Evidence for lateral premotor and parietal overactivity in Parkinson's disease during sequential and bimanual movements. A PET study

On the basis of the data presented in our Table 4, which shows an inverse correlation between the latency to nadir of symptoms and the chance of complete recovery, we agree with Professor Hughes and colleagues that a longer latency to nadir was an adverse prognostic factor in our study. However, the duration of active disease (measured as the time from onset to remission or stabilization of symptoms) also seemed to adversely affect the prognosis of Guillain– Barré syndrome in our cases (see table 4 in Italian Guillain– Barré Study Group, 1996). This latter finding is in keeping with other reports (Ravn, 1967; Kaur et al., 1986; Raphael et al., 1986; Winer et al., 1988) and is mentioned in the Discussion of the Italian Guillain–Barré Study Group (1996) as the feature our data confirmed. Probably, the sentence ‘We confirmed these findings’ should be changed to ‘We partly confirmed these findings’. Although details of the neurological examination are given for most patients, arm disability was not specifically assessed as a prognostic variable. However, the report of an adverse effect of complete paralysis of the arms is in agreement with personal observations and with clinical experience. We agree with Professor Hughes’ criticism that there is incompatibility between the text (reporting a faster recovery among patients receiving immunoglobulins) and Fig. 3 (showing that people treated with plasma exchange had a faster recovery). This was due to an erroneous label in the figure (plasma exchange and immunoglobulins were the wrong way round). Finally, at the time of submission of this paper, the results of the trial of plasma exchange, intravenous immunoglobulins and combined treatments in Guillain–Barré syndrome (Plasma Exchange/Sandoglobulin Guillain–Barré Syndrome Trial Group, 1997) were not available. At that time, the need for comparative trials was justified as only plasma exchange was known to be superior to placebo (Guillain–Barré Syndrome Study Group, 1985; French Cooperative Group on Plasma Exchange in Guillain–Barré Syndrome, 1992), there was only one study comparing immunoglobulins and plasma exchange (van der Meché et al., 1991), and evidence of a long-term efficacy of this therapeutic strategy was insufficient (French