J. A. O. Besson

Differential diagnosis in dementia using the cerebral blood flow agent 99mTc HM-PAO: a SPECT study.

One of the potential clinical uses of the new cerebral blood flow agent 99mTc-hexamethylpropyleneamineoxime (HM-PAO) is the investigation of dementia, in particular to differentiate between dementia of the Alzheimer type (DAT) and multiinfarct dementia (MID). In this study 27 patients, 17 with DAT and 10 with MID, and three normal volunteers were imaged both with single photon emission CT and magnetic resonance. The HM-PAO perfusion deficits were much more common in the DAT group than in the MID group, especially in the temporoparietooccipital (TPO) regions. The two groups of patients were found to be significantly different (p less than 0.02), as regards the frequency of occurrence of bilateral TPO perfusion deficits. Four of the 17 DAT patients did not have bilateral TPO deficits but these included the three least impaired patients as assessed by psychometric testing.

Clinical features predicting dementia in idiopathic Parkinson's disease A follow‐up study

We followed up, after 31/2 years, a whole population cohort of 249 patients with Parkinsons disease (PD) 1st examined in 1983 to 1984. Of the survivors, 23.6% qualified for a DSM III-R diagnosis of dementia. In univariate tests, age, certain items of the Webster scale, the Hoehn and Yahr scale, a 10-question mental status questionnaire, and a history of smoking were associated with a diagnosis of dementia 31/2 years later. Logistic regression with DSM III-R diagnosis (demented versus nondemented) as the dependent variable, and age and symptom scales for PD as predictor variables, revealed that PD symptoms predicted dementia even after controlling for age. We conclude that dementia is probably more common in PD patients than would be expected in the general population and is associated with the severity of PD symptoms and signs independently of age.

The clinical manifestation of mental disorder in Huntington's disease: a retrospective case record study of disease progression.

All cases (86) of Huntingtons Disease presenting between 1970 and 1987 in the Grampian Health Board region were identified and a case note analysis of neurological and psychiatric syndromes carried out ‐ the latter using the PSE syndrome check‐list. The commonest syndromes were organic impairment, irritability, loss of interest and concentration and simple depression and these were often the presenting psychiatric syndromes. General anxiety, worrying and social unease occurred early, commonly before movement disorder and were associated with longer survival.

Construct validity of the National Adult Reading Test: a factor analytic study

Abstract Factor analysis was carried out on the National Adult Reading Test (NART) and Wechsler Adult Intelligence Scale (WAIS) performance of 139 normal subjects. The NART loaded very highly on factor I extracted by principal components analysis (PCA), suggesting that the NART has high construct validity as a measure of general intelligence. Varimax rotation of the three factors extracted by PCA produced a factor structure that was consistent with previous factor analytic studies of the WAIS. The NART loaded highly on Factor I (verbal intelligence) but not on Factor II (non-verbal intelligence) or Factor III (attention/concentration).

Estimation of premorbid intelligence: combining psychometric and demographic approaches improves predictive accuracy

Abstract Regression equations have been developed to estimate premorbid WAIS IQ from (a) psychometric tests which are relatively resistant to the effects of cerebral dysfunction, and (b) demographic variables (e.g. education, occupation). The purpose of the present study was to determine whether regression equations based on the combination of psychometric and demographic variables would account for more WAIS IQ variance than either of the two methods alone. Normal subjects (n = 151) were administered the WAIS and the National Adult Reading Test and had their demographic details recorded (age, sex, education, and occupation). Equations incorporating the NART and demographic variables accounted for 73, 78 and 39% of the variance in Full Scale, Verbal, and Performance IQ. The corresponding figures for equations derived from the NART alone or demographics alone were 66, 72 and 33%, and 50, 50, and 30% respectively.

The use of technetium-99m-HM-PAO in the assessment of patients with dementia and other neuropsychiatric conditions.

One hundred fourteen patients suffering from neuropsychiatric conditions have been studied using 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) and single photon emission computed tomography (SPECT). Ninety-one patients had a firm clinical diagnosis while 23 were examined without knowledge of the clinical diagnosis. Of the 91 patients, 51 were suffering from dementia, 25 multi-infarct type and 26 Alzheimers disease. In 19 of the Alzheimers patients, a characteristic pattern of decreased perfusion in the parieto-occipital regions was demonstrated while those with multi-infarct type showed varying degrees of irregular uptake in the cerebral cortex. These appearances are similar to those shown with positron emission tomography (PET) and we believe that HM-PAO will provide a widely available method for identifying patients with Alzheimers disease. Twenty-nine patients were suffering from diseases involving the basal ganglia. Fifteen patients with Parkinsons disease showed no significant abnormality in basal ganglia uptake, while 7 or 8 patients with Huntingtons disease who had full examinations showed decreased uptake in the caudate nuclei. Similarly, four of six patients with other basal ganglia diseases showed impaired uptake by basal ganglia, and it is concluded that HM-PAO may be useful for the diagnosis and management of this type of patient. Twenty-three patients received HM-PAO imaging as part of their diagnostic work-up; in 19 of them, detailed follow-up was obtained, which indicated that in 7 cases the result of the HM-PAO scan altered the clinical diagnosis and in 9 cases resulted in a change in management. In the remaining 13 cases, the study was found to be helpful in confirming the diagnosis.

Event related potentials, reaction time, and cognitive performance in idiopathic Parkinson's disease

Sixteen non-demented patients with idiopathic Parkinsons disease (PD) with varying degrees of cognitive impairment and sixteen age-, sex- and education-matched normal controls were examined with (1) an auditory oddball paradigm requiring counting or a motor response in separate determinations, (2) a reaction time task with movement time component and (3) a detailed clinical and neuropsychological test battery. Patients were impaired on a number of neuropsychological tests. They also showed an increased P2 and N2 latency, but no significant increase in P3 latency. Their response initiation times and reaction times during the oddball experiment were not different from controls, whereas movement time was significantly increased. Increased peak latencies, particularly for N2, were moderately associated with Parkinsonian motor impairment in patients and with the Benton Multiple Choice Visual Retention Test in patients and controls. Movement time was associated with P3 latency only in controls and in both groups with the Benton Multiple Choice Visual Retention Test. The observed pattern of results suggests that in non-demented PD patients ERP peak latencies, visuo-spatial task performance and Parkinsonian motor impairment share a significant degree of variance. While impairments in neuropsychological tests and delay in the earlier peaks P2 and N2 do not appear to be sensitive to medication with L-DOPA, normal P3 latencies might indicate good pharmacological symptom control in the absence of dementia.

Mortality and causes of death in idiopathic Parkinson's disease: results from the Aberdeen whole population study.

Two hundred and forty-nine patients with Parkinsons disease previously examined by Mutch et al 1,2 were followed up three and a half years after the original study. Cognitive impairment, age, some postural signs and symptoms of Parkinsons disease and high scores on the Hoehn and Yahr scale predicted premature death. Patients were more likely to die from respiratory infections than controls. Respiratory diseases as cause of death recorded on the death certificate were not related to kyphosis, posture scores or Hoehn and Yahr scores before death. The hypothesis is advanced that death of respiratory causes might be associated with signs of general autonomic dysregulation.

Nuclear magnetic resonance imaging and single photon emission tomography with radio-iodine labelled compounds in the diagnosis of dementia

ABSTRACT— White matter lesions and T1 changes were identified using NMR and then compared between groups of patients suffering from dementia of the Alzheimer type (DAT), Multiple infarct dementia (MID) and normal controls. All DAT and MID patients were also imaged with a gamma camera using 123Iodo‐n‐isopropylamphetamine, a radiopharmaceutical whose uptake in the brain follows the regional blood flow. While NMR was not able to differentiate between DAT and MID, 19 out of 21 DAT patients compared to four out of 18 MID patients showed bilateral parietal lesions on IMP scans.

P300 and smooth eye pursuit: concordance of abnormalities and relation to clinical features in DSM-III schizophrenia.

Twenty‐five DSM‐III‐diagnosed schizophrenics and 37 normal and age‐matched controls were examined using an oddball paradigm for the generation of P300 and smooth eye‐pursuit tasks. Results were compared between groups and related to clinical characteristics, including a family history of psychiatric illness. Group differences were found for P300 amplitudes, latencies and eye‐tracking. A family history of psychiatric illness was associated with normal eye‐tracking in patients. Small P300 amplitudes alone and in combination with long P300 latencies were associated with a family history in controls.