Deep brain stimulation of the subthalamic nucleus (STN-DBS) in patients with Parkinson's disease (PD) affects speech inconsistently. Recently, stimulation of the caudal zona incerta (cZi-DBS) has shown superior motor outcomes for PD patients, but effects on speech have not been systematically investigated. The aim of this study was to compare the effects of cZi-DBS and STN-DBS on voice intensity in PD patients. Mean intensity during reading and intensity decay during rapid syllable repetition were measured for STN-DBS and cZi-DBS patients (eight patients per group), before- and 12 months after-surgery on- and off-stimulation. For mean intensity, there were small significant differences on- versus off-stimulation in each group: 74.2 (2.0)?dB contra 72.1 (2.2)?dB ( ) for STN-DBS, and 71.6 (4.1)?dB contra 72.8 (3.4)?dB ( ) for cZi-DBS, with significant interaction ( ). Intensity decay showed no significant changes. The subtle differences found for mean intensity suggest that STN-DBS and cZi-DBS may influence voice intensity differently. 1. Introduction Deep brain stimulation (DBS) in the subthalamic nucleus (STN) is an established and effective treatment for motor symptoms associated with Parkinson’s disease (PD). Effects of STN-DBS on speech motor function, however, are less well defined and have been reported either as variable [1] or as an adverse side effect of the stimulation [2]. Recently, the caudal zona incerta (cZi) has been suggested as an alternative target in PD treatment [3, 4]. The effects of cZi-DBS on speech have not yet been reported in the literature. We have, therefore, decided to evaluate its effects on speech in conjunction with an on-going study on surgical outcomes of cZi-DBS, and to compare these with the effects of STN-DBS. Speech problems have been reported to occur in 70% [5] and 89% [6] of PD patients at some stage during the course of the disease, with higher prevalence as the disease advances in its severity and/or its time course [7]. The cardinal symptoms of speech dysfunction in PD (hypokinetic dysarthria) are weak voice, variable speech rate, short rushes of speech, imprecise consonants, breathy and harsh voice, and monotonous pitch. Of those symptoms, the perception of weak voice has been corroborated by acoustic measures of vocal intensity that demonstrate that PD patients have reduced intensity compared with healthy controls [8]. Reduced intensity is associated with the early stages of speech deterioration in PD and is often severely affected when profound speech problems exist [9]. Studies have shown that PD patients
References
[1]
B. E. Murdoch, “Surgical approaches to treatment of Parkinson's disease: implications for speech function,” International Journal of Speech-Language Pathology, vol. 12, no. 5, pp. 375–384, 2010.
[2]
G. Deuschl, J. Herzog, G. Kleiner-Fisman et al., “Deep brain stimulation: postoperative issues,” Movement Disorders, vol. 21, no. 14, pp. S219–S237, 2006.
[3]
P. Plaha, Y. Ben-Shlomo, N. K. Patel, and S. S. Gill, “Stimulation of the caudal zona incerta is superior to stimulation of the subthalamic nucleus in improving contralateral parkinsonism,” Brain, vol. 129, no. 7, pp. 1732–1747, 2006.
[4]
P. Blomstedt, A. Fytagoridis, and S. Tisch, “Deep brain stimulation of the posterior subthalamic area in the treatment of tremor,” Acta Neurochirurgica, vol. 151, no. 1, pp. 31–36, 2009.
[5]
L. Hartelius and P. Svensson, “Speech and swallowing symptoms associated with Parkinson's disease and multiple sclerosis: a survey,” Folia Phoniatrica et Logopaedica, vol. 46, no. 1, pp. 9–17, 2004.
[6]
J. A. Logemann, H. B. Fisher, B. Boshes, and E. R. Blonsky, “Frequency and cooccurrence of vocal tract dysfunctions in the speech of a large sample of Parkinson patients,” Journal of Speech and Hearing Disorders, vol. 43, no. 1, pp. 47–57, 1978.
[7]
S. Sapir, A. A. Pawlas, L. O. Ramig et al., “Voice and speech abnormalities in Parkinson disease: relation to severity of motor impairment, duration of disease, medication, depression, gender, and age,” Journal of Medical Speech-Language Pathology, vol. 9, no. 4, pp. 213–226, 2001.
[8]
C. M. Fox and L. O. Ramig, “Vocal sound pressure level and self-perception of speech and voice in men and women with idiopathic Parkinson disease,” American Journal of Speech-Language Pathology, vol. 6, no. 2, pp. 85–94, 1997.
[9]
A. K. Ho, R. Iansek, C. Marigliani, J. L. Bradshaw, and S. Gates, “Speech impairment in a large sample of patients with Parkinson's disease,” Behavioural Neurology, vol. 11, no. 3, pp. 131–137, 1998.
[10]
G. M. Schulz and M. K. Grant, “Effects of speech therapy and pharmacologic and surgical treatments on voice and speech in Parkinson's disease: a review of the literature,” Journal of Communication Disorders, vol. 33, no. 1, pp. 59–88, 2000.
[11]
A. K. Ho, R. Iansek, and J. L. Bradshaw, “Motor instability in Parkinsonian speech intensity,” Neuropsychiatry, Neuropsychology and Behavioral Neurology, vol. 14, no. 2, pp. 109–116, 2001.
[12]
K. M. Rosen, R. D. Kent, and J. R. Duffy, “Task-based profile of vocal intensity decline in parkinson's disease,” Folia Phoniatrica et Logopaedica, vol. 57, no. 1, pp. 28–37, 2005.
[13]
M. J. Hammer, S. M. Barlow, K. E. Lyons, and R. Pahwa, “Subthalamic nucleus deep brain stimulation changes speech respiratory and laryngeal control in Parkinson's disease,” Journal of Neurology, vol. 257, no. 10, pp. 1692–1702, 2010.
[14]
O. Suchowersky, G. Gronseth, J. Perlmutter, S. Reich, T. Zesiewicz, and W. J. Weiner, “Practice parameter: neuroprotective strategies and alternative therapies for Parkinson disease (an evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology,” Neurology, vol. 66, no. 7, pp. 976–982, 2006.
[15]
L. D'Alatri, G. Paludetti, M. F. Contarino, S. Galla, M. R. Marchese, and A. R. Bentivoglio, “Effects of bilateral subthalamic nucleus stimulation and medication on Parkinsonian speech impairment,” Journal of Voice, vol. 22, no. 3, pp. 365–372, 2008.
[16]
C. Dromey, R. Kumar, A. E. Lang, and A. M. Lozano, “An investigation of the effects of subthalamic nucleus stimulation on acoustic measures of voice,” Movement Disorders, vol. 15, no. 6, pp. 1132–1138, 2000.
[17]
M. Gentil, P. Chauvin, S. Pinto, P. Pollak, and A. L. Benabid, “Effect of bilateral stimulation of the subthalamic nucleus on parkinsonian voice,” Brain and Language, vol. 78, no. 2, pp. 233–240, 2001.
[18]
M. Gentil, S. Pinto, P. Pollak, and A. L. Benabid, “Effect of bilateral stimulation of the subthalamic nucleus on parkinsonian dysarthria,” Brain and Language, vol. 85, no. 2, pp. 190–196, 2003.
[19]
F. Klostermann, F. Ehlen, J. Vesper et al., “Effects of subthalamic deep brain stimulation on dysarthrophonia in Parkinson's disease,” Journal of Neurology, Neurosurgery and Psychiatry, vol. 79, no. 5, pp. 522–529, 2008.
[20]
S. Pinto, M. Gentil, P. Krack et al., “Changes induced by Levodopa and subthalamic nucleus stimulation on Parkinsonian speech,” Movement Disorders, vol. 20, no. 11, pp. 1507–1515, 2005.
[21]
M. Pützer, W. J. Barry, and J. R. Moringlane, “Effect of bilateral stimulation of the subthalamic nucleus on different speech subsystems in patients with Parkinson's disease,” Clinical Linguistics and Phonetics, vol. 22, no. 12, pp. 957–973, 2008.
[22]
M. Rousseaux, P. Krystkowiak, O. Kozlowski, C. ?zsancak, S. Blond, and A. Destée, “Effects of subthalamic nucleus stimulation on parkinsonian dysarthria and speech intelligibility,” Journal of Neurology, vol. 251, no. 3, pp. 327–334, 2004.
[23]
P. Santens, M. De Letter, J. Van Borsel, J. De Reuck, and J. Caemaert, “Lateralized effects of subthalamic nucleus stimulation on different aspects of speech in Parkinson's disease,” Brain and Language, vol. 87, no. 2, pp. 253–258, 2003.
[24]
E. Tripoliti, P. Limousin, S. Tisch, E. Bottell, and M. Hariz, “Speech in Parkinson's disease following subthalamic nucleus deep brain stimulation: preliminary results,” Journal of Medical Speech-Language Pathology, vol. 14, pp. 309–315, 2006.
[25]
E. Tripoliti, L. Zrinzo, I. Martinez-Torres, et al., “Effects of subthalamic stimulation on speech of consecutive patients with Parkinson's disease,” Neurology, vol. 76, pp. 80–86, 2011.
[26]
E. Wang, L. Verhagen Metman, R. Bakay, J. Arzbaecher, and B. Bernard, “Effect of unilateral electrostimulation of the subthalamic nucleus on speech in Parkinson's disease,” Movement Disorders, vol. 19, no. S9, p. S176, 2004.
[27]
E. Wang, L. Verhagen Metman, R. Bakay, J. Arzbaecher, and B. Bernard, “The effect of unilateral electrostimulation of the subthalamic nucleus on respiratory/phonatory subsystems of speech production in Parkinson's disease—a preliminary report,” Clinical Linguistics and Phonetics, vol. 17, no. 4-5, pp. 283–289, 2003.
[28]
E. Wang, L. Verhagen Metman, R. Bakay, J. Arzbaecher, B. Bernard, and D. M. Corcos, “Hemisphere-specific effects of subthalamic nucleus deep brain stimulation on speaking rate and articulatory accuracy of syllable repetitions in Parkinson's disease,” Journal of Medical Speech-Language Pathology, vol. 14, pp. 323–334, 2006.
[29]
D. Van Lancker Sidtis, T. Rogers, V. Godier, M. Tagliati, and J. J. Sidtis, “Voice and fluency changes as a function of speech task and deep brain stimulation,” Journal of Speech, Language, and Hearing Research, vol. 53, no. 5, pp. 1167–1177, 2010.
[30]
J. van Doorn, E. Schalling, L. Hartelius, and A. Asplund, “Stimulation of zona incerta in Parkinson's disease: a first look at speech outcomes,” Movement Disorders, vol. 25, p. S456, 2010.
[31]
F. Karlsson, E. Unger, S. Wahlgren, et al., “Deep brain stimulation of caudal zona incerta and subthalamic nucleus in patients with Parkinson's disease: effects on diadochokinetic rate,” Parkinson's Disease. In press.
[32]
P. Blomstedt and M. I. Hariz, “Are complications less common in deep brain stimulation than in ablative procedures for movement disorders?” Stereotactic and Functional Neurosurgery, vol. 84, no. 2-3, pp. 72–81, 2006.
[33]
A. Asplund, “How loud was it? A calibration system for voice recording in clinical and research applications,” in Proceedings of the 26th World Congress of Logopedics and Phoniatrics, B. Murdoch, J. Goozee, B.-M. Whelan, and K. Docking, Eds., Speech Pathology Australia, Brisbane, Australia, 2004.
[34]
P. Boersma and D. Weening, “Praat: doing phonetics by computer (Version 5.1.32),” [Computer program], 2010, http://www.praat.org/.
[35]
K. Tjaden and E. Watling, “Characteristics of diadochokinesis in multiple sclerosis and Parkinson's disease,” Folia Phoniatrica et Logopaedica, vol. 55, no. 5, pp. 241–259, 2003.
[36]
M. De Letter, J. Van Borsel, P. Boon, M. De Bodt, I. Dhooge, and P. Santens, “Sequential changes in motor speech across a levodopa cycle in advanced Parkinson's disease,” International Journal of Speech-Language Pathology, vol. 12, no. 5, pp. 405–413, 2010.
[37]
A. Goberman, C. Coelho, and M. Robb, “Phonatory characteristics of Parkinsonian speech before and after morning medication: the ON and OFF states,” Journal of Communication Disorders, vol. 35, no. 3, pp. 217–239, 2002.
[38]
J. Jiang, E. Lin, J. Wang, and D. G. Hanson, “Glottographic measures before and after levodopa treatment in Parkinson's disease,” The Laryngoscope, vol. 109, no. 8, pp. 1287–1294, 1999.