Fatigue is a subjectively experienced and complex phenomenon and one of the most
common symptoms in the post-polio syndrome (PPS) occurring in up to 90% of the
patients. Experiencing fatigue, negatively impacts work performance, family life, social
relationships, and the quality of life (QOL). The origin of fatigue can be central or
peripheral and can be experienced in different ways, for example as general, physical,
mental, or muscle fatigue.
The overall aim of the thesis was to evaluate and analyse fatigue in PPS patients.
Specific aims were: to find if generally fatigued PPS patients demonstrate deficits in
cognition compared with non-fatigued: to evaluate vitality and fatigue and the relative
contribution of physiological and psychological parameters on the level of vitality: to
characterise fatigued and non fatigued PPS patients, and to define subgroups across the
fatigue continuum; and finally, to describe quality of life characteristics as measured by
SF-36 in responders and non-responders after intravenous immunoglobulin treatment
(IVIG).
The work encompasses three samples of PPS patients. Study I includes twenty PPS
patients with and without general fatigue from the post-polio out-patient clinic at
Huddinge University Hospital. Study II and III analyses baseline data from 143 PPS
patient from a Swedish multicenter study and Study IV is based on follow-up data from
112 patients from the post-polio out-patient clinic at Danderyds University Hospital
before and after IVIG treatment.
Cognitive performance differences could not be detected between the fatigued and nonfatigued
PPS patients and systematic varying of the test order did not significantly
trigger mental fatigue. Vitality in PPS patients was mostly dependent on physiological
rather than psychological parameters and mental fatigue was not a prominent predictor.
On the contrary to what were expected vitality increased and fatigue as well as pain
decreased with increasing age. Fatigued PPS patients were characterized by significant
lower age, more physical problems and lower QOL than non-fatigue PPS patients.
Furthermore, in the fatigued group mental fatigue had a relatively greater importance
than physical fatigue. In the total sample of PPS patients the scores for SF-36 sub
domains Vitality, Bodily pain, Social function, Role emotional and MCS were
significantly improved after IVIG treatment at the 6-month follow-up. Vitality and
Bodily pain were identified as possible outcome variables for IVIG treatment and
positive-, non- and negative responders were identified. Responders for treatment were
characterised by a low vitality i.e. a high fatigue before treatment.
It is concluded that fatigue in PPS is mostly physical in its character; General fatigue
does not affect cognition in PPS. Mental fatigue is not a prominent phenomenon.
Fatigued PPS patients may be considered as a subgroup and there are PPS patients with
both positive and negative responses to IVIG treatment. PPS patients with high levels of
fatigue and pain before treatment are the ones who may benefit from the IVIG
treatment
