Paolo Boldrini

Localised proton MR spectroscopy of brain metabolism changes in vegetative patients

Abstract We examined 14 vegetative brain-injured patients with proton magnetic resonance single-volume spectroscopy (1H MRS) at 1.5 T to establish whether there were changes in relative concentrations of N -acetyl aspartate (NAA), choline (Cho) and creatine (CR) metabolites from those found in healthy brains. Spectra were obtained from two different (2 × 2 × 2 cm) volumes of interest in the left and in the right frontal cortex, normal on MRI. All spectra revealed abnormalities compared with normal spectra obtained from age-matched control subjects. Values outside the normal range for at least one of the metabolite ratios were observed in all patients. Cho/Cr was markedly higher and NAA/Cho and NAA/Cr were markedly lower than in the control subjects. At different times six patients regained awareness and the ability to obey commands, and four were re-examined; changes in metabolite ratios were observed, which were different in individual patients. The NAA/Cho ratio reaches statistical significance in discriminating between the patients with a poor outcome (death or prolonged vegetative state) and those who regained awareness; the dividing line appears to be at a value of about 1.6.

The frequency of multiple sclerosis in Mediterranean Europe: an incidence and prevalence study in Barbagia, Sardinia, insular Italy

Recent investigations on multiple sclerosis (MS) distribution in Italy, based on relatively small population groups, contradict the current thesis, derived from studies undertaken in populations exceeding 300,000, of a lower spreading of the disease in Mediterranean Europe. Intensive surveys on small populations strengthen the suggestion that Italy is a high‐risk area, although MS studies based on prevalence rather than incidence could also be biased by geographic variables making prevalence unsuitable for comparing MS prevalence rates found in different years and/or zones. We report a further epidemiologic study in Barbagia, Sardinia, insular Italy, undertaken both to establish the MS incidence in the last 20 years, and to estimate a new prevalence rate. Based on 31 probable incident cases, the mean incidence per year for the years 1961‐1980 was 2.9 per 100,000 (3.2 if age‐ and sex‐standardized to the Italian population). On October 24, 1981, the prevalence per 100,000 was 65.3 (77.9 if standardized to the Italian population). These results confirm that in Barbagia, MS occurs more frequently than expected in a Mediterranean area, and give further support to the idea that MS frequency in Italy is similar to that established for most central and northern European countries.

Partial Hemispheric Disconnection Syndrome of Traumatic Origin

A patient presented left-sided apraxia, constructional disturbances with the right hand and left tactile anomia after a severe head injury. MRI showed a callosal lesion involving the middle and posterior third of the truncus. This finding supports the thesis that the posterior callosum plays a predominant role in the interhemispheric mediation for praxis, as well as in the right-left transfer of spatial information guiding constructional performance. Left-sided apraxia was evident on imitation, on verbal command and on visual presentation of an object, but not on tactual presentation and during the actual use of objects. Moreover, apraxia on imitation showed a more rapid recovery than apraxia on verbal command. These data are consistent with the hypothesis of a left-hemisphere dominance for praxis, which is almost absolute when the retrieval of the appropriate gesture requires a semantic analysis of the stimulus.