temporal arteritis and hallucinations

   Temporal arteritis is also known as giant cell arteritis (GCA). Both names are used to denote a vasculitis which affects (especially) the large and medium-sized arteries of the head. The name temporal arteritis refers to the temporal artery, the vessel most frequently involved. The name giant cell arteritis refers to the characteristic type of inflammatory cell involved in the vasculitic process, as seen on biopsy. Temporal arteritis may be complicated by various concomitant disorders, including visual loss (which is associated with ischaemia of any part of the visual system, ranging from the retina to the occipital cortex), and * visual hallucinations. In a group of 31 individuals with temporal arteritis, the Israeli internists Gideon Nesher et al. found five subjects with a combination of permanent visual loss and *visual hallucinations, and one with a combination of *amaurosis fugax and visual hallucinations. Visual hallucinations occurring in the context of temporal arteritis tend to confine themselves to the areas of visual loss. As the combination of * amaurosis and visual hallucinations is also seen in *Charles Bonnet syndrome, it has been suggested that the mechanism underlying the hallucinations may be more or less the same. Special attention has been given to the mechanism of * deafferentiation, which in the case of temporal arteritis has been attributed to posterior cerebral circulation ischaemia. The differential diagnosis of visual hallucinations concomitant with temporal arteritis should take into account the possibility of hallucinatory activity secondary to comorbid conditions such as * delirium, infarcts affecting the primary sensory pathways or visual cortex, and * steroid therapy. The role ofsteroids in these hallucinations would seem to be ambiguous. Although a well-known risk factor for the mediation of hallucinations, their application has been found to result in a prompt resolution of hallucinations in cases of temporal arteritis.

   References

   Hart, C.T. (1967). Formed visual hallucinations: A symptom of cranial arteritis. British Medical Journal, 9, 643-644.

   Nesher, G., Nesher, R., Rozenman, Y., Sonnenblick, M. (2001). Visual hallucinations in giant cell arteritis: Association with visual loss. Journal of Rheumatology, 28, 2046-2048.

   Razavi, M., Jones, R.D., Manzel, K., Fattal, D., Rizzo, M. (2004). Steroid-responsive Charles Bonnet syndrome in temporal arteritis. Journal ofNeuropsychiatry and Clinical Neurosciences, 16, 505-508.