug for the first time than in chronically treated patients. The changes were antagonized by domperidone, a peripheral dopamine receptor antagonist. Apomorphine treated patients who were receiving long-term domperidone had similar abnormalities of cardiovascular reflexes to those who had been able to withdraw it.
The auditory startle response in the Steele-Richardson-Olszewski syndrome and Parkinson's disease.
The startle response to an unexpected auditory stimulus was studied in eight patients with a clinical diagnosis of the Steele-Richardson-Olszewski syndrome (SRO), 11 patients with idiopathic Parkinson's disease (PD) and 12 normal subjects. The patients with PD were studied 'on' at the time of maximal effect of their treatment; five of these patients were also studied in their 'off' state without treatment. The auditory startle response was absent in three patients with SRO: in the remaining five the latency to onset of earliest electromyography activity (EMG) of the auditory startle response was delayed and few muscles (orbicularis oculi, sternocleidomastoid and rectus abdominis) were recruited in the response. In PD the auditory startle response was similar to that recorded in normal subjects, both in terms of the pattern of muscles recruited and the amplitude of the EMG responses, but the latency of responses in orbicularis oculi and sternocleidomastoid muscles were significantly delayed. This result was not influenced by treatment with L-dopa. In patients with SRO the finding of an abnormal startle response is consistent with loss of neurons in the lower pontine reticular formation. This region is intimately involved in the startle response in animal studies. In patients with PD the late auditory startle response might be related to withdrawal of facilitatory input to brainstem centres and reticulospinal pathways from basal ganglia. The similarity of the responses in patients when 'on' and 'off' suggests these pathways are not under potent dopaminergic control.
The dopaminergic response in multiple system atrophy.
Fifteen of 23 pathologically confirmed cases of multiple system atrophy (MSA) showed some initial response to levodopa and eight of these remained at least partially responsive at the time of death. Eleven developed motor oscillations, and drug-induced dyskinesias, often involving the face and jaw, were also seen in 11 cases. Acute levodopa and apomorphine challenges were administered to 11 patients with clinical MSA who were considered levodopa responsive. A short duration relatively small amplitude response with associated dyskinesias occurred in six and a further three developed dyskinesias without any motor response. Following levodopa withdrawal, a delayed deterioration occurred after three to six days in six patients, five of whom had shown no short duration motor response to the acute challenges. The occurrence of levodopa-induced dyskinesias without a concomitant motor response and delayed deterioration several days after levodopa withdrawal may be more typical of patients with MSA than Parkinson's disease.
Beginning-of-dose motor deterioration following the acute administration of levodopa and apomorphine in Parkinson's disease.
Six Parkinsonian patients on long term levodopa therapy complained of short-lived deterioration of Parkinsonian symptoms immediately after levodopa intake. After withdrawal of the drug overnight, and following an oral challenge with levodopa/carbidopa (250/25) in all six cases, and with subcutaneous apomorphine (3 mg) in two, deterioration below base line levels of disability were observed which would not be explained by loss of sleep benefit. This occurred 10-20 minutes after levodopa challenge and lasted for 10-20 minutes. The latency and duration of this phenomenon were shorter with apomorphine but the characteristics were similar. This phenomenon may be due to an inhibitory effect of levodopa acting via presynaptic dopamine receptors.
Accuracy of clinical diagnosis of idiopathic Parkinson's disease: a clinico-pathological study of 100 cases.
Few detailed clinico-pathological correlations of Parkinson's disease have been published. The pathological findings in 100 patients diagnosed prospectively by a group of consultant neurologists as having idiopathic Parkinson's disease are reported. Seventy six had nigral Lewy bodies, and in all of these Lewy bodies were also found in the cerebral cortex. In 24 cases without Lewy bodies, diagnoses included progressive supranuclear palsy, multiple system atrophy, Alzheimer's disease, Alzheimer-type pathology, and basal ganglia vascular disease. The retrospective application of recommended diagnostic criteria improved the diagnostic accuracy to 82%. These observations call into question current concepts of Parkinson's disease as a single distinct morbid entity.
Gamma vinyl GABA in the treatment of levodopa-induced dyskinesias in Parkinson's disease.
Explore the source record for details and available documents.
What features improve the accuracy of clinical diagnosis in Parkinson's disease: a clinicopathologic study.
Many authorities have drawn attention to the difficulties in clinically distinguishing Parkinson's disease (PD) from other parkinsonian syndromes. We assessed the clinical features of 100 patients diagnosed prospectively by a group of consultant neurologists as having idiopathic PD according to their pathologic findings. Seventy-six percent of these cases were confirmed to have PD. By using selected criteria (asymmetrical onset, no atypical features, and no possible etiology for another parkinsonian syndrome) the proportion of true PD cases identified was increased to 93%, but 32% of pathologically confirmed cases were rejected on this basis. These observations suggest that studies based on consultant diagnosis of PD, using standard diagnostic criteria, will include cases other than PD, thus distorting results from clinical trials and epidemiologic studies. The strict use of additional criteria can reduce misdiagnosis but at the cost of excluding genuine PD cases.
PET studies on the integrity of the pre and postsynaptic dopaminergic system in Tourette syndrome.
Explore the source record for details and available documents.
Rectal apomorphine in Parkinson's disease.
Explore the source record for details and available documents.