Kawasaki A, Purvin V
Department of Neuro-Ophthalmology, Hôpital Ophtalmique Jules Gonin, Lausanne, Switzerland.
Klin Monbl Augenheilkd. 2006 May;223(5):459-61. doi: 10.1055/s-2006-926576.
Dolichoectasia (elongation, dilatation and tortuosity) of the basilar artery can cause an isolated cranial neuropathy. The trigeminal nerve and facial nerve are most frequently affected. Dysfunction of one of the ocular motor cranial nerves due to basilar artery dolichoectasia is uncommon, and an isolated IVth (trochlear) nerve palsy has not been previously described in the literature.
Two men, ages 70 and 59 years, respectively, presented with vertical diplopia due to a IVth nerve palsy. In one patient, the onset of the IVth nerve palsy was painless and gradual and in the other patient, the onset was acute and associated with periorbital pain. Neuroimaging in both patients revealed pathological tortuosity of the basilar artery around the midbrain and displacement of the artery toward the side of the affected trochlear nerve.
The patients were observed clinically. One patient had gradual worsening of his palsy for three and one-half years then suffered a stroke. The second patient whose IVth nerve palsy had an acute onset experienced spontaneous resolution of his palsy but later developed dysfunction of other cranial nerves.
Basilar artery dolichoectasia should be considered in the differential diagnosis of an isolated IVth nerve palsy. The clinical course may be variable, and the prognosis is not always benign.
基底动脉迂曲扩张（延长、扩张和迂曲）可导致孤立性颅神经病变。三叉神经和面神经最常受累。基底动脉迂曲扩张导致眼动颅神经之一功能障碍并不常见，文献中此前未描述过孤立性滑车神经麻痹。
两名男性，年龄分别为70岁和59岁，因滑车神经麻痹出现垂直性复视。一名患者滑车神经麻痹起病无痛且渐进性，另一名患者起病急性且伴有眶周疼痛。两名患者的神经影像学检查均显示中脑周围基底动脉病理性迂曲，且动脉向患侧滑车神经侧移位。
对患者进行临床观察。一名患者麻痹逐渐加重三年半后发生中风。第二名滑车神经麻痹急性起病的患者麻痹自行缓解，但后来出现其他颅神经功能障碍。
孤立性滑车神经麻痹的鉴别诊断应考虑基底动脉迂曲扩张。临床病程可能多变，预后并非总是良好。
