Amaurosis

A transient rise in blood pressure occurs immediately after the administration of protirelin (10). In very rare cases, transient amaurosis and bronchospasm have been reported, thought to be due to either vasopressor syncope or cardiac arrhythmias (11-13). 

Drury PL, Belchetz PE, McDonald WI, Thomas DG, Besser GM. Transient amaurosis and headache after thyrotropin releasing hormone. Lancet 1982 l(8265) 218-9. 

Cimino A, Corsini R, Radaeli E, Bollati A, Giustina G. Transient amaurosis in patient with pituitary macroadenoma after intravenous gonadotropin and thyrotropin releasing hormones. Lancet 1981 2(8237) 95. 

Table 1. Selected pathogenic mutations in GC1 (Additional mutations can be found in (Hanein et al., 2004)). LCA1, Leber congenital amaurosis type 1 ar, autosomal recessive ad, autosomal dominant RP, retinitis pigmentosa CORD, cone-rod dystrophy IRP, juvenile isolated RP fs, frameshift mis, missense splice, splice site mutation non, nonsense mutation...

Gene Therapy Rescue of Visual Functions in a Blind Mouse Model of Leber Congenital Amaurosis. PLoS. Med. 2 e333. 

El-Shanti, H., Al-Salem, M., El-Najjar, M., Ajlouni, K., Beck, J., Sheffiled, V.C., and Stone, E.M. (1999). A nonsense mutation in the retinal specific guanylate cyclase gene is the cause of Leber congenital amaurosis in a large inbred kindred from Jordan. J. Med. Genet. 36 862-865. 

Rozet, J.M., Perrault, I., Gerber, S., Hanein, S., Barbet, F., Ducroq, D., Souied, E., Munnich, A., and Kaplan, J. (2001). Complete abolition of the retinal-specific guanylyl cyclase (retGC-1) catalytic ability consistently leads to leber congenital amaurosis (LCA). Invest Ophthalmol. Vis. Sci 42 1190-1192. 

Tucker, C.L., Ramamurthy, V., Pina, A.L., Loyer, M., Dharmaraj, S., Li, Y., Maumenee, I.H., Hurley, J.B., and Koenekoop, R.K. (2004). Functional analyses of mutant recessive GUCY2D alleles identified in Leber congenital amaurosis patients protein domain comparisons and dominant negative effects. Mol. Vis. 10 297-303. 

An important warning sign for occlusive ICA disease is an episode of transient monocular visual disturbance also called amaurosis fugax or ocular TIA (Wray 1993). Patients often describe this phenomenon as a dimming, darkening, obscuration or a curtain from above or from the side, which resolves after seconds or a few minutes. These attacks are... 

Clinically stereotyped TIAs or the opticocerebral symptom with simultaneous amaurosis and contralateral hemiparesis due to critically low blood supply through an occluded or almost occluded ICA herald a pending borderzone ischemia (Tsiskaridze et al. 2001). Rarely so-called limb shaking TIAs may point to a hemodynamic ischemia in ICA occlusive disease (Baquis et al. 1985). 

Stroke is a clinical diagnosis and the acute onset of focal neurological symptoms is the major indicator of stroke. Whereas typical stroke symptoms such as hemiparesis, amaurosis or dysarthria are easy to recognize, other stroke syndromes such as vertebrobasilar strokes or predominant neuropsychological manifestations are subject to misdiagnosis especially for non-neurologists. Misdiagnosis may be due to a non-vascular medical condition that simulates a stroke syndrome - a condition coined stroke mimicry . Or, a stroke may resemble another non-vascular clinical entity - a circumstance termed as stroke chameleon (Huff 2002). 

Ubogu E. Amaurosis fugax associated with phencyclidine inhalation. Eur Neurol 2001 46(2) 98-9. 

There has been reported success in using gene therapy for a type of inherited blindness, Leber congenital amaurosis. 

Box 8.2. Causes of transient monocular blindness (amaurosis fugax)... 

Exposure keratopathy Elevated intraocular pressure Contralateral amaurosis Respiratory arrest Bradycardia... 

CRX Mutation R90W Leber congenital amaurosis Hum Mol Genet, 1999. 8(2) p. 299-305. 

Transient episodes of amaurosis or scotomata, both of which recurred after aldesleukin rechallenge, have been described (37). Three other patients had visual phenomena, including diplopia, scotomata, and palinopsia during treatment, which resolved on withdrawal of aldesleukin (38). 

Amaurosis fugax has been reported in association with topical timolol (362). 

The local adverse effects of topical glucocorticoids (1,2) are listed in Table 1. They include transient local erythema, calcinosis cutis, cramps (due to injection of crystals into a vessel), amaurosis (a dubious report), depigmentation, skin atrophy, and skin necrosis (3,4). The systemic adverse effects of topical glucocorticoids (5-8), which are those to be expected from systemic use, are also listed in Table 1. 

Strandvik B, Zetterstrom R. Amaurosis after broxyquiuo-line. Lancet 1968 l(7548) 922-3. 

A 76-year-old man undergoing trabeculectomy developed bilateral amaurosis after a peribulbar block with 6 ml of a mixture of 2% lidocaine, 0.5% bupivacaine, and hyaluronidase (318). The authors thought it unlikely that the optic nerve sheath had been penetrated and suggested that local spread to the optic nerves via the subarachnoid or subdural space had been responsible. 

Hamel P, Boghen D. Bilateral amaurosis following peribulbar anesthesia. Can J Ophthalmol 1998 33(4) 216-18. 

Infection of the cerebrum, basal ganglia and cerebellum are observed less commonly. Depression is associated with other cerebral abnormalities but is uncommon in EPM. Protozoal infections in the cerebrum may be focal and associated with seizure activity and electroencephalographic abnormalities. Alternatively, asymmetric amaurosis (central blindness) and facial hypalgesia may be observed. Infection of the cerebellum results in cerebellar ataxia that is usually not associated with weakness or proprioceptive deficits. Involvement of the reticular activating system is also uncommon but may produce a narcolepsy-like syndrome in the absence of any other neurological signs. Occasionally, lameness that cannot be eliminated with nerve and joint local anesthesia may be the only evidence of a neurological deficit. 

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