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Higher-Level Gait Disorder (HLGD) is a type of gait disorder estimated to affect up to 6% of the older population. By definition, its symptoms originate from the higher-level nervous system, yet its association with brain morphology remains unclear. This study hypothesizes that there are patterns in brain morphology linked to HLGD. For the first time in the literature, this work investigates whether deep learning, in the form of convolutional neural networks, can capture patterns in magnetic resonance images to identify individuals affected by HLGD. To handle this new classification task, we propose setting up an ensemble of models. This leverages the benefits of combining classifiers instead of determining which network is the most suitable, developing a new architecture, or customizing an existing one. We introduce a computationally cost-effective search algorithm to find the optimal ensemble by leveraging a cost function of both traditional performance scores and the diversity among the models. Using a unique dataset from a large population-based cohort (VESPR), the ensemble identified by our algorithm demonstrated superior performance compared to single networks, other ensemble fusion techniques, and the best linear radiological measure. This emphasizes the importance of implementing diversity into the cost function. Furthermore, the results indicate significant morphological differences in brain structure between HLGD-affected individuals and controls, motivating research about which areas the networks base their classifications on, to get a better understanding of the pathophysiology of HLGD.

Background: Higher-level gait disorders (HLGDs) are slow, unsteady neurological GDs in older people. GDs can reduce quality of life (QoL) and cause depression. This has not been investigated in HLGD even though some HLGD causes are treatable, potentially affecting associated problems. We aimed to investigate gait and balance confidence, depressive symptoms and QoL in HLGD.

Methods: In a population (n=3769, 65-84y), 798 reported gait impairment (questionnaire) and were clinically examined together with 249 age- and sex-matched controls. Gait property groups were formed: 'HLGD', 'other neurological GD', 'non-neurological GD' or 'no GD'. Swedish Falls Efficacy Scale (FES(S)), Modified Gait Efficacy Scale (mGES), Euro Quality of Life 5-Dimension 5-Level index, Euro Quality of Life Visual Analogue Scale (EQ VAS) and Geriatric Depression Scale-15 (GDS-15) were compared.

Results: In the general population, 38% had GDs, of which 16% (n=87/561) were HLGDs, giving an HLGD prevalence of 5.8%; 26% (n=145/561) were other neurological GDs; and 59% (n=329/561) non-neurological GDs. HLGD had more depressive symptoms than non-neurological GD and no GD (GDS-15 HLGD, 3.9 +/- 3.4; non-neurological GD, 2.5 +/- 2.8; no GD, 1.4 +/- 2.0; p<0.05), lower EQ VAS (HLGD, 63 +/- 17; non-neurological GD, 71 +/- 18; no GD, 82 +/- 14; p<0.001), lower gait confidence (mGES HLGD, 60 +/- 22; non-neurological GD, 74 +/- 21; no GD, 90 +/- 13; p<0.001) and lower balance confidence (FES(S) HLGD, 93 +/- 32; non-neurological GD, 111 +/- 25; no GD, 124 +/- 13; p<0.001).

Conclusions: HLGDs are common and associated with reduced QoL, reduced confidence in gait and balance, and depressive symptoms, emphasising awareness of mental health among older people with slow unsteady gait.

Background and purpose: Disproportionately enlarged subarachnoid space hydrocephalus (DESH) is a radiological biomarker for idiopathic normal pressure hydrocephalus (iNPH). DESH is a subjective measure, based on visual assessments, which may limit its reliability. The aim of this study was to develop and validate a method for the objective quantification of DESH.

Materials and methods: By using a semiautomatic quantitative method, we calculated quantitative DESH (qDESH), defined as a ratio between CSF volumes at high convexities and Sylvian fissures. The analysis was based on three-dimensional T1-weighted images from 35 subjects with iNPH (mean age 74 yrs; 10 females) and 45 controls (mean age 72 yrs; 13 females). The interrater agreement for qDESH was evaluated by the intraclass correlation coefficient, and qDESH was compared with visual assessments performed by two neuroradiologists.

Results: All subjects with iNPH and 13% of the controls visually scored DESH positive. The median qDESH was 2.48 (5th to 95th percentile 0.88 to 5.42) for iNPH and 0.63 (5th to 95th percentile 0.37 to 1.73) for the controls. The area under the receiver operating characteristic curve for qDESH was 0.95 (95% confidence interval 0.90–1) in separating iNPH patients from controls. The interrater agreement for qDESH was 0.99 (95% CI 0.986–0.994, p < 0.001).

Conclusion: Unlike visual DESH, qDESH generates a continuous variable, enabling reproducible quantification of DESH severity. With this method we can objectively investigate the diagnostic accuracy and prognostic assessment of DESH in iNPH.

White matter hyperintensities (WMH), perivascular spaces (PVS) and lacunes are common MRI features of small vessel disease (SVD). However, no shared underlying pathological mechanism has been identified. We investigated whether SVD burden, in terms of WMH, PVS and lacune status, was related to changes in the cerebral arterial wall by applying global cerebral pulse wave velocity (gcPWV) measurements, a newly described marker of cerebral vascular stiffness. In a population-based cohort of 190 individuals, 66–85 years old, SVD features were estimated from T1-weighted and FLAIR images while gcPWV was estimated from 4D flow MRI data. Additionally, the gcPWV’s stability to variations in field-of-view was analyzed. The gcPWV was 10.82 (3.94) m/s and displayed a significant correlation to WMH and white matter PVS volume (r = 0.29, p < 0.001; r = 0.21, p = 0.004 respectively from nonparametric tests) that persisted after adjusting for age, blood pressure variables, body mass index, ApoB/A1 ratio, smoking as well as cerebral pulsatility index, a previously suggested early marker of SVD. The gcPWV displayed satisfactory stability to field-of-view variations. Our results suggest that SVD is accompanied by changes in the cerebral arterial wall that can be captured by considering the velocity of the pulse wave transmission through the cerebral arterial network.

Background: To study gait is of great importance for the health of the aging population. Higher-level gait disorders (HLGD) are characterized by a slow, symmetrical, unsteady gait. Its cause is most often unknown. HLGD in combination with ventriculomegaly (i.e., large brain ventricles) is obligatory for the diagnosis of Idiopathic Normal pressure hydrocephalus (INPH), a syndrome that is sometimes treatable with insertion of a CSF shunt. It is therefore important to investigate the prevalence of HLGD in the population and brain morphometry in individuals with HLGD. Further, self-perceived confidence in gait and balance among patients with HLGD and INPH is unknown and important to study as slow gait velocity is associated with falls, injuries, and death. CSF shunts in INPH are associated with adverse events and little is known about epilepsy after surgery or minor and moderate adverse events such as headache and abdominal pain.

Objective: In the older population investigate the prevalence of HLGD, and its association to ventriculomegaly. To investigate quality of life (QoL), depressive symptoms, and balance confidence in an HLGD population. In patients shunted for INPH, assess falls, fear of falling, balance confidence and prevalence of the possible adverse events headache, epilepsy, and abdominal pain after shunt surgery. 

Methods: Two population-based case-controlled cohorts were studied. In the first study, the "Ventriculomegaly and gait disturbance in the senior population in the region of Västerbotten" (VESPR) study, individuals (65-84 years) were recruited through a questionnaire (n=6467 dispatched). The final population consisted of 798 cases with gait disorders and 249 controls without gait disorders, age- and sex-matched to individuals with HLGD. All had been examined by a physician and were categorized: 1. "HLGD"; 2. "neurological gait disorder"; 3. "non-neurological gait disorder" or; 4. "no gait disorder". Participants were assessed with: the Swedish modification of the Falls-Efficacy Scale (FES(S)), the Modified Gait-Efficacy Scale (mGES), the Euro Quality of Life 5-Dimension 5-Level (EQ5D5L) instrument (EQ5D5L index and Euro Quality of life visual analogue scale (EQ VAS)) and the Geriatric depression scale 15 (GDS-15). Cases and controls had an MRI of the brain and ventricular size was measured. 

The second study, the "Comorbidities and vascular risk factors associated with idiopathic normal pressure hydrocephalus" (INPH-CRasH) study, consisted of 176 shunted INPH patients and 368 age- and sex-matched controls. Mean age was 74 years in INPH and 73 in controls. All had a visit to a healthcare facility. Information regarding adverse events, falls and fear of falling were gathered through a questionnaire. Additional information on diagnoses and prescribed drugs were obtained from the Swedish national patient- and drug registries. Data was compared between the groups, and before- and after surgery for INPH. 

Results: In the VESPR study, 87 individuals were categorized as HLGD, corresponding to a prevalence of 5.8% (95% confidence interval (CI) 4.6-7.0) in the older population. A definite cause was found in 13% (n=11) of individuals with HLGD, but ventriculomegaly was present in 63% (n=46/73, controls: 38%, n=70/184; OR 2.8 95% CI 1.6-4.9, p<0.001). HLGD had more depressive symptoms and lower quality of life (QoL), compared with individuals without gait disorder (GDS-15: 3.9±3.4 vs. 2.5±2.8, p=0.004; EQ VAS: 63±17 vs. 71±18; p<0.001; EQ5D5L index: 0.671±0.188 vs. 0.840±0.126, p<0.001). HLGD had low confidence in gait and to avoid falls compared to those without gait disorder (mGES: 60±22 vs. 74±21; p<0.001; FES(S): 93±32 vs. 111±25 p<0.001). 

The INPH-CRasH study revealed that patients with INPH feared falling more often (3.3±1.1) and had lower balance confidence (78±40) than controls (fear of falling: 1.6±0.9, balance confidence: 126±14; p<0.001 in both comparisons). After surgery, the proportions were reduced in INPH (p<0.001). More INPH than controls were fallers (before surgery: 67% vs. 11% OR 15.48 95% CI 9.85-24.32; after surgery: 35% vs 11% OR 4.15 95% CI 2.65-6.50, p<0.001). The proportion was reduced after surgery (p<0.001). In shunted INPH, epilepsy, antiepileptic drug (AED) treatment and headache was more common than in controls (epilepsy: 4.5% vs. 1.1% OR 4.3, 95% CI 1.3-14.6, p=0.023; AED treatment: 14.8% vs. 7.3% OR 0.5 95% CI 0.3-0.8, p=0.010; headache: 36.1% vs 11.6% OR 0.2 95% CI 0.2-0.4, p<0.001). Forty percent INPH (n=70) had abdominal pain after surgery. 

Conclusions: HLGD was common in the general older population and associated to ventriculomegaly. HLGD was also associated with low quality of life and depressive symptoms. Both individuals with HLGD and patients with INPH had low confidence in their balance but it was less common after surgery for INPH. However, patients shunted for INPH still had more problems with low balance confidence, falls, and fear of falling than controls. After shunt surgery for INPH, a significant portion of patients developed epilepsy, headache, and abdominal pain. The findings motivate investigations of causal relationships between HLGD and ventriculomegaly and if treatment options exist for HLGD. The observed adverse events in patients shunted for INPH should be considered in pre- and postoperative evaluations of shunt surgery, and in the development of new techniques for shunt placement. Additional interventions directed towards low balance confidence, falls and fear of falling should be considered for patients with INPH, and for individuals with HLGD.

BACKGROUND: Gait and balance impairment are typical symptoms of idiopathic normal pressure hydrocephalus (INPH), implicating that falls may afflict these patients.

OBJECTIVE: To investigate falls, related injuries, and associated psychological features, before and after shunt surgery for INPH and compared to the general population.

METHODS: The study included 176 patients shunted for INPH and 368 age- and sex-matched controls. Falls, fear of falling (FOF), fall-related injuries (mild-severe), confidence in avoiding falls (Swedish Falls Efficacy Scale (FES(S)), quality of life (QoL; EuroQoL 5-dimension 5 level instrument), and symptoms of depression (Geriatric Depression Scale 15) were investigated. Pre- and postoperative observational times were 12 mo before surgery and 21 mo after (mean). Recurrent fallers fell ≥2 times.

RESULTS: More INPH patients than controls were recurrent fallers (67% vs 11%; P < .001). They feared falling more often (FOF, mean ± standard deviation: 3.3 ± 1.1 vs 1.6 ± 0.9; P < .001) and had lower confidence in avoiding falls (FES(S) 78 ± 40 vs 126 ± 14; P < .001). After surgery, INPH patients improved in all parameters but they did not reach the levels of the controls. Among fallers there was no difference between patients and controls in the severity of injuries suffered. Low QoL and symptoms of depression were more common among recurrent fallers than one-time or nonfallers in both shunted patients and controls (P ≤ .001).

CONCLUSION: Falls, FOF, and low confidence in avoiding falls are considerable problems in INPH that may be reduced by shunt surgery. We suggest that remaining risk of falling and preventative measures are routinely considered in postoperative follow-ups and rehabilitation planning.

OBJECTIVE: Idiopathic normal pressure hydrocephalus (INPH) is a dementia treatable by insertion of a shunt that drains CSF. The cause of the disease is unknown, but a vascular pathway has been suggested. The INPH-CRasH (Comorbidities and Risk Factors Associated with Hydrocephalus) study was a modern epidemiological case-control study designed to prospectively assess parameters regarding comorbidities and vascular risk factors (VRFs) for INPH, quality of life (QOL), and adverse events in patients with shunted INPH. The objective of this review was to summarize the findings of the INPH-CRasH study.

METHODS: VRFs, comorbidities, QOL, and adverse events were analyzed in consecutive patients with INPH who underwent shunt placement between 2008 and 2010 in 5 of 6 neurosurgical centers in Sweden. Patients (n = 176, within the age span of 60-85 years and not having dementia) were compared to population-based age- and gender-matched controls (n = 368, same inclusion criteria as for the patients with INPH). Assessed parameters were as follows: hypertension; diabetes; obesity; hyperlipidemia; psychosocial factors (stress and depression); smoking status; alcohol intake; physical activity; dietary pattern; cerebrovascular, cardiovascular, or peripheral vascular disease; epilepsy; abdominal pain; headache; and clinical parameters before and after surgery. Parameters were assessed through questionnaires, clinical examinations, measurements, ECG studies, and blood samples.

RESULTS: Four VRFs were independently associated with INPH: hyperlipidemia, diabetes, obesity, and psychosocial factors. Physical inactivity and hypertension were also associated with INPH, although not independently from the other risk factors. The population attributable risk percent for a model containing all of the VRFs associated with INPH was 24%. Depression was overrepresented in patients with INPH treated with shunts compared to the controls (46% vs 13%, p < 0.001) and the main predictor for low QOL was a coexisting depression (p < 0.001). Shunting improved QOL on a long-term basis. Epilepsy, headache, and abdominal pain remained common for a mean follow-up time of 21 months in INPH patients who received shunts.

CONCLUSIONS: The results of the INPH-CRasH study are consistent with a vascular pathophysiological component of INPH. In clinical care and research, a complete risk factor analysis as well as screening for depression and a measurement for QOL should probably be included in the workup of patients with INPH. The effect of targeted interventions against modifiable VRFs and antidepressant treatment in INPH patients should be evaluated. Seizures, headache, and abdominal pain should be inquired about at postoperative follow-up examinations.

OBJECTIVE Adverse events related to shunt surgery are common and might have a negative effect on outcome in patients with idiopathic normal pressure hydrocephalus (INPH). The authors' objectives were to establish the frequencies of epilepsy, headache, and abdominal pain and determine their impact on patient quality of life (QOL), in long-term follow-up after shunt surgery for INPH.

METHODS One hundred seventy-six shunt-treated patients with INPH (mean age 74 years) and 368 age- and sex-matched controls from the population were included. The mean follow-up time after surgery was 21 months (range 6-45 months). Each participant answered a questionnaire regarding present frequency and severity of headache and abdominal pain. Confirmed diagnoses of epilepsy and all prescriptions for antiepileptic drugs (AEDs) before and after shunt surgery for INPH were gathered from national registries. Equivalent presurgical and postsurgical time periods were constructed for the controls based on the date of surgery (the division date for controls is referred to as virtual surgery). All registry data covered a mean period of 6 years (range 3-8 years) before surgery/virtual surgery and 4 years (range 2-6 years) after surgery/virtual surgery. Provoked epileptic seizures were excluded. Patient QOL was assessed with the EuroQoL 5-dimension 5-level instrument.

RESULTS Epilepsy was more common in shunt-treated patients with INPH than in controls (4.5% vs 1.1%, respectively; p = 0.023), as was treatment with AEDs (14.8% vs 7.3%, respectively; p = 0.010). No difference was found between the populations before surgery/virtual surgery (epilepsy, 2.3% [INPH] vs 1.1% [control], p = 0.280; AED treatment, 8.5% [INPH] vs 5.4% [control], p = 0.235). New-onset epilepsy and new AED treatment after surgery/virtual surgery were more common in INPH (epilepsy, 2.3% [INPH] vs 0.0% [control], p = 0.011; AED, 8.5% [INPH] vs 3.3% [control], p = 0.015). At follow-up, more patients with INPH than controls experienced headache several times per month or more often (36.1% vs 11.6%, respectively; p < 0.001). Patients with INPH and unilateral headache had more right-sided headaches than controls (p = 0.038). Postural headache was experienced by 16% (n = 27 of 169) of the patients with INPH. Twenty percent (n = 35) of the patients with INPH had persistent abdominal pain. Headache was not correlated to lower QOL. The study was underpowered to draw conclusions regarding QOL in patients with INPH who had epilepsy and abdominal pain, but the finding of no net difference in mean QOL indicates that no correlation between them existed.

CONCLUSIONS Epilepsy, headache, and abdominal pain are common in long-term follow-up in patients after shunt surgery for INPH and are more common among patients with INPH than in the general population. All adverse events, including mild and moderate ones, should be considered during postoperative follow-ups and in the development of new methods for shunt placement.