deployed elsewhere, more frequently reported the following symptoms: skin rash, cough, depression, unintentional weight loss, insomnia, and memory problems. The pattern of symptom reporting is similar to that reported by men and women who participated in the Iowa study. In addition, women deployed to the Gulf War were more likely than controls to report gender-specific problems, such as breast cysts and lumps, and abnormal cervical cytology (Pierce, 1997).

The first published study to search for new syndromes was conducted by Haley and collaborators (1997b). They studied a battalion of naval reservists called to active duty for the Gulf War (n = 249). More than half of the battalion had left the military by the time of the study. Of those participating, 70 percent reported having had a serious health problem since returning from the Gulf War, while about 30 percent reported having no serious health problems. The study was the first to cluster symptoms into new syndromes by applying factor analysis (see above). Through standardized symptom questionnaires and two-stage factor analysis, the investigators defined what they considered to be either six separate syndromes or six variants of a single syndrome, which they labeled impaired cognition, confusion–ataxia, arthromyoneuropathy, phobia–apraxia, fever–adenopathy, and weakness–incontinence. One-quarter of the veterans in this uncontrolled study (n = 63) were classified as having one of the six syndromes. The first three of the syndromes had the strongest factor clustering of symptoms (see earlier discussion of factor analysis and Chapter 6).

In a follow-up study of the same cohort, Haley and colleagues (1997a) used a case-control design to examine neurological function. They chose as cases the 23 veterans who had scored highest on the three syndromes with the strongest factor clustering. The results of extensive neurological and neuropsychological testing, demonstrated that cases had significantly greater evidence of neurological dysfunction when compared with two small groups of healthy controls from the same battalion.14 Investigators concluded that the three syndromes, derived from factor analysis of symptoms, may signify variant forms of expression of a generalized injury to the nervous system.15 In a subsequent study, cases with one of the three syndromes were more likely than healthy controls to exhibit vestibular dysfunction (Roland et al., 2000).

The three syndromes identified by Haley and colleagues (1997b) were the focus of a companion case-control study that examined their relationship to self-reported exposures to neurotoxins. The study tested the hypothesis that exposure

14  

One group of healthy controls (n = 10) was deployed to Gulf War, whereas the other group (n = 10) was not.

15  

Neuropsychological or neurological impairments have been the focus of several smaller studies as well. Some found subtle changes in nerve conduction velocity and cold sensation (Jamal et al., 1996) and in certain tests of finger dexterity and executive functioning (Axelrod and Milner, 1997), while other studies found no significant differences in measures of nerve conduction and neuromuscular functioning (Amato et al., 1997) or neuropsychological performance (Goldstein et al., 1996). Numerous ongoing studies are designed to probe further whether Gulf War veterans have measurable impairments of neurological or neuropsychological performance (CDC, 1999; Research Working Group, 1999).



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