Möbius syndrome
Möbius syndrome is a rare congential condition characterised by the absence or under-development of the abducens nerve (CN VI) and facial nerve (CN VII) nuclei.
Additional brainstem involvement is also common and may include other cranial nerves as well as the musculoskeletal system. Grading schema have been proposed which include these other manifestations (e.g. CLUFT (cranial nerve, lower limb, upper limb, face, and thorax)).
The combination of Möbius syndrome and Poland syndrome has been well described (thus Poland-Möbius syndrome) 4.
The earliest sign is the inability of the newborn to suckle, with an expressionless face, floppy limbs and drooling.
Aetiology is multi-factorial, and several theories have been proposed, with the most supported theory being a of transient ischaemic or hypoxic insult to the foetus. Infectious and genetic aetiologies have also been proposed.
MRI findings are those of brainstem hypoplasia (pons and medulla) with straightening of the floor of the fourth ventricle as a result of absence of the facial colliculus. Cerebellar hypoplasia, calcification of the pons in the region of the abducens nuclei and even absence of the middle cerebellar peduncles have been reported.
Etymology
The clinical syndrome was first described by:
- Paul Julius Möbius (1853-1907): German neurologist 3
