Nardo Nardocci

Pediatric movement disorder (PMD) is a fascinating field of pediatric neurology, continuously evolving in clinical, molecular genetic, and pathophysiological aspects. Despite this increasing knowledge, the diagnosis of a movement disorder in a child is still based on the personal experience of the physician, but many efforts should be made to establish a rationale and shared diagnostic approach. The correct description of the phenomenology of the movement disorder is the first and essential diagnostic step; this may be even more difficult in the pediatric age due to the variability and possible age-dependent expression of a definite movement disorder. The list of disorders that cause a movement disorder in the pediatric population is very wide, from benign transient conditions to several genetic and metabolic diseases; and still in a high proportion of patients a definite diagnosis is not reached. The planning of a rationale treatment strategy mainly relies on the appropriate diagnosis, and since there are many treatable movement disorders, a correct diagnosis is mandatory. This special issue is aimed at providing an updated overview of PMD. It presents the fundamental aspects of the classification and etiology and differential diagnosis of the main neurological syndromes, and focuses on the most recent aspect in genetic and pathophysiology. Internationally acknowledged experts in the field have accepted to participate, and we wish that this volume will serve as a useful guide for all clinicians and persons who deal with children affected by movement disorders and with their families.

Background: To review the descriptive epidemiological data on neuronal ceroid lipofuscinoses (NCLs) in Italy, identify the spectrum of mutations in the causative genes, and analyze possible genotype-phenotype relations. Methods: A cohort of NCL patients was recruited through CLNet, a nationwide network of child neurology units. Diagnosis was based on clinical and pathological criteria following ultrastructural investigation of peripheral tissues. Molecular confirmation was obtained during the diagnostic procedure or, when possible, retrospectively. Results: One hundred eighty-three NCL patients from 156 families were recruited between 1966 and 2010; 124 of these patients (from 88 families) were tested for known NCL genes, with 9.7% of the patients in this sample having not a genetic diagnosis. Late infantile onset NCL (LINCL) accounted for 75.8% of molecularly confirmed cases, the most frequent form being secondary to mutations in CLN2 (23.5%). Juvenile onset NCL patients accounted for 17.7% of this cohort, a smaller proportion than found in other European countries. Gene mutations predicted severe protein alterations in 65.5% of the CLN2 and 78.6% of the CLN7 cases. An incidence rate of 0.98/100,000 live births was found in 69 NCL patients born between 1992 and 2004, predicting 5 new cases a year. Prevalence was 1.2/1,000,000. Conclusions: Descriptive epidemiology data indicate a lower incidence of NCLs in Italy as compared to other European countries. A relatively high number of private mutations affecting all NCL genes might explain the genetic heterogeneity. Specific gene mutations were associated with severe clinical courses in selected NCL forms only.

Psychogenic movement disorders are heterogeneous and diagnostically challenging. Despite the growing literature on adult forms, clinical features in children have received relatively little attention. We retrospectively reviewed medical records and video of patients <18 years diagnosed with a psychogenic movement disorder at our institute between 2007 and 2010. We identified 14 patients (6 males and 8 females) with a mean onset age of 11.5 years. Levels of diagnostic confidence were documented (2 patients), clinically established (8 patients), and probable (4 patients). A single movement disorder was present in 10 patients (71%); 4 patients (29%) presented an association of two or more movement disorders. Eleven patients presented other medically unexplained symptoms associated with their movement disorders. Five patients, among 6 with chronic occurrence, performed a polymyographic study showing significant modifications of frequency, amplitude, and distribution of electromyographic activity, related to distracting maneuvers. The present series represents 5% of all movement disorders observed in the considered period and 32% of nonorganic neurological manifestations. The most frequent movement disorders were tremor (36%) and dystonia (29%). We describe two phenotypes not previously reported among psychogenic movement disorders: myoclonus and association of myoclonus with dystonia. We remark on the presence of psychogenic symptoms associated with movement disorders (79%) as being one of the most useful clinical clues as well as on the value of polymyographic study in chronic psychogenic movement disorders, which provide evidence of the inconsistency of movement disorders. © 2012 Movement Disorder Society

Myoclonus–dystonia syndrome (MDS) is an inherited movement disorder with clinical and genetic heterogeneity. The epsilon sarcoglycan (SGCE) gene is an important cause of MDS. We report the results of a clinical and genetic study of 20 patients from 11 families. We disclosed six novel and two previously described mutations in nine families. The majority of patients had a phenotype of myoclonus and dystonia in combination, but clinical findings considered atypical, such a very early onset, distal myoclonus, and legs involvement, were detected in a significant proportion of cases. The disease course was variable, from progression to spontaneous remission of the motor symptoms. There were no obvious differences between mutation‐positive and ‐negative cases. © 2007 Movement Disorder Society