Acquired colour deficiency in patients with Parkinson's disease

The blue cone pathway is reported to be affected early in Parkinson's disease (PD) and acquired type three (tritan) defects may occur. Sixty-one patients attending a treatment and rehabilitation centre for PD were examined with clinical colour vision tests. Seven of 13 patients, for whom the diagnosis of PD was equivocal or who had other medical conditions, were identified as having tritan colour deficiency. Results for the remaining 44 PD patients were compared with 40 age matched controls. Ten PD patients (22.7%) had tritan defects. Tritan defects were not found in the control group but performance on some tests was age related. We conclude that clinical tests for tritan colour deficiency are unlikely to be helpful in identifying PD.     

Event-related potentials associated with covert orientation of visual attention in Parkinson's disease

Event-related potentials (ERPs) were measured in a group of patients with idiopathic Parkinson's disease and compared with a matched control group during a task involving covert orientation of visual attention. Central warning cues directed attention to the probable location of a lateralized signal that required a button-press response. Parkinson patients had enhanced post-cue P1 (at Oz) and P2 (at Cz) amplitudes, delayed N1 (at Oz) latencies, and diminished CNV amplitudes. Post-target amplitudes were similar to controls, except for an enhanced P1 to invalidly cued targets, and delayed N1 and P3 target latencies. These results indicate that Parkinson patients, in addition to their motor deficits, process spatial cues more effortfully and slowly, have impaired response preparation, and process imperative stimuli more slowly.     

Memory and learning strategies in patients with Parkinson's disease

Parkinson's disease patients (PD) do not differ from control subjects (CS) when they have to execute a problem solving task in which external cues for solving the problem are given. However, when PD have to solve a problem by means of an internally generated strategy, they show a serious decrease in performance. We hypothesised that this distinction may also apply to the way PD and CS organize recall. In order to test our hypothesis the California Verbal Learning Test (CVLT) was administered to 59 PD and 30 CS. The test consists of five learning trials using a 16-word target list, composed of four items from each of four semantic categories. The fact that the word list was built on this implicit organization was not divulged in advance. The sequence in which the words were read is fixed; each subsequent word belongs to a category being different from the category to which the preceding word belongs. The organization in recall according to the semantic categories is considered to be the result of an unprompted, internally generated strategy. Recall according to the sequence in which the words are read by the experimenter, is viewed as an externally offered strategy. The results prove to be in line with our hypothesis: unlike CS who appeared to rely mainly and increasingly on an internally generated semantic organization, PD showed evidence of gradually adhering more to the externally imposed serial sequence.     

Perceptual bias for affective and nonaffective information in asymmetric Parkinson's disease.

Objective: To relate lateralized impairments of visual perception in Parkinson's disease to asymmetries in the severity of motor symptoms. Method: Ten patients with worse left-sided motor symptoms (LPD), 15 with worse right-sided (RPD), and 13 healthy age-matched controls (all right-handed) viewed mirror-imaged pairs of emotional chimeric faces, (left side smiling, right neutral, and vice versa), of greyscales (strips whose luminance varied smoothly from black on the left to white on the right, and vice versa) and of gender chimeric faces (left side male, right female, and vice versa). Participants signaled which stimulus appeared happier, brighter, or more feminine, respectively, so showing which side received more attention. Results: For emotional chimeras, controls and LPD showed little bias, whereas RPD showed a strong bias to left hemispace (p = .018, r = .45). Across all patients, this bias was associated with severity of right-sided motor impairment (p = .018, r = .49). The bias was much weaker and insignificant for greyscales (p = .72, r = .14). For gender chimeras, RPD again showed a significantly greater left hemispace bias than did LPD (p = .037, r = .47), although neither patient group differed significantly from controls. Across all patients, this bias correlated with ratio of right-to-left symptom severity (p = .044, r = .48). Conclusions: The left hemispace bias in RPD is greater for facial than for luminance judgments, and is amplified for emotional judgments. Asymmetrical degeneration of the striatum, particularly involving the left side, appears to underlie this deficit in visual processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of sensory manipulation on postural control in Parkinson's disease

Postural control was assessed on a tilting platform system in 20 patients with idiopathic Parkinson's disease and 20 age-matched controls. The amount of information provided by vision and lower limb proprioception was varied during the experiment to investigate the influence of changes in sensory cues on postural control. The patient group with clinical evidence of impaired postural control (Hoehn and Yahr III) had significantly higher sway scores over all sensory conditions than either the Hoehn and Yahr II group or controls. The pattern of sway scores indicated that no obvious deficit in the quality, or processing, of sensory information was responsible for the postural instability observed in this group. The patients in both Hoehn and Yahr groups were also able to respond appropriately to potentially destabilising sensory conflict situations and significantly improved their sway scores when provided with visual feedback of body sway. The results indicate that in Parkinson's disease, the main site of dysfunction in postural control is likely to be at a central motor level.     

The role of visual and body movement information in infant search.

Three experiments investigated the use of visual input and body movement input arising from movement through the world on spatial orientation. Infants between 9.5 and 18 months participated in a search task in which they searched for a toy hidden in 1 of 2 containers. Prior to beginning search, either the infants or the containers were rotated 180*; these rotations occurred in a lit or dark environment. These experiments were distinguished by the environmental cues for object location; Experiment 1 used a position cue, Experiment 2 a color cue, and Experiment 3 both position and color cues. Accuracy was better in Experiments 2 and 3 than in Experiment 1. All studies found that search was best after infant movement in the light; all other conditions led to equivalently worse performance. These results are discussed relative to a theoretical characterization of spatial coding focusing on the uses of spatial information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increased serum IgD concentrations in patients with Hodgkin's disease

Serum IgD concentrations have been determined in twenty-one patients with Hodgkin's disease, in eight patients with non-Hodgkin's lymphomas and in twenty-eight normal (control) individuals by both a solidphase radio-immuno-assay and radial-immunodiffusion. Fourteen of the Hodgkin's patients displayed three to forty-five-fold increased serum IgD levels as compared to control individuals, while in the remaining seven patients IgD concentrations were practically normal. Patients with non-Hodgkin's lymphomas had decreased IgD concentrations.     

Irrelevant peripheral visual stimuli impair manual reaction times in Parkinson's disease

In three experiments, the effects of irrelevant visual information on the time to initiate and to complete a simple movement of the hand in response to a visual signal were studied in patients with a diagnosis of Parkinson's disease, and in age-matched normal controls. Subjects gazed at the centre of a TV monitor and were instructed to move their preferred hand from one metal plate to another as soon as a blue disc appeared in the centre of the screen. This control condition was compared with other conditions in which the surrounding area of the screen was simultaneously filled with fields of irrelevant discs, which in Experiment 1 were either stationary, or streamed out from or in towards the centre of the screen. Reaction times, but not movement times, were significantly slowed in the patients (but not the controls) by the irrelevant disc fields. When the irrelevant dots were continuously present (between as well as within trials--Experiment 2), they had no effect on RT. When they were present between trials, but turned off as the movement signal was turned on, RT was again slowed in patients. The results are discussed in relation to the akinesia ("freezing") experienced by some patients in confined spaces (such as doorways), and to possible abnormalities of visual cortical and striato-nigro-collicular activity.     

Movement-related potential measures of different modes of movement selection in Parkinson's disease

Movement-related potentials were recorded preceding self-paced voluntary movements in patients with Parkinson's disease and in healthy subjects of the same age group. We compared the Readiness Potential preceding joystick movements in a fixed direction and preceding joystick movements in freely selected directions. In normal subjects the Readiness Potential amplitude was higher preceding freely selected movements than preceding movements in a fixed direction. The Readiness Potential in Parkinson patients failed to be modified by the different modes of movement selection. The modulation of the Readiness Potential by different ways of preparing for movement might be due to the supplementary motor area (SMA) being more strongly engaged by tasks requiring internal control of movements than by tasks that are externally structured. The results suggest that this task-dependent variation of SMA activity is reduced in Parkinson's disease. A failing capacity to adapt SMA activity to different task demands has previously been suggested by evidence from positron emission tomography studies using similar tasks.     

Quantitative modeling of visual attention processes in patients with Parkinson's disease: Effects of stimulus integrality on selective attention and dimensional integration.

Parkinson's disease (PD) patients and normal controls (NCs) were administered a series of visual attention tasks. The dimensional integration task required integration of information from 2 stimulus dimensions. The selective attention task required selective attention to 1 stimulus dimension while ignoring the other stimulus dimension. Both integral- and separable-dimension stimuli were examined. A series of quantitative models of attentional processing was applied to each participant's data. The results suggest that (a) PD patients were not impaired in integrating information from 2 stimulus dimensions, (b) PD patients were impaired in selective attention, (c) selective attention deficits in PD patients were not due to perceptual interference, and (d) PD patients were affected by manipulations of stimulus integrality and separability in much the same way as were NCs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is visual experience necessary for the maturation of vestibular control of eye movement

The vestibular system contributes to the stabilisation of visual images on the retina by means of vestibulo-ocular compensatory reactions. The development of vestibular control of eye movements has been studied in twelve week old kittens, reared in total darkness, which have been compared with a control group of kittens reared in normal conditions. Post-rotatory nystagmus, nystagmus during sinusoidal oscillations, visual suppression of vestibular nystagmus by fixation, have been used as indicators of the functional state of the vestibulo-ocular control system. The results show that most of the essential features of this control are present in dark-reared kittens. However differences have been noted which possibly concern precise regulation of compensatory movements and head-eye coordination. The frequency of vestibular nystagmus is much smaller in dark-reared animals and the initial deviation of post rotatory nystagmus in the direction of the change of movement is absent in dark-reared kittens. Habituation also seems to operate differently in the two groups of kittens. Visual suppression of vestibular nystagmus is present.     

Cerebrospinal fluid levels of transition metals in patients with Parkinson's disease

We compared CSF and serum levels of iron, copper, manganese, and zinc, measured by atomic absorption spectrophotometry, in 37 patients with Parkinson's disease (PD) and 37 matched controls. The CSF levels of zinc were significantly decreased in PD patients as compared with controls (p < 0.05). The serum levels of zinc, and the CSF and serum levels of iron, copper, and manganese, did not differ significantly between PD-patient and control groups. There was no influence of antiparkinsonian therapy on CSF levels of none of these transition metals. These values were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale of the Hoehn and Yahr staging in the PD group, with the exception of CSF copper levels with the duration of the disease (r = 0.38, p < 0.05). These results suggest that low CSF zinc concentrations might be related with the risk for PD, although they could be related with oxidative stress processes.     

Mortality and hallucinations in nursing home patients with advanced Parkinson's disease

We monitored 11 patients with advanced Parkinson's disease (PD) who entered nursing homes over a 5-year period and assessed chronicity of nursing home care, mortality, and hallucinatory status. Two years after the original study's close, none of these patients had ever been discharged from the nursing homes and all were dead. The mortality rate among the nursing home patients was significantly greater than that in 22 community-dwelling subjects with PD who were matched for age, gender, and disease duration. Hallucinatory status was generally stable; 82% of patients had the same hallucinatory status (presence or absence) at the two assessments. Four subjects from the original community-dwelling control group entered nursing homes during the follow-up period. Whereas motor and intellectual impairment scores were similar between these patients and the remaining 18 in the community, the presence of hallucinations was significantly greater among patients transferred to nursing homes. The study demonstrates the permanency of nursing home placement in advanced PD and the high mortality associated with such placement. It also documents the chronicity of hallucinatory behavior in these patients with advanced PD and reinforces our previously reported observations on the relationship between hallucinations and placement in chronic-care facilities.     

Cerebrospinal fluid selenium and chromium levels in patients with Parkinson's disease

We compared CSF and serum levels of selenium and chromium, measured by atomic absorption spectrophotometry, in 28 patients with Parkinson's disease (PD) and 43 matched controls. The CSF and serum levels of these trace metals did not differ significantly between PD patients and controls. CSF selenium and chromium levels were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale of the Hoehn and Yahr staging in the PD group. Although antiparkinsonian therapy did not influence significantly the CSF levels of selenium, PD patients not treated with levodopa had significantly higher CSF selenium levels than controls (p < 0.01). It is possible that increased CSF selenium levels could indicate an attempt of protection against oxidative stress. The normality of CSF and serum chromium levels suggest that these values are not related with the risk for PD.     

Increased gastric and intestinal permeability in patients with Crohn's disease

OBJECTIVES: Patients with Crohn's disease exhibit marked changes in intestinal permeability that can be assessed by lactulose and mannitol. Sucrose is a novel marker for gastric permeability. We combined these three sugars to investigate whether patients with Crohn's disease demonstrate changes in gastric permeability and if so, whether these changes are matched with altered intestinal permeability. METHODS: Fifty patients with Crohn's disease and 30 healthy subjects each drank a solution containing 20 g of sucrose, 10 g of lactulose, and 5 g of mannitol. Patients' and subjects' 5-h sugar urinary excretion levels were determined by high performance liquid chromatography and an enzymatic method (sucrose). Furthermore, patients with Crohn's disease underwent endoscopy of the upper GI tract and were grouped according to endoscopic and histological findings. RESULTS: Patients with Crohn's disease showed higher gastric and intestinal permeability compared with healthy control subjects. Gastric permeability was correlated with intestinal permeability. Patients with granuloma had more pronounced changes in both gastric and intestinal permeability than patients with various endoscopic and histological lesions. Patients with normal mucosa had normal permeability. CONCLUSIONS: Alterations in gastric mucosa caused by Crohn's disease are reflected by changes in gastric permeability and can be used to noninvasively screen for Crohn's disease involvement of the upper GI tract.     

The effect of cisapride on delayed colonic transit time in patients with idiopathic Parkinson's disease

Disorders of autonomic regulation are common in patients with Parkinson's disease (PD). Patients most frequently complain of dysphagia and therapy resistant constipation, as far as the gastrointestinal tract is concerned. These symptoms have to be attributed to a neuronal degeneration. In a pilot study we therefore investigated the effect of stimulation of the myenteric plexus by cisapride. 11 women and 13 men were examined, the average age was 67.3 years, the Webster rating 17 points. In 2 out of 24 patients, colonic transit was prolonged up to the limit, both with and without therapy. The other 22 patients showed an acceleration in transit on response to cisapride. On average the colonic transit of 130 hours was reduced to 79 hours. This objective improvement was associated with a subjective improvement. Central side effects or a worsening of Parkinsonian symptoms were not found. We conclude that cisapride is effective in the treatment of constipation in idiopathic PD.     

Increased expression of costimulatory molecules on peripheral blood monocytes in patients with Crohn's disease

BACKGROUND: Activation of T lymphocytes and monocytes/macrophages has been implicated in the pathogenesis of Crohn's disease (CD). Costimulatory molecules play important roles in optimal T-cell activation. METHODS: With flow cytometric analysis we have investigated the expression of the costimulatory molecules B7-1 (CD80), B7-2 (CD86), and CD18 and the intercellular adhesion molecule-1 (ICAM-1) on peripheral blood monocytes and the expression of the activation markers HLA-DR and IL-2R (CD25) on peripheral blood T lymphocytes from 31 CD patients, 17 ulcerative colitis (UC) patients, and 10 healthy controls. RESULTS: In CD patients the percentage of activated T cells (CD3+ HLA-DR+ and CD3+ IL-2R+) was significantly increased compared with those of controls and UC patients (P < 0.05). Most monocytes from all three groups expressed B7-2, CD18, and ICAM-1 molecules (all > 79%), but only a few positive cells expressed B7-1 molecules (< 5%). No significant differences were detected in the percentage positivity of all costimulatory molecules tested among CD, UC, and controls. The mean fluorescence intensity (MFI) of B7-1 in all three groups was very weak and not significantly different. However, in CD patients there was a significantly increased MFI of B7-2, CD18, and ICAM-1 molecules compared with UC and controls (P < 0.05). On the other hand, both the percentage positivity and MFI of HLA-DR molecules on monocytes of UC patients were significantly lower than those of CD patients and controls (P < 0.05). CONCLUSIONS: Expression of the costimulatory molecules B7-2, CD18, and ICAM-1 on peripheral blood monocytes of CD patients is increased. In CD patients activation of peripheral T lymphocytes may correlate with increased expression of these costimulatory molecules on peripheral blood monocytes.     

The effect of task complexity on reaction times in memory scanning and visual discrimination in Parkinson's disease

Within the context of the bradyphrenia debate, two experiments designed to measure the cognitive speed of Parkinson patients (PD) were conducted with 58 subjects. The experiments took the form of a high-speed memory scanning task using memory sets consisting of one-six words or one-six abstract figures. In a visual discrimination task, two simultaneously presented abstract images had to be compared, the complexity of the images being varied through four stages. Motor response was constant, reaction time was the dependent variable. PD differed from matched controls in the level (significant only in scanning) but in neither experiment in the slope of reaction time curves. Interaction group x complexity (MANOVA) was not significant. Correlations between disease parameters and a 'complexity effect' measure were low throughout. However, the link to general intelligence was significant. The findings contradict the conventional bradyphrenia hypothesis.     

Bilateral posteroventral pallidotomy in advanced Parkinson's disease in three patients

In this report, we describe the effect of staged bilateral posteroventral pallidotomy in three patients with advanced Parkinson's disease who were all of the young-onset type. Two patients had developed response fluctuations after the use of levodopa, with severe hypokinesia, painful dystonia, and rigidity in the "off" phase and violent dyskinesias in the "on" phase. One patient, in a continuous hypokinetic rigid state, was totally unresponsive to dopaminergic medication. All were at Hoehn and Yahr stage 5 in the "off" phase before surgery. After surgery, the hypokinetic state was reversed and dyskinesias were abolished in all patients. Hoehn and Yahr stages were 3 in the "off" phase postoperatively. Overall functional improvement was marked and lasting after follow-up for 7, 12, and 13 months, respectively. Complications were visual field deficit and transient central facial paresis, both in the same patient. Bilateral posteroventral pallidotomy can ameliorate response fluctuations, hypokinesia, rigidity, and painful dystonia in advanced Parkinson's disease.