L A A GENCIA PARA EL D ESARROLLO I NTERNACIONAL DE E STADOS U NIDOS

Following the Yom-Kippur War of 1973 in Israel, Yehuda Ben-Yishay, who had studied under Kurt Goldstein in the late 1950s, had an opportunity to develop the first holistic program for brain-injured soldiers. He observed that the residual cognitive, emotional and behavioural sequelae of head injury greatly exceed the physical, as a cause of difficulties in long-term vocational rehabilitation (Ben-Yishay, Silver, Piasetsky, & Rattok, 1987). A number of studies (Bond, 1975; Bruckner & Randle, 1972; Weddell, et al., 1980) had indicated that TBI patients with greater memory, learning and personality deficits had poorer work adjustments, than those with similar degrees of injury-severity but fewer deficits in those areas. Other problems, such as social isolation, spontaneity and a tendency to fatigue were barriers to return to

premorbid occupations in a number of other studies (Barth, et al., 1983; Prigatano, Fordyce, & Zeiner, 1984).

In order to respond to these observations, Ben-Yishay developed a holistic (cognitive, interpersonal and vocational) neuropsychological rehabilitation outpatient program for young TBI patients who had failed to benefit from conventional

rehabilitation approaches (Ben-Yishay & Diller, 1981; Ben-Yishay, et al., 1987). This program comprised three phases: the first phase was devoted to a 20-week intensive and systematic holistic individual and group remedial intervention, to ameliorate cognitive deficits in basic attention, finger dexterity, constructional praxis, visual-spatial

information processing and verbal logical reasoning. A small-group procedure was designed to improve interpersonal communication, social competence, awareness and acceptance of the consequences of the head injury. The second phase was devoted to guided occupational trials, with a detailed and explicit treatment plan for each patient, based on the findings from the first phase. Occupational trials were conducted in actual work situations (offices, shops, libraries, services etc) under the guidance and

supervision of a vocational counsellor. Work competence, level of productivity and the interpersonal appropriateness of the patients were judged jointly by the vocational counsellor and the actual supervisor at the work place. Participants were given an “employability” rating which was used in the third phase of the study to find work commensurate with their proven ability. Follow-up in this third phase was designed to assist participants to make initial adjustments to the new work environment. Discharge procedures included the establishment of a close liaison with the new employer, and with the local private or community services, agency-based mental health workers and/or vocational guidance practitioners, who provided the maintenance support service to the patient once he or she was back in the community.

The program was initially tested with 94 TBI patients, with an average age of 27 years. All but two were at least 12 months post-injury, when they began the program and, all were deemed unemployable, or unable to pursue academic studies, in any capacity. At the completion of the program, 84% were found to have attained the ability to engage in productive endeavours, 63% at a competitive level and 21% in a subsidized capacity; 16% were rated as unemployable/unproductive in any capacity. Over the three-year follow-up period, the percentage of patients who were rated as unemployable did increase, with decrements in employability being related to three factors: social isolation coupled with the absence of adequate maintenance and support systems, forgetting to consistently apply the rehabilitation strategies they had been taught, and financial disincentives to work.

Evaluating the results of this program, it was noted that participation yielded statistically significant improvement on a majority of measures in the areas of

neuropsychological functioning, interpersonal and social skills and daily-life functional competence. However the magnitude of the improvements was modest. The authors concluded that the principal sources of the successful vocational outcomes were improvements in self-awareness, acceptance of the consequences of the injury and increase in the effectiveness of functional application of the residual information processing abilities (rather than an increment in the capacity levels per se). The basic model of Ben-Yishay’s program has been emulated in many countries (Holsinger, et al., 2002; Prigatano, et al., 1984; Scherzer, 1986) and there is substantial evidence to

4.2 Mild TBI

Despite the fact that approximately 80% of TBIs are mild (Cassidy, et al., 2004b), little attention was paid to mild TBI (mTBI) until the 1980s (Ruff, 2005), when a number of papers documented the fact that, in a percentage of cases, long-term

sequelae of the injury prevented return to work (Barth, et al., 1983; Rimel, Giordani, & Barth, 1981). Because many of the patients with persisting symptoms in these studies were seeking follow-up services, questions arose about whether or not they were representative of all mild injuries. In response to these questions, Levin, Mattis and Ruff (1987) undertook a prospective study of 57 mTBI patients (LOC of 20 minutes or less, GCS score of 13 to 15, no focal neurological deficits, no complications on CT scan and no history of neurological disorder, previous TBI, sustained alcohol or drug use and no hospitalisation for a psychiatric disorder) and 56 healthy controls, matched according to age, education, race and socio-economic background. These two groups were

followed-up at one and three months post-injury. The conclusion that these authors came to was that “a single uncomplicated minor head injury rarely produces chronic disability or permanent cognitive impairment ” (Levin, et al., 1987, p. 242).

Experimental studies in humans and animals in the late 80s confirmed findings from earlier studies of mTBI patients who died of other causes, that diffuse microscopic axonal injuries were associated with mTBI (Oppenheimer, 1968). This evidence

supported the hypothesis that microscopic brain damage can result from even a mild injury, and the inference that this is the cause of ongoing PCS. Over time this idea was challenged by those who maintain psychopathology, and not neuropathology, to be the primary cause of ongoing symptoms, and two conflicting schools of thought emerged (Ruff, 2005), with debate continuing to the present time. However clinical consensus

needed to be identified in order for appropriate rehabilitation interventions to be

designed and implemented. Kay et al. (1992) have proposed a model (see figure 4.1) for understanding functional disability after mTBI.

Figure 4.1 Neuropsychological Model of Mild Traumatic Brain Injury (Kay, et al., 1992)

The model contains the following three factors, represented by boxes on the left: Physical Factors related to the TBI, co-morbid injuries and/or treatment that can directly affect the ability to function. For example pain, fatigue, sleep problems, sensory deficits or hypersensitivity, balance problems and effects of medication.

Psychological Factors are internal structures or responses that affect the ability to function. These can include personality style, affective status (especially anxiety and depression), sense of self, degree of psychological overlay, psychosocial situation (friends, family, job), and response to or motivations for being in litigation.

Neurological Factors include both pre-existing factors such as age, brain integrity and previous damage to the brain, and injury-related factors, which includes both structural damage and also non-structural damage such as neurotransmitter changes. In

Neurological Factors Objective Cognitive Subjective Cognitive Psychological Factors Physical Factors Functional Outcome

combination, these factors determine the extent of damage to the brain, and whether the effects are temporary or permanent.

An important aspect of the model is the distinction between objective cognitive deficits and subjective cognitive deficits, each represented by an oval. Objective

cognitive deficits are those primary cognitive changes determined directly by damage to the brain. The subjective cognitive deficits are the breakdowns in mental processing experienced by the injured-person and manifested on neuropsychological testing. These can be caused not only by objective cognitive deficits due to the brain injury, but by psychological and physical factors as well.

The dotted lines in the model indicate paths of influence that may weaken and even disappear with time. This can result in functional disability that continues, even after the disappearance of the objective factors that set the system in motion.

The three factors interact in complex ways, as indicated by the lines and arrows in the model. For example, a patient may complain of being unable to concentrate and show neuropsychological deficits on a number of tests of attention. The model suggests two possibilities. In one case neurological damage may be directly causing primary cognitive deficits that directly impact functioning. Under a second scenario, objective cognitive impairment is quite minimal, but, because of psychological factors, the presence of even mild distractibility causes enormous anxiety and fear, resulting in a strong flow from the psychological factor into the subjective cognitive factor. In the first case, the link between objective cognitive factors and functional outcome carries the greatest weight of influence; in the second, the connection between psychological factors and subjective cognitive causes the greatest impact on functional outcome. In these two cases the implications for intervention are profoundly different: in case one a

cognitive remedial intervention would be appropriate, while in the second case an intervention to reduce anxiety would be indicated.

The authors of this model outline its implications for treatment and set out clinical guidelines for both early preventative therapy, and late interventions in patients who present for rehabilitation, months or even years post-injury. The model has been validated empirically in both adults (Paniak, Toller-Lobe, Reynolds, Melnyk, & Nagy, 2000; Ponsford et al., 2002) and children (Ponsford et al., 2001).