菱脑融合

【双语病例】Rhombencephalosynapsis 菱脑融合

来自：双语学影像本期病例选自AJNR Case of the Week

Elana Smith, Nazmus Sakib, Jose Rios；Morristown Medical Center, Morristown, NJ

Description

A 45-year-old man with congenital hydrocephalus and headache

45岁男性，先天性脑积水，头痛。

图A:

图B:

图C:

图D:

图E:

Legends

Axial (A) and coronal (B) T2WI through the cerebellum demonstrate fusion of the cerebellar hemispheres. The cerebellar folia are transversely oriented and cross the midline. No vermis is present. The lateral ventricles are dilated. Axial T2WI (C) demonstrates a keyhole-shaped fourth ventricle. Sagittal T1WI (D) through the midline demonstrates a narrowed cerebral aqueduct and resultant hydrocephalus. There is absence of the primary and secondary cerebellar fissures. Coronal T2WI (E) demonstrates that the septum pellucidum is not visualized.

小脑的T2WI横断位(A)和冠状位(B)显示小脑半球融合，横向穿过中心。小脑蚓部缺如。侧脑室扩张。

横断位T2WI(C)示第四脑室呈“锁眼状”。

中线水平矢状位T1WI(D)示导水管狭窄导致脑积水。第一、第二小脑裂隙（？）消失。

冠状位T2WI（E）示透明隔未显示。

Rhombencephalosynapsis

菱脑融合

• Rhombencephalosynapsis is a rare developmental malformation of the cerebellum with an unknown etiology and pathogenesis. It is characterized by abscence of the vermis and dorsal fusion of the cerebellar hemispheres, dentate nuclei, and superior cerebellar peduncles.

  菱脑融合（RES）是一种罕见的小脑发育畸形，原因和发病机制尚不明确。典型表现为小脑蚓部缺如，小脑半球背部、齿状核、小脑上脚融合。

• The majority of patients are nonsyndromic. However, rhombencephalosynapsis is a key feature of Gómez-López-Hernández syndrome (parietal alopecia, trigeminal anesthesia, and craniofacial dysmorphic signs) and may be seen in patients with associated VACTERL (vertebral anomalies, anal atresia, cardiovascular anomalies, tracheoesophageal fistula, renal anomalies, and limb defects).

  大部分RES患者没有症状，但RES是Gómez-López-Hernández综合征（戈麦斯-洛佩斯-赫尔南德斯综合征，顶部脱发、三叉神经麻痹、颅面部畸形）的典型表现之一，也可以是VACTERL（脊柱畸形、肛门闭锁、心血管异常、气管食管瘘、肾脏异常、肢体缺损）的合并症。

• Clinical manifestation and prognosis depend on posterior fossa findings and associated supratentorial anomalies. These anomalies include hydrocephalus (often from aqueductal stenosis), dysgenesis of corpus callosum, absence of septum pellucidum, and fusion of the thalami. Though rare, extracranial abnormalities involve the musculoskeletal, urinary, cardiac, and respiratory systems. Common symptoms include mental retardation, ataxia, spasticity, and epilepsy. Patients may be asymptomatic if rhombencephalosynapsis is an isolated finding.

  临床表现和预后取决于后颅凹及幕上异常情况，包括脑积水（多为导水管狭窄所致）、胼胝体发育不全、透明隔缺如、丘脑融合。虽然数量很少，但可累及颅外，如骨骼肌肉、泌尿系统、心血管系统、和呼吸系统。临床常见症状包括精神发育迟缓、共济失调、强直状态、癫痫。如果仅为孤立性RES，可无明显临床症状。

Key Diagnostic Features

• Complete agenesis or hypogenesis of the cerebellar vermis (indicated by a diamond-shaped 4th ventricle) with fusion of the cerebellar hemispheres, dentate nuclei, and superior cerebellar peduncles.

  小脑扁桃体发育不良或完全缺如（第四脑室呈菱形）伴小脑半球、齿状核、小脑上脚融合。

• Other indicators include a flat-based cerebellum, large corpus medullare, and horizontal folial orientation with no vermis present.

  其他征象包括：小脑底部扁平、髓体增大、小脑叶水平未见小脑蚓部显示。

DDx

None. Findings are pathognomonic of this entity.

该病表现有一定的特异性，无需鉴别诊断。

Rx

• No medical management is required for isolated cases of rhombencephalosynapsis.

  孤立性RES无需药物治疗。

• Surgical management may be needed in cases with associated anomalies; presence of hydrocephalus may require the placement of a ventriculoperitoneal shunt.

  如合并其他异常需手术治疗。如合并脑积水，可采取脑室-腹腔分流术。

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