Papers by Michael Perdices
General Hospital Psychiatry, 1998
causes. The findings from this preliminary study suggest that a PTSD response to HIV diagnosis ha... more causes. The findings from this preliminary study suggest that a PTSD response to HIV diagnosis has clinical validity and requires further investigation in this population and other medically ill groups. The results support the inclusion of the diagnosis of life-threatening illness as a traumatic incident that may lead to a posttraumatic stress disorder, which is consistent with the DSM-IV criteria.
Australian and New Zealand Journal of Psychiatry, 1998
Objective: This study aimed to investigate rates of psychiatric disorder in human immunodeficienc... more Objective: This study aimed to investigate rates of psychiatric disorder in human immunodeficiency virus (HIV) infection, in an Australian sample of homosexual and bisexual men. Method: A cross-sectional study of a total of 65 HIV sero-negative (HIV-) and 164 HIV sero-positive men (HIV+) (79 CDC stage I I/I 11 and 85 CDC stage IV) was conducted in three centres. Lifetime and current prevalence rates of psychiatric disorder were evaluated using the Diagnostic Interview Schedule Version IIIR (DIS-IIIR). Results: Elevated current and lifetime rates of major depression were detected in both HIV negative and HIV positive homosexual/bisexual men. Lifetime rates of alcohol abuse/dependence were significantly elevated in HIV positive men (CDC group IV) when compared with HIV negative men. Among the HIV positive group the majority of psychiatric disorders detected were preceded by a pre-HIV diagnosis of psychiatric disorder. Major depression represented the disorder most likely to have first onset after HIV infection diagnosis. Conclusions: Lifetime rates of major depression were elevated in this sample of HIV-negative and HIV-positive men. In the HIV-positive men, psychiatric disorder was significantly associated with the presence of lifetime psychiatric disorder prior to HIV infection diagnosis. The findings indicate the importance of evaluation of psychiatric history prior to HIV infection and the clinical significance of depressive syndromes in this population.
Annals of Neurology, 1989
The performance of 56 homosexual men infected with human immunodeficiency virus (HIV) was compare... more The performance of 56 homosexual men infected with human immunodeficiency virus (HIV) was compared to that of 23 HIV antibody-seronegative controls on simple (SRT) and choice (CRT) reaction time tasks. Patients were classified into 3 groups according to Centers for Disease Control clinical criteria. There were 18 patients who had acquired immunodeficiency syndrome (AIDS), 18 who had AIDS-related complex (ARC), and 20 who were HIV antibody-seropositive but otherwise asymptomatic (HIV-Ab+). The SRT task consisted of 5 trials, each containing 10 target stimuli. The CRT task consisted of 10 trials, each containing 5 target stimuli randomly interspersed with 5 nontarget stimuli. The mean response latency of each of the patient groups on the SRT task was not significantly different from that of controls. However, the performance of patients with AIDS or ARC on the CRT task was significantly lower than that of controls, whereas that of HIV-Ab+ patients was not. Analysis of the quality of RT task performance also indicated that the impairment of processing efficiency at higher levels of task difficulty reflected a disruption of processing prior to the response selection stage.
Australian and New Zealand Journal of Psychiatry, 1992
Levels of anxiety and depression were assessed for 207 HIV seropositive homosexual/bisexual men (... more Levels of anxiety and depression were assessed for 207 HIV seropositive homosexual/bisexual men (AIDS= 34, ARC= 72, asymptomatic HIV infection= 101), and 36 seronegative controls. Lymphocyte subset enumeration, history of opportunistic infections, and occurrence of HIV-related symptoms were recorded at the time of assessment. No differences between groups were found on age, educational level, state/trait anxiety or depression scores. Neither the number of symptoms reported, their duration, severity, ...
Internal Medicine Journal, 1989
Neurological manifestations of unknown cause occurring in patients who become or are HIV antibody... more Neurological manifestations of unknown cause occurring in patients who become or are HIV antibody positive with presumed normal immune function have been described recently. This report adds a further six cases, all of whom had normal CD4 + cell counts either throughout the period of observation or after the episode of seroconyersion. Three had an acute presentation, two in the context of documented seroconversion consisting of one of the following: an encephalitis, an ataxia, and confusion with neuralgic amyotrophy. Three had a subacute disorder occurring at a later phase of HIV infection but before opportunistic infections or neoplasms, and marked by a static mild cognitive deficit. This report extends the range of abnormalities that may be seen at seroconversion and documents the presence of a non-progressive cognitive deficit occurring in the latent phase of HIV infection.
Journal of Clinical and Experimental Neuropsychology, 1994
There have been conflicting reports as to whether significant neuropsychological deterioration oc... more There have been conflicting reports as to whether significant neuropsychological deterioration occurs in asymptomatic HIV-1 infection. Comparisons among studies have been hindered by substantial variations in sample size, statistical methods, definitions of neuropsychological abnormality, and attention to potential confounding factors. In this study, the neuropsychological performance of 44 subjects with asymptomatic HIV-1 infection and 41 seronegative (SN) controls was compared using analysis of variance models. Rates of abnormality were also determined using commonly employed impairment criteria. The seropositive (SP) subjects performed comparably to SN controls once differences in full scale IQ were taken into account. Rates of abnormality for HIV-1 SP subjects were estimated at 10%, 17.5%, and 67.5% by three different criteria, and were not significantly different from the rates of the control group. The findings indicated that both premorbid characteristics, and the validity and biases of definitions of impairment should be examined and incorporated into the interpretation of study findings.
Objective: To identify clinical, laboratory and demographic markers which are associated with the... more Objective: To identify clinical, laboratory and demographic markers which are associated with the presence of dementia and neuropsychological impairment in severely immunodeficient patients. Method: Fifty-nine HIV+ patients participated in the study. Patients were assessed neurologically and neuropsychologically, and a subset of patients underwent lumbar punctures. Logistic regression was used to determine which variables from a set including age, education, IQ, depression, anxiety, CD4 cell counts, haemoglobin, serum and CSF â2 microglobulin and neopterin, constitutional symptoms, past opportunistic infections and use of antiretroviral therapy was associated with the occurrence of dementia and neuropsychological impairment. Results: An increased likelihood of neurological and neuropsychological dysfunction was associated with diarrhoea at some time in the recent past, elevated serum neopterin at the time of assessment, and increased age. A decreased likelihood of impairment was associated with a higher estimated IQ, more years of education, and the presence of an AIDS-defining illness at the time of assessment. Conclusion: Recent diarrhoea, elevated serum neopterin, advanced age and low education and IQ can serve as ''signals'' for the presence of neurological and neuropsychological dysfunction.
Clinical Neuropsychologist, 1998
Journal of Head Trauma Rehabilitation, 2001
To determine a set of variables that would reliably predict duration of posttraumatic amnesia (PT... more To determine a set of variables that would reliably predict duration of posttraumatic amnesia (PTA) in patients with traumatic brain injury and to test the efficacy of the model. Design: Simultaneous standard multiple regression analyses. Participants: Two independent samples of patients with traumatic brain injury who were in the early stages of PTA: a test sample (n = 61) and a cross-validation sample (n = 25). Main Outcome Measure: The Modified Oxford PTA Scale (MOPTAS) is a 12-item test measuring orientation (8 items) and anterograde memory (4 items). The Galveston Orientation and Amnesia Test (GOAT) was also used on a subset of the test sample. Procedure: Patients were examined daily until they emerged from PTA. Results: A statistically significant model, using three predictor variables, was derived that reliably predicted duration of PTA, accounting for 89% of the variance. A second model, using two predictor variables readily available to the clinician (day posttrauma on which PTA testing began and aggregate PTA scores over the first 5 days of testing) had comparable predictive accuracy. A third model, using GOAT data, was also statistically significant and successfully accounted for 72% of the variance. The MOPTAS model showed excellent application to an independent (validation) sample, with an intraclass correlation coefficient between observed and predicted durations of PTA of 0.95. Regression equations for all three models are provided to enable calculation of the predicted duration of PTA. Conclusions: These models can be readily applied in clinical practice and will provide clinically useful estimates of the duration of PTA within the first week of testing after admission to rehabilitation. This information will be important in terms of family counseling and planning of rehabilitation programs.
Aphasiology, 2009
Background: This paper examines the methodological quality of aphasia therapy research using the ... more Background: This paper examines the methodological quality of aphasia therapy research using the Psychological database for Brain Impairment Treatment Efficacy (www.psycbite.com). PsycBITETM includes five designs: Systematic Reviews (SR), Randomised Controlled Trials (RCT), non‐RCTs (NRCT), Case Series (CS), and Single Subject Designs (SSD). Aim: To provide an overview of the types of research designs and levels of compliance used in aphasia treatment research studies, and assess the methodological quality of aphasia research. Methods & Procedures: A search was completed on 27 September 2007 of all papers in the target area Communication/Language/Speech on the PsycBITETM database. Papers were listed according to the methodology used and a mean methodological quality rating (MQR) score was determined for RCTs, and NRCTs based on the PEDro scale. Finally, the rate of compliance of RCTs and NRCTs for each of the criteria on the PEDro scale was analysed. Outcomes & Results: Of 339 studies indexed for aphasia: SR = 9 (3%); RCT = 23 (7%); NRCT = 18 (5%); CS = 51 (15%); and SSD = 238 (70%). Methodological quality ratings (MQR) using the PEDro scale (scored out of 10) were available for 21 RCTs (mean MQR = 4.4, SD = 1.7, range = 2–8), and 14 NRCTs (mean MQR = 2.6, SD = 1.0, range = 1–4). Conclusions: Methodological quality of current aphasia treatment studies is modest. The current examination of a small sample of RCTs and non‐RCTs indicates that sources of bias are not sufficiently well controlled. These results have implications for aphasia therapy researchers in the design and report of their work. It is hoped that access to databases such as PsycBITETM and rating scales such as PEDro will facilitate this process.
Neuropsychological Rehabilitation, 2004
Aphasiology, 2006
Background: Clinicians face significant obstacles in their access to evidence for the efficacy of... more Background: Clinicians face significant obstacles in their access to evidence for the efficacy of different communicative and cognitive treatments after brain impairment. These include the need to search across diverse journals and different clinical conditions to find potential treatments and the lack of easily accessible standards by which to evaluate the methodological rigour of treatment studies once found. Aims: We aimed to address these issues by developing a freely available, user‐friendly database of all relevant treatment trials for psychologically based disorders that arise from brain impairment. Methods & Procedures: PsycBITETM (http://www.psycbite.com) was developed as an internet‐based database and was officially launched in 2004. Included on PsycBITETM are all trials that have been published that evaluate treatment for any communication, cognitive, or psychological disorder arising from any form of acquired brain impairment in children (above the age of 5 years) and adults. PsycBITETM also provides a rating for the methodological rigour of each trial using the previously established PEDro scale (Maher, Sherrington, Herbert, Moseley, & Elkins, 2003) for randomised controlled trials (RCT) and non‐RCT group comparisons. A PsycBITETM rating scale for single case experimental studies is still under development. This report overviews the database, its contents, and the methodology by which papers are selected for inclusion. Outcomes & Results: As of June 2005 there are 1167 treatment studies listed on PsycBITETM with prospective searches being conducted on a regular basis. The highest proportion of studies report treatments for communication disorders followed by behavioural problems and memory. Ratings of the randomised controlled trials, group comparisons, and single case studies are available for a proportion of papers and are being updated continuously. Conclusions: PsycBITETM is an invaluable resource for clinicians and researchers interested in an evidence‐based practice approach to treatment. It is a free, fast, and effective way of accessing and evaluating treatments for communicative and cognitive disorders following brain impairment.
Neuropsychological Rehabilitation, 2009
Archives of Physical Medicine and Rehabilitation, 2006
Neuropsychological Rehabilitation, 2008
Australian and New Zealand Journal of Psychiatry, 2007
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Papers by Michael Perdices