Visual hallucinations in Parkinson's disease are associated with thinning of the inner retina.

Visual hallucinations (VH) are common in patients with Parkinson's disease (PD), yet the underlying pathophysiological mechanisms are still unclear. We aimed to explore the association of the presence of VH with inner retinal thinning and, secondarily, with visual acuity. To this end, we included 40 PD patients in this exploratory study, of whom 14 had VH, and 22 age- and sex-matched healthy controls. All participants were interviewed for the presence of VH by a neurologist specialized in movement disorders and underwent a thorough ophthalmologic examination, including measurement of the best-corrected visual acuity (BCVA) and optical coherence tomography to obtain macular scans of the combined ganglion cell layer and inner plexiform layer (GCL-IPL). Patients with VH had a thinner GCL-IPL than patients without VH, which persisted after correction for age, disease stage, levodopa equivalent daily dose (LED) and cognitive function. Furthermore, BCVA was lower in the PD group with VH than in the PD group without VH, although only a trend remained after correction for age, disease stage, LED and cognitive function. Taken together, in patients with PD, visual hallucinations appear to be associated with a thinning of the inner retinal layers and, possibly, with reduced visual acuity. Further research using a longitudinal design is necessary to confirm these findings and to establish the causality of these relationships.

Verbal fluency assessment of patients with multiple sclerosis: test-retest and inter-observer reliability.

OBJECTIVE: To establish the reliability and validity of verbal fluency testing in patients with multiple sclerosis (MS). DESIGN: Each patient was assessed twice 7-14 days apart on a test of phonological fluency and again 7-14 days later when half of the patients were assessed for phonological fluency by a second assessor while the other half was assessed by the first assessor using a test of semantic fluency. SETTING: A specialist young disabled unit. SUBJECTS: Thirty-five patients with multiple sclerosis. MEASURES: Phonological fluency (PF) was tested giving the patient 60 seconds to generate words starting with 'F' 'A' and 'S'; semantic fluency (SF) with names of animals and fruits. Also used were the Short Orientation-Memory-Concentration Test and the Barthel ADL Index. RESULTS: On the first occasion 31/35 patients could be tested, and the average (SD) score of the PF was 21.9 (12.1), median 18. The test-retest reliability (n = 30/35) of the PF was good (Pearson r = 0.85). The score difference between the first two occasions ranged from +17 to -15 (median -3, mean -2.9, SD 6.7). The inter-observer reliability (n = 13/16) of the PF was good (Pearson r = 0.90). The difference of the score between the two assessors ranged from -9 to +6 (median 0, mean -1.2, SD 4.9). The correlation (Pearson) of the PF score with the SF, Barthel and SOMC was respectively r = 0.59, r = 0.27 and r = 0.63. CONCLUSIONS: Phonological fluency testing is reliable in people with MS.

The Adult Memory and Information Processing Battery (AMIPB) test of information-processing speed: a study of its reliability and feasibility in patients with multiple sclerosis.

OBJECTIVE: To investigate how useful the Adult Memory and Information Processing Battery Task A (AMIPB) is as a test of the speed of information processing in patients with multiple sclerosis (MS) by comparing various methods of presenting the test and assessing the reliability (test-retest and inter-rater) and utility of each version. DESIGN: Each patient was assessed twice verbally by the same assessor 1-2 weeks apart. Then 1-2 weeks later half were assessed by another observer, and half were assessed by the first observer using a written method. SETTING: A specialist young disabled unit. SUBJECTS: Thirty-three patients with MS. MEASURES: The AMIPB, the Short Memory-Orientation-Concentration Test (SOMC) and the Barthel ADL Index. RESULTS: The average (SD) number of correct responses after 4 min was 23.3 (18.6), median 21. The test-retest reliability (n = 24) of the 4-min AMIPB was high (r = 0.98) and the difference of the score ranged from -7 to 9: median 3, mean (SD) 1.88 (4.01) and interquartile range 0 to 3.25. The inter-observer reliability (n = 12) of the 4-min AMIPB was also high (r = 0.97) and the mean (SD) differences between scores were 4.3 (5.8), median 4, range +19 to -2. The score at 60 seconds and the score at 240 seconds were highly correlated (r = 0.98). The scores obtained verbally and by writing were closely correlated (r = 0.99). CONCLUSIONS: The AMIPB used over 120 seconds with verbal responses is a reliable and reasonable test for major information-processing deficits.