Computer-Mediated Measurement and Subjective Ratings of White Matter Hyperintensities in Vascular Dementia: Relationships to Neuropsychological Performance

White matter hyperintensities (WMHs) are frequently found on MRI studies of vascular dementia (VaD) patients. As several studies have demonstrated that WMHs are often associated with severity of illness, cognitive impairment, and functional decline, the accurate and reliable measurement of WMHs on MRI is an important, yet often overlooked, prerequisite for accurate interpretation of neuroimaging studies. Using a sample of 39 VaD patients, we evaluated the reliability and validity of a visual ordinal rating scale and a computer-mediated thresholding technique to evaluate WMHs. Results indicated the computer-mediated technique had slightly stronger inter-rater reliability than the visual ordinal rating scale. Furthermore, the computer-mediated thresholding technique was correlated with measures of neuropsychological functioning believed to be compromised in VaD (i.e., psychomotor speed, executive functioning) while the visual rating scale was not. Results suggest that this computer-mediated thresholding technique is superior to visual ratings of WMHs.     

Hippocampal size and dementia in stroke patients: the Sydney stroke study

BACKGROUND: Hippocampal atrophy is an early feature of Alzheimer's disease (AD) but it has also been reported in vascular dementia (VaD). It is uncertain whether hippocampal size can help differentiate the two disorders. METHODS: We assessed 90 stroke/TIA patients 3-6 months after the event, and 75 control subjects, with neuropsychological tests, medical and psychiatric examination and brain MRI scans. A diagnosis of VaD, vascular mild cognitive impairment (VaMCI) or no cognitive impairment (NCI) was reached by consensus on agreed criteria. T1-weighted MRI was used to obtain total intracranial volume (TICV), gray and white matter volume, CSF volume, hippocampus and amygdala volumes, and T2-weighted scans for white matter hyperintensity (WMH) ratings. RESULTS: Stroke/TIA patients had more white matter hyperintensities (WMHs), larger ventricle-to-brain ratios and smaller amygdalae than controls, but hippocampus size and gray and white matter volumes were not different. WMHs and amygdala but not hippocampal volume distinguished stroke/TIA patients with VaD and VaMCI and without NCI and amygdala volumes. Right hippocampus volume significantly correlated with new visual learning. CONCLUSIONS: Stroke/TIA patients and patients with post-stroke VaMCI or mild VaD do not have hippocampal atrophy. The amygdala is smaller in stroke/TIA patients, especially in those with cognitive impairment, and this may be accounted for by white matter lesions. The hippocampus volume relates to episodic memory, especially right hippocampus and new visual learning. A longitudinal study of these subjects will determine whether hippocampal atrophy is a late development in VaD.     

White matter hyperintensities and rating scales—observer reliability varies with lesion load

Abstract.Background: Cerebral white matter hyperintensities (WMHs) are common in older people. Their presence correlates with cognitive decline and vascular risk factors. Various scales have been developed to quantify the amount and type of WMH, but with few observer reliability studies. We evaluated several scales in different cohorts to determine their observer reliability.Methods: Two observers independently rated T2-weighted MR images from five groups (total n = 494: normal older subjects [97]; patients with minor stroke [221]; young insulin dependent diabetics [141]; maturity onset diabetics [10]; and hepatic encephalopathy [25]), using seven rating scales (Breteler, Fazekas, Longstreth, Mirsen, Shimada, Van Swieten and Wahlund). Inter-observer reliability was determined using Kappa statistics.Results: Patients with maturity onset diabetes had the most WMHs and young insulin-dependent diabetics the least. Inter-observer reliability varied with the amount of WMH. In maturity onset diabetics (most WMHs) the weighted Kappas were: Breteler 0.74; Fazekas 0.89 and 0.72; Van Swieten 0.76 and 0.88; and in young insulin-dependent diabetics (least WMH): Breteler 0.3; Fazekas 0.2 and 0.24; Van Swieten 0.39 and 0.30. These findings were consistent across the groups.Conclusion: WMH rating scale performance varied with WMH prevalence, and hence with subject cohort. In patients with most WMHs the apparent better kappas may reflect a ceiling effect rather than true better agreement. These factors should be considered in studies where risk factors for, or associations with, the early development of WMHs are being determined.     

Prevalence of White Matter Hyperintensities in a Young Healthy Population

BACKGROUND AND PURPOSE: White matter hyperintensities (WMHs) are bright objects observed in the white matter on brain magnetic resonance (MR) imaging. WMHs are often reported as "normal" findings but may represent pathological changes. The prevalence of WMHs appears to increase with increasing age although both the typical timing and clinical significance of their appearance among medically and neurologically healthy persons remains unclear. We assessed the prevalence of WMHs in a cohort of younger healthy subjects. METHODS: Our study comprised 243 healthy subjects ages 16-65 years from our prospective normative MR imaging database. MR scans were rated for presence of periventricular and centrum semiovale WMHs using a four-point visual semi-quantitative scale. RESULTS: WMHs occurred in 5.3% (13 of 243) of subjects. All WMHs were small (rating of 0.5) except one subject age 65 years who had large WMHs (ratings of 2). The median age for subjects with no WMHs was 34.5 years compared to 57.0 years for subjects with WMHs. There were no gender differences (P= .76). Older age correlated with presence of WMHs (r = 0.24; P= .01). Age greater than 55 years had a 10-fold increase in the prevalence of WMHs compared to age < or =55 years (odds ratio = 10.01; 95% confidence interval = 3.1-32.3; P < .001). CONCLUSION: WMHs were uncommon in a younger healthy population screened for comorbid diseases, but increased 10-fold in subjects over 55 years of age. When present, the WMHs are generally small (rating of 0.5). While large WMHs appear to be associated with cognitive deterioration, the optimum threshold for identification, clinical significance, and prognostic value of smaller white matter changes requires further research.     

Brain perfusion correlates of medial temporal lobe atrophy and white matter hyperintensities in mild cognitive impairment

Abstract Objective To assess the association of Medial Temporal lobe Atrophy (MTA) and White Matter Hyperintensities (WMHs) with gray matter perfusion in Mild Cognitive Impairment (MCI). Methods 56 MCI patients (age = 69.3 ± 7.0, 32 females) underwent brain MR scan and ^99mTc ECD SPECT. We evaluated MTA according to Scheltens' fivepoint scale on T1 MR images, and assessed WMHs using the rating scale for age-related white matter changes on T2-weighted and FLAIR MR images. We divided MCI into age-matched subgroups with high and low MTA and high and low WMHs load. We processed SPECT images with SPM2 following an optimized protocol and performed a voxel-based statistical analysis comparing high vs. low MTA and high vs. low WMHs, setting p-value at 0.001 uncorrected, thresholding cluster extent at 100 voxels, using proportional scaling and entering age and WMHs or MTA respectively as nuisance covariates. Results MCI with high compared with low MTA showed hypoperfusion in the left hippocampus and in the left parahippocampal gyrus. MCI with high compared with low WMHs showed a hypoperfusion area in the left insular region and superior temporal gyrus. Conclusions MTA in MCI is associated with hippocampal gray matter hypoperfusion while WMHs is associated with gray matter hypoperfusion in areas of the insula and temporal neocortex. These results confirm that MTA is associated with local functional changes and suggest that WMHs may be associated with remote brain cortical dysfunction.     

The relationship of subcortical MRI hyperintensities and brain volume to cognitive function in vascular dementia.

The relationship between MRI findings (i.e., subcortical hyperintensities; SH, whole brain volume) and the cognitive dysfunction of vascular dementia (VaD) was examined. Participants included 24 persons that met NINDS-AIREN criteria for VaD (MMSE = 19.9 +/- 4.2) and underwent comprehensive neuropsychological assessment and MRI brain imaging. The volume of subcortical hyperintensities (SH) was strongly associated with executive-psychomotor performance, but not with performance across other cognitive domains or global cognitive functional level. Conversely, WBV was strongly associated with global cognitive functioning and performance across most cognitive domains (memory, language, visual integration), but not with executive-psychomotor functioning. The failure of SH to account for either the global dementia evident in these VaD patients or impairments across most cognitive domains suggests that deep subcortical white matter disease may only indirectly contribute to the global cognitive dysfunction of VaD. That WBV emerged as a stronger correlate of dementia raises further questions regarding the cerebral mechanisms that contribute to the development of VaD.     

White matter hyperintensities and chronicity of depression

OBJECTIVE: White matter hyperintensities (WMHs) on T(2)-weighted magnetic resonance imaging (MRI) of the brain are associated with advanced age and late-life depression. Most investigations predominantly found these lesions in frontal lobe and basal ganglia supporting the hypothesis of a fronto-striatal dysfunction in depression. A prospective study was undertaken to investigate the association between extent of WMHs and clinical outcome in elderly depressed patients. METHODS: Thirty-one non-demented depressed subjects underwent a 1.5 T cranial MRI scan. The MRI scans were analysed in consensus by two experienced radiologists. Each MRI scan was assessed for presence and extent of WMHs, which are differentiated in periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs). A total of 21 patients of the original cohort of 31 patients were re-assessed 5 years after baseline assessment. We ascertained the severity of depressive symptoms, the longitudinal course of depression, the cognitive decline and the global assessment of functioning at follow-up visit. RESULTS: (1) Subjects with greater extent of WMHs had a significant higher Hamilton Depression Rating Scale (HAM-D) score, (2) had more severe longitudinal courses of depression (3) and had a lower Mini-Mental State Examination (MMSE) score. CONCLUSIONS: WMHs on MRI are associated with poorer outcome in elderly depressed subjects. Further studies are needed to evaluate WHMs as prognostic factor for an appropriate treatment decision-making.     

The impact of silent vascular brain burden in cognitive impairment in Parkinson’s disease

Background and purpose: White matter hyperintensities (WMHs) detected by magnetic resonance imaging (MRI) of the brain are associated with dementia and cognitive impairment in the general population and in Alzheimer’s disease. Their effect in cognitive decline and dementia associated with Parkinson’s disease (PD) is still unclear. Methods: We studied the relationship between WMHs and cognitive state in 111 patients with PD classified as cognitively normal (n = 39), with a mild cognitive impairment (MCI) (n = 46) or dementia (n = 26), in a cross‐sectional and follow‐up study. Cognitive state was evaluated with a comprehensive neuropsychological battery, and WMHs were identified in FLAIR and T2‐weighted MRI. The burden of WMHs was rated using the Scheltens scale. Results: No differences in WMHs were found between the three groups in the cross‐sectional study. A negative correlation was observed between semantic fluency and the subscore for WMHs in the frontal lobe. Of the 36 non‐demented patients re‐evaluated after a mean follow‐up of 30 months, three patients converted into MCI and 5 into dementia. Progression of periventricular WMHs was associated with an increased conversion to dementia. A marginal association between the increase in total WMHs burden and worsening in the Mini Mental State Examination was encountered. Conclusions: White matter hyperintensities do not influence the cognitive status of patients with PD. Frontal WMHs have a negative impact on semantic fluency. Brain vascular burden may have an effect on cognitive impairment in patients with PD as WMHs increase overtime might increase the risk of conversion to dementia. This finding needs further confirmation in larger prospective studies.     

White matter hyperintensities in the forties: their prevalence and topography in an epidemiological sample aged 44-48

White matter hyperintensities (WMHs) are a frequent finding on T2-weighted MRI of the brain in elderly individuals, but their prevalence and severity in younger asymptomatic populations is less well studied. We report the topography of WMHs on T2-weighted fluid inversion recovery (FLAIR) MRI in 428 individuals aged 44-48 years recruited randomly from a healthy community sample. WMHs were delineated from FLAIR and T1-weighted scans by using a computer algorithm, further verified and then classified using k-nearest neighbor (kNN) algorithm into deep WMH (DWMH), and periventricular WMH (PVWMH), which included extended periventricular "rims" and frontal and occipital "caps". Small caps and pencil-thin rims were not taken as WMHs for this analysis. The new computer algorithm was validated and compared with the scores of visual rating, and the correspondence between the two methods was high. We found that 218 (50.9%) subjects had WMHs. 146 of the 218 (34.1% of whole sample population of 428) subjects had deep white matter hyperintensities (DWMHs). The average number of WMH clusters (occurrences) per brain was 1.37 (0.94 for DWMH and 0.43 for pathological PVWMH) and the mean WMH tissue volume was 0.278 ml. There was no significant sex difference in the severity and distribution of WMHs. The study suggests that small punctate or focal WMHs are common in the brains of individuals in their 40s, and may represent an early stage of development of these lesions.     

轻度血管性痴呆患者的认知特征研究

目的　分析轻度血管性痴呆 (VaD)患者的认知特征。方法　符合美国国立神经疾病与脑卒中研究所(NINDS AIREN)编制的VaD诊断标准的 31例患者 ,与年龄、性别、教育程度等匹配的卒中后非痴呆患者和正常老人(各 31例 )均完成智能、记忆、语言、注意、结构、计算及执行功能的 16种神经心理测验。结果　VaD患者的认知损害是全面性的 ,最为显著的是总体智力、回忆策略、视觉空间能力及筹划执行功能指标 ,反映其额叶和皮质下功能损害。结论　VaD患者脑部额叶和皮质下功能障碍最为突出。     

Guidelines for brain imaging in vascular dementia clinical trials

Imaging should be included in the workup of dementia patients and is mandatory for the diagnosis of vascular dementia (VaD). MRI is the preferred imaging modality and should include axial T2 and FLAIR, preferably accompanied by a 3D T1-weighted sequence in clinical trials to determine white-matter lesions, infarcts, lacunes, and atrophy. Gradient echo images are needed for microbleeds. Diagnostic criteria should be operationalized and validated visual rating scales are available. In clinical trials, standardized acquisition protocols and central data analysis are mandatory. More work is needed to determine the natural progression in VaD and the possible use of MRI-based outcome measures.     

White matter lesions on magnetic resonance imaging in dementia with Lewy bodies, Alzheimer's disease, vascular dementia, and normal aging

OBJECTIVES: Alzheimer's disease and vascular dementia are associated with an increase in changes in white matter on MRI. The aims were to investigate whether white matter changes also occur in dementia with Lewy bodies and to examine the relation between white matter lesions and the cognitive and non-cognitive features of dementia with Lewy bodies, Alzheimer's disease, and vascular dementia. METHODS: Proton density and T2 weighted images were obtained on a 1.0 Tesla MRI scanner in patients with dementia with Lewy bodies (consensus criteria; n=27, mean age=75.9 years), Alzheimer's disease (NINCDS/ADRDA; n=28, mean age=77.4 years), vascular dementia (NINDS/AIREN; n=25, mean age=76.8 years), and normal controls (n=26, mean age=76.2 years). Cognitive function, depressive symptoms, and psychotic features were assessed using a standardised protocol. Periventricular hyperintensities (PVHs), white matter hyperintensities (WMHs) and basal ganglia hyperintensities (BGHs) were visually rated blind to diagnosis using a semiquantitative scale. RESULTS: Periventricular hyperintensities were positively correlated with age and were more severe in all dementia groups than controls. Total deep hyperintensities scores (WMHs plus BGHs) were significantly higher in all dementia groups than controls and higher in patients with vascular dementia than those with dementia with Lewy bodies or Alzheimer's disease. In all patients with dementia, frontal WMHs were associated with higher depression scores and occipital WMHs were associated with an absence of visual hallucinations and delusions. CONCLUSION: In common with Alzheimer's disease and vascular dementia, PVHs and WMHs were significantly more extensive in dementia with Lewy bodies than in controls. This overlap between different dementias may reflect shared pathological mechanisms. The link between frontal WMHs and depression and the absence of occipital WMHs and psychotic symptoms has important implications for understanding the neurobiological basis of these symptoms.     

Diffusion-weighted MRI in vascular dementia

OBJECTIVE: To examine the ability of diffusion-weighted MRI (DWI) to detect ongoing cerebral ischemia in patients with vascular dementia (VaD). BACKGROUND: VaD due to small-vessel disease results from the cumulative impact of recurrent cerebral ischemia. Cerebral ischemia may produce clinical manifestations, producing the "stepwise" decline characteristic of VaD. Conventional MRI can detect small regions of ischemic damage but cannot determine when injury developed. In contrast, DWI shows sensitivity in detecting ischemia of recent onset. DESIGN/METHODS: Patients with VaD (n = 30) underwent DWI in addition to standard MRI sequences. Patients were divided into two groups according to the presence of new focal deficits or mental change within 10 days before MRI. In 10 patients of positive group, symptomatic neurologic decline occurred an average of 4.2 days before the imaging procedure. RESULTS: Seven (70%) of 10 patients with a recent neurologic event showed 15 new regions of signal abnormality on DWI. The anatomic distribution of signal change could account for the patients' new symptoms or signs in all but one patient. Similar signal abnormality was detected in 4 (20%) of 20 patients without a recent neurologic event. New foci of altered signal intensity were distinguishable from prior injuries only with DWI. No significant difference was found between patients with and without DWI abnormalities in gender, age, Mini-Mental State Examination score, Hachinski Ischemic Score, vascular risk factors, or severity of increased signal on T2-weighted MRI scans. CONCLUSION: Small foci of abnormal signal on diffusion-weighted MRI (DWI), presumably representing recent small infarcts, occur often in vascular dementia (VaD) from small-vessel disease, even in patients without a recent "stepwise decline." The results suggest that DWI might be used to monitor VaD progression in future observational and interventional studies of this disorder.     

Montreal cognitive assessment in assessing clinical severity and white matter hyperintensity in Alzheimer's disease with normal control comparison

Purpose: Use Taiwanese version of the Montreal Cognitive Assessment (MoCA) in evaluating patients in different stages of Alzheimer's disease (AD) and correlate with white matter change. Methods: Ninety-seven normal controls (NC), 52 very-mild AD (clinical dementia rating [CDR] = 0.5), 48 mild AD (CDR = 1) and 38 moderate AD (CDR = 2) patients were enrolled for the MoCA, Mini- Mental State Examination (MMSE) and the Cognitive Assessment Screening Instrument (CASI). White matter hyperintensities (WMHs) on brain MRI were visually rated and classified as deep or periventricular WMHs. Results: In NC group, education (β = 0.326) but not age (β = -0.183, p = 0.069), was significantly related to MoCA score. However, while we added two points to the AD patients with less than 6 years education, the effects of education disappeared as compared with those of 7 years of education. For all educational levels, the cutoff value of MoCA for very-mild AD was 22/23 (sensitivity = 82.7%, specificity = 87.6%). No significant differences were found in the areas under the curves that differentiated NC from the patients with AD for MoCA and MMSE (differences = 0.008, p = 0.490), or for MoCA and CASI (differences = 0.023, p = 0.082). Total WMHs, frontal deep and periventricular WMHs were inversely correlated with the attention and delayed-recall subdomain. Conclusion: The MoCA is a good clinical tool for screening very-mild stage AD if the educational effects are carefully considered. The correlation between the executive subdomains with the frontal WMHs also makes it a useful tool for detecting subtle WMHs.     

Pain assessment in patients with possible vascular dementia

PREVIOUS studies comparing Alzheimer's disease (AD) patients with the normal elderly suggest that AD patients experience less pain. In the present study, pain reporting in 20 patients with possible vascular dementia (VaD) was compared to 20 nondemented elderly who had comparable pain conditions. It was hypothesized that, due to de-afferentiation, the possible VaD patients would experience more pain than the cognitively intact elderly. Pain assessment was conducted using three visual analogue scales, (1) the Coloured Analogue Scale (CAS) for Pain Intensity, (2) the CAS for Pain Affect, and (3) the Faces Pain Scale (FPS); a verbal pain questionnaire, Number of Words Chosen--Affective (NWC-A) of the McGill Pain Questionnaire; and an observation scale, the Checklist of Nonverbal Pain Indicators (CNPI). Results showed a significant increase in the scores on the CAS for Pain Affect and the FPS in the demented patients compared to the control group. There was a tendency for an increase in scores on the CNPI in the VaD group. These results suggest that patients with possible VaD suffer more pain than healthy elderly without cognitive impairment.     

Intracranial volume in mild cognitive impairment,Alzheimer's disease and vascular dementia: evidence for brain reserve?

OBJECTIVE: The possibility of brain volume reserve effects was examined in a sample of geriatric outpatients with mild cognitive impairment (MCI), Alzheimer's disease (AD) and vascular dementia (VaD). The total intracranial volume (ICV) served as an estimate of the maximum attained brain volume in life. METHODS: Subjects (n = 181, mean age 60.7) were consecutive referrals to a geriatric outpatients clinic (n = 96) and a group of age-matched healthy control subjects (n = 85). ICV and brain volume were attained from T1-weighted magnetic resonance images using a stereological method. Hippocampal atrophy was assessed with a visual rating scale. RESULTS: ICV was significantly smaller in patients with AD and VaD than in control subjects, but effect size was small. After adjusting for age and gender, having ICV in the smallest quartile significantly increased the risk of cognitive impairment (either MCI or dementia). In patients with dementia, but not in MCI, severity of cognitive impairment and ICV were moderately correlated. The effect of ICV on cognition was not mediated by hippocampal atrophy. CONCLUSIONS: These findings are compatible with volume reserve effects that modify the clinical expression of symptoms in both AD and VaD. They may have implications for the design of neuroimaging studies that use ICV for normalization procedures.     

Know Not What They Do†

Abstract

Previous studies comparing Alzheimer's disease (AD) patients with the normal elderly suggest that AD patients experience less pain. In the present study, pain reporting in 20 patients with possible vascular dementia (VaD) was compared to 20 nondemented elderly who had comparable pain conditions. It was hypothesized that, due to de-afferentiation, the possible VaD patients would experience more pain than the cognitively intact elderly. Pain assessment was conducted using three visual analogue scales, (1) the Coloured Analogue Scale (CAS) for Pain Intensity, (2) the CAS for Pain Affect, and (3) the Faces Pain Scale (FPS); a verbal pain questionnaire, Number of Words Chosen—Affective (NWC-A) of the McGill Pain Questionnaire; and an observation scale, the Checklist of Nonverbal Pain Indicators (CNPI). Results showed a significant increase in the scores on the CAS for Pain Affect and the FPS in the demented patients compared to the control group. There was a tendency for an increase in scores on the CNPI in the VaD group. These results suggest that patients with possible VaD suffer more pain than healthy elderly without cognitive impairment.     

Cerebral white matter hyperintensities are not increased in patients with primary Sjögren’s syndrome

Background and purpose: It is frequently thought that cerebral white matter hyperintensities (WMHs) on T‐2 weighted MRI scans are increased in patients with autoimmune diseases. An increased frequency of WHMs has been described in primary Sjögren’s syndrome (PSS), but no controlled studies exist. The aim of this study was therefore to compare WMHs in PSS patients and healthy subjects applying the new European‐American criteria for PSS. Methods: Cross‐sectional controlled study of 68 unselected PSS patients and 68 healthy subjects was carried out. WMHs were rated using Scheltens method. Results: There were no differences in total or any regional WMH scores between PSS patients and healthy subjects. Conclusions: Patients with PSS do not have increased WMH load or distribution when compared with healthy subjects.     

Improving assessment in small fiber neuropathy

Interval measures at the impairment level addressing symptoms and at the activity/participation level addressing daily and social restrictions have not been developed for small fiber neuropathy (SFN). We developed an SFN‐specific Rasch‐built overall disability scale (SFN‐RODS©), an activity/participation scale at the interval level. A preliminary SFN‐RODS containing 146 activity/participation items was assessed twice (reliability studies) in 238 patients with SFN. The ordinal‐based 13‐item SFN‐symptoms inventory questionnaire (SFN‐SIQ©) and pain‐visual‐analogue‐scale were also assessed (validity studies). The pre‐SFN‐RODS and SFN‐SIQ data were subjected to the Rasch analyses. The pre‐SFN‐RODS did not meet Rasch model expectations. Based on requirements, such as misfit statistics, differential item functioning, and local dependency, items were systematically removed and model fit improved. Finally, a 32‐item SFN‐RODS© scale was constructed that fulfilled all Rasch requirements, demonstrating acceptable reliability and validity scores. The 13‐item SFN‐SIQ© was successfully transformed to an interval Rasch‐built measure fulfilling model's requirements. In conclusion, the 32‐item SFN‐RODS© is a disease‐specific interval measure suitable for detecting activity limitations and participation restrictions in patients with SFN. The 13‐item SFN‐SIQ© was transformed through Rasch to an interval measure. The use of these scales is recommended in future clinical interventional trials involving patients with SFN.     

Development, reliability and acceptability of a new version of the DSM-IV Social and Occupational Functioning Assessment Scale (SOFAS) to assess routine social functioning

OBJECTIVE: Development of a scale to assess patients' social functioning, the Personal and Social Performance scale (PSP). METHOD: PSP has been developed through focus groups and reliability studies on the basis of the social functioning component of the DSM-IV Social and Occupational Functioning Assessment Scale (SOFAS). The last reliability study was carried out by 39 workers with different professional roles on a sample of 61 psychiatric patients admitted to the rehabilitation unit. Each patient was rated independently on the scale by the two workers who knew them best. RESULTS: The PSP is a 100-point single-item rating scale, subdivided into 10 equal intervals. The ratings are based mainly on the assessment of patient's functioning in four main areas: 1) socially useful activities; 2) personal and social relationships; 3) self-care; and 4) disturbing and aggressive behaviours. Operational criteria to rate the levels of disabilities have been defined for the above-mentioned areas. Excellent inter-rater reliability was also obtained in less educated workers. CONCLUSION: Compared to SOFAS, PSP has better face validity and psychometric properties. It was found to be an acceptable, quick and valid measure of patients' personal and social functioning.