Lid jaw co-movementsの珍らしい型を呈した2症例

Two CASES PRESENTING WITH UNUSUAL PATTERN OF LID JAW CO-MOVEMENTS

I．はじめに

　1883年7月6日，Ophthalmological Society of theUnited Kingdomの集会でR．Marcus Gunnによつて15歳の少女が紹介された^5）。その少女は先天性の左側眼瞼下垂があり，生後5週目に，下垂している左上眼瞼が授乳時には挙上するのに気づかれた。その後咀嚼するとき，会話するときに下顎の運動に伴う左上眼瞼の挙上がおこり，左側の瞳孔が右側に比して縮少しているという症例であつた。その症例に対しGowersらによる調査がおこなわれ，外側翼突筋の収縮に連動して同側上眼瞼挙筋が収縮し，患側上眼瞼挙筋と動眼神経支配の他の筋との共上司運動は十分ではなく，軽く閉眼させると患側上眼瞼の弛緩は不十分であり，患側に縮瞳を認めると報告され，この連合運動は患側上眼瞼挙筋が動眼神経核と三叉神経核の両方から支配されていると推論された^5）。

　後に，この連合運動はMarcus Gunn現象と呼ばれ，今日までこの現象を示す数多くの症例^{4,12,13,15,21,22）}や他の異常所見と合併した症例^3,6,19,24）が報告された。下顎の運動と動眼神経文配の筋の共同運動には他にも内側翼突筋と上眼瞼挙筋の共同運動^18）があり，Reeves McLeodらは嚥下に伴う上斜筋の連合運動^16）を報告している。

General review of the literature makes it appar-ent that there exist various combinations of as-sociated movements between cranial nerves. Mostof them involve four of nerves, the oculomotor,the abducens, the facial, and the motor potion ofthe trigeminal nerve.

We report two patients in whom left upper eye-lids produced peculior up and down movements inaccompany with mastication.

The one was a 9-year-old female who had shownleft eye-lid retraction since 3 months ; the other,a 4-year-old male, had produced the synkinesis oneyear since.

Either children showed contraction of left palpeb-ral levators associated with volitional mouth open-ing, deviation of the mandible toward the right, andsucking. Their pupils were normal and their uppereye-lids showed no ptosis on the affected side.

The EEG showed high voltage rhythmic slowwaves in parieto-occipital areas bilaterally.

Head injuries or hereditary defects not beingrecorded in their histories, their synkinesis isassumed to be congenital in orgin.

Abnormal neural connections have been presum-ed to be affected in the course of the developmentbetween the trigeminal and the oculomotor nucleiwithin the midbrain. In triggering the synkinesis,however, stretched muscle-spindles of the massetermuscle most play an important role.

After all, synchronizing lid-jaw co-movements asobserved in our two children represent an unusualpattern of the Marcus Gunn phenomenon.