The aim of this study was to verify and confirm the close correlation between the absence of the medullary arcuate nucleus and sudden death in a 4-month-old infant. Careful neuropathological examination of the cerebral hemispheres, basal ganglia, and cerebellum demonstrated no relevance to the death. The brainstem region, normally occupied by the nuclei, was cut into several serial sections so as not to lose any details. The largest median part of the medullary arcuate nucleus was completely absent, and only very small groups of residual neurons in its most lateral part were still detectable; the rest of the brainstem showed no abnormalities. In the absence of other lesional, degenerative, or malformative causes, the sudden and unexpected death of this infant was likely due to severe hypoplasia/aplasia of the medullary arcuate nucleus. The anatomo-functional development of the nucleus and its crucial role in the control of respiratory and cardiac autonomic reactivity in sleep during the first year of life may provide an important contribution to the pathogenic interpretation.

The study did not need the approval of the Ethical Committee of our University Administration, as it is not required for the publication of a single case of particular interest to the scientific community (Regulations of the Ethical Committee of Area Vasta Emilia Nord, Italy, approved on September 22, 2020).

The informed consent has been obtained and the patient's anonymity has been preserved.

Conceptualization: E.D.G., T.S., L.R.B. Data curation: E.D.G., T.S., L.R.B., L.M. Writing-original draft preparation: E.D.G., T.S., L.F. Writing-review and editing: E.D.G., T.S., L.R.B., A.M. All authors have read and agreed to the published version of the manuscript.

Received: 27 September 2023

Accepted: 01 June 2024

Article published online:
04 July 2024

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