Yee R D, Purvin V A, Azzarelli B, Nelson P B
Trans Am Ophthalmol Soc. 1996;94:207-23; discussion 223-6.
Two cases illustrate the symptoms, signs, etiologies, and treatment of ocular neuromyotonia (ONM).
The histories, neuroradiologic tests, and/or biopsy revealed the etiologies of ONM in both patients. Clinical observations, videotaping, and electronic eye movement recordings documented the eye movements.
A 72-year-old man with chronic arachnoiditis following myelography with thorium dioxide (Thorotrast) developed intermittent diplopia and a partial right third nerve palsy. Left gaze induced spasm of the right medial rectus. Right gaze produced right lateral rectus spasm. A 66-year-old woman, who had radiation treatment for a pituitary tumor and acromegaly, had intermittent spasm of the left medial rectus muscle and left esotropia. The episodes occurred spontaneously and were induced by right gaze. A left internuclear ophthalmoplegia was also found. Carbamazepine (Tegretol) abolished the ONM in both patients.
Although ONM is an unusual cause of intermittent diplopia and strabismus, its distinctive clinical features identify it. Injury to the peripheral cranial nerves probably leads to segmental demyelination, axonal hyperexcitability, and a self-perpetuating, reverberating circuit, which causes spasms of the extraocular muscles.
通过两个病例阐述眼部神经肌强直(ONM)的症状、体征、病因及治疗方法。
病史、神经放射学检查及/或活检揭示了两名患者ONM的病因。临床观察、录像及电子眼动记录记录了眼动情况。
一名72岁男性,在接受二氧化钍(钍造影剂)脊髓造影后发生慢性蛛网膜炎,出现间歇性复视及右侧动眼神经部分麻痹。向左注视诱发右侧内直肌痉挛。向右注视导致右侧外直肌痉挛。一名66岁女性,因垂体瘤和肢端肥大症接受放射治疗,出现左侧内直肌间歇性痉挛及左眼内斜视。发作自发出现,并由向右注视诱发。还发现左侧核间性眼肌麻痹。卡马西平(痛痉宁)消除了两名患者的ONM。
虽然ONM是间歇性复视和斜视的不常见病因,但其独特的临床特征可对其进行识别。外周颅神经损伤可能导致节段性脱髓鞘、轴突兴奋性过高及自我持续的折返环路,从而引起眼外肌痉挛。