Delayed presentation of Diencephalic-Mesencephalic Junction Dysplasia with Compulsive truncal movements and Blepharospasm: A Case Report from India

Diencephalic-mesencephalic junction dysplasia (DMJD) is a rare congenital midbrainhindbrain malformation caused by an early anterior-posterior patterning defect during embryonic development.This defective anteroposterior patterning leads to a caudal expansion of the diencephalon and the development of an aberrant short-thick midbrain in DMJD(1,2).Three types of DMJD patterns have been described based on the anatomic level of the diencephalon involvement (hypothalamus or thalamus), and the degree of separation between the diencephalon-mesencephalon, including type A with hypothalamicmesencephalic continuity; type B with incomplete thalamic-mesencephalic cleavage, type C with complete or near complete thalamic-midbrain union.The specific causative gene mutation is unclear, but associations include mutations in PCDH12, L1CAM, FOXA2, and VRK1 (3).DMJD usually presents in infantile and early childhood period with facial dysmorphism, global developmental delay, spastic quadriparesis and seizures(4).However type-B DMJD can have delayed presentation in adult life.Cognitive impairment, headache, cranial nerve involvement, pyramidal tract signs, ataxia and complex motor tics were