Abstracts

Chronic inflammatory demyelinating polyneuropathy (CIDP) is considered to be an autoimmune disease of the peripheral nervous system, characterized by symmetrical weakness of the distal and proximal muscles, which increases progressively and persists for more than two months. It is associated with reduced sensitivity, lack or reduction of tendon reflexes, elevated protein levels in the cerebrospinal fluid, changes in nerve conduction due to demyelinization, and signs of demyelinization also in a nerve biopsy. CIDP may present in the recurrent form (with relapses) or in the chronic and progressive form ¹1 . Erdmann PG, van Meeteren NLU, Kalmijn S, Wokke JHJ, Helders PJM, van den Berg LH. Functional health status of patients with chronic inflammatory neuropathies. J Peripher Nerv Syst 2005;10:181-189. ^{, 2}2 . Köller H, Kieseier BC, Jander S, Hartung HP. Chronic inflammatory demyelinating polyneuropathy. N Engl J Med 2005;352:1343-1356. .

Axonal loss may occur as a result of demyelinization, leading to functional damage and a variable extent of physical symptoms that may impair the performance of daily life activities. Thus, evaluation of the magnitude of axonal loss is relevant to the prognosis of the disease, and the assessment of a positive response to treatment should consider improvement in patient strength, sensitivity and functional capacity ²2 . Köller H, Kieseier BC, Jander S, Hartung HP. Chronic inflammatory demyelinating polyneuropathy. N Engl J Med 2005;352:1343-1356. .

Since CIDP is a chronic condition that may have a progressive course leading to physical and functional limitations, an evaluation of quality of life and of the possible impact of the disease on the mental state of the patient can contribute to an understanding of the evolution of the disease and its prognosis.

Studies have suggested the importance of evaluating the quality of life of patients in order to complete an assessment of CIDP since this information would expand the doctor’s knowledge about the functional limitations of his/her pati<1?show=[fo]?>ent and the psychosocial impairment caused by the disease ³3 . Merkies ISJ, Schmitz PIM, van der Meché FGA, Samijn JPA, van Doorn PA, for the INCAT group. Quality of life complements traditional outcome measures in immune-mediated polyneuropathies. Neurology 2002;59:84-91. .

Evaluation of the quality of life of patients with CIDP has shown that this condition leads to greater impairment of functional capacity and physical health conditions than emotional and social aspects ³3 . Merkies ISJ, Schmitz PIM, van der Meché FGA, Samijn JPA, van Doorn PA, for the INCAT group. Quality of life complements traditional outcome measures in immune-mediated polyneuropathies. Neurology 2002;59:84-91.

4 . Harbo T, Andersen H, Overgaard K, Jakobsen J. Acute motor response following a single IVIG treatment course in chronic inflammatory demyelinating polyneuropathy. Muscle Nerve 2009;39:439-447.

5 . Westblad ME, Forsberg A, Press R. Disability and health status in patients with chronic inflammatory demyelinating polyneuropathy. Disabil Rehabil 2009;31:720-726. ^{- 6}6 . Merkies ISJ, Hughes RAC, Donofrio P, et al. Understanding the consequences of chronic inflammatory demyelinating polyradiculoneuropathy from impairments to activity and participation restrictions and reduced quality of life: the ICE study. J Peripher Nerv Syst 2010;15:208-215. . In addition, it seems that these physical limitations do not interfere with the emotional and social functioning of the patients ⁴4 . Harbo T, Andersen H, Overgaard K, Jakobsen J. Acute motor response following a single IVIG treatment course in chronic inflammatory demyelinating polyneuropathy. Muscle Nerve 2009;39:439-447. .

Regarding the instruments for evaluation, a study on patients with CIDP demonstrated that self-report measures about physical functions are as effective as clinical measures, although it was suggested that the most appropriate instruments for the evaluation of body function may vary according to the type of neuropathy studied ¹1 . Erdmann PG, van Meeteren NLU, Kalmijn S, Wokke JHJ, Helders PJM, van den Berg LH. Functional health status of patients with chronic inflammatory neuropathies. J Peripher Nerv Syst 2005;10:181-189. .

In view of the fact that an evaluation of quality of life and of the possible impacts on the mental status of the patient can contribute to an understanding of the evolution of the disease and its prognosis, the objective of the present study was to determine the sociodemographic and health-related quality of life profile of patients with CIDP managed by a general hospital.

METHOD

Study design and participants

This is a descriptive cross-sectional study approved by the Research Ethics Committee of the hospital in agreement with the Declaration of Helsinki regarding research on humans. Initial contact with the patient was made on the day of a routine visit to an outpatient clinic or during hospitalization, together with an evaluation of the patient. Participation in the study was random. All patients gave written informed consent to participate.

In this study, 41 out of 112 patients diagnosed with CIDP (and seen at the same clinic) were evaluated at the Neuromuscular Diseases Outpatient Clinic of the University Hospital of the Ribeirao Preto School of Medicine, University of Sao Paulo, from October 2009 to February 2012. We excluded three patients younger than 18 years and one patient with another suspected diagnosis that might have excluded CIDP if confirmed. The CIDP diagnosis was made in accordance with the European Federation of Neurological Societies and the Peripheral Nerve Society Guidelines ⁷7 . Joint Task Force of the EFNS and the PNS. European Federation of Neurological Societies/Peripheral Nerve Society Guideline on management of chronic inflammatory demyelinating polyradiculoneuropathy: report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society—First Revision. J Peripher Nerv Syst 2010;15:1-9. .

The mean age of the participants was 50.6 years (range: 26 to 76 years) and the mean duration of the disease was 5.7 years at the time of evaluation.

The sample consisted of 26 (63.4%) men and 15 (36.6%) women. Thirty-five patients (85.4%) declared that they followed a religion and only 11 (26.8%) were professionally active. Most participants had at least 8 years of schooling (58.5%) and cohabited with a companion (73.2%). Two participants could not respond to the SF-36 questionnaire owing to their time limitation.

Instruments

The patients were interviewed in order to gather sociodemographic data and information about the disease, i.e., information about sex, age, schooling, religion, housing conditions, habits and life routine, health problems, time of onset of symptoms, time since diagnosis, and previous and current treatments.

The Mini Mental State Examination (MMSE) was applied to evaluate cognitive abilities. The MMSE investigates temporal and spatial orientation, memory and language, with a score ranging from 0 to 30. The lower the score, the worse the cognitive status of the patient.

A 36-item Short-Form Health Survey (SF-36) (which originally formed part of the Health Outcomes Study) was applied in order to assess quality of life. This is a multidimensional questionnaire consisting of 36 items divided into eight categories: functional capacity, physical aspect, pain, general health status, vitality, social aspects, emotional aspects, and mental health.

RESULTS

General health

The information about general health is summarized in Table 1 . It can be seen that 27 (65.9%) participants had some health problem in addition to CIDP; 16 (39%) reported that they needed help to perform some daily life activities (bathing, getting dressed, going to the bathroom, transferring from the bed or the chair, controlling waste elimination, eating); 20 (49%) slept less than 8 hours per night, and 14 (34.1%) reported some memory difficulties. In addition, habits such as smoking and drinking alcohol were present, as well as physical and leisure activities.

Regarding the presence of other health problems, 12 (29.3%) participants had arterial hypertension, 12 (29.3%) had diabetes mellitus, 4 (9.8%) had hypothyroidism, and 14 (34.1%) had other diseases (each reported a different disease, and one stated that he had motor neuron disease).

Chronic inflammatory demyelinating polyneuropathy

The mean duration of CIDP (since the onset of symptoms) was 7.25 years (2-12) and the mean time since diagnosis was 5.74 years (1-10); 15 (36.6%) patients were under pharmacological treatment at the time of evaluation. The disease started exclusively with symptoms in the lower limbs (feet or legs) in 18 (43.9%) patients, in the lower and upper limbs in 17 (41.5%), and exclusively in the upper limbs (hands and arms) in 2 (4.9%), with 4 (9.8%) being unable to provide this information. More than half the participants (58.5%) reported that they had undergone some other type of treatment before receiving a diagnosis of CIDP, and 5 (12.2%) associated the onset of symptoms with a stressful event in their life. Table 2 presents the patients’ complaints at the time of evaluation.

Mental state and quality of life

The mean MMSE score was 26 (22-30) and the results of the SF-36 indicated greater impairment of functional capacity (mean 40.64) and pain (mean 58.68) ( Table 3 ).

DISCUSSION

The patients evaluated represented a little more than 40% of all patients with a CIDP diagnosis seen in a neuromuscular outpatient clinic of a CIDP referral center. Considering the low incidence of CIDP in the population, and despite the small number of participants, it was possible to outline the profile of these patients, favoring more information about the CIDP patients and raising new possibilities of investigation of the disease.

As also reported in studies conducted in other countries, CIDP patients are aged about 50 years old and the prevalence is twice as high among men ⁴4 . Harbo T, Andersen H, Overgaard K, Jakobsen J. Acute motor response following a single IVIG treatment course in chronic inflammatory demyelinating polyneuropathy. Muscle Nerve 2009;39:439-447. ^{, 8}8 . Saperstein DS. Chronic acquired demyelinating polyneuropathies. Semin Neurol 2008;28:168-184. ^{, 9}9 . Wadwekar V, Kalita J, Misra UK. Does the chronic inflammatory demyelinating polyradiculoneuropathy due to secondary cause differ from primary? Neurol India 2011;59:664-668. . So far, there are no scientific data to explain this male predominance, nor any hypothesis.

The mean age of the participants in our study was also similar to that reported in other studies, showing that CIDP affects a middle-aged population, with important socioeconomic impacts since the disease can impair the functional capacity of the patients, consequently leading to work losses.

The rate of professionally active patients (26.8%) demonstrates the socioeconomic impact of CIDP, despite a low overall incidence. Prevalence rates of 0.15-5 per 100,000 individuals have been found in developed countries ¹⁰10 . Baig F, Knopp M, Rabajally YA. Diagnosis, epidemiology and treatment of inflammatory neuropathies. Br J Hosp Med 2012;73:380-385. . There is an obvious importance to expanding our knowledge about the clinical course of the disease and the associated functional and quality of life changes.

There appear to be no previous studies concerning the level of activity of patients with CIDP. Although some studies evaluated functional capacity, they did not mention work activity, leisure or physical activity. One exception was a study that aimed to determine the impact of physical activity on muscle strength ¹¹11 . Garssen MP, Bussmann JB, Schmitz PI, et al. Physical training and fatigue, fitness and quality of life in Guillain Barré syndrome and CIDP. Neurology 2004;63:2393-2395. .

If we compare the information about daily physical activity (80.5% of the patients reported an active routine, with activities inside and outside home) with the number of professionally active patients (26.8%) in the present study, we may question whether some of these patients could have returned to the job market or even never have abandoned it if patients with CIDP received a more health-integrated care package (complete diagnostic tests, physiotherapy and physical activity, appropriate pharmacotherapy) and an earlier diagnosis. It is known that, with treatment, 60% of patients have a monophasic or recurrent form of the disease, while 40% have a progressive form ¹²12 . Whitesell J. Inflammatory neuropathies. Semin Neurol 2010;30:356-364. .

Regarding general health, almost two-thirds of the patients reported some other problems, including arterial hypertension and diabetes mellitus (DM). Although some studies have pointed out the co-occurrence of CIDP and DM, we found no evidence of an association between the two diseases. In our sample, we detected a rate of DM incidence that was almost five times higher than that reported in an epidemiological study conducted in a North American city ¹³13 . Laughlin RS, Dyck PJ, Melton LJ, Leibson C, Ransom J, Dyck PJB. Incidence and prevalence of CIDP and the association of diabetes mellitus. Neurology 2009;73:39-45. , namely 29.3% compared with 4% in the cited study.

Regarding the co-occurrence of hypertension, we found no information in the literature, except that hypertension has been reported to be a side-effect of treatment with intravenous immunoglobulin ¹⁴14 . Hughes RA, Donofrio P, Bril V, et al. Intravenous immune globulin (10% caprylate-chromatography purified) for the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (ICE study): a randomised placebo-controlled trial. Lancet Neurol 2008;7:136-144. .

With respect to the use of tobacco and alcohol, the rate of smoking observed in the present study was higher than the prevalence rate for Brazil as a whole (17.2%), a fact that may be possibly explained by the larger number of men in our sample, since cigarette smoking is higher among men than among women ¹⁵15 . Almeida L, Szklo A, Sampaio M, et al. Global adult tobacco survey data as a tool to monitor the WHO Framework Convention on Tobacco Control (WHO FCTC) implementation: the Brazilian case. Int J Environ Res Public Health 2012;9:2520-2536. .

Specifically regarding CIDP, we observed an interval of one and a half years between the mean time of disease onset (the start of symptoms reported by the patient) and the mean time of diagnosis. This difference may result from a variety of factors: a delay in the patient seeking health advice or a delay in being referred for specialized evaluation; scarcity or absence of equipment and of qualified personnel in the services to which the patient was referred for specialized exams, e.g., electroneuromyography or nerve biopsy; difficulty in reaching a differential diagnosis with Guillain-Barré syndrome and Lewis-Sumner syndrome; and a variety of subtypes of the disease, also impairing a differential diagnosis of CIDP ²2 . Köller H, Kieseier BC, Jander S, Hartung HP. Chronic inflammatory demyelinating polyneuropathy. N Engl J Med 2005;352:1343-1356. ^{, 16}16 . Joint Task Force of the EFNS and the PNS. Guideline on management of chronic inflammatory demyelinating polyradiculoneuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society. J Peripher Nerv Syst 2005; 10:220-228. .

The abovementioned conditions may explain the large number of patients who stated that they had undergone other treatments before receiving their diagnosis.

Almost all patients reported initial symptoms affecting the lower limbs. Although this is characteristic of the disease, it is possible that impaired walking is more often remembered by the patients because it has a greater impact on their quality of life and on their activities and relationships since it can limit both mobility and independence. After evaluation by the neurology service, almost half of the patients in our study (18 of 41) had difficulty in walking and moving; they also experienced tripping and falls.

The results of the MMSE were similar to those reported in another study on the Brazilian population ¹⁷17 . Castro-Costa E, Fuzikawa C, Uchoa E, Firmo JO, Lima-Costa MF. Norms for the mini-mental state examination: adjustment of the cut-off point in population-based studies (evidences from the Bambuí health aging study). Arq Neuropsiquiatr 2008;66:524-528. , and the Brazilian cut-off scores were as expected for the MMSE (13 for illiterates, 18 for low/middle school age and 26 for high school age) ¹⁸18 . Brito DMS, Araújo TL, Galvão MTG, Moreira TMM, Lopes MVO. Qualidade de vida e percepção da doença entre portadores de hipertensão arterial. Cad Saúde Pública 2008;24:933-940. . However, even though cognitive screening did not suggest impairment in cognitive function, one-third of the patients reported memory deficits, a fact that needs further investigation, with special emphasis on this function.

Regarding quality of life, the results for the patients in our study were similar to those obtained in other studies, though slightly better for hypertensive patients in the following categories: physical aspects, pain, general health status, emotional aspects and mental health ¹⁸18 . Brito DMS, Araújo TL, Galvão MTG, Moreira TMM, Lopes MVO. Qualidade de vida e percepção da doença entre portadores de hipertensão arterial. Cad Saúde Pública 2008;24:933-940. . The greatest difference in results was observed in the functional capacity category – 40.64 for CIDP patients and 66.28 for hypertensive patients. Functional capacity data were quite similar to those obtained for patients with rheumatoid arthritis ¹⁹19 . Campolina AG, Bortoluzzo AB, Ferraz MB, Ciconelli RM. O questionário SF-6D Brasil: modelos de construção e aplicações em economia da saúde. Rev Assoc Med Bras 2010;56:409-414. . It is possible that our CIDP patients had specialized neurological evaluation or received a diagnosis only when functional impairment was already significant. It should be borne in mind that perhaps most of the patients evaluated had progressive CIDP with consequent lower results regarding functional capacity. It should be remembered that in the present study we did not determine whether CIDP was monophasic, recurrent or progressive.

Compared with one Danish study ⁴4 . Harbo T, Andersen H, Overgaard K, Jakobsen J. Acute motor response following a single IVIG treatment course in chronic inflammatory demyelinating polyneuropathy. Muscle Nerve 2009;39:439-447. , our patients showed greater impairment of quality of life, except in the categories of general health status and vitality. However, the Danish study evaluated 14 patients, whereas our study evaluated 41. Furthermore, the differences may also be related to cultural differences since the quality of life construct is not objective and the data were derived from a self-report measure.

Regarding health questions, many patients reported sleep and memory difficulties. We may hypothesize that paresthesias and pain interfere with the sleep of the patients. However, a more in-depth evaluation is necessary, also to determine the need for a direct intervention regarding this problem. Improved sleep may favor quality of life for patients with CIDP. Similarly, new investigations may clarify whether or not there is a link between the memory difficulties reported by patients and the disease or its treatment. It is possible that, facing such uncomfortable symptoms as paresthesias, weakness or difficulty in walking or moving the hands, the patients dismiss small memory difficulties or even other non-physical symptoms. We have not been able to find any reports in the literature about the association between memory and CIDP, or about a possible impact of this condition on sleep.

We wish to thank the psychologist Fabiana Ponton for collaboration with the data collection.

References

Publication Dates

History