Clinical and Electrophysiological Characterization of Essential Tremor in 18 Children and Adolescents.

Background: Essential tremor (ET) is considered the most frequent abnormal movement in the general population, with childhood onset in 5 to 30% of the patients. Methods: A multicenter, descriptive cross-sectional study enrolled patients ⩽18 years with a definite diagnosis of ET according to the International Parkinson and Movement Disorders Society criteria. Demographic data, clinical and electrophysiological characteristics of the tremor, neurological examination and impact on quality of life were collected. Results: 9 males and 9 females were included (mean age of 13.9 years). Tremor was characterized by : upper limb onset at a mean age of 6.5 years; at enrollment, upper limbs localization, and involvement of an additional body region in 28% of the patients; kinetic tremor in all of the patients combined with postural tremor in 17 and rest tremor in 3; tremor mean frequency of 7.6 Hz, mean burst duration of 82.7 ms; identification of mild myoclonic jerks on the polymyographic recordings in 7 patients; altered quality of life with worse emotional outcomes in girls and when a disease duration >5 years was suggested. Discussion: Childhood-onset ET is associated with delayed diagnosis and remarkable functional impact. Electromyographic identification of additional mild myoclonus is a new finding whose significance is discussed. Highlights: ET onset involved upper limbs and at inclusion, 28% of the patients exhibited involvement of an additional body region.ET impacted quality of life for all patients.Girls and patients affected for >5 years reported worse emotional outcomes.Mild myoclonic jerks were identified on 7/17 polymyographic recordings.

Intraputaminal Gene Delivery in Two Patients with Aromatic L-Amino Acid Decarboxylase Deficiency.

Background: Aromatic l-amino acid decarboxylase deficiency (AADCD) is a rare, early-onset, dyskinetic encephalopathy mostly reflecting a defective synthesis of brain dopamine and serotonin. Intracerebral gene delivery (GD) provided a significant improvement among AADCD patients (mean age, ≤6 years). Objective: We describe the clinical, biological, and imaging evolution of two AADCD patients ages >10 years after GD. Methods: Eladocagene exuparvovec, a recombinant adeno-associated virus containing the human complimentary DNA encoding the AADC enzyme, was administered into bilateral putamen by stereotactic surgery. Results: Eighteen months after GD, patients showed improvement in motor, cognitive and behavioral function, and in quality of life. Cerebral l-6-[18F] fluoro-3, 4-dihydroxyphenylalanine uptake was increased at 1 month, persisting at 1 year compared to baseline. Conclusion: Two patients with a severe form of AADCD had an objective motor and non-motor benefit from eladocagene exuparvovec injection even when treated after the age of 10 years, as in the seminal study.