Handbook of Solvents - George Wypych - ChemTech - Ventech!

20.2 Cognitive and psychosocial outcome 1329
fered peak exposures, the occupational physician will examine and interview the worker
(and where possible a close family member) and make an initial assessment regarding the
worker’s symptoms. It is not uncommon at this interview stage for the worker, often a middle-aged
tradesman not accustomed to talking about his cognitive or emotional problems, to
break down in tears. Most health professionals experienced in assessing OSN are in no
doubt that it is a real syndrome with devastating consequences for the worker and family. 6
If the symptom complex generally fits with that typical of OSN, the symptoms are significant
enough to be causing the worker or his family concern, and other possible causes
have been explored and considered to be unlikely as the primary cause of the problems, the
worker will proceed to a neuropsychological assessment. Whenever possible, this should
take place following two or more weeks away from solvents. This is again a somewhat arbitrary
time period, arrived at in an attempt to find a balance between the real time it takes for
any acute effects of a mixture and range of solvents to resolve, and the amount of time (usually
unpaid) an undiagnosed worker is willing or able to take away from his workplace. The
assessment usually commences with a psychological assessment, which may include both
an interview and standard questionnaires on mood, fatigue levels, motivation, memory
problems in daily life and so on. Often, with the worker’s permission, information is also
obtained from family members and work colleagues. Not only does this allow an assessment
of the problems the worker is experiencing at work and at home, but also gives the
neuropsychologist some idea of the time course of these problems. Other possible confounding
psychosocial factors are checked out at this point. Whilst factors such as a high use
of alcohol, or a series of minor head injuries whilst playing sport 10 years previously, or a
recent marriage breakup, may not negate the possibility of the worker being diagnosed as
suffering from OSN, clearly these factors must be taken into account in making the diagnosis
and the confidence that can be placed in that diagnosis, as well as when designing an intervention
or rehabilitation program for the worker.
Having ascertained that the worker’s exposure levels and psychological and subjective
cognitive symptoms (e.g., complaints of memory problems) meet the criteria for possible
OSN, a battery of carefully chosen neuropsychological tests is then given. This is often
scheduled for a later session, given the distress that the worker may have expressed during
the interview, and the high fatigue levels that are a common consequence of OSN. This battery
should include one or more tests which can, along with education and occupational history,
provide an estimate of the worker’s cognitive ability level prior to working with
solvents. Also included should be some tests which one would not expect to be impaired by
solvents, such as well-established vocabulary (meanings of words). Tests which are included
because of their sensitivity to OSN symptoms include tests of concentration and attention,
new verbal and visuospatial learning and memorizing (old, well-established
memories are rarely impaired), reaction time, psychomotor speed, and planning, organizational
and abstraction abilities.
If the pattern of spared and impaired psychological and neuropsychological test results
is typical of OSN, and other factors can be ruled out as the primary cause of this profile,
the worker will be diagnosed as having OSN. 6,10 This pattern analysis provides one way of
guarding against malingering, as the worker does not know which tests he or she should remain
unimpaired on and which are commonly impaired following OSN. In addition, on
many tests, it is very difficult or impossible for the malingerer to perform in a way that is
consistent with true organic impairment, even if he or she has been coached on how to per-