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Karlsson, Fredrik, DocentORCID iD iconorcid.org/0000-0003-3373-0934
Publications (10 of 41) Show all publications
Karlsson, F., Schalling, E., Laakso, K., Johansson, K. M. & Hartelius, L. (2020). Assessment of speech impairment in patients with Parkinson's disease from acoustic quantifications of oral diadochokinetic sequences. Journal of the Acoustical Society of America, 147(2), 839-851
Open this publication in new window or tab >>Assessment of speech impairment in patients with Parkinson's disease from acoustic quantifications of oral diadochokinetic sequences
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2020 (English)In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 147, no 2, p. 839-851Article in journal (Refereed) Published
Abstract [en]

This investigation aimed at determining whether an acoustic quantification of the oral diadochokinetic (DDK)task may be used to predict the perceived level of speech impairment when speakers with Parkinson's disease(PD) are reading a standard passage. DDK sequences with repeated [pa], [ta], and [ka] syllables were collectedfrom 108 recordings (68 unique speakers with PD), along with recordings of the speakers reading a standardizedtext. The passage readings were assessed in five dimensions individually by four speech-language pathologists ina blinded and randomized procedure. The 46 acoustic DDK measures were merged with the perceptual ratings ofread speech in the same recording session. Ordinal regression models were trained repeatedly on 80% of ratingsand acoustic DDK predictors per dimension in 10-folds, and evaluated in testing data. The models developedfrom [ka] sequences achieved the best performance overall in predicting the clinicians' ratings of passage readings. The developed [pa] and [ta] models showed a much lower performance across all dimensions. The additionof samples with severe impairments and further automation of the procedure is required for the models to be usedfor screening purposes by non-expert clinical staff.

Place, publisher, year, edition, pages
Acoustical Society of America, 2020
National Category
Other Medical Sciences not elsewhere specified
Research subject
language studies; medical informatics
Identifiers
urn:nbn:se:umu:diva-167937 (URN)10.1121/10.0000581 (DOI)
Available from: 2020-02-06 Created: 2020-02-06 Last updated: 2020-02-07Bibliographically approved
Sandström, L., Schalling, E., Karlsson, F., Blomstedt, P. & Hartelius, L. (2020). Speech following DBS for essential tremor: Effects of chronic and high-amplitude stimulation in the posterior subthalamic area. In: : . Paper presented at Twentieth Biennial Conference on Motor Speech: Motor Speech Disorders & Speech Motor Control, Feb 19 – 23, 2020, Santa Barbara, CA.
Open this publication in new window or tab >>Speech following DBS for essential tremor: Effects of chronic and high-amplitude stimulation in the posterior subthalamic area
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2020 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Deep brain stimulation (DBS) can be very effective in alleviating tremor, but adverse effects on speech are frequently reported, especially following bilateral DBS. Most of the existing literature on DBS and speech deals with the effects of DBS targeting the subthalamic nucleus or the ventral intermediate nucleus of the thalamus, which are the traditional targets for Parkinson’s disease and essential tremor, respectively. More recently, the posterior subthalamic area (PSA) has been highlighted as a particularly effective target for tremor; however, there are limited studies of PSA-DBS effects on speech.

We report speech outcomes for 14 persons with essential tremor during chronic PSA-DBS and at unilateral high-amplitude PSA-stimulation.

The objectives were to answer the following questions:

  • To what extent is speech function, and in particular articulation and voice, affected by chronic PSA-DBS?
  • How is speech affected by unilateral high-amplitude stimulation
  • Is bilateral chronic PSA-DBS worse for speech than unilateral PSA-stimulation?
National Category
Other Medical Sciences not elsewhere specified
Identifiers
urn:nbn:se:umu:diva-168038 (URN)
Conference
Twentieth Biennial Conference on Motor Speech: Motor Speech Disorders & Speech Motor Control, Feb 19 – 23, 2020, Santa Barbara, CA
Available from: 2020-02-13 Created: 2020-02-13 Last updated: 2020-02-19Bibliographically approved
Karlsson, F. & Hartelius, L. (2019). How Well Does Diadochokinetic Task Performance Predict Articulatory Imprecision?: Differentiating Individuals with Parkinson's Disease from Control Subjects. Folia Phoniatrica et Logopaedica, 71(5-6), 251-260
Open this publication in new window or tab >>How Well Does Diadochokinetic Task Performance Predict Articulatory Imprecision?: Differentiating Individuals with Parkinson's Disease from Control Subjects
2019 (English)In: Folia Phoniatrica et Logopaedica, ISSN 1021-7762, E-ISSN 1421-9972, Vol. 71, no 5-6, p. 251-260Article in journal (Refereed) Published
Abstract [en]

OBJECTIVE: To investigate whether syllables produced in an oral diadochokinetic (DDK) task may be quantified so that persons with Parkinson's disease (PD) perceived to have reduced articulatory precision when reading may be correctly identified using that quantification.

PATIENTS AND METHODS: Syllable sequences from 38 speakers with PD and 38 gender- and age-matched control speakers (normal controls [NC]) were quantified acoustically and evaluated in terms of (1) the speakers' ability to accurately predict speaker group membership (PD or NC) and (2) their ability to predict reduced/non-reduced articulatory precision.

RESULTS: A balanced accuracy of 80-93% in predicting speaker group membership was achieved. The best measures were related to the proportion of a syllable made up of a vowel, amplitude slope and syllable-to-syllable variation in duration and amplitude. The best material was that based on /ka/. Reduced articulatory precision was accurately predicted from DDK measures in 89% of the samples. Release-transient prominence and voicing during the onset of plosives were particularly strong predictors.

CONCLUSIONS: DDK sequences can predict articulatory imprecision as observed in another speech task. The linking of performance across speech tasks probably requires measures of stability in syllable durations and amplitudes, as well as measures of subsyllabic acoustic features.

Place, publisher, year, edition, pages
S. Karger, 2019
Keywords
Diadochokinetic task, Dysarthria, Parkinson’s disease
National Category
Other Medical Sciences not elsewhere specified
Research subject
Linguistics
Identifiers
urn:nbn:se:umu:diva-159341 (URN)10.1159/000498851 (DOI)000492150200006 ()31117108 (PubMedID)
Available from: 2019-05-27 Created: 2019-05-27 Last updated: 2019-11-20Bibliographically approved
Sandström, L., Blomstedt, P. & Karlsson, F. (2019). Long-term effects of unilateral deep brain stimulation on voice tremor in patients with essential tremor. Parkinsonism & Related Disorders, 60, 70-75
Open this publication in new window or tab >>Long-term effects of unilateral deep brain stimulation on voice tremor in patients with essential tremor
2019 (English)In: Parkinsonism & Related Disorders, ISSN 1353-8020, E-ISSN 1873-5126, Vol. 60, p. 70-75Article in journal (Refereed) Published
Abstract [en]

INTRODUCTION: Voice tremor (VT) is a common symptom of Essential tremor (ET). Deep brain stimulation (DBS) is an established treatment for ET overall, however, its effect on VT is less clear. The aim of this study was to evaluate long-term effects of DBS on VT and to investigate how VT symptoms develop over time in patients with ET.

METHODS: VT scores for the cohort of 81 ET patients that had undergone DBS surgery in the caudal zona incerta (cZi) were analyzed retrospectively. Thirty-four patients had preoperative VT and long-term evaluations were available for 19 patients. Longitudinal effects of cZi-DBS were investigated 1, 3 and 5 years postoperatively. VT progression was evaluated based on preoperative-, and off stimulation postoperative assessments.

RESULTS: Unilateral cZi-DBS reduced average voice tremor by 58% at the 3-year follow-up and by 67% 5 years after surgery. Four patterns of VT development were identified among patients, and the effectiveness of cZi-DBS in alleviating voice tremor symptoms showed differing patterns for these subgroups.

CONCLUSIONS: This retrospective analysis of a small cohort of patients suggests that cZi-DBS may reduce VT in the long-term for patients with ET overall, but the pattern of VT progression likely influences the effectiveness of the treatment. These results also suggest that unilateral cZi-DBS may be more efficacious when treating patients with mild to moderate VT. A prospective, blinded, controlled clinical trial in patients with ET is needed to determine developmental patterns of VT, and the safety and efficacy of cZi-DBS for the treatment of VT.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Deep brain stimulation, Essential tremor, Long-term evaluation, Voice tremor
National Category
Neurology Otorhinolaryngology
Research subject
Neurosurgery; Oto-Rhino-Laryngology
Identifiers
urn:nbn:se:umu:diva-152704 (URN)10.1016/j.parkreldis.2018.09.029 (DOI)000466258400013 ()30297208 (PubMedID)
Available from: 2018-10-19 Created: 2018-10-19 Last updated: 2019-12-31Bibliographically approved
Karlsson, F., Malinova, E., Olofsson, K., Blomstedt, P., Linder, J. & Nordh, E. (2019). Voice Tremor Outcomes of Subthalamic Nucleus and Zona Incerta Deep Brain Stimulation in Patients With Parkinson Disease. Journal of Voice, 33(4), 545-549
Open this publication in new window or tab >>Voice Tremor Outcomes of Subthalamic Nucleus and Zona Incerta Deep Brain Stimulation in Patients With Parkinson Disease
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2019 (English)In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 33, no 4, p. 545-549Article in journal (Refereed) Published
Abstract [en]

Objectives: We aimed to study the effect of deep brain stimulation (DBS) in the subthalamic nucleus (STN) and caudal zona incerta (cZi) on level of perceived voice tremor in patients with Parkinson disease (PD).

Study Design: This is a prospective nonrandomized design with consecutive patients.

Methods: Perceived voice tremor was assessed in patients with PD having received either STN-DBS (8 patients, 5 bilateral and 3 unilateral, aged 43.1-73.6 years; median = 61.2 years) or cZi-DBS (14 bilateral patients, aged 39.0-71.9 years; median = 56.6 years) 12 months before the assessment. Sustained vowels that were produced OFF and ON stimulation (with simultaneous L-DOPA medication) were assessed perceptually in terms of voice tremor by two raters on a four-point rating scale. The assessments were repeated five times per sample and rated in a blinded and randomized procedure.

Results: Three out of the 22 patients (13%) were concluded to have voice tremor OFF stimulation. Patients with PD with STN-DBS showed mild levels of perceived voice tremor OFF stimulation and a group level improvement. Patients with moderate/severe perceived voice tremor and cZi-DBS showed marked improvements, but there was no overall group effect. Six patients with cZi-DBS showed small increases in perceived voice tremor severity.

Conclusions: STN-DBS decreased perceived voice tremor on a group level. cZi-DBS decreased perceived voice tremor in patients with PD with moderate to severe preoperative levels of the symptom.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
DBS; Parkinson disease; STN; Voice tremor; cZi
National Category
Other Clinical Medicine
Research subject
Oto-Rhino-Laryngology; Neurosurgery
Identifiers
urn:nbn:se:umu:diva-144189 (URN)10.1016/j.jvoice.2017.12.012 (DOI)000476489700020 ()29361338 (PubMedID)
Funder
Swedish Research Council, 2009-946
Available from: 2018-01-25 Created: 2018-01-25 Last updated: 2019-09-06Bibliographically approved
Karlsson, F., Karlsson, M. & Hartelius, L. (2018). How well does DDK task performance predict fluent speech articulation?. In: : . Paper presented at Nineteenth Biennial Conference on Motor Speech: Motor Speech Disorders & Speech Motor Control, Feb 22 – 25, 2018, Savannah, Georgia.
Open this publication in new window or tab >>How well does DDK task performance predict fluent speech articulation?
2018 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

The oral diadokochinesia (DDK) task is an established tool for assessing speech motor control that has been used across a range of conditions. The predominant outcome measure reported after the patient have performed the task is the maximum syllable rate achieved by the patient. More recent reports have also highlighted stability in pace of the sequence as quantifications that may be indicative of speech impairment. While the DDK task affords quick and easy administration, concerns have been raised regarding the strength of association between DDK task performance and patients’s articulation in fluent speech. It may not be assumed that a reduced DDK rate or rate stability will cause fluent speech also to be perceived as slowed or dysrhythmic. And, patients may well improve their syllable rate at the expense of articulatory quality, which is currently not easily captured in an objective outcome measure.

We report here on an effort to assess to what degree information from an expanded quantification of DDK sequences may be used identify patients with dysarthria and to model clinical assessments of fluent speech. Acoustic quantifications of the consonant and consonant-vowel relationship are combined with previously used measures, and applied to manually processed DDK sequences produced by patients with Parkinson’s disease and normal control speakers. We observe how well these quantifications may form the basis for accurate identification of patients among normal controls, and predict the outcome of blinded and randomized clinical assessments of patients’ production of fluent speech.Rapid repetition of CV syllables (oral diadochokinesis, DDK) puts pressure on the speech motor system in order to afford detection of a deteriorating articulatory ability.

This study assessed

  1.  how well objective quantifications of DDK

    sequences can be used to identify PD speakers

    among age matched controls (NC), and

  2. how well a reduced articulatory ability in PD

    speakers may be predicted using quantifications of DDK sequences performed in the same recording session.

The comprehensive DDK sequence quantification achieved a 93% classification accuracy for speaker group and a 79% accuracy for reduced fluent speech articulatory quality. 

National Category
Other Medical Sciences not elsewhere specified
Research subject
Linguistics
Identifiers
urn:nbn:se:umu:diva-144767 (URN)
Conference
Nineteenth Biennial Conference on Motor Speech: Motor Speech Disorders & Speech Motor Control, Feb 22 – 25, 2018, Savannah, Georgia
Available from: 2018-02-14 Created: 2018-02-14 Last updated: 2018-06-09Bibliographically approved
Lohmander, A., McAllister, A., Hansson, K., Hartelius, L., Blom Johansson, M., Karlsson, F., . . . van Doorn, J. (2017). Kommunikations- och sväljstörningar genom hela livet: ett logopediskt ståndpunktsdokument. Umeå: Umeå universitet
Open this publication in new window or tab >>Kommunikations- och sväljstörningar genom hela livet: ett logopediskt ståndpunktsdokument
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2017 (Swedish)Report (Other academic)
Abstract [sv]

Den forskning som bedrivs inom logopedi i Sverige idag spänner över ett brett spektrum av medfödda, utvecklingsrelaterade och förvärvade kommunikationsstörningar på grund av röst-, tal- och språksvårigheter samt sväljstörningar. Precis som i andra länder pågår en snabb utveckling både mot en breddning av det urval av områden som det forskas kring och ett ökat fokus på nationellt samarbete. Även om de framsteg som görs inom respektive fält kan mätas genom de forskningsrapporter som publiceras av respektive forskargrupper, finns det ett behov av att granska vilka forskningsinsatser som bedrivs jämte det demografiska sammanhanget. I detta ståndpunktsdokument ger vi en översikt över logopediämnet och den forskning som bedrivs i Sverige. I en kubmodell illustreras hur kommunikations- och sväljstörningar kan beskrivas. Stratifierade (per åldersintervall) uppskattningar av prevalensen av kommunikations- och sväljstörningar ges baserat på 2016 års befolkningsstruktur. Genom att presentera dessa två komponenter identifieras forskningsområden och riktningar inom logopedi som behöver ges ökad uppmärksamhet i det kommande forskningsarbetet.

Place, publisher, year, edition, pages
Umeå: Umeå universitet, 2017. p. 11
Keywords
Logopedi, Forskningsöversikt
National Category
Other Medical Sciences not elsewhere specified
Identifiers
urn:nbn:se:umu:diva-139757 (URN)
Available from: 2017-09-26 Created: 2017-09-26 Last updated: 2020-01-29Bibliographically approved
Hägglund, P., Sandström, L., Blomstedt, P. & Karlsson, F. (2016). Voice Tremor in Patients With Essential Tremor: Effects of Deep Brain Stimulation of Caudal Zona Incerta. Journal of Voice, 30(2), 228-233
Open this publication in new window or tab >>Voice Tremor in Patients With Essential Tremor: Effects of Deep Brain Stimulation of Caudal Zona Incerta
2016 (English)In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 30, no 2, p. 228-233Article in journal (Refereed) Published
Abstract [en]

Objectives. The present study aimed at evaluating the effect of deep brain stimulation (DBS) of the caudal zona incerta (cZi) on voice tremor in patients with essential tremor (ET). Study Design. This is a prospective nonrandomized design with consecutive patients.

Methods. Twenty-six patients operated with cZi DBS were evaluated under two conditions: without stimulation (Stim OFF) and with stimulation (Stim ON). Voice tremor was assessed on the basis of recordings of sustained vowel productions using a four-point rating scale in a blinded and randomized procedure. Averaged values of multiple assessments for each stimulus were used in statistical testing. The group of patients with voice tremor in Stim OFF was analyzed separately from the group of patients without voice tremor.

Results. Voice tremor was significantly reduced on stimulation compared with off for the subgroup with initial voice tremor. Voice tremor prevalence was found to be 50% (13 patients). Individual differences in voice tremor outcome were noticeable. Six of the patients with voice tremor at baseline improved substantially by cZi DBS treatment.

Conclusions. On the group level, voice tremor in patients with ET was found to reduce when stimulating the cZi. Bilateral stimulation was indicated to be more effective in reducing voice tremor than unilateral stimulation. However, individual voice tremor outcomes suggest that not all patients benefit from cZi DBS. Severity of voice tremor at baseline may not be a good predictor of voice tremor outcome after cZi DBS. Patients should be informed before surgery regarding individual differences in response to DBS treatment.

Keywords
Essential tremor, DBS, cZi, Voice tremor, Perceptual evaluation
National Category
Otorhinolaryngology Neurology
Research subject
Oto-Rhino-Laryngology; Neurosurgery
Identifiers
urn:nbn:se:umu:diva-103576 (URN)10.1016/j.jvoice.2015.04.003 (DOI)000373452800015 ()26001501 (PubMedID)
Available from: 2015-05-21 Created: 2015-05-21 Last updated: 2018-06-07Bibliographically approved
Eklund, E., Qvist, J., Sandström, L., Viklund, F., Doorn, J. v. & Karlsson, F. (2015). Perceived articulatory precision in patients with Parkinson’s disease after deep brain stimulation of subthalamic nucleus and caudal zona incerta. Clinical Linguistics & Phonetics, 29(2), 150-166
Open this publication in new window or tab >>Perceived articulatory precision in patients with Parkinson’s disease after deep brain stimulation of subthalamic nucleus and caudal zona incerta
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2015 (English)In: Clinical Linguistics & Phonetics, ISSN 0269-9206, E-ISSN 1464-5076, Vol. 29, no 2, p. 150-166Article in journal (Refereed) Published
Abstract [en]

The effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) and caudal zona incerta (cZi) on speech articulation in patients with Parkinson’s disease (PD) was investigated. Read speech samples were collected from nine patients with STN-DBS and ten with cZi-DBS. The recordings were made preoperatively and 12 months postoperatively with stimulator on and off (on medication). Blinded, randomized, repeated perceptual assessments were performed on words and isolated fricatives extracted from the recordings to assess 1) overall articulatory quality ratings, 2) frequency of occurrence of misarticulation patterns, and 3) fricative production. Statistically significant worsening of articulatory measures on- compared with off-stimulation occurred in the cZi-DBS group, with deteriorated articulatory precision ratings, increased presence of misarticulations (predominately altered realizations of plosives and fricatives) and a reduced accuracy in fricative production. A similar, but not significant, trend was found for the STN-DBS group. 

Keywords
Assessment, deep brain stimulation, dysarthria, Parkinson’s disease, phonetics
National Category
Other Medical Sciences not elsewhere specified
Research subject
Linguistics; Neurosurgery
Identifiers
urn:nbn:se:umu:diva-93676 (URN)10.3109/02699206.2014.971192 (DOI)000348045700005 ()25333411 (PubMedID)
Projects
En kontrastiv och longitudinell studie gällande effekten av djup hjärnstimulering på Parkinsons-patienters artikulatoriska förmåga.
Funder
Swedish Research Council, 2009-946Swedish Research Council, 2011-2294
Available from: 2014-09-30 Created: 2014-09-30 Last updated: 2018-06-07Bibliographically approved
Sandström, L., Hägglund, P., Johansson, L., Blomstedt, P. & Karlsson, F. (2015). Speech intelligibility in Parkinson's disease patients with zona incerta deep brain stimulation. Brain and Behavior, 5(10), Article ID e00394.
Open this publication in new window or tab >>Speech intelligibility in Parkinson's disease patients with zona incerta deep brain stimulation
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2015 (English)In: Brain and Behavior, ISSN 2162-3279, E-ISSN 2162-3279, Vol. 5, no 10, article id e00394Article in journal (Refereed) Published
Abstract [en]

Objectives

To investigate the effects of l-dopa (Levodopa) and cZi-DBS (deep brain stimulation in caudal zona incerta) on spontaneous speech intelligibility in patients with PD (Parkinson's disease).

Materials and Methods

Spontaneous utterances were extracted from anechoic recordings from 11 patients with PD preoperatively (off and on l-dopa medication) and 6 and 12 months post bilateral cZi-DBS operation (off and on stimulation, with simultaneous l-dopa medication). Background noise with an amplitude corresponding to a clinical setting was added to the recordings. Intelligibility was assessed through a transcription task performed by 41 listeners in a randomized and blinded procedure.

Results

A group-level worsening in spontaneous speech intelligibility was observed on cZi stimulation compared to off 6 months postoperatively (8 adverse, 1 positive, 2 no change). Twelve months postoperatively, adverse effects of cZi-DBS were not frequently observed (2 positive, 3 adverse, 6 no change). l-dopa administered preoperatively as part of the evaluation for DBS operation provided the overall best treatment outcome (1 adverse, 4 positive, 6 no change).

Conclusions

cZi-DBS was shown to have smaller negative effects when evaluated from spontaneous speech compared to speech effects reported previously. The previously reported reduction in word-level intelligibility 12 months postoperatively was not transferred to spontaneous speech for most patients. Reduced intelligibility due to cZi stimulation was much more prominent 6 months postoperatively than at 12 months.

Place, publisher, year, edition, pages
John Wiley & Sons, 2015
Keywords
Deep brain stimulation, Levodopa, Parkinson's disease, posterior subthalamic area, spontaneous speech intelligibility, zona incerta
National Category
Other Medical Sciences not elsewhere specified
Research subject
Neurosurgery; Linguistics
Identifiers
urn:nbn:se:umu:diva-109416 (URN)10.1002/brb3.394 (DOI)000363423500010 ()
Funder
Swedish Research Council, 2011-2294
Available from: 2015-09-28 Created: 2015-09-28 Last updated: 2018-06-07Bibliographically approved
Projects
Effects of deep brain stimulation treatment of Parkinson´s decease on speech and articulation proficiency: A longitudinal and contrastive study. [2009-00946_VR]; Umeå UniversityIntonation and rhythm in speech of patients with Parkinson´s disease - a longitudinal investigation of effects of the disease and its treatment [2011-02294_VR]; Umeå University
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-3373-0934

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