In Patients with Early Parkinson's Disease
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41040ournal ofNeurology, Neurosurgery, and Psychiatry 1997;62:410-413 SHORT REPORT J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.62.4.410 on 1 April 1997. Downloaded from Impairment in dating and retrieving remote events in patients with early Parkinson's disease Annalena Venneri, Paolo Nichelli, Giacomo Modonesi, Maria Angela Molinari, Riccardo Russo, Carla Sardini Abstract target event, and only when they failed to Remote memory has been studied in a recall it, did we offer a multiple choice recogni- group of 25 non-demented patients with tion procedure. A graded score was thus Parkinson's disease and their perfor- obtained depending on the number of cues mance has been compared with that of 22 needed to recall each event. Because we were healthy control subjects. Only patients interested in the effect of a putative prefrontal who scored > 27 on the mini mental state dysfunction in causing remote memory examination and with no anticholinergic impairment in patients with Parkinson's dis- treatment were included in the sample. A ease we only examined patients with early remote memory questionnaire was given, Parkinson's disease, without any detectable to evaluate memory for public events that sign of dementia. occurred from 1966 to 1990. Each event was probed with five questions concern- ing its content and one for the date. Methods Compared with healthy subjects, patients SUBJECTS with Parkinson's disease were signifi- The subject group comprised 25 patients with cantly impaired both in recalling the con- Parkinson's disease (mean age 60-4 (SD 7 3); tent and in dating remote events. These mean education 5-8 (SD 1-9) years), and 22 results support the claim that remote age matched healthy control subjects (mean memory in patients with Parkinson's dis- age 62-3 (SD 4.7); mean education 6-9 (SD ease is disrupted independently of 2 7) years). The mean duration of disease was dementia. This impairment might result 3 05 (SD 3T0) years. The mean mini mental from a dysfunction at the level of the cir- state score for the patients with Parkinson's cuit connecting the basal ganglia to the disease was 28-7 (SD 1.1), and 29-4 (SD 09) frontal lobes. for the control subjects. Subjects were recruited through the out- http://jnnp.bmj.com/ (7 Neurol Neurosurg Psychiatry 1997;62:410-413) patient clinic of the neurological department of the University of Modena (Italy). Only ambulatory patients with early idiopathic Department of Keywords: remote memory; Parkinson's disease; Parkinson's disease were included. One Psychology, University frontal lobe patient was in stage 1 of the Hoehn and Yahr ofAberdeen, UK were in A Venneri scale.3 The remaining 24 patients stage 2. The diagnosis of idiopathic Parkinson's dis- on September 25, 2021 by guest. Protected copyright. Sezione di Neurologia, Two previous studies have directly considered Dipartimento di the issue of remote memory in patients with ease was made by a neurologist based on the Patologia Parkinson's disease. In the first study, asymmetric onset of bradykinesia associated Neuropsicosensoriale, et all found that only demented with either rigidity or resting tremor. Only UniversitA di Modena, Freedman Italy patients with Parkinson's disease showed an patients with pronounced responsiveness to A Venneri impairment in recognising faces that were in levodopa were included in the study. P Nichelli the news in the years from 1920 to 1979. In a Exclusion criteria were history of neurological G Modonesi M A Molinari second study, Sagar et al2 found defective dat- illness other than Parkinson's disease, psychi- C Sardini ing of both public and personal events in non- atric illness, head trauma with loss of con- Department of demented patients with early Parkinson's dis- sciousness, medical illnesses, or medications Psychology, University ease, whereas content recall was only impaired adversely affecting cognition, and substance of Essex, UK disease. misuse. Patients either taking anticholinergic R Russo in demented patients with Parkinson's However, as information about content was medications or scoring < 27 on the mini mental Correspondence to: Professor Paolo Nichelli, obtained via a recognition task, the testing state examination4 were also excluded from Sezione di Neurologia, could have missed a retrieval the study. All patients were receiving anti- Dipartimento di Patologia procedure Neuropsicosensoriale, deficit. parkinsonian medication at the time of the Universita degli Studi di overcome we devised a study. These comprised carbidopa-levodopa, Modena, Via del Pozzo, 71, To this problem, 41100 MODENA, Italy. questionnaire in which information about benserazide-levodopa, amantadine HC1, L- Received 18 April 1996 public events was requested via a cued recall deprenyl, and bromocriptine. Normal controls and in revised form with progres- were spouses or relatives of patients participat- 15 October 1996 procedure. We provided subjects Accepted 10 December 1996 sively more detailed verbal cues about each ing in the study. Impairment in dating and retrieving remote events in patients with early Parkinson's disease 41 Patients with Parkinson's disease did not formance were separately scored for each J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.62.4.410 on 1 April 1997. Downloaded from differ from normal controls with respect to age question. (t45 = 0 99, NS) or years of formal education (t45 = 1 56, NS). Content information score Content information score depended on the MATERIALS AND PROCEDURE number of cues needed to produce the right Stroop test answer. Subjects recalling the target event This test measures cognitive flexibility. We without any cue obtained a score of five. Four, used a 30 item shortened version5 of the origi- three, and two points were assigned to subjects nal test. It comprises three parts: naming the requiring respectively one, two, or three cues. colour of dots, reading black and white colour When subjects could only recognise the correct names, and naming the colour in which colour answer among the alternatives, they scored one names are printed. Performance was evaluated point. Scores on questions concerning five in terms of errors and execution time. consecutive years were summed together. Five scores were hence obtained, one for each of the Wisconsin card sorting test periods: 1966-70; 1971-5; 1976-80; 1981-5; The purpose of this test is to assess the ability 1986-90. to form abstract concepts, and to maintain and shift the set. We used the modified proce- Dating dure of Nelson et al6 which requires subjects Dating performance was evaluated taking into to sort 48 cards one by one according to a cat- account three different variables: egory that must be deduced from the exam- Dating error-The absolute values of the dif- iner's feedback. After six consecutive correct ference between the estimated and the real responses, the subject is informed that the date of the event were clustered and averaged sorting category has changed. Performance across five consecutive years resulting in five was evaluated in terms of percentage of perse- five year period values for each subject. verative errors and number of sorting cate- Dating bias-The slope of the linear regres- gories that had been identified. sion of estimated versus real dates of the events was computed to measure the so called Public event questionnaire "forward telescoping effect"-that is, the The test explored the subjects' knowledge effect by which subjects tend to report a date about 25 events which occurred between 1966 more recent than the real one. and 1990. This period was chosen to match Dating precision-From the linear regression adulthood of the patients and normal subjects. of estimated versus real dates we computed a We selected one event for each year. Only score defined by the following formula: events that were likely to be familiar to most of 1-(residual variance/total variance) the Italian population were chosen. For each This score was used to indicate the close- event we prepared a question asking for infor- ness with which dates provided agreed with mation related to the event. If the subject one another (they were consistent with any could not respond correctly, information specific bias). about the target event was provided with a progressive cueing method. For example, a STATISTICS http://jnnp.bmj.com/ question was the following: "A bomb The distribution of data points did not always destroyed the waiting room of a train station in conform to a normal distribution and vari- an Italian town. What is the name of the ances were not homogeneous between data town?" If the subjects could not remember the sets. Therefore, unless stated otherwise, P val- correct answer (Bologna), we added the fol- ues reported were obtained by means of the lowing cue: "Several 10s of people died and non-parametric Mann-Whitney two tailed U many were wounded as a consequence of the test. Results are presented as means (SEM) explosion". If there was no correct response, on September 25, 2021 by guest. Protected copyright. two further cues were added, one at a time: "The event occurred at 10 25 am" (a photo- Results graph of the event depicting the station clock Patients with Parkinson's disease showed no at the precise time of the explosion had been interference effects on the Stroop test. Their printed by the main Italian newspapers and performance did not differ either in terms of shown on television) and "A neofascist group errors (patients 3-2 (0 53); normal controls was charged with having placed the bomb". If 1-5 (0 4), NS) or in terms of execution time none of these cues triggered the production of (patients 25-9 (3 42); normal controls 21-2 the correct answer, subjects were offered four (2-57), NS).