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Nodding syndrome phenotypes.

P S Spencer¹, R Mazumder², V S Palmer¹

¹Department of Neurology, Oregon Health & Science University, Portland, OR, USA.

Revue Neurologique

|November 23, 2019

Summary

Nodding syndrome (NS) is a progressive encephalopathy in children causing seizures and head nodding. Environmental factors like malnutrition and nematode infection are suspected causes, but the exact origin remains unknown.

Keywords:

Electrocencephalography Endocrine disorder Environmental etiology Nakalanga syndrome Tauopathy

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Area of Science:

Neurology
Pediatrics
Neurodegenerative Diseases

Background:

Nodding syndrome (NS) is a progressive encephalopathy affecting children and adolescents.
It is characterized by seizures and distinctive vertical head nodding, with epidemic forms in East Africa.
NS shares clinical features with Nakalanga syndrome (NLS), a brain disorder linked to pituitary dwarfism in sub-Saharan Africa.

Purpose of the Study:

To describe the clinical characteristics, electroencephalographic findings, neuroimaging, and neuropathology of Nodding Syndrome.
To explore potential environmental etiologies for NS and NLS.

Main Methods:

Clinical observation and characterization of NS patients.
Electroencephalography (EEG) to record head nodding episodes.
Brain imaging (MRI) to assess structural changes.
Neuropathological examination of brain tissue from affected children.

Main Results:

NS progresses through stages including inattention, head nodding, seizures, and severe cognitive/motor disability with parkinsonism features.
EEG shows diffuse slow waves during nodding, followed by electrodecremental patterns.
Brain imaging reveals cerebral cortical and cerebellar atrophy.
Neuropathology shows tau-positive neurofibrillary tangles and dystrophic neurites in cases with frontotemporal atrophy.

Conclusions:

Nodding syndrome is a progressive neurodegenerative disorder in children.
Environmental factors such as malnutrition, displacement, and nematode infections are implicated in the etiology of NS and NLS.
The precise cause of NS and NLS requires further investigation.