DOI: 10.5061/dryad.kkwh70s2v
title: Data from: Differential neuropsychological profile of ALS patients with and without C9orf72 mutation

description: Objective. To determine whether the neuropsychological profiles of ALS
 patients with (ALSC9+) and without (ALSC9-) C9orf72 expansion are
 different we administered a battery of neuropsychological tests to 741 ALS
 patients (68 ALSC9+ and 673 ALSC9-) and 129 controls. Methods. The study
 population includes 741 ALS patients who were consecutively diagnosed at
 the Turin ALS expert center in the period 2010-2018 and who underwent both
 cognitive/behavioral and genetic testing. Patients’ neuropsychological
 patterns were compared (a) at the same degree of cognitive and behavioral
 deficit according to the revised ALS-FTD Consensus Criteria; and (b) at
 the same level of motor impairment according to the King’s staging system.
 Results. Despite being about 7 years younger, ALSC9+ patients had
 significant lower scores in tests exploring executive functions, and
 verbal memory both when classified as cognitively normal and when
 diagnosed in the intermediate cognitive categories. Considering the
 clinical perspective, ALSC9+ patients showed significantly lower scores
 compared to ALSC9- patients at King’s stage 1 and 3 in almost all the
 examined neuropsychological domains, while at King’s stage 2 ALSC9+
 patients were more severely affected only in the verbal memory domain.
 Behavioral function was comparably impaired in the two cohorts.
 Conclusions. ALSC9+ patients show a different neuropsychological profile
 compared to ALSC9- ones, being more impaired in executive functions and
 verbal memory domains at all King’s stages. Verbal memory emerged as a
 particularly vulnerable function in ALSC9+, with worse performances even
 when patients were still classified as cognitively normal.
description: The study population
 includes all ALS patients who were consecutively seen at the Turin ALS
 expert center in the period 2010-2018 and who underwent both
 cognitive/behavioral and genetic testing. Patients were diagnosed
 according to El Escorial revised criteria.<sup>10</sup>All
 patients were evaluated with the ALS Functional Rating Scale revised
 (ALSFRS-R) at time of cognitive testing. Patients with history of
 neurological disorders affecting cognition (major stroke, severe head
 injuries, mental retardation), alcohol-dependence and drug-dependence,
 severe mental illness, and use of high-dose psychoactive medications were
 tested but not included in data analysis. Patients who were not of Italian
 mother tongue were assessed only through an unstructured interview and
 therefore were excluded from the analysis. A total of 129 population-based
 controls were also tested with the same battery. <b>Neuropsychological
 battery</b>. ALS patients underwent a battery of neuropsychological
 tests encompassing executive function, memory, visuospatial function, and
 language, selected according to the Diagnostic Criteria for the
 Behavioural variant of Frontotemporal Dementia,<sup>11</sup>
 and ALS-FTD Consensus Criteria.<sup>4</sup> Patients underwent
 the following neuropsychological battery: Letter Fluency test (FAS);
 Category Fluency Test (CAT); Frontal Assessment Battery (FAB); Trail
 Making Test (TMT) A, B and B-A; Rey-Osterrieth Complex Figure Test (ROCF),
 immediate (IR) and differed recall (DR); Rey Auditory Verbal Learning Test
 (RAVL), immediate (IR) and differed recall (DR); Babcock Story Recall Test
 (BSRT), immediate (IR) and differed recall (DR); Digit Span Forward and
 Backward; Raven’s Colored Progressive Matrices (CPM47); Mini Mental State
 Examination (MMSE). The raw scores of all tests were age-, sex-, and
 education-corrected using the more recent Italian normative (for reference
 see Supplementary Table 1). In selected cases, according to
 the judgment of the neuropsychologist, supplementary tasks were
 administered for a comprehensive evaluation of language; the following
 tests were used: semantic systems tests (7 and 8) of the Battery for the
 Analysis of Aphasic Deficits and the Token test. However, since these test
 were not performed in all patients, they results are not
 reported. Neurobehavioral dysfunction was
 determined with the Frontal Systems Behaviour Scale (FrSBe), using the
 Family-form evaluated by a close relative/caregiver (scores: normal ≤59,
 borderline 60-64; pathological ≥65). For the purpose of this study, we
 considered the change in points for each of the 3 domains of FrSBe
 (apathy, disinhibition, executive) from the before disease to the disease
 scores. If a subject had scores reflecting a frontal systems abnormality
 both in the premorbid and in the post-illness forms, he/she was considered
 pathological only if there was an increase of ≥10 points at the T-score
 between the two forms.<sup>3</sup> Anxiety and depression were
 assessed with the Hospital Anxiety and Depression Scale (HADS); the item
 “I feel slowed down” was discussed with patients in order to have him/her
 not to refer to physical disability.<sup>3</sup>
 <b>Domain
 classification</b>. Tests were classified according the main
 neuropsychological domain they assess (Table
 1).<sup>4,12-14</sup> A domain was considered impaired if at
 least one of the tests exploring that domain had a score under the
 normative cut-off, with the exception of executive functions and verbal
 memory, which were considered impaired if at least two not overlapping
 tests had a score under the cut-off.<sup>4</sup>
 <b>Classification of cognitive phenotypes</b>. Patients were classified according to the consensus criteria for the diagnosis of frontotemporal cognitive and behavioral syndromes in ALS.<sup>4</sup> We considered five categories: ALS-CN,  ALSci, ALSbi, ALScbi and ALS co-morbid with frontotemporal dementia (ALS-FTD). For the aims of this study, intermediate cognitive categories (ALSbi, ALSci and ALScbi) were merged. <b>ALS Staging</b>. Patients’ motor impairment was classified according to the King’s staging system. King’s staging is based on the spreading of motor symptoms in three different body regions (bulbar, upper limbs, and lower limbs), and on the use of non-invasive ventilation (NIV) and enteral nutrition.<sup>9</sup> The five stages of the King’s staging are: 1, one region involved; 2, two regions involved; 3 three regions involved; 4A, patient needs gastrostomy; 4B, patient needs non-invasive ventilation. The stage can be derived from the direct observation of the patients and also from the ALSFRS-R scale.<sup>15</sup> For the purpose of this study, we considered only stages 1 to 3, since stages 4A and 4B are not anatomical but functional and thus do not necessarily correspond to the spreading of the anatomical lesions. <b>Genetic testing</b>. All the coding exons and 50 bp of the flanking intron-exon boundaries of SOD1, of exon 6 of <i>TARDBP</i>, and of exons 14 and 15 of <i>FUS</i> have been PCR amplified, sequenced using the Big-Dye Terminator v3.1 sequencing kit (Applied Biosystems Inc.), and run on an ABIPrism 3130 genetic analyzer. These exons were selected as the vast majority of known pathogenic variants are known to lie within these mutational hotspots. A repeat-primed PCR assay was used to screen for the presence of the GGGGCC hexanucleotide expansion in the first intron of <i>C9orf72</i>. A cut-off of ≥30 repeats was considered pathological.<sup>16</sup> <b><i>Statistical analysis</i></b>. Comparisons were performed on age-, sex-, and education-corrected scores. Since all cognitive tests had not a normal distribution, the Mann-Whitney U test was used for comparisons. Data were analyzed in subsequent steps. First, we compared the results of cognitive tests of ALSC9+ vs ALSC9- patients for each cognitive and behavioral level, merging the intermediate cognitive categories (ALS-CN; ALSci/ALSbi/ALScbi; ALS-FTD). Second, we compared the results of cognitive tests of ALSC9+ vs ALSC9- patients for each King’s stage, independently from their level of cognitive impairment. Third, we grouped the tests according to their domain and compared the number of ALSC9+ vs. ALSC9- cases who showed an impairment in each domain. Two-tailed p-values are reported; Holmes correction for multiple testing was used. Effect sizes were also calculated (Supplementary Table 2).<sup>17</sup> All analyses were performed with SPSS 26.0 statistical package (SPSS, Chicago, IL, USA).