Macrocerebellum is a rare condition marked by an aberrant growth in the size of the cerebellum without any morphological or signal abnormalities. It can occur in isolation (nonsyndromic) or as part of various clinical syndromes such as Costello's syndrome, Sotos syndrome, Williams' syndrome, macrocephaly-capillary malformation syndrome, mucopolysaccharidosis, and Lhermitte–Duclos' syndrome. The most common clinical features described with macrocerebellum are developmental delay, hypotonia, ataxia, nystagmus, oculomotor apraxia, seizures, and facial dysmorphism. The exact pathophysiological basis underneath this condition is still unknown. We report the case of a 13-month-old boy who presented with developmental delay, nystagmus, and generalized hypotonia. The presence of nystagmus made us suspect cerebellar pathology in this child. Magnetic resonance imaging of brain showed macrocerebellum which was confirmed by volumetric analysis. He did not have any clinical features to suggest a syndrome associated with macrocerebellum. His developmental quotient was 45, and his receptive and expressive language age was around 5 to 6 months. His genetic analysis by whole exome sequencing did not reveal any disease-causing variants. A repeat clinical evaluation after 4 months showed an improvement in motor domains.

B.B. contributed to manuscript writing, data collection, and devising the therapeutic interventions. M.U. participated in data collection and critical revision of manuscript. G.N, and M.L.A. performed volumetric analysis and interpreted radiology-related findings. A.K. contributed to data collection and manuscript writing. S.S. contributed to study concept, design, supervision, and critical revision of manuscript.

The consent for publication has been obtained from mother of the child.

The authors certify that all appropriate consent forms from parents have been obtained.

Received: 04 May 2023

Accepted: 12 December 2023

Article published online:
16 January 2024

© 2024. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany