Ascertainment bias in dementias: a secondary to tertiary centre analysis in Central Italy and conceptual review.

BACKGROUND AND AIMS: Ascertainment bias (AB) indicates a bias of an evaluation centre in estimating the prevalence/incidence of a disease due to the specific expertise of the centre. The aim of our study was to evaluate classification of different types of dementia in new cases appearing in secondary and tertiary centres, in order to evidence possible occurrence of AB in the various (secondary to tertiary) dementia centres. METHODS: To assess the mechanism of AB, the rates of new cases of the different forms of dementia reported by different centres were compared. The centres involved in the study were 11 hospital-based centres including a tertiary centre, located in the University Department of Clinical Neurology. The tertiary centre is endowed with state-of-the-art diagnostic facilities and its scientific production is prominently focused on dementia with Lewy bodies (DLB) thus suggesting the possible occurrence of a bias. Four main categories of dementia were identified: Alzheimer's disease (AD), DLB, fronto-temporal dementia (FTD), vascular dementia (VaD), with other forms in a category apart. The classification rate of new cases of dementia in the tertiary centre was compared with rates reported by secondary centres and rates of recoding were calculated during a follow-up of 2 years. RESULTS: The study classified 2,042 newly diagnosed cases of dementia in a population of 1,370,000 inhabitants of which 315,000 were older than 65. AD was categorized in 48-52 % of cases, DLB in 25-28 %, FTD in 2-4 % and VaD in 17-28 %. During the 2-year follow-up the diagnosis was re-classified in 40 patients (3 %). The rate of recoding was 5 % in the tertiary centre, 2-8 % in referrals from secondary to tertiary centre, 2-10 % in recodings performed in secondary centres and addressed to tertiary centre. Recoding or percentages of new cases of AD or DLB were not different in the comparison between secondary or between secondary and tertiary centres. FTD and VaD were instead significantly recoded. CONCLUSION: The results of the study suggest that in a homogeneous area, AB is not interfering with diagnosis of AD or DLB.

Prevalence and incidence of Multiple Sclerosis in Campobasso (Molise region chieftown, southern Italy).

OBJECTIVE: Multiple Sclerosis in southern Italy was not epidemiologically studied until 2006 in Salerno (Campania region), with data based on the registry of district MS centers established since 1996 by Italian Ministry of Health. This paper reports data about Molise region by the same metodology as Campanian study. PATIENTS AND METHODS: The registry of MS center was searched for the city of Campobasso, chief town of Molise region. Population screened: 51,633 units. ISTAT 2005 data were used for comparison and age standardization. Prevalence day: September 30, 2009; incidence was calculated by cumulative rates 1996-2000 and 2001-2005. RESULTS: 47 patients were collected, 17 males, 30 females, age 44.10 (9-74, SD 14.38); female/male ratio=1.76/1; age onset 34.61 (4-61, SD 12.40); mean disease duration 9.48 years (0-24; SD 4.28). Males prevalence: 68.62/100,000; females: 111.68/100,000. Total prevalence: 91.02/100,000; standardized: 90.91/100,000. Incidence rates: 1996-2000: 10.84/100,000; 2001-2005: 4.26/100,000. CONCLUSIONS: Prevalence is coherent with previous Campanian data, and with last epidemiologic papers on middle Italy, confirming also the validity of MS district centers registries. A possible underestimation of data, for some patients could still migrate to northern centers, could contribute to the differences in incidence. Nevertheless, prevalence data confirm southern Italy as high risk area for MS, and stands against a latitude gradient in this country.

An innovative hand brace for carpal tunnel syndrome: a randomized controlled trial.

We developed a hand brace and studied its efficacy and tolerability in patients with carpal tunnel syndrome (CTS). We randomized 83 subjects into a treated group, which wore the hand brace at night for 4 weeks, and a control group, which received no treatment. The primary efficacy measure was change in the Boston Carpal Tunnel Questionnaire (BCTQ) score. Secondary measures were Subjects' Global Impression of Change Questionnaire (SGICQ), median distal motor latency, sensory conduction velocity and amplitude, and neurophysiological class of severity. The treated group showed a reduction in BCTQ symptomatic score (from 2.75 to 1.54 at 4 weeks; P < 0.001) and functional score (from 1.89 to 1.48; P < 0.001). There were no significant changes in the control subjects. SGICQ documented improvement in all treated subjects (P = 0.006). No significant difference was found in electrophysiological measurements, but overall neurophysiological classification shifted to less severe classes in the treated group (P < 0.05). Thus, the study demonstrates that this hand brace is highly efficient in relieving symptoms and functional loss in CTS.

Exclusive electrophysiological motor involvement in carpal tunnel syndrome.

OBJECTIVE: To define the frequency of exclusive electrophysiological motor involvement in carpal tunnel syndrome (CTS). METHODS: We reviewed the electrophysiological studies of 2727 consecutive hands with typical symptoms and signs of CTS and at least one abnormal test of the following: median distal motor latency (DML), digit two sensory conduction velocity (D2-SCV), segmental D2-SCV from wrist to palm, median-ulnar sensory latency difference from ring finger stimulation. RESULTS: Thirty-one hands (1.2%) had prolonged median DML ( > 4.4 ms) with normal SCV ( > 48 m/s). In 17 of 31 hands, segmental D2-SCV from wrist to palm or median-ulnar latency difference from ring finger stimulation were also performed with normal results in 8 hands, demonstrating a true exclusive electrophysiological motor involvement. CONCLUSIONS: In CTS, exclusive electrophysiological involvement of median motor fibers is rare. It may be related to preferential compression of the intraneural motor fascicles clumped superficially in the most volar-radial nerve quadrant or, more probably, to the fact that the recurrent thenar branch may exit the carpal tunnel through a separate ligamentous tunnel within the transverse carpal ligament where it may be preferentially or selectively compressed.