[The Imon Cognitive Impairment Screening Test (ICIS): A new brief screening test for mild cognitive impairment or dementia].

AIM: To develop an ultra-brief test (the Imon Cognitive Impairment Screening Test: ICIS) to screen for mild cognitive impairment (MCI) or dementia. METHODS: The ICIS consists of four subtests exploring the following: time orientation (year, month, day, day of week, each assigned one point, for a total of four points), finger construction of a fox and pigeon (fox successfully made with both hands: 1 point, only one hand: 0.5 point, pigeon made smoothly: 1 point, succeeded after trial and error: 0.5 point, failure: 0 point, total 2 points), letter fluency (subjects need to recall as many words as they can beginning with a given letter in a one-minute trial. 0-2 words: 0 point, 3-5 words: 1 point, 6-9 words: 2 points, 10 words or more: 3 points), and delayed free verbal recall (1 point each, total 3 points), so a perfect score is 12 points. The test takes less than three minutes to administer. The authors studied 76 patients with dementia (51 mild, 18 moderate and seven severe cases), 30 normal elderly controls (C) and 34 patients with mild cognitive impairment (MCI). RESULTS: The mean scores on the ICIS were 5.5 for the mild, 3.0 for the moderate and 0.7 for the severe dementia patients, 8.3 for those with MCI and 10.5 for the C group. Using a cut-off value of 9/9.5, the ICIS had a sensitivity of 94% for MCI or dementia, and a specificity of 93%. The positive likelihood ratio for MCI or dementia was 14.0, and the negative likelihood ratio was 0.07. The ICIS scores correlated with the Mini-Mental State Examination scores (r=0.82, p<0.0001). CONCLUSIONS: The ICIS has the potential to identify patients who warrant further cognitive evaluation for MCI or dementia.

Quantitative assessment of cerebral blood flow in genetically confirmed spinocerebellar ataxia type 6.

BACKGROUND: Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant cerebellar ataxia caused by CAG trinucleotide expansion. The characteristics of regional cerebral blood flow (rCBF) in SCA6 patients have not been established, whereas it has been reported that decreased rCBF in the cerebrum seems to be a remote effect of cerebellar impairment in other cerebellar disorders. OBJECTIVE: To clarify the characteristics of rCBF, including cerebro-cerebellar relationship, and its correlation with clinical manifestations in patients with genetically confirmed SCA6 using quantitative assessment of rCBF by brain single-photon emission computed tomography (SPECT). DESIGN: Technetium Tc 99m ethyl cysteinate dimer SPECT study using a Patlak plot. Patients Hiroshima University Hospital, Hiroshima, Japan. Ten patients with SCA6 and 9 healthy controls. Main Outcome Measure The rCBF of the cerebellar vermis, cerebellar hemisphere, and frontal lobes. RESULTS: In SCA6 patients, rCBF was decreased only in the cerebellar vermis and hemisphere compared with healthy controls, and this was inversely correlated with duration of illness. The rCBF in the frontal lobes was slightly correlated with duration of illness without statistical significance. The rCBF in the vermis was inversely correlated with severity of dysarthria, but there was no significant correlation with CAG repeated expansions. CONCLUSIONS: Decrease in rCBF was found only in the cerebellum and was associated with duration of illness, dysarthria and ataxia, and cerebellar atrophy. No remote effect of cerebellar hypoperfusion was found in the SCA6 patients.

Magnetization transfer measurements of cerebral white matter in patients with myotonic dystrophy.

To determine whether patients with myotonic dystrophy (MyD) have structural changes in the cerebral white matter, we performed magnetization transfer (MT) imaging of the cerebral white matter in 14 MyD patients and 11 age-matched normal controls. We calculated MT ratios in both the white matter lesions (WMLs) and the normal-appearing white matter (NAWM) of MyD patients using region of interest (ROI) analysis. MT ratios in WMLs were markedly decreased, and all ROIs in NAWM also showed significantly lower MT ratios in MyD patients than in normal controls. The average MT ratio of all ROIs in WMLs and NAWM in each patient showed a significant negative correlation with duration of illness, but not with the patient's age or age at onset. The results of the present study indicate not only the presence of pathological changes in WMLs but also the widespread involvement of NAWM in MyD patients. The results also suggest that structural changes in the white matter may be progressive during the clinical course of MyD.

Magnetization transfer measurements of brain structures in patients with multiple system atrophy.

To determine whether magnetization transfer imaging (MTI) demonstrates abnormalities in the brain structures of patients with multiple system atrophy (MSA), we examined 12 patients with clinically probable MSA and 11 control subjects. We calculated magnetization transfer ratios (MTRs) using region of interest analysis from MTI and assessed abnormal signal changes on T2-weighted images. MTRs of the base of the pons, middle cerebellar peduncle, putamen, and white matter of the precentral gyrus were significantly lower in the MSA patients than in the controls. Abnormal signal changes on T2-weighted images were observed in the base of the pons (n = 6), middle cerebellar peduncle (n = 7), and putamen (n = 7). MTRs of regions with abnormal signals were significantly lower than those of regions without abnormal signals and those in the controls. Even the MTRs of the regions without abnormal signals were lower than those in the controls. MTRs of the pyramidal tract, including white matter of the precentral gyrus, posterior limb of the internal capsule, cerebral peduncle, and base of the pons, were significantly lower in patients with pyramidal tract sign (n = 7) than in the controls. Patients with asymmetrical parkinsonism (n = 5) showed significantly lower MTRs in the putamen contralateral to the predominant side of parkinsonian symptoms than the ipsilateral side, although asymmetry of abnormal signal changes on T2-weighted images was not evident in more than half of those patients. This study showed that MTI demonstrates abnormalities in the brains of patients with MSA that seem to reflect underlying pathological changes and that the pathological changes detected by MTI seem to give rise to clinical symptoms. This study also showed that the abnormalities are detected more sensitively and over a larger area by MTI than by conventional magnetic resonance imaging.