Improvement in social function and health-related quality of life after shunt surgery for idiopathic normal-pressure hydrocephalus

Clinical article

Full access

Object

To investigate the impact of shunt surgery on the activity, participation, autonomy, and health-related quality of life (HRQOL) of patients with idiopathic normal-pressure hydrocephalus (iNPH) as well as the effect on caregiver burden.

Methods

Thirty-seven patients (median age 70 years, range 50–89 years) with iNPH were evaluated before and 6 months after surgery. Symptoms and signs were assessed by the iNPH scale, activities of daily living (ADL) with the Functional Independence Measure (FIM) and Assessment of Motor and Process Skills (AMPS), autonomy and participation with Impact on Participation and Autonomy (IPA), and caregiver burden with the Caregiver Burden Scale (CBS). HRQOL was evaluated with the EQ-5D (EuroQol Group–5 Dimension health survey).

Results

Twenty-four patients (65%) improved clinically (iNPH scale score) and 31 (86%) improved their HRQOL after surgery, almost to the same level as found in the normal population. The patients became more independent in physical and cognitive activities, and participation and autonomy improved. The caregiver burden was decreased among caregivers to male patients but remained unchanged on the overall group level.

Conclusions

After shunt surgery, patients with iNPH showed improvement in most aspects of social life, they became more independent, and their quality of life returned to nearly normal.

Abbreviations used in this paper:ADL = activities of daily living; AMPS = Assessment of Motor and Process Skills; CBS = Caregiver Burden Scale; EQ-VAS = EQ-5D visual analog scale; FIM = Functional Independence Measure; HRQOL = health-related quality of life; ICF = International Classification of Functioning, Disability and Health; ICP = intracranial pressure; iNPH = idiopathic normal-pressure hydrocephalus; IPA = Impact on Participation and Autonomy; TTO = time trade off; ZBI = Zarit burden interview.

Abstract

Object

To investigate the impact of shunt surgery on the activity, participation, autonomy, and health-related quality of life (HRQOL) of patients with idiopathic normal-pressure hydrocephalus (iNPH) as well as the effect on caregiver burden.

Methods

Thirty-seven patients (median age 70 years, range 50–89 years) with iNPH were evaluated before and 6 months after surgery. Symptoms and signs were assessed by the iNPH scale, activities of daily living (ADL) with the Functional Independence Measure (FIM) and Assessment of Motor and Process Skills (AMPS), autonomy and participation with Impact on Participation and Autonomy (IPA), and caregiver burden with the Caregiver Burden Scale (CBS). HRQOL was evaluated with the EQ-5D (EuroQol Group–5 Dimension health survey).

Results

Twenty-four patients (65%) improved clinically (iNPH scale score) and 31 (86%) improved their HRQOL after surgery, almost to the same level as found in the normal population. The patients became more independent in physical and cognitive activities, and participation and autonomy improved. The caregiver burden was decreased among caregivers to male patients but remained unchanged on the overall group level.

Conclusions

After shunt surgery, patients with iNPH showed improvement in most aspects of social life, they became more independent, and their quality of life returned to nearly normal.

Idiopathic normal-pressure hydrocephalus (iNPH) is a condition in the elderly with enlarged ventricles and normal intracranial pressure (ICP), clinically characterized by an insidious onset and gradual progression of impairments of gait, balance, cognition, and urinary continence.10

The prevalence of iNPH is high—for example, in Japan among people older than 65, the prevalence is between 0.5% and 2.9%14,15,26—and the syndrome is both underdiagnosed and undertreated.3,4

The standard treatment of iNPH is insertion of a ventriculoperitoneal or a ventriculoatrial shunt, and both are considered equally effective.1

Although shunt placement operations have been performed for more than 50 years, there are very few reports on how the surgery affects the patient's everyday life. The World Health Organization (WHO) released a standardized nomenclature to understand and describe people's health in 2001: the International Classification of Functioning, Disability and Health (ICF). It has its focus on the impact of the present condition rather than its cause and takes social aspects of disability into account. It consists of 2 lists of domains: a list of function and structure and a list of domains of activity and participation.30

The patients' perceived quality of life and the burden experienced by caregivers are also important. Taking care of patients with disabilities is very stressful, and a lot of caregivers spend a substantial amount of time on informal care.29 In one of few reports, Kazui et al. found that caregiver burden decreased after iNPH surgery, with improvement in patients' cognitive functions having the highest impact on the reduction of caregiver burden.16

The aim of this study was to investigate the social impact of shunt surgery in iNPH patients, specifically changes in activities of daily living (ADL), participation, autonomy, caregiver burden, and patient's health-related quality of life (HRQOL).

Methods

Patients

Thirty-seven patients with iNPH (median age 70 years, range 50–89 years) were examined by an occupational therapist (J.B.) before and 6 months after surgery (Table 1).

TABLE 1:

Demographic characteristics, frequency of risk factors, and caregivers' status for 37 patients with iNPH*

VariableValue
demographic characteristics
 age (yrs)
  median70
  range50–89
 sex
  male23
  female14
 employment
  working6
  retired31
 MMSE score
  mean24
  range15–30
risk factors
 diabetes9 (24%)
 hypertension19 (51.4%)
 vascular disease7 (18.9%)
caregiver
 partner22 (20 living w/ pt)
 sibling1 (0 living w/ pt)
 children8 (0 living w/ pt)

Values represent numbers of patients or caregivers except as otherwise indicated. MMSE = Mini-Mental State Examination; pt = patient.

The inclusion criteria were a gradually developed gait and balance disturbance and/or mental deterioration and/or bladder disturbance according to the guidelines developed by Marmarou et al.20 Enlarged ventricles with an Evans index > 0.30 and evidence of an open aqueduct on MRI were also required. A lumbar puncture was performed in all cases, and the ICP was determined (< 18 mm Hg in all) and CSF specimens were collected for biomarker analyses. Patients with periventricular and deep white matter changes and lacunar infarction were included. The study was part of a multicenter trial to investigate the optimal pressure setting and all patients had an infusion manometric examination performed prior to surgery. Those who diagnosed the patients and those who made the clinical assessments discussed in this article were blinded to the results of the infusion measurements. Evaluation of function, ADL, participation, autonomy, HRQOL, and caregiver burden were only done locally.

Exclusion criteria were acute hydrocephalus, more than 1 cortical infarct, inability to participate in the tests or investigations, and restricted life expectancy or medical contraindications to surgery. Presence of antecedent causes of secondary NPH was also ground for exclusion.

All patients received a ventriculoperitoneal shunt with a Codman Hakim programmable valve with an antisiphon device.

Six of the 37 patients had home service prior to surgery. Five patients needed help with personal ADL and 23 needed help with instrumental ADL.

The study was approved by the regional ethics committee of Gothenburg, Sweden. Informed consent was obtained from the patient and/or family member.

Instruments

The iNPH scale developed by Hellström et al. measures symptoms and signs in 4 different domains: gait, cognition, continence, and balance.13 The domain scores as well as the total score are between 0 and 100, where 100 represents absence of symptoms and 0 the most severe state. Improvement is defined as an increase of 5 or more points in the total score. Examination was performed by a physician, a physiotherapist, and a neuropsychologist at the iNPH unit of Sahlgrenska University Hospital.

Functional Independence Measure (FIM) is an ordinal scale measuring the severity of disability by rating how independently a patient can perform different activities in 2 main domains; one physical and one cognitive. The physical domain consists of 13 activities of different difficulty, ranging from eating to climbing stairs. The cognitive domain consists of 5 activities, including communication and social and cognitive ability in activities. Each activity is ranked from 1 to 7 (1 is total dependence and 7 total independence). The total score in each domain is presented.18

Assessment of Motor and Process Skills (AMPS) is an observational evaluation method that measures a person's motor and processing ability while performing instrumental and personal ADL in a familiar environment. It consists of 16 ADL motor skill items and 20 ADL process skill items that the examiner rates (4 = competent, 3 = questionable, 2 = ineffective, 1 = deficit) across 2 ADL tasks. The raw scores are converted to linear motor scores and process scores using the many-faceted Rasch model.9

Impact on Participation and Autonomy (IPA) is a patient-reported questionnaire for evaluation of participation and autonomy. It consists of 5 subscales: autonomy indoors (7 items), family role (7 items), autonomy outdoors (5 items), social life and relationship (7 items), and work and education (6 items). Each item is graded by the patient from 0 (very good) to 4 (very poor).6

The EQ-5D (EuroQoL–5 Dimension health survey) is an instrument for measuring HRQOL.28 It consists of a 5-dimensional questionnaire measuring mobility, selfcare, usual activities, pain/discomfort, and anxiety/depression. Every dimension can be scored using 3 levels: no problem, some or moderate problems, and extreme problems, corresponding to a score. This gives 243 different health status combinations that can be converted into an index value. The value is based on data generated from a national general public survey using the time-trade-off (TTO) method to elicit mean TTO values to each health state. Since there is no Swedish TTO tariff for EQ-5D health states, the UK EQ-5D index tariff was used.24 EQ-5D also contains a visual analog scale (EQ-VAS) with which patients can rate their HRQOL from 0 to 100, where 0 is the worst imaginable health state and 100 the best imaginable health state. Improvement is defined as a gain of 0.05 index points or 10 points on EQ-VAS. The result was related to values for healthy individuals.5,25

The Caregiver Burden Scale (CBS) is a questionnaire with 22 questions about caregiver burden divided into 5 different categories: general strain (8 questions), isolation (3 questions), disappointment (5 questions), emotional involvement (3 questions), and environment (3 questions). Answers are scored from 0 to 3 (not at all, hardly, somewhat, and definitely). Each category score is presented as the mean of included questions.7

Patients also filled out a questionnaire with questions on how many hours of help they need with ADL and whether they have home service or not.

Data Analysis

All statistical analyses were performed using IBM SPSS Statistics 21. Due to the ordinal nature of most of the outcome scales and the fact that the variables were not normally distributed, nonparametric methods were used. To determine if there was a difference between the scores on a certain scale before and after surgery, the Wilcoxon signed-ranks test was used. Values for change were calculated based on the cases for which both preoperative and postoperative data were available. To look for differences in outcome or changes between groups, the Mann-Whitney U-test or Kruskal-Wallis test was used. A correlation between 2 independent variables was investigated by using Spearman rank-order correlation test. The significance level was set to 0.05 and only correlations that were significant before and after surgery are reported, with the highest coefficient; p values were not adjusted for multiple comparisons, partly because of variations in sample sizes and partly to avoid Type II errors when the results displayed consistent patterns.

To be able to compare patients' HRQOL with values for the normal population, patients were divided into 4 different age groups (50–59, 60–69, 70–79 and 80+ years).

Results

Twenty-four (65%) of the patients showed improvement (> 5 points in total iNPH scale score) after surgery (p < 0.001) and 12 (32%) did not. One patient could not be properly evaluated, and this patient's condition was considered not improved. Gait and cognition improved significantly after surgery (p < 0.01 for both), while the domains balance and continence did not. The total iNPH scale score improved after surgery (p < 0.001) (Table 2).

TABLE 2:

Pre- and postoperative scores on the iNPH scale, FIM, AMPS, IPA, CBS, and HRQOL in 37 patients with iNPH

MeasurePreopPostopChangeNo. of Pts.
function
 iNPH gait47.0 (32.3–62.0)79.4 (50.5–90.3)21.3 (3.3–42.4)**35
 iNPH cognition65.0 (40.0–86.9)76.3 (56.3–85.6)7.5 (−2.5–15.0)**32
 iNPH balance67.0 (67.0–83.0)67.0 (67.0–83.0)0 (0–16.0)35
 iNPH continence60.0 (50.0–80.0)80.0 (60.0–100.0)0 (0–20.0)36
 iNPH total61.2 (48.9–75.0)75.3 (62.8–82.5)13.5 (1.8–21.7)**36
activity
 FIM physical77 (70–80)83 (80–87)6 (3.5–10)**37
 FIM cognition30 (28–33)33 (30.5–34)1 (0–3)**37
 AMPS motor0.5 (0.2–0.7)1.3 (0.8–1.55)0.7 (0.25–1.25)**25
 AMPS process0.6 (0.25–1.25)1.3 (0.95–1.6)0.5 (0.15–0.95)**25
autonomy & participation
 IPA autonomy indoors1.22 (0.63–1.7)0.4 (0–1.15)−0.45 (−1.0 to 0)**36
 IPA family role1.7 (1.03–2.38)1.4 (0.9–1.95)−0.40 (−0.98 to 0.1)**36
 IPA autonomy outdoors1.7 (1.0–2.4)1.0 (0.7–2.0)−0.55 (−1.15to 0.35)**36
 IPA social life & relationship1.1 (0.7–2.05)1.0 (0.55–1.4)−0.40 (−0.7 to 0.1)**36
 IPA work & education2.3 (1.4–2.9)1.8 (0–2.35)−0.6 (−1.3 to 0.3)*6
caregiver burden
 CBS general1.3 (0.4–1.8)1.1 (0.3–1.9)0 (−0.4 to 0.3)31
 CBS isolation0.7 (0–1.7)0.7 (0.3–1.7)0 (−0.2 to 0.2)31
 CBS disappointment0.8 (0–1.4)0.4 (0–1.6)0 (−0.4 to 0.3)31
 CBS emotional1.0 (0.3–1.3)0.7 (0–1.3)0 (−0.3 to 0.4)31
 CBS environment0.7 (0–1.3)0.3 (0–1.0)0 (−0.7 to 0.3)31
HRQOL
 EQ-Index0.66 (0.53–0.74)0.80 (0.66–0.85)0.11 (0.01–0.21)**36
 EQ-VAS60 (42–70)80 (60–85)15 (6–35)**36

Change statistically significant (p < 0.05).

Change statistically significant (p < 0.01).

The median score and interquartile ranges are given. Change is presented for those patients with valid scores at both occasions. AMPS = Assessment of Motor and Process Skills; CBS = Caregiver Burden Scale; FIM = Functional Independence Measure; HRQOL = health-related quality of life; iNPH = iNPH scale; IPA = Impact on Participation and Autonomy.

Seven patients (19%) had complications during the first 6 months. In 3 cases, the complications could be managed conservatively (the patients had subdural hematomas that could be treated by temporarily increasing the opening pressure); in 4 cases surgical revision was required (for shunt dysfunction in 3 cases and infection in 1 case). All shunts were functioning at the 6-month evaluation.

Activities of Daily Living and Participation and Autonomy

The FIM score was high in both the physical and cognitive domains before surgery and improved after surgery (Fig. 1). Thirty-five patients (95%) improved their independence in physical activities (p < 0.001) and 25 patients (68%) improved their independence in cognitive activities (p < 0.001) measured with FIM. Five patients became more dependent and 7 patients remained unchanged in cognitive activities after surgery (Table 2).

Fig. 1.
Fig. 1.

Level of independence for 37 iNPH patients presented as median Functional Independence Measure (FIM) score in each activity before and after surgery.

Twenty-five patients were evaluated with AMPS before and after surgery, and 21 (84%) of these 25 patients showed improvement in their motor skills (p < 0.001). Motor skills deteriorated in 3 patients and were unchanged in one. Processing skills improved in 20 patients (80%, p < 0.001), deteriorated in 2, and did not change in 3 (Table 2).

Significant improvement was seen in all 5 IPA subscales after surgery (Table 2). The work and education subscales were only relevant to 6 patients, 5 of whom reported their work situation as improved after surgery. Twenty-five patients (68%) reported improved autonomy indoors (7 reported deterioration), 25 (68%) reported improved family role (10 deterioration), and 20 (54%) reported improved autonomy outdoors (11 deterioration). Twenty-six patients (70%) reported improved social life and relationships, while 9 reported deterioration.

Most subscale scores of the 3 scales above correlated significantly with each other both before and after surgery (r values between 0.35 and 0.81). The perceived improvement in autonomy indoors correlated with improved independence in physical activities measured by FIM (r = 0.35), while increased autonomy and participation in social life correlated with increased independence in cognitive activities (r = 0.43)

Improvement rate was not related to patient sex or age in any of the scales.

Caregiver Burden

Thirty-five patients (95%) had a caregiver at the time of surgery, and 31 caregivers (22 partners, 8 children, and 1 sister) completed the questionnaire before and after surgery. Eighty-two percent of the caregivers to male patients were the patients' partners compared with 50% of the caregivers to female patients. Of the 22 partner caregivers, 20 lived together with the patient. After surgery, the burden for caregivers to male patients was reduced in the categories isolation (p < 0.05) and environment (p < 0.01), while caregivers of female patients perceived no change in any of the 5 categories (Fig. 2). At a group level, caregiver burden did not change significantly after surgery. No statistically significant differences were seen between partners and other caregivers. Caregivers who lived together with the patients experienced greater isolation than caregivers who lived apart from the patient (p < 0.05).

Fig. 2.
Fig. 2.

Median change of Caregiver Burden Scale (CBS) in the 3 categories that differed significantly by patient sex. Whiskers indicate interquartile range (25th–75th percentile).

Low general burden correlated significantly with higher AMPS process skills and IPA autonomy outdoors both before and after surgery (r values between 0.38 and 0.61). Reduced general burden among caregivers to men correlated with improved autonomy indoors (r = 0.49) and reduced emotional burden correlated with improved autonomy indoors (r = 0.53) and outdoors (r = 0.66).

Health-Related Quality of Life

Health-related QOL was improved in 31 (86%) of 36 patients 6 months after surgery in either EQ-VAS or EQIndex (p < 0.001) (Table 3). In 19 cases, improvement was demonstrated in both EQ-VAS and EQ-Index, in 6 cases only in EQ-VAS, in 6 cases only in EQ-Index, and in 5 cases in neither of the two scales. No significant differences were seen between sex and age groups. The 7 patients with complications rated their HRQOL lower after surgery (median 59, range 15–80) than those without complications (median 84, range 45–100, p = 0.006). Three of the patients with complications had improved HRQOL after surgery, while it was reduced in 4. Fewer patients reported problems in mobility, self-care, usual activities of daily living, and anxiety/depression after treatment than before (Table 4).

TABLE 3:

Health-related quality of life measured by EQ-VAS and EQ-Index before and after surgery in 37 iNPH patients and in a normal population in different age groups*

Measure & Age GroupPreopPostopNormal Population
EQ-VAS
 50–59 (n = 5)65 (48–70)80 (45–87)90 (80–96)
 60–69 (n = 13)61 (40–73)84 (75–86)89 (75–95)
 70–79 (n = 16)50 (36–67)71 (52–84)80 (60–95)
 80+ (n = 2)66 (—)93 (—)
EQ-Index
 50–59 (n = 5)0.620 (0.604–0.699)0.796 (0.726–0.925)0.839
 60–69 (n = 13)0.656 (−0.160–0.727)0.727 (0.656–0.849)0.808
 70–79 (n = 16)0.640 (0.434–0.744)0.744 (0.620–0.962)0.794
 80+ (n = 2)0.763 (—)0.898 (—)0.733

Age is given in years. Values for EQ-VAS and EQ-Index scores are given as medians with interquartile ranges.

Normal population values for the EQ-VAS and EQ-Index were obtained from Szende et al.25 and Cardol et al.,5 respectively.

TABLE 4:

Idiopathic NPH patients' reported level of problems in 5 different dimensions before and after surgery

DimensionNo ProblemModerate ProblemsSevere Problems
Preop (n = 36)Postop (n = 37)Preop (n = 36)Postop (n = 37)Preop (n = 36)Postop (n = 37)
mobility518311900
self-care243312301
usual activities152716753
pain/discomfort1314192043
anxiety/depression1121221432

Before and after surgery EQ-VAS correlated to EQIndex (r = 0.61), FIM physical (r = 0.47), IPA autonomy indoors (r = 0.59), and IPA autonomy outdoors (r = 0.69). EQ-Index correlated besides EQ-VAS to FIM physical (r = 0.43), IPA autonomy indoors (r = 0.61), and IPA autonomy outdoors (r = 0.70).

Improved HRQOL, measured with EQ-VAS, correlated with reduced gait disturbances (r = 0.54), increased total iNPH-scale score (r = 0.38), and at trend level with reduced neuropsychological symptoms (r = 0.35, p = 0.054). Increased EQ-VAS also correlated with increased EQ-Index (r = 0.43), FIM physical (r = 0.40), and autonomy outdoors (r = −0.38). Improved EQ-Index correlated besides EQ-VAS with improved autonomy and participation in social life (r = −0.37).

Discussion

HRQOL and Social Function

The essential result of this study is that there was an increase in iNPH patients' HRQOL after shunt surgery. An interesting finding was that iNPH patients perceived and reported their HRQOL nearly at the same level as an age-matched reference population in spite of persisting neurological and cognitive deficits.11,17 We measured HRQOL using 2 instruments, a self-reported visual analog scale and an objectively measured EQ-Index, which showed the same degree of improvement and a high inter-correlation, supporting the validity of the result. The HRQOL was reported/measured 6 months after surgery. This is important since it excludes a number of factors that have an impact on HRQOL immediately after surgery, such as happiness for having been successfully operated, relief of postoperative discomfort, the placebo effect of the operation, and gratitude toward the hospital staff. There were, however, fewer patients reporting problems with anxiety and depression after surgery, which can be an expression of the reduction of stress patients experience after getting diagnosed and treated for iNPH after having lived in uncertainty, in many cases for several years.

The multifaceted aspects of iNPH patients' health and disability were measured by well-validated scales in agreement with ICF recommendations covering function and structure and activity and participation.30 All the instruments showed a very good interrelationship and improvement was statistically related to improved HRQOL. This supports the validity of the observed improvement and it also highlights the wide range of consequences the improvement has for patients' social life.

The FIM score was high in both the physical and cognitive domains before surgery, indicating that the patients had low dependency in most of the activities studied without treatment. However, small improvements after surgery measured by FIM can still be very valuable for patients, as decrease in dependence in just one activity, like dressing or locomotion, can improve HRQOL. The FIM domains are complex and many activity scores correlate, as many of the physical activities require cognitive skills such as understanding and planning.

It was interesting to note that 6 of 12 patients whose iNPH scale scores were unchanged after surgery did demonstrate postoperative improvement in HRQOL. The iNPH scale measures performance using specific physical and neuropsychological tests, such as walking 10 m, standing upright with the feet together, and tests of memory and processing speed, using an index score13 that we found was related to HRQOL to a certain degree, specifically the gait domain. (Improvement in motor functions after shunting was also reported as important for patients by Toma et al.27) Seemingly, however, there are aspects relevant to HRQOL that are not covered by the iNPH scale. Patients with iNPH often tell us that life is easier, things they see and hear appear clearer to them, and they feel more alert after shunt treatment. Such changes, being subjective and subtle, are difficult to capture with objective measures, but are probably, to some extent, captured by the self-reported EQ-VAS.

We have to remember that very few of those 80% who experience improvement after surgery, will show full recovery after surgery estimated by the iNPH scale.12,17 This study add the important information that most patients will show an improvement in performing ADL and will experience an improvement in participation and autonomy as well as better HRQOL after shunt surgery.

Caregiver Burden

The caregiver burden did not decrease significantly on the group level after shunt surgery. This is surprising in the light of the improvements in independence and autonomy. Our results differ from those of Kazui et al., who found a decreased total burden after treatment according to the Zarit Burden Interview (ZBI).16 The difference could be due to differences in sensitivity between the 2 scales, but there is no validated Swedish version of ZBI.

That functional improvement after surgery did not affect caregivers' situations is supported by Lundin et al., who performed an actigraphy study and did not find any improvement in ambulatory activity and energy expenditure after surgery in spite of improved time-upand-go and gait speed. They speculated that the patients are caught in the role of being cared for and are not able or motivated to change their habits in spite of improved performance.19 This can also be true for the caregivers; the slow development of iNPH symptoms, in many cases over several years, gives rise to very gradual changes in the roles of family members. At the time of surgery these new roles may well have become firmly established and may be perceived as the normal way of living.

Another explanation could be that the cognitive functions of the patients are most important for the caregiver burden, and the cognitive symptoms did not improve as much as gait symptoms. A correlation between cognitive symptoms and caregiver burden was found in the study by Kazui et al.,16 and we found the same result with our study, as processing skills correlated to level of burden.

Analyzing the data from relatives of male and female patients separately, however, we found a reduced burden in the former group. For this group, improvement in autonomy indoors and outdoors seemed especially important. Most of the male patients in this study had partners as caregivers, in contrast to the female patients, who had other relatives. It may seem reasonable to assume that partners would be more favored by improvements than other caregivers, but there was no difference in outcome between caregivers who lived together with the patient and those who did not.

Another explanation for the sex-related difference might be that traditionally female tasks like cleaning, cooking, and laundry are easier to hire someone else to do; this is even subsidized by the government in Sweden. The traditionally male tasks like managing finances, driving, and taking care of the car, and physically demanding tasks, are harder to hire someone to do and therefore have to be taken over by other family members during the male patient's illness.

Clinical Outcome and Study Design

The patients in this study are representative iNPH patients in our NPH unit except for the sex distribution, which is usually equal in iNPH studies.17,22,23 We have no reason to believe that this is anything else than accidental. All patients were diagnosed based on clinical symptoms and MRI findings according to the guidelines and no supplementary tests were used for inclusion. We know from the European multicenter study17 that the number of patients who experience improvement after shunt surgery, without using any supplementary test, is around 80%, similar to studies using such tests for inclusion. The severity of symptoms in this group was similar to groups in earlier studies using the iNPH scale.13,17 In these studies most of the patients presented with symptoms in all measured domains. The degree of improvement in motor and cognitive functions was expected, but, surprisingly, balance and continence did not improve after surgery, which differs from other studies.2,17 In some cases gait improved but balance did not, which is uncommon, as improvement in gait and balance normally correlate.2,13,17

The improvement rate in the present study was lower than in the study by Klinge et al. but higher than in the guidelines,21 referring to a review of studies that did not use any supplementary tests for patient selection, similar to our study. The complication rate was, however, lower than in the study by Klinge et al. Our rate was reported after 6 months and not after 1 year as in their study,17 and the rates would probably have been more similar if we had followed our patients for a longer period of time. The complication rate in this study is nevertheless relatively high and slightly higher than the usual rate in our unit, which is around 10%.8 From the patients' perspective, it is extremely important to keep the complication rate low, as the group of patients with complications also rated their HRQOL lower in our study. It is also important in a health economics view, since economic benefits of surgery can be eliminated by the costs of complications, especially in a short-term perspective.

The size of the sample, unfortunately, became smaller than was originally intended. This was due mainly to logistic problems, and we consider it a weakness of the study.

To our knowledge, this is the first study measuring the multifaceted aspects of health and disability in iNPH patients using the WHO's ICF classification as a guide when choosing instruments.30 Another strength of our study is that all the evaluations before and after surgery were performed by the same occupational therapist to eliminate interevaluator differences. We made sure that all shunts were working at time of evaluation, and, in order to reflect the normal clinical situation, both patients with complications and nonresponders were included in the study.

Conclusions

Shunt surgery improved iNPH patients' HRQOL almost to the level of an age-matched normal population, even in those cases in which no actual clinical improvement could be measured. Improvement after surgery is not restricted to symptoms and signs but also includes independence in ADL, motor and process skills, participation, and autonomy. Caregivers to male patients reported reduced isolation and a better home environment after surgery but no change was seen among caregivers on group level.

Acknowledgments

We wish to express our gratitude toward all patients and caregivers who participated in this study. To complete all the questionnaires and tests took a great amount of time and effort and without it this study would not have been possible.

We also thank Jurgen Broeren for collecting all data.

Disclosure

This study was supported by funding from the Collection Foundation for Neurological Research. Carsten Wikkelsø receives honoraria for lecturing and consulting from Codman and Johnson & Johnson. Jakob Petersen, Per Hellström and Åsa Lundgren-Nilsson have no disclosures.

Author contributions to the study and manuscript preparation include the following. Conception and design: Wikkelsø, Lundgren-Nilsson. Acquisition of data: Lundgren-Nilsson. Analysis and interpretation of data: Petersen, Lundgren-Nilsson. Drafting the article: Petersen. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Petersen. Statistical analysis: Petersen. Administrative/technical/material support: Hellström, Wikkelsø, Lundgren-Nilsson. Study supervision: Hellström, Wikkelsø, Lundgren-Nilsson.

An abstract of this work was presented orally at Hydrocephalus 2013 Athens, the Fifth Meeting of the International Society of Hydrocephalus and CSF Disorders (ISHCSF), Athens, Greece, July 1, 2013.

References

  • 1

    Bergsneider MBlack PMKlinge PMarmarou ARelkin N: Surgical management of idiopathic normal-pressure hydrocephalus. Neurosurgery 57:3 SupplS29S39iiv2005

  • 2

    Blomsterwall EBilting MStephensen HWikkelsö C: Gait abnormality is not the only motor disturbance in normal pressure hydrocephalus. Scand J Rehabil Med 27:2052091995

  • 3

    Brean AEide PK: Prevalence of probable idiopathic normal pressure hydrocephalus in a Norwegian population. Acta Neurol Scand 118:48532008

  • 4

    Brean AFredø HLSollid SMüller TSundstrøm TEide PK: Five-year incidence of surgery for idiopathic normal pressure hydrocephalus in Norway. Acta Neurol Scand 120:3143162009

  • 5

    Burström KJohannesson MDiderichsen F: A comparison of individual and social time trade-off values for health states in the general population. Health Policy 76:3593702006

  • 6

    Cardol Mde Haan RJvan den Bos GAMde Jong BAde Groot IJM: The development of a handicap assessment questionnaire: the Impact on Participation and Autonomy (IPA). Clin Rehabil 13:4114191999

  • 7

    Elmståhl SMalmberg BAnnerstedt L: Caregiver's burden of patients 3 years after stroke assessed by a novel caregiver burden scale. Arch Phys Med Rehabil 77:1771821996

  • 8

    Farahmand DHilmarsson HHögfeldt MTisell M: Perioperative risk factors for short term shunt revisions in adult hydrocephalus patients. J Neurol Neurosurg Psychiatry 80:124812532009

  • 9

    Fisher AG: Assessment of Motor and Process Skills. Development, Standardization and Administration Manual. ed 5Fort Collins, COThree Star Press2003

  • 10

    Hakim SAdams RD: The special clinical problem of symptomatic hydrocephalus with normal cerebrospinal fluid pressure. Observations on cerebrospinal fluid hydrodynamics. J Neurol Sci 2:3073271965

  • 11

    Hellström PEdsbagge MArcher TTisell MTullberg MWikkelsø C: The neuropsychology of patients with clinically diagnosed idiopathic normal pressure hydrocephalus. Neurosurgery 61:121912282007

  • 12

    Hellström PKlinge PTans JWikkelsø C: The neuropsychology of iNPH: findings and evaluation of tests in the European multicentre study. Clin Neurol Neurosurg 114:1301342012

  • 13

    Hellström PKlinge PTans JWikkelsø C: A new scale for assessment of severity and outcome in iNPH. Acta Neurol Scand 126:2292372012

  • 14

    Iseki CKawanami TNagasawa HWada MKoyama SKikuchi K: Asymptomatic ventriculomegaly with features of idiopathic normal pressure hydrocephalus on MRI (AVIM) in the elderly: a prospective study in a Japanese population. J Neurol Sci 277:54572009

  • 15

    Kato TIseki CTakahashi YWada MKawanami TSato H: [iNPH (Idiopathic normal pressure hydrocephalus) and AVIM (asymptomatic ventriculomegaly with features of iNPH on MRI).]. Rinsho Shinkeigaku 50:9639652010. (Jpn)

  • 16

    Kazui HMori EHashimoto MIshikawa MHirono NTakeda M: Effect of shunt operation on idiopathic normal pressure hydrocephalus patients in reducing caregiver burden: evidence from SINPHONI. Dement Geriatr Cogn Disord 31:3633702011

  • 17

    Klinge PHellström PTans JWikkelsø C: One-year outcome in the European multicentre study on iNPH. Acta Neurol Scand 126:1451532012

  • 18

    Linacre JMHeinemann AWWright BDGranger CVHamilton BB: The structure and stability of the Functional Independence Measure. Arch Phys Med Rehabil 75:1271321994

  • 19

    Lundin FUlander MSvanborg EWikkelsø CLeijon G: How active are patients with idiopathic normal pressure hydrocephalus and does activity improve after shunt surgery? A controlled actigraphic study. Clin Neurol Neurosurg 115:1921962013

  • 20

    Marmarou ABergsneider MRelkin NKlinge PBlack PM: Development of guidelines for idiopathic normal-pressure hydrocephalus: Introduction. Neurosurgery 57:3 SupplS2-1S2-32005

  • 21

    Marmarou ABlack PBergsneider MKlinge PRelkin N: Guidelines for management of idiopathic normal pressure hydrocephalus: progress to date. Acta Neurochir Suppl 95:2372402005

  • 22

    Pujari SKharkar SMetellus PShuck JWilliams MARigamonti D: Normal pressure hydrocephalus: long-term outcome after shunt surgery. J Neurol Neurosurg Psychiatry 79:128212862008

  • 23

    Savolainen SHurskainen HPaljärvi LAlafuzoff IVapalahti M: Five-year outcome of normal pressure hydrocephalus with or without a shunt: predictive value of the clinical signs, neuropsychological evaluation and infusion test. Acta Neurochir (Wien) 144:5155232002

  • 24

    Szende AOppe MDevlin N: EQ-5D Value Sets: Inventory Comparative Review and User Guide Dordrecht, The NetherlandsSpringer2007

  • 25

    Szende AWilliams A: Measuring Self-Reported Population Health: An International Perspective based on EQ-5D Rotterdam, the NetherandsEuroQol Group2004. (http://www.euroqol.org/fileadmin/user_upload/Documenten/PDF/Books/Measuring_Self-Reported_Population_Health_-_An_International_Perspective_based_on_EQ-5D.pdf) [Accessed June 12 2014]

  • 26

    Tanaka NYamaguchi SIshikawa HIshii HMeguro K: Prevalence of possible idiopathic normal-pressure hydrocephalus in Japan: the Osaki-Tajiri project. Neuroepidemiology 32:1711752009

  • 27

    Toma AKTarnaris AKitchen NDWatkins LD: Working towards patient oriented outcome assessment in normal pressure hydrocephalus, what is the most important?. Acta Neurochir (Wien) 153:1771802011

  • 28

    Williams A: EuroQol—a new facility for the measurement of health-related quality of life. Health Policy 16:1992081990

  • 29

    Wimo Avon Strauss ENordberg GSassi FJohansson L: Time spent on informal and formal care giving for persons with dementia in Sweden. Health Policy 61:2552682002

  • 30

    World Health Organization: The International Classification of Functioning: Disability and Health GenevaWorld Health Organization2001

If the inline PDF is not rendering correctly, you can download the PDF file here.

Article Information

Address correspondence to: Jacob Petersen, M.D., Hydrocephalus Research Unit, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, 413 45 Gothenburg, Sweden. email: gusjako10@student.gu.se.

Please include this information when citing this paper: published online July 18, 2014; DOI: 10.3171/2014.6.JNS132003.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Level of independence for 37 iNPH patients presented as median Functional Independence Measure (FIM) score in each activity before and after surgery.

  • View in gallery

    Median change of Caregiver Burden Scale (CBS) in the 3 categories that differed significantly by patient sex. Whiskers indicate interquartile range (25th–75th percentile).

References

1

Bergsneider MBlack PMKlinge PMarmarou ARelkin N: Surgical management of idiopathic normal-pressure hydrocephalus. Neurosurgery 57:3 SupplS29S39iiv2005

2

Blomsterwall EBilting MStephensen HWikkelsö C: Gait abnormality is not the only motor disturbance in normal pressure hydrocephalus. Scand J Rehabil Med 27:2052091995

3

Brean AEide PK: Prevalence of probable idiopathic normal pressure hydrocephalus in a Norwegian population. Acta Neurol Scand 118:48532008

4

Brean AFredø HLSollid SMüller TSundstrøm TEide PK: Five-year incidence of surgery for idiopathic normal pressure hydrocephalus in Norway. Acta Neurol Scand 120:3143162009

5

Burström KJohannesson MDiderichsen F: A comparison of individual and social time trade-off values for health states in the general population. Health Policy 76:3593702006

6

Cardol Mde Haan RJvan den Bos GAMde Jong BAde Groot IJM: The development of a handicap assessment questionnaire: the Impact on Participation and Autonomy (IPA). Clin Rehabil 13:4114191999

7

Elmståhl SMalmberg BAnnerstedt L: Caregiver's burden of patients 3 years after stroke assessed by a novel caregiver burden scale. Arch Phys Med Rehabil 77:1771821996

8

Farahmand DHilmarsson HHögfeldt MTisell M: Perioperative risk factors for short term shunt revisions in adult hydrocephalus patients. J Neurol Neurosurg Psychiatry 80:124812532009

9

Fisher AG: Assessment of Motor and Process Skills. Development, Standardization and Administration Manual. ed 5Fort Collins, COThree Star Press2003

10

Hakim SAdams RD: The special clinical problem of symptomatic hydrocephalus with normal cerebrospinal fluid pressure. Observations on cerebrospinal fluid hydrodynamics. J Neurol Sci 2:3073271965

11

Hellström PEdsbagge MArcher TTisell MTullberg MWikkelsø C: The neuropsychology of patients with clinically diagnosed idiopathic normal pressure hydrocephalus. Neurosurgery 61:121912282007

12

Hellström PKlinge PTans JWikkelsø C: The neuropsychology of iNPH: findings and evaluation of tests in the European multicentre study. Clin Neurol Neurosurg 114:1301342012

13

Hellström PKlinge PTans JWikkelsø C: A new scale for assessment of severity and outcome in iNPH. Acta Neurol Scand 126:2292372012

14

Iseki CKawanami TNagasawa HWada MKoyama SKikuchi K: Asymptomatic ventriculomegaly with features of idiopathic normal pressure hydrocephalus on MRI (AVIM) in the elderly: a prospective study in a Japanese population. J Neurol Sci 277:54572009

15

Kato TIseki CTakahashi YWada MKawanami TSato H: [iNPH (Idiopathic normal pressure hydrocephalus) and AVIM (asymptomatic ventriculomegaly with features of iNPH on MRI).]. Rinsho Shinkeigaku 50:9639652010. (Jpn)

16

Kazui HMori EHashimoto MIshikawa MHirono NTakeda M: Effect of shunt operation on idiopathic normal pressure hydrocephalus patients in reducing caregiver burden: evidence from SINPHONI. Dement Geriatr Cogn Disord 31:3633702011

17

Klinge PHellström PTans JWikkelsø C: One-year outcome in the European multicentre study on iNPH. Acta Neurol Scand 126:1451532012

18

Linacre JMHeinemann AWWright BDGranger CVHamilton BB: The structure and stability of the Functional Independence Measure. Arch Phys Med Rehabil 75:1271321994

19

Lundin FUlander MSvanborg EWikkelsø CLeijon G: How active are patients with idiopathic normal pressure hydrocephalus and does activity improve after shunt surgery? A controlled actigraphic study. Clin Neurol Neurosurg 115:1921962013

20

Marmarou ABergsneider MRelkin NKlinge PBlack PM: Development of guidelines for idiopathic normal-pressure hydrocephalus: Introduction. Neurosurgery 57:3 SupplS2-1S2-32005

21

Marmarou ABlack PBergsneider MKlinge PRelkin N: Guidelines for management of idiopathic normal pressure hydrocephalus: progress to date. Acta Neurochir Suppl 95:2372402005

22

Pujari SKharkar SMetellus PShuck JWilliams MARigamonti D: Normal pressure hydrocephalus: long-term outcome after shunt surgery. J Neurol Neurosurg Psychiatry 79:128212862008

23

Savolainen SHurskainen HPaljärvi LAlafuzoff IVapalahti M: Five-year outcome of normal pressure hydrocephalus with or without a shunt: predictive value of the clinical signs, neuropsychological evaluation and infusion test. Acta Neurochir (Wien) 144:5155232002

24

Szende AOppe MDevlin N: EQ-5D Value Sets: Inventory Comparative Review and User Guide Dordrecht, The NetherlandsSpringer2007

25

Szende AWilliams A: Measuring Self-Reported Population Health: An International Perspective based on EQ-5D Rotterdam, the NetherandsEuroQol Group2004. (http://www.euroqol.org/fileadmin/user_upload/Documenten/PDF/Books/Measuring_Self-Reported_Population_Health_-_An_International_Perspective_based_on_EQ-5D.pdf) [Accessed June 12 2014]

26

Tanaka NYamaguchi SIshikawa HIshii HMeguro K: Prevalence of possible idiopathic normal-pressure hydrocephalus in Japan: the Osaki-Tajiri project. Neuroepidemiology 32:1711752009

27

Toma AKTarnaris AKitchen NDWatkins LD: Working towards patient oriented outcome assessment in normal pressure hydrocephalus, what is the most important?. Acta Neurochir (Wien) 153:1771802011

28

Williams A: EuroQol—a new facility for the measurement of health-related quality of life. Health Policy 16:1992081990

29

Wimo Avon Strauss ENordberg GSassi FJohansson L: Time spent on informal and formal care giving for persons with dementia in Sweden. Health Policy 61:2552682002

30

World Health Organization: The International Classification of Functioning: Disability and Health GenevaWorld Health Organization2001

TrendMD

Cited By

Metrics

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 203 203 26
PDF Downloads 121 121 16
EPUB Downloads 0 0 0

PubMed

Google Scholar