Related Experiment Videos
Involuntary rhythmic leg movements time-locked with the respiratory cycle
Insights
Childhood involuntary rhythmic leg movements may originate from the brain's respiratory center. This study identifies a potential generator linked to respiratory cycles, offering new insights into this rare condition.
Area of Science:
- Neurology
- Pediatrics
- Movement Disorders
Background:
- Involuntary rhythmic leg movements in childhood are rare and their origin is unknown.
- Understanding the generators is crucial for diagnosis and treatment.
Observation:
- A 3-year-old male presented with continuous, low-frequency rhythmic leg movements starting at 7 months.
- These movements impacted gait acquisition, with walking delayed until 2 years, 4 months.
- Neonatal automatic stepping was absent, but neurological examination was otherwise normal.
Findings:
- Polygraphic recordings showed rhythmic leg movements (0.5 Hz, later 0.35 Hz) time-locked with respiration.
- Magnetic resonance imaging revealed abnormalities in the upper medulla-lower pons region.
- The respiratory center is a potential generator, possibly via an aberrant pathway to reticulospinal neurons.
Implications:
- This case suggests a link between the respiratory center and involuntary leg movements.
- Further research may elucidate the pathophysiology of these movements.
- Potential for novel therapeutic targets based on respiratory-neural pathways.
Abstract:
Involuntary rhythmic leg movements in childhood is an uncommon condition, the generators of which remain unknown. We report on a male 3 years of age with distinct features providing important clues concerning the location of one of these generators. At the age of 7 months, the previously healthy young male started with low frequency, rhythmic, and continuous (both during wakefulness and sleep) flexion/extension movements of the lower limbs. Movements interfered significantly with gait acquisition, and, despite normal cognitive development, he was able to walk only at age 2 years, 4 months. The neurologic examination revealed the absence of automatic stepping in the neonatal period, but was otherwise normal. A polygraphic electroencephalogram/electromyogram (EEG/EMG) recording, at the age of 2 years, 9 months, revealed rhythmic and synchronous legs with EMG activity at 0.5 Hz. A more complete polygraphic recording at the age of 3 years, 10 months, showed a lower frequency (0.35 Hz) for the movements, which were time-locked with the respiratory cycle. Magnetic resonance imaging (MRI) of the brain revealed an increased T(2) signal in the upper medulla-lower pons regions. The generator of the rhythmic legs movements is postulated to be the respiratory center, connecting with the reticulospinal projecting neurons through an aberrant pathway.