REFERENCES 1. Baum EW, Sams WM Jr, Payne RR. Giant cell arteritis: A systemic disease with rare cutaneous manifestations. J Am Acad Dermatol 1982;6:1081–1088. 2. Dudenhoefer EJ, Cornblath WT, Schatz MP. Scalp necrosis with giant cell arteritis. Ophthalmology 1998;105:1875–1878. 3. Currey J. Scalp necrosis in giant cell arteritis and review of the literature. Br J Rheumatol 1997;36:814–816. 4. Pye M. Lingual and scalp infarction as a manifestation of giant cell arteritis: Delay in diagnosis leading to blindness. J Rheumatol 1988;15:1597–1598. 5. Soderstrom CW, Seehafer JR. Bilateral scalp necrosis in temporal arteritis. A rare complication of Horton’s disease. Am J Med 1976;61:541–546. 6. Bhatti MT. Scalp necrosis and visual loss due to giant cell arteritis. J Emerg Med 2001;21:67–68. 7. Dummer W, Zillikens D, Schultz A et al. Scalp necrosis in temporal (giant cell) arteritis. Implications for the dermatologic surgeon. Clin Exp Dermatol 1996;21:154–158. 8. Rudd JC, Fineman MS, Sergott RC et al. Ischemic scalp necrosis preceding loss of visual acuity in giant cell arteritis. Arch Ophthalmol 1998;116:1690–1691. 9. Rigon JL, Schmutz JL, Cuny JF et al. Ne ´crose du cuir chevelu et de la vou ˆ te cranienne dans la maladie de Horton. Ann Dermatol Venerol 1987;114:1561– 1565. 10. Ashara T, Masuda H, Takahashi T et al. Bone marrow origin of endothelial progenitor cells responsible for postnatal vasculogenesis in physiological and pathological neovascularization. Circ Res 1999;85:221–228. EFFECT OF MAGNETIC INSOLES ON BALANCE IN OLDER ADULTS To the Editor: The use of complementary and alternative therapies has become increasingly popular among American consumers, including many older adults. Recent studies indicate that 30% to 64% of geriatric subjects admit to using one or more types of alternative care. 1–5 One example of these alternative therapies is the use of magnets, which have primarily been promoted for their analgesic and energizing effects. Magnets are frequently imbedded in clothing, shoe inserts, chair or mattress pads, pillows, and comforters for ease of application. Despite many impressive anecdotal reports and demonstrations, scientific studies of magnets applied to human subjects have produced mixed results and cannot conclusively validate manufacturer claims. One claim made by some distributors is that magnetic insoles improve postural stability. If true, these products may have therapeutic value in preventing falls in the geriatric population. Only one previous study has investigated these effects. In comparing the static balance of 14 older and younger healthy adults, a recent study 6 reported small reductions in postural sway in older subjects when wearing magnetic insoles; younger subjects demon- strated no changes. However, their study had several limitations, including a relatively young, healthy sample and a lack of blinding (subjects or investigators) due to the different surface textures of insoles that were used. Thus, we conducted another experiment to determine whether magnetic insoles influenced the standing balance of older adults who reported a history of falls or balance deficits. Using a repeated measures design, we observed the immediate effects of magnetic versus nonmagnetic insoles on 56 community-dwelling older adults between the ages of 57 and 89 (mean 5 76 years). All subjects performed a series of six balance tests three times (in varying sequence) while wearing different types of insoles. One pair of magnetic insoles contained 15 unipolar magnets each with a gauss rating of 12,000. Another pair of insoles contained 15 weaker magnets rated at 3,900 gauss. The placebo insoles were of similar size and texture but contained no magnets. A double-blind approach was used to apply the insoles in random order to prevent any biasing from the investigators or the subjects. Measures of static and dynamic balance included standing with feet together and in a tandem stance with eyes closed, standing on a foam pad with eyes open, functional reach in the anterior and lateral directions, and a stability index produced by a moveable force plate using the Biodex Balance System. Subjects’ balance measures did not differ significantly when wearing any of the three types of insoles (F 5 0.843, P 5.605), but a ceiling effect was observed with some balance measures that could have affected these results. In addition, these preliminary findings only reflect the immediate effects of the magnets. Any potential influence that a magnetic field has on kinesthetic awareness may require longer-term wearing of these insoles. Previous investigations on the analgesic effects of magnets suggest that there might be some selective inhibition of slow- conducting afferent fibers, 7–9 but there is currently no evidence to indicate that magnetic fields influence the function of more-discriminant sensory fibers. Therefore, additional studies of longer duration are needed to determine whether magnets activate some other neurologi- cal or vascular mechanism that could directly or indirectly affect postural control over time. Until further studies are conducted, the use of magnets as a balance intervention should probably not be recommended. Martha R. Hinman, EdD Department of Physical Therapy The University of Texas Medical Branch Galveston, TX REFERENCES 1. Cherniack EP, Senzel RS, Pan CX. Correlates of use of alternative medicine by the elderly in an urban population. J Altern Complement Med 2001;7:277–280. 2. Cohen RJ, Ek K, Pan CX. Complementary and alternative medicine (CAM) use by older adults: A comparison of self-report and physician chart documenta- tion. J Gerontol A Biol Sci Med Sci 2002;57A:M223–M227. 3. Foster DF, Phillips PR, Hamel MB et al. Alternative medicine use in older Americans. J Am Geriatr Soc 2000;48:1560–1565. 4. Ramsey SD, Spencer AC, Topolski TD et al. Use of alternative therapies by older adults with osteoarthritis. Arthritis Rheum 2001;45:222–227. 5. Spoelhof GD, Foerst LF. Herbs to magnets: Managing alternative therapies in the nursing home. Ann Long Term Care 2002;10:51–57. 6. Suomi R, Koceja DM. Effect of magnetic insoles on postural sway measures in men and women during a static balance test. Percept Motor Skills 2001;92:469–476. 7. McLean MJ, Holcomb RR, Wamil AWet al. Effects of steady magnetic fields on action potentials of sensory neurons in vitro. Environ Med 1991;8:36–44. 8. McLean MJ, Holcomb RR, Wamil AWet al. Blockade of sensory neuron action potentials by a static magnetic field in the 10 mT range. Bioelectomagnetics 1995;16:20–32. 9. Cavapol AV, Wamil AW, Holcomb RR et al. Measurement and analysis of static magnetic fields which block action potentials in cultured neurons. Bioelec- tromagnetics 1995;16:197–206. IS THERE A ROLE FOR PUPILLOMETRY IN THE DIAGNOSTIC APPROACH OF ALZHEIMER’S DISEASE? A REVIEW OF THE DATA To the Editor: In Alzheimer’s disease (AD), the main neurotransmitter deficit is believed to be acetylcholine (Ach), which is also involved in the pupil reaction to light, 166 LETTERS TO THE EDITOR JANUARY 2004–VOL. 52, NO. 1 JAGS