Brain & Language 127 (2013) 317–322

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Speech in spinocerebellar ataxia Ellika Schalling a,b,⇑, Lena Hartelius c a

Department of Clinical Science, Intervention and Technology, Division of Speech and Language Pathology, Karolinska Institutet, 141 86 Stockholm, Sweden Department of Speech and Language Pathology, Karolinska University Hospital, 171 76 Stockholm, Sweden c Institute of Neuroscience and Physiology, Division of Speech and Language Pathology, Sahlgrenska Academy at the University of Gothenburg, Göteborg, Sweden b

a r t i c l e

i n f o

Article history: Available online 30 October 2013 Keywords: Spinocerebellar ataxia Ataxic dysarthria Progression of dysarthria Perceptual analysis Instrumental acoustic analysis Speech and language pathology intervention

a b s t r a c t Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal dominant cerebellar ataxias clinically characterized by progressive ataxia, dysarthria and a range of other concomitant neurological symptoms. Only a few studies include detailed characterization of speech symptoms in SCA. Speech symptoms in SCA resemble ataxic dysarthria but symptoms related to phonation may be more prominent. One study to date has shown an association between differences in speech and voice symptoms related to genotype. More studies of speech and voice phenotypes are motivated, to possibly aid in clinical diagnosis. In addition, instrumental speech analysis has been demonstrated to be a reliable measure that may be used to monitor disease progression or therapy outcomes in possible future pharmacological treatments. Intervention by speech and language pathologists should go beyond assessment. Clinical guidelines for management of speech, communication and swallowing need to be developed for individuals with progressive cerebellar ataxia. Ó 2013 Elsevier Inc. All rights reserved.

1. Spinocerebellar ataxia Spinocerebellar ataxias, SCAs, are a heterogeneous group of hereditary, neurodegenerative, progressive disorders affecting the cerebellum and its efferent and afferent pathways. Age of onset is often in the third or fourth decade of life (Dürr, 2010). Clinical phenotype is dominated by progressive gait and limb ataxia, but in addition there is generally a range of concomitant neurological symptoms, e.g. oculomotor disturbance, retinopathy, spasticity, extrapyramidal movement disorders, peripheral neuropathy, sphincter disturbances. Dysarthria and cognitive impairment is also present in many cases. The first gene causing autosomal dominant hereditary ataxia (spinocerebellar ataxia, type 1) was identified in 1993 (Orr et al., 1993). Since then there has been a rapid development of molecular genetic diagnostics, and to date up to 30 genetic loci and 20 genes have been identified (Perlman, 2011). Autosomal dominantly inherited ataxias were initially considered to be caused by expansions of coding CAG repeats within the coding region of the gene, as in SCA1, SCA2, SCA3, SCA6, SCA7, SCA17, and DRPLA (dentatorubro-pallidoluysian atrophy), subtypes of SCAs that were identified early (often referred to as polyglutamine expansion SCAs). The CAG repeats lead to a toxic process resulting in neurodegeneration and

neuronal cell death. In addition, expansions in non-coding regions of genes have also been discovered as in SCA10, SCA12, and SCA31, referred to as non-coding-expansion SCAs. SCA4, SCA5, SCA11, SCA13, SCA14 and SCA27 result from point mutations, SCA15 and 16 with deletions and SCA6 is a channelopathy (Bird, 2013; Dürr, 2010; Perlman, 2011). Anticipation is seen in many SCAs; i.e. increasing severity and earlier onset of disease in subsequent generations, related to increased repeat expansion from one generation to another (Mariotti & Di Donato, 2001). Prevalence of SCA is uncertain but has been suggested to be between 3–8/100,000 individuals (Craig, Keers, Archibald, Curstin, & Chinnery, 2004; Koht & Tallaksen, 2007; Van De Warrenburg, Sinke, Verschuuren-Bemelmans, Scheffer et al., 2002). Thus, SCA is a rare disorder, compared to e.g. Parkinson’s disease with a prevalence in Europe of around 200/100,000 individuals over the age of 65 (Campenhausen et al., 2005; de Rijk et al., 2000) but comparable to e.g. Huntington’s disease which has a prevalence of up to 10/100,000 (Hoppit, Calvert, Pall, Rickards, & Sackley, 2010; Morrison, 2010). Regional differences in prevalence of SCA exist, and the most common subtypes have been suggested to be SCA1, SCA2, SCA3, SCA6 and SCA7, accounting for about 70% of dominant SCA cases (Margolis, 2002). 2. Ataxic dysarthria

⇑ Corresponding author at: Department of Clinical Sciences, Intervention and Technology, Division of Speech and Language Pathology, Karolinska Institutet, 141 86 Stockholm, Sweden. Fax: +46 (0)8 58581505. E-mail address: [email protected] (E. Schalling). 0093-934X/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.bandl.2013.10.002

Ataxic dysarthria was characterized based on perceptual ratings of speech samples from individuals with cerebellar pathology by Brown, Darley, and Aronson (1970). Symptoms were found in the

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three clusters associated with cerebellar pathology defined by Darley, Aronson, and Brown (1969); i.e. articulatory inaccuracy, prosodic excess and phonatory–prosodic insufficiency. Most prominent speech dimensions related to articulation were imprecise consonants, irregular articulatory breakdown and distorted vowels. Prominent speech dimensions related to prosodic excess were excess and equal stress, prolonged phonemes and intervals. Dimensions related to phonatory–prosodic insufficiency were harsh voice, monopitch and slow speech rate. Some of the speech dimensions are less frequent in less severe impairment, e.g. distorted vowels, harsh voice, phonemes prolonged and monotony. Later descriptions of ataxic dysarthria, particularly based on acoustic methods, have included reduced speech rate in a range of different speech tasks, alterations in speech rhythm and lengthening of segments as well as increased duration and variability of interstress intervals (Hartelius, Runmarker, Andersen, & Nord, 2000; Kent et al., 2000). Articulatory imprecision has also been confirmed in subsequent studies of ataxic dysarthria, and has been associated with reduced control of range, velocity, force and timing of the articulators (e.g. Kent, Netsell, & Abbs 1979). In studies using more recently available methodology articulatory kinematics in ataxic dysathria has been studied. Using electromagnetic articulography (EMA), slower articulatory durations were found in subjects with ataxic dysarthria secondary to Friedreich’s ataxia. In addition, it was demonstrated that longer consonant phase durations were associated with greater articulatory distances and not only with slowed movement execution (Folker et al., 2011). Acoustic studies of phonation in ataxic dysarthria have shown both increased jitter and shimmer (cycle-to-cycle variations in frequency and amplitude) which relate to the perceptual dimension ‘‘harsh voice’’ as well as long-term phonatory instability which relates perceptually to ‘‘vocal instability’’ or ‘‘voice tremor’’ (Kent et al., 2000). In summary, the overall impression of ataxic speech is that it is slow, imprecise and with a characteristically changed prosody. Common patient complaints include a sense of ‘‘drunk’’ or intoxicated speech, stumbling over words, speech deterioration with alcohol and poor coordination of breathing with speech (Duffy, 2005). Patients have often noted that speech difficulties are reduced when speech is slowed down.

3. Dysarthria in spinocerebellar ataxia, SCA Based on neuropathological considerations, dysarthria in SCA would be expected to resemble previous descriptions of ataxic dysarthria. Dysarthria is a feature in most clinical characterizations of subtypes of SCA, but there are very few more detailed descriptions of type and degree of speech symptoms to date. Several speech tasks were studied with acoustic instrumentation in two subjects with SCA7 and one subject with SCA2 by Schalling and Hartelius (2004). Reduced speech rate, increased pause duration, increased and more variable durations of alternating motion rate (AMR), sequential motion rate (SMR) syllables and interstress intervals (ISI) in addition to vocal instability was demonstrated in the three subjects. Schalling, Hammarberg, and Hartelius (2007) studied 21 individuals with hereditary, progressive ataxia and 21 matched control subjects, with perceptual and acoustic methods. Twelve of the subjects had a diagnosis of SCA2, 3, 7 or 8, based on molecular testing, and nine were diagnosed clinically by a neurologist with cerebellar ataxia (of unknown etiology). Perceptual analysis was performed by four experienced speech–language pathologists. The most prominent speech symptoms were equalized stress, imprecise consonants, vocal instability, monotony and reduced speech rate. A factor analysis showed that perceptual

speech symptoms were associated primarily with two major factors. The first factor was called speech-timing and articulation (including characteristics such as imprecise consonants, prolonged intervals, imprecise vowels and equalized stress, all speech characteristics related to difficulties with coordination and timing). It was hypothesized that this factor mainly reflected common underlying speech motor programming difficulties related to articulatory disturbance. The second factor was called voice quality (including characteristics such as harsh voice, strained–strangled voice and glottal fry, all related to vocal hyper-function). This factor may reflect other aspects of underlying neurophysiological pathology, associated with phonatory aspects. The third factor only had one speech characteristic with a high factor loading and was therefore not considered important. Acoustic findings in Schalling et al. (2007) confirmed perceptual impressions and included reduced speech rate, increased variability of segment durations as well as increased vocal instability shown as significantly higher coefficient of variation of F0 compared to control subjects. Another term for the prominent and frequently found perceptual symptom equalized stress is ‘‘scanning speech’’. In a study by Ikui et al. (2012) of 20 Japanese-speaking subjects with spinocerebellar degeneration of different etiologies, speech was investigated particularly with reference to this concept. Potential differences in the manifestations of ataxic speech between a syllable-timed language like Japanese and stress-timed languages like the Germanic languages were explored. In a syllable-timed language the syllables durations are of equal length, whereas in stress-timed languages, stress is placed at equal intervals in the phrase, thus inter-stress intervals are isochronous but syllable durations are more variable. Ikui and colleagues found that speech rate was reduced in ataxic subjects compared to control subjects. In addition, duration of vowel segments (morae) was both longer and more variable in speech produced by ataxic subjects. In addition, long Japanese vowels were also produced with more variable duration in ataxic subjects compared to controls and the distinction between long and corresponding ordinary vowel became unclear. Thus, scanning speech in Japanese is caused by a breakdown of isochrony, i.e. a difficulty in maintaining invariable vowel length in speech. In addition, a tendency towards shortening of long vowels also contribute to the impression of ‘‘scanning’’ and also contribute to unclear distinction between long and ordinary vowel in Japanese. The findings by Ikui et al. differ from previous studies of scanning speech in stress-timed languages, e.g. by Hartelius et al. (2000) or by Ackerman and Hertrich (1994), who found more isochronous syllables in ataxic subjects compared to healthy controls, and may reflect differences in the nature of syllable-timed and stress-timed languages. In an effort to look for differences in perceptual characteristics across SCA subtypes and also differences in speech signs across speech tasks, Sidtis, Ahn, Gomez, and Sidtis (2011) examined speech in 26 subjects with SCA1, 5 or 6. Perceptual ratings were performed by speech–language pathology master students. Speech samples were rated from 1 to 5 on primary and secondary dimensions. Primary dimensions included articulation, rate, rhythm and prosody (rhythm referring to pitch accents and prosody referring to melodic contour of the intonational entity). Samples rated as abnormal on the primary dimensions were also rated on 11 secondary dimensions derived from the Mayo Clinic protocol in order to further characterize the speech abnormality (Duffy, 2005). The secondary dimensions were irregular articulatory breakdown, imprecise consonants, distorted vowels, prolonged phonemes, excess and equal stress, excess loudness variation, hypernasality, voice tremor, harsh voice, breathy voice, strained–strangled voice. Some differences between SCA-subtypes were identified. A global measure of impairment indicated that the group with SCA6 was

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rated as more perceptually deviant than the participants with SCA5. Articulation was the most impaired primary dimension, both across speech tasks and SCA-types, however most impaired in SCA6. Articulatory impairment was most effectively identified in the rapid syllable repetition task whereas word repetition was the task that revealed least impairment. The picture description task was the most effective to use for ratings of secondary dimensions. Participants with SCA6 had more severely impaired articulation than participants with SCA1 and SCA5. On the other hand, perceptual dimensions related to voice impairment were rated to be more impaired in participants with SCA1 than in the groups with SCA5 and SCA6. Articulatory and voice dimensions were also core symptoms in the perceptual assessment of all subjects with SCA studied by Schalling et al. (2007), but the work of Sidtis, Ahn, Gomez, and Sidtis (2011) is the first study to indicate more clearly that characterization of speech and voice symptoms could possibly be of value in differentiating genotypes. The differences in speech dimensions between types of SCA do not only relate to differences e.g. in disease severity but may actually reflect variations in symptom profiles (see Fig. 1). In a study of two males with SCA3 and one male with SCA2 speech was again characterized mainly by altered voice quality and by reduced speech rate in all speech tasks. Perceptual voice characteristics were hoarseness, breathiness, tremulous, unstable and strained–strangled voice (Dos Santos Barreto, Mantovani Nagagoka, Chapchap Martins, & Zazo Ortiz, 2009). In a recent report, Story and McKinley Gardner (2012) described clinical features of the newly characterized spinocerebellar ataxia type 20. Clinical description of SCA20 was based on examination of 16 members of a family in Australia. The disorder was characterized by slow progression of gait disturbance and dysarthria. About two thirds of affected patients demonstrated palatal tremor (myoclonus) and phonatory changes resembling spasmodic adductor dysphonia. Onset of dysarthria was sudden in several of the family members and the dysarthria presented before onset of ataxia in about two thirds of patients, sometimes with several years, which is unusual. Cognition was not impaired. For an overview of speech characteristics in different subtypes of SCA discussed above and also other clinical distinguishing features and genetic information, see Table 1. To date there are no studies that specifically have looked at the effect of the disease on communicative participation in patients with SCA. Subjective health status is only partly related to disease

Fig. 1. Factors 1, 2 and 3 from Schalling et al. (2007).

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status, but may also be influenced by other factors such as e.g. emotional status, coping strategies and expectations. Ability to communicate is a critical factor related to quality of life (Hoffman et al., 2005) and instruments targeting quality of life may therefore also reflect reduced communicative function. In a large European multi-center study, a generic measure of health related quality of life (EQ-5D) and also a screening questionnaire for affective disorders were given to 526 patients with SCA1, SCA2, SCA3 and SCA6. The EQ-5D includes 5 items (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) and patients respond with 1 (no problem), 2 (some problem) or 3 (severe problem). Patients reported problems with mobility and usual activities most frequently. ‘‘Usual activities’’ was the item which could be expected to be affected by communication difficulties and also the item which most frequently was rated as a severe problem (Schmitz-Hübsch et al., 2010).

4. Neuroimaging studies of SCA-patients Lesions studies have suggested a degree of right-sided lateralization of speech motor control in the cerebellum. To investigate functional anatomy of speech in cerebellar disease blood flow during a speech task (syllable repetition) was studied with Positron Emission Tomography (PET) in 24 subjects with hereditary ataxia and dysarthria and 13 age-matched controls (Sidtis, Gomez, Groshong, Strother, & Rottenberg, 2006). Speech rates were reduced in ataxic subjects. Significant reductions in mean regional blood flow in the cerebellum but not in supratentorial regions were also seen in the SCA-subjects but not in controls. Multiple linear regression was used to study interaction between speech rate and regional blood flow and showed a relationship between speech rate and the cortical left inferior frontal and transverse temporal regions and the right inferior cerebellar region and the caudate nucleus in ataxic subjects. It was hypothesized that the role of the cerebellum in speech motor control may be amplified by cerebellar disease, as activation was seen in ataxic subjects but not in healthy controls, possibly reflecting a compensatory mechanism. The inverse relationship between speech rate and blood flow in the cortical temporal region may be related to an increased role of auditory feedback in dysarthric speakers. To evaluate disease progression, seven of the subjects from the previous study by Sidtis et al. (2006) were studied longitudinally over an average period of 20.9 months (Sidtis, Strother, Groshong, Rottenberg, & Gomez, 2010). There was a significant decline in blood flow in the cerebellum during the speech task between the first and second assessment for all seven subjects. Speech rate during syllable repetition (surprisingly) increased with 6% between the first and second assessment, whereas blood flow in the right inferior cerebellum decreased with 7%, the flow in the right caudate nucleus decreased with 2%, the flow in the left transverse temporal gyrus remained unchanged, and the left inferior frontal gyrus flow increased with 3.6%. Possibly the increased blood flow in Broca’s area reflect a compensation for the decreased cerebellar blood flow which may indicate that the cortical–cerebellar relationship during speech is changed in subjects with cerebellar disease. It is somewhat unexpected that speech rate actually increased with disease progression. The selected speech task in this study was syllable repetition (sequential motion rate SMR, i.e. pa-ta-kapa-ta-ka, etc.) and while it is known that slower and more irregular alternating motion rates (AMR, i.e. papapa, etc.) is a distinguishing characteristic of ataxic dysarthria it is a clinical impression that SMR is less difficult to perform for patients with ataxic dysarthria. In addition, a repeated assessment might also have contributed to a training effect.

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Table 1 Clinical and molecular information and speech characteristics (when available) for subtypes of spinocerebellar ataxia, SCA discussed in the text. Disorders Gene symbol or chromosomal locusa,b

Prevalence

Speech characteristics

Clinical characteristics beyond gait ataxia and dysarthriaa,b

SCA1

ATXN 1 (6p23)

SCA2

ATXN 2 (12q24)

6–27% of dominant ataxias worldwide 13–18% of dominant ataxias worldwide

Hyperreflexia/spasticity, cerebellar tremor, dysphagia, and optic atrophy Slow saccades, hyporeflexia, cerebellar tremor, parkinsonism, and dementia

SCA3

ATXN 3 (14q24.3-q31)

23–36% of dominant ataxias worldwide

Dysarthria (voice more affected than articulationc) Dysarthria (breathy, hoarse, strain-strangled voiced, reduced speech rate, increased AMR, SMR, pause durations, ISIs, vocal instabilitye) Dysarthria (breathy, hoarse voice quality, reduced speech rated)

SCA5

SPTBN2 (11p11-q11)

SCA6

CACNA1A (19p13)

SCA7

ATXN7 (3p21.1-p12)

SCA8

ATXN8/ATXN80S (13q21)

SCA17

TBP (6q27)

SCA20

11p13–q11

Lincoln family in USA; families in Germany and France 10–30% of dominant ataxias worldwide 2–5% of dominant ataxias worldwide; may be more common in Sweden and Finland 2–4% of dominant ataxias worldwide; genetic testing results may be open to interpretation Japanese, German, Italian, and French families Anglo-Celtic family in Australia

Dysarthria (voice more affected than articulationc) Dysarthria, (articulation more severely impaired than phonationc) Dysarthria (reduced speech rate, increased AMR, SMR, pause durations, ISIs, vocal instabilitye) Dysarthria

Dysarthria Early dysarthria, palatal tremor, spasmodic dysphonia

Nystagmus, spasticity (onset < 35 years), neuropathy (onset > 45 years), basal ganglia features, lid retraction, and facial fasciculations Bulbar signs, otherwise ‘‘pure cerebellar’’, and slow progression Nystagmus, otherwise ‘‘pure cerebellar,’’ onset > 50 years, and slow progression Macular pigmentary retinopathy, slow saccades, and pyramidal signs Nystagmus, cerebellar tremor

Dementia, psychosis, extrapyramidal features, hyperreflexia, and seizures Speech symptoms preceding gait disturbance

AMR, alternating motion rates. SMR, sequential motion rates. ISI, Inter-stress Intervals. a Perlman (2011). b Bird (2013). c Sidtis et al. (2011). d Dos Santos et al. (2009). e Schalling and Hartelius (2004).

5. Progression of speech symptoms Time of disease onset is generally difficult to determine in slowly progressive disorders and this is also the case for SCA. Characterization of early symptoms is of importance to facilitate early diagnosis. Early symptoms were therefore investigated in a study of 287 patients with SCA1, SCA2, SCA3 and SCA6, the most prevalent subtypes of SCA in Europe, by Globas, Tezenas du Montcel, Baliko, Depondt, et al. (2008). Gait disturbance was reported as the initial symptom by 66% of all SCA patients. Speech symptoms were reported to precede gait ataxia by a mean of only 5% of the subjects with SCA. SCA6 was the subtype of SCA from which patients reported the highest occurrence of speech symptoms preceding gait ataxia (8.2%). In the 16 cases of SCA20 described by Storey and McKinley (2012) speech symptoms did however precede gait disturbance in about 66% of the patients. Progression of speech symptoms in SCA was studied longitudinally in nine subjects with SCA over close to three years by Schalling, Hammarberg, and Hartelius (2008). Speech recordings and clinical dysarthria assessments were done at three occasions during this time interval. Speech samples were analyzed perceptually and acoustically. A statistically significant increase of the mean dysarthria score could be seen, reflecting a general progression of speech symptoms. In addition, speech symptoms related to articulation and prosody seemed to aggravate more rapidly than speech symptoms related to voice quality, based on perceptual ratings. When results from subjects with early disease onset and later disease onset were analyzed separately it was even more pronounced that perceptual symptoms related to speech function progressed faster than symptoms related to voice function in the group with early disease onset. Progression of all speech and voice symptoms was in general slower in subjects with later disease onset.

Progression of diseases with ataxia (SCA2, SCA3, SCA6 and SCA17 and multiple system atrophy-cerebellar variant, MSA-C) were studied in 119 patients over up to 38 months by Lee et al. (2011) using the Scale for the Assessment and Rating of Ataxia (SARA). The SARA includes eight items: gait, stance, sitting, speech disturbance, finger chase, nose-finger test, fast alternating hand movements, and heel-shin slide. Disease progression was faster in MSA-C than in the SCAs, including progression of speech disturbance. For the different subtypes of SCAs, speech disturbance progressed fastest in SCA17 followed by SCA3. Longitudinal development of speech symptoms has also been studied in Friedreich’s ataxia (FA), an autosomal recessive hereditary ataxia, with approximately the same prevalence as SCA. Rosen et al. (2012) studied acoustic changes in speech of 29 subjects with FA at yearly intervals over four years. Longitudinal changes related to utterance duration, variability of pauses and spectral dynamics could be seen in intervals of two years or longer and the authors suggest that speech changes have potential for monitoring disease progression or treatment outcomes. 6. Discussion The spinocerebellar ataxias are a heterogeneous group of progressive neurodegenerative disorders characterized by cerebellar ataxia presenting as unsteady gait, reduced fine-motor control, speech impairment and varying combinations of other neurological symptoms. Some clinical features may help differentiate between genotypes, but many symptoms overlap. Clinical differential diagnosis is therefore uncertain and only genetic testing is definite. Genetic testing is commercially available for 13 of the SCAs. A complete test battery is however costly and may not be available for all patients (Perlman, 2011). To date, no cure for

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SCA is available. Disease progression and prognosis differ between different genotypes. Uncertainty of diagnosis often leads to great distress and a definite diagnosis may be of great value for patients and their families. A definite diagnosis may be of help in more long-term life-planning decisions and may also lead to better management of symptoms (Powell, Chandrasekharan, & Cook-Deegan, 2010). Dysarthria is a common feature in almost all clinical descriptions of SCAs, but in many studies description of speech symptoms is based on a more general rating of overall severity, possibly based on information from an ataxia rating scale where speech is only one of several items being rated. Only a limited number of studies have characterized the speech symptoms in SCAs in more detail and these studies often include a limited number of patients. In the few studies with more detailed descriptions of speech symptoms in SCA that are available, the dysarthria resembles previous characterizations of ataxic dysarthria, but changes in vocal quality seem to be more pronounced, at least in some subtypes, maybe due to neurological impairment extending beyond the cerebellum, including also e.g. spinocerebellar tracts, pyramidal tracts and basal ganglia. The clinical characterizations of speech in SCA may be compared to perceptual and instrumental descriptions of speech in Friedreich’s ataxia and Folker et al. (2010, 2012) have shown variability in speech symptoms, suggesting different symptom profiles in FA. In particular, a distinction between presence of hypernasality and phonatory dysfunction was shown. Sidtis et al. (2011) found that perceptual voice symptoms were more prominent in patients with SCA1 than patients with SCA5 and SCA6 whereas symptoms related to impaired articulation were more prominent in patients with SCA6. Schalling et al. (2007) showed a differentiation between perceptual symptoms related to articulation and prosody and perceptual symptoms related to voice quality – possibly related to different underlying neuropathology, but the work of Sidtis and colleagues is to the authors’ knowledge the only study to date to find a difference in speech and voice symptoms directly related to different genotypes. This is important and motivates continued efforts to explore speech and voice symptoms in relation to genotypes in more detail. Possibilities to facilitate clinical characterization of subtypes of SCA based on variations in dysarthria-profiles could be quite valuable. Better clinical differentiation may help reduce the number of genetic tests to run and thus reduce costs, and may also be valuable in cases where genetic testing is not available. In addition, more detailed characterization of dysarthria symptoms related to the differences in neuropathological involvement in SCAs may also contribute to better understanding of the neurological basis of speech production. It is conceivable, that the subtypes which involve more pronounced phonatory symptoms such as strained– strangled voice quality (e.g. SCA1, 2, 3) have more extracerebellar involvement than the ones which have more specific articulatory timing difficulties (e.g. SCA6). In this review speech changes in SCA have been discussed in relation to genotypes since this relates to underlying cause of the different types of SCA. The few findings concerning connections between different speech profiles and genotypes known to date have been highlighted. Another perspective would be to analyze speech changes as they relate more directly to pathophysiological changes, e.g. effects on speech primarily caused by degeneration of cerebellar nuclei such in SCA3 or by degeneration of cerebellar cortex as in SCA6. This approach does however have limitations since pathology rarely is limited to one single structure and this perspective was therefore not in focus in this review. Acoustic analysis can be used to quantify different speech symptoms and reliably discriminate between different neurological conditions (e.g. Liss, LeGendre, & Lotto, 2010) and has recently also been shown to be useful in monitoring disease progression

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(Rosen et al., 2012). The methodology has also been successfully tried in search for early or incipient symptoms of neurologic disease, e.g. Huntington’s disease (Vogel, Shirbin, Churchyard, & Stout, 2012). In particular, acoustic measures of timing seem to be extremely sensitive to motor speech dysfunction and symptom progression. Since difficulties with various aspects of speech timing is one of the most prominent features of ataxic dysarthria, quantification of temporal speech characteristics may assist in early identification of disease symptoms and differentiation of SCA subtypes. There is not yet any disease modifying treatment for the spinocerebellar ataxias so intervention is focused on management of symptoms as the disease progresses. D’Abreu et al. (2010) suggest that symptomatic treatment for patients with SCA3 should include treatment of e.g. cramps, pain, sleep-related disorders, fatigue, depression and anxiety. Physical therapy is recommended to maintain strength, balance and to learn to compensate for the movement dysfunction. Speech therapy evaluation is also recommended for dysarthria and dysphagia. Our clinical experience is that speech and language pathologists should not only evaluate patients, but that intervention focused on optimizing respiratory and vocal resources as well as training compensatory strategies may help patients with dysarthria secondary to SCA. In addition, intervention aimed at reducing restrictions in communicative participation is expected to be of value for quality of life aspects. Developing guidelines on the management of speech, communication and swallowing in individuals with progressive ataxic dysarthria, staging interventions according to severity of symptoms as outlined for other degenerative diseases in Yorkston, Miller, and Strand (2004), is urgent in order to assist these individuals in managing the effect of their illness on everyday life and communication.

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