Definition of the neurological phenotype associated with dup(X)(p11.22-p11.23)

The aim of this study was to describe in detail the neurological features of nine patients carrying the recently reported microduplication at Xp11.22-11.23. Clinical and neurological examination, brain magnetic resonance imaging (except for two patients), electroencephalography and a neuropsychological assessment specific for language disturbances were performed in nine patients with microduplication at Xp11.22-11.23, disclosed by comparative genomic hybridisation array. Six patients were familial cases belonging to three unrelated pedigrees and three were sporadic cases. The patients had the following characteristics: mild dysmorphic facial features (except for two patients), mental retardation with moderate to severe global language deterioration, electroencephalographic epileptiform discharges during wakefulness and especially during sleep or electrical status epilepticus during slow sleep in younger cases, and negative brain magnetic resonance imaging. The main clinical features of this new microduplication syndrome were mild facial dysmorphisms, from increased electroencephalogram abnormalities during sleep to electrical status epilepticus during slow sleep, and mental retardation mainly involving language function in the absence of detectable brain lesions. In the absence of detectable brain lesions, speech delay may be associated with electrical status epilepticus during slow sleep or, alternatively, related to abnormal brain expression of a dosage-sensitive gene contained within the duplication region

Positron emission tomography (PET)--its potential to provide surrogate markers in ALS.

Positron emission tomography (PET) has enabled us to study the human brain with unrivalled sensitivity, and has already established its place in the research of neurological conditions such as Parkinson's disease and epilepsy. PET has been used as a tool in the study of patients with motor neuron disease (MND) for well over ten years now, but its potential in diagnosis and to identify surrogate markers of disease expression (phenotype) and progression has yet to be fully realized. The early studies using 2-18fluoro-2-deoxy-D-glucose to measure regional changes in cerebral metabolic rate for glucose gave the first clues to the more widespread involvement of the brain in MND. Later studies exploited the development of activation studies using 15O-containing tracers, which allowed correlation with neuropsychological measures, and the refinement of mapping techniques to delineate the extra-motor areas involved in the disease process. More recently, studies involving ligands such as 11C-flumazenil have allowed the exploration of functional reorganisation in MND, and inhibitory interneuronal pathways which may be crucial in modulation of disease expression. In the future new ligands will be applied in combination with other modalities of investigation (multimodal magnetic resonance imaging; neurophysiological studies) in order to understand the pathophysiology of this heterogeneous condition. Although the potential of PET has not yet been realized in ALS, it is likely to play a part in defining new diagnostic and surrogate markers of disease extent and severity