We report on 4 boys from 3 families presenting initially in infancy with an acute onset of flaccid tetraparesis and areflexia, resembling Guillain-Barré syndrome (GBS). However, the cerebrospinal fluid (CSF) protein was normal, while serum and CSF lactate were elevated. All patients had recurrent similar episodes, usually associated with infections. Brain MRI showed T (2) hyperintensities in the basal ganglia in two boys, in one of them at the first clinical presentation; the other one had a normal brain MRI during the first episode. A third boy had a normal MRI twice but an increased lactate peak in the basal ganglia in (1)H-MR spectroscopy. Motor nerve conduction velocities (NCV) were normal in all patients. Biochemical analyses of muscle tissue, performed in two patients, revealed a deficiency of the pyruvate dehydrogenase (PDH). Molecular genetic analysis of the X-chromosomal E1alpha subunit of PDH showed three new mutations in phylogenetically conserved areas of the protein: Glu358Lys in patient 1; Arg88Lys in patient 2 and 3 (brothers); and Leu216Ser in patient 4. In conclusion, children with "atypical GBS" should be evaluated for a mitochondrial disorder, including pyruvate dehydrogenase deficiency, even after a first episode.

Routinely performed EEG/VEP investigations are not very helpful measures to predict the presence or degree of behavioural deficiencies, neurological disturbances, or morphological CNS abnormalities. Patients who received cranial irradiation or systemic methotrexate applications showed the same incidence of neurophysiological disturbances without evidence for specific neurotoxic correlates.

SLWAnT is a highly reliable method to measure single-leg power. The above equation provides good estimates of optimal braking force. The SLWAnT can, therefore, be used to monitor changes in single-leg power and to assess leg-dominance.

No abstract

No abstract