Type B diencephalic–mesencephalic junction dysplasia, a congenital brainstem malformation that may be silent until adulthood: a case report

Type‐B Diencephalic‐Mesencephalic Junction Dysplasia Initially Presented With Secondary Cough‐Induced Headaches: A Case Report

“…Axial MRI of the midbrain shows a midline cleft with the classic appearance of the “butterfly” sign caused by extension of the third ventricle and other diencephalic structures into the midbrain 3 . To the best of our knowledge, only 2 cases of type‐B DMJD in adulthood have been reported in the literature 1,5 . These patients presented with slowly progressive symptoms including: cognitive dysfunction, movement disorders, hemiparesis, hearing loss, speech dysfunction, and gait dysfunction.…”

“…The patient’s obstructive hydrocephalus was promptly relieved following a third ventriculostomy as evidenced by his MRI changes resulting in significant reduction of headaches suggesting that this was a primary factor in their development. In the other two type‐B patients, their symptoms progressed slowly over time and were not diagnosed until past the age of 40 years 1,5 . It is possible that if this had not developed headaches that this malformation would have gone unnoticed.…”

“…3 To the best of our knowledge, only 2 cases of type-B DMJD in adulthood have been reported in the literature. 1,5 These patients presented with slowly progressive symptoms including: cognitive dysfunction, movement disorders, hemiparesis, hearing loss, speech dysfunction, and gait dysfunction. Unlike our patient, these 2 patients did not present with headaches.…”

“…In the other two type-B patients, their symptoms progressed slowly over time and were not diagnosed until past the age of 40 years. 1,5 It is possible that if this had not developed headaches that this malformation would have gone unnoticed. It is also possible that our patient may have developed progressive neurologic dysfunction as he gets older.…”

“…Diencephalic-mesencephalic junction dysplasia (DMJD) is a rare, congenital malformation caused by a anteroposterior patterning defect of the neural tube, which occurs at the junction between the diencephalon and mesencephalon. 1 It leads to caudal expansion of the diencephalon and a short-thick midbrain. The mechanism is not clear, but it is thought to be related to impaired regulation of signaling molecules.…”