Cerebral PET with [18FJ-2-fluoro-2-deoxy-D-glucose has been performed in four patients with neurofibromatosis type 1 (NF1) to assess the relation between cerebral metabolic activity, MRI, and the presence of neurological symptoms, including seizures, as well as mental and language retardation. Widespread hypometabolism occurred in three of the patients. The lesions on MRI, which were localised in the subcortical white matter and grey structures, had normal rates of glucose metabolism. This finding suggests that the abnormalities seen on MRI are not due to defective blood supply, localised oedema, or grey matter heterotopic foci as previously hypothesised. The presence of the hypometabolic areas seems to be inconsistently related to the occurrence of seizures and is not proportional to the degree of mental impairment. This study provides evidence of a widespread cerebral hypometabolism that is not related to the presence of MRI abnormalities; conversely normal metabolism was present in the areas with an abnormal 1RI signal.

This study provides the first large sample of paediatric patients presenting to the ED for AHMDs, helping to elucidate the epidemiology, aetiology and clinical presentation of these disorders.

ObjectivesTo evaluate the causes and management of acute ataxia (AA) in the paediatric emergency setting and to identify clinical features predictive of an underlying clinically urgent neurological pathology (CUNP).Study designThis is a retrospective medical chart analysis of children (1–18 years) attending to 11 paediatric emergency departments (EDs) for AA in an 8-year period. A logistic regression model was applied to identify clinical risk factors for CUNP.Results509 patients (mean age 5.8 years) were included (0.021% of all ED attendances). The most common cause of AA was acute postinfectious cerebellar ataxia (APCA, 33.6%). Brain tumours were the second most common cause (11.2%), followed by migraine-related disorders (9%). Nine out of the 14 variables tested showed an OR >1. Among them, meningeal and focal neurological signs, hyporeflexia and ophthalmoplegia were significantly associated with a higher risk of CUNP (OR=3–7.7, p<0.05). Similarly, the odds of an underlying CUNP were increased by 51% by each day from onset of ataxia (OR=1.5, CI 1.1 to 1.2). Conversely, a history of varicella-zoster virus infection and vertigo resulted in a significantly lower risk of CUNP (OR=0.1 and OR=0.5, respectively; p<0.05).ConclusionsThe most frequent cause of AA is APCA, but CUNPs account for over a third of cases. Focal and meningeal signs, hyporeflexia and ophthalmoplegia, as well as longer duration of symptoms, are the most consistent ‘red flags’ of a severe underlying pathology. Other features with less robust association with CUNP, such as seizures or consciousness impairment, should be seriously taken into account during AA evaluation.

We re-examined 21 children with the possible diagnosis of peripheral neurofibromatosis (NF1) based on the presence of café-au-lait (CAL) spots as the single clinical finding. We evaluated whether "typical" or "atypical" appearance of the spots was important for the final diagnosis and whether the co-existence of other non-specific signs (e.g. pectus excavatum) were of any significance for the final diagnosis. In 8/14 (57.1%) cases with "typical" CAL spots, the diagnosis of NF1 was finally established on the basis of other criteria. For the other 6 patients the diagnosis is not yet definitive but highly probable on the basis of the presence of macrocephaly, pectus excavatum and/or MRI findings. Only one patient among five with "atypical" CAL spots possibly has NF1.

We report the results of the reevaluation of 24 patients with neurofibromatosis type 1 (NF1) using central nervous system (CNS) imaging techniques. The first examination by computed tomography (CT) or magnetic resonance imaging (MRI) indicated the presence of optic glioma in three cases, "unidentified bright objects" (UBOs) in six, and a suspected right frontal tumor in one. In two patients optic glioma and UBOs were both present and in one of them a bulbar tumor was also suspected. Later imaging examinations revealed the appearance of optic glioma in three more cases and UBOs in nine. In two of these patients both optic glioma and UBOs were present. This study indicates that the likelihood of detecting imaging abnormalities in patients with NF1 increases when systematic follow-up is performed. Optic gliomas are characteristic of pediatric patients; they rarely give rise to clinical manifestations (1/6 cases) and in general progress very slowly. For these reasons, therapeutic strategy must be carefully considered and individually decided. UBOs are very frequent findings in pediatric patients with NF 1 and therefore they must be considered diagnostically relevant. They are not related to clinical manifestations and spontaneous regression has been observed. The nature of these imaging abnormalities is still unknown, but because they do not behave like tumors, useless and dangerous therapeutic procedures should not be employed.