Clinicopathologic Correlations of Jaw Tremor in a Longitudinal Aging Study.

Background and Objectives: The aim of this study is to assess clinical and pathologic correlations of jaw tremor in 3 cohorts enrolled in a long-term aging study. Jaw/lip tremor has been described in various movement disorders but the impact of seeing a jaw tremor on clinician diagnosis and whether the presence of isolated jaw tremor is correlated with subsequent phenoconversion to a different movement disorder are unclear. Methods: Data from the Arizona Study of Aging and Neurodegenerative Disease, a longitudinal clinicopathologic study, were used. Control subjects (n = 708) did not have any tremor or parkinsonism. At initial evaluation, 276 subjects who had jaw tremor were categorized as isolated jaw tremor (jaw tremor without limb action tremor or parkinsonism), suspect/possible PD (1 or 2 cardinal features of PD without a history of dopaminergic treatment), parkinsonism (probable PD and other parkinsonian disorders), or nonparkinsonian tremor (e.g., essential tremor). Initial clinical diagnosis was compared with "final diagnosis" based on longitudinal assessments and with clinicopathologic diagnosis when available. Results: In subjects with jaw tremor, we identified 45 isolated jaw tremor, 92 nonparkinsonian tremor, 56 suspect/possible PD, and 83 parkinsonism cases at baseline and followed longitudinally. Neuropathologic diagnosis was available for 137 cases. The mean time from initial to final assessment or autopsy was 6.8 years (SD 4.4). Of the subjects with follow-up data, only 15.4% of those with isolated jaw tremor (6/39) and 8.8% of those with nonparkinsonian tremor (6/68) evolved into a clinical parkinsonian disorder. Neither of these groups was associated with clinicopathologic PD: isolated jaw tremor (1/18) and nonparkinsonian tremor (1/43). Those with jaw tremor initially classified into a parkinsonian group were more highly associated with clinicopathologic PD: 27 of 51 subjects with parkinsonism other and 4 of 25 possible PD. Discussion: The presence of either jaw tremor in isolation or associated with nonparkinsonian tremor does not portend a neurodegenerative diagnosis.

In vivo distribution of α-synuclein in multiple tissues and biofluids in Parkinson disease.

OBJECTIVE: The Systemic Synuclein Sampling Study (S4) measured α-synuclein in multiple tissues and biofluids within the same patients with Parkinson disease (PD) vs healthy controls (HCs). METHODS: S4 was a 6-site cross-sectional observational study of participants with early, moderate, or advanced PD and HCs. Motor and nonmotor measures and dopamine transporter SPECT were obtained. Biopsies of skin, colon, submandibular gland (SMG), CSF, saliva, and blood were collected. Tissue biopsy sections were stained with 5C12 monoclonal antibody against pathologic α-synuclein; digital images were interpreted by neuropathologists blinded to diagnosis. Biofluid total α-synuclein was quantified using ELISA. RESULTS: The final cohort included 59 patients with PD and 21 HCs. CSF α-synuclein was lower in patients with PD vs HCs; sensitivity/specificity of CSF α-synuclein for PD diagnosis was 87.0%/63.2%, respectively. Sensitivity of α-synuclein immunoreactivity for PD diagnosis was 56.1% for SMG and 24.1% for skin; specificity was 92.9% and 100%, respectively. There were no significant relationships between different measures of α-synuclein within participants. CONCLUSIONS: S4 confirms lower total α-synuclein levels in CSF in patients with PD compared to HCs, but specificity is low. In contrast, α-synuclein immunoreactivity in skin and SMG is specific for PD but sensitivity is low. Relationships within participants across different tissues and biofluids could not be demonstrated. Measures of pathologic forms of α-synuclein with higher accuracy are critically needed. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that total CSF α-synuclein does not accurately distinguish patients with PD from HCs, and that monoclonal antibody staining for SMG and skin total α-synuclein is specific but not sensitive for PD diagnosis.

Feasibility and Safety of Multicenter Tissue and Biofluid Sampling for α-Synuclein in Parkinson's Disease: The Systemic Synuclein Sampling Study (S4).

BACKGROUND: α-synuclein is a lead Parkinson's disease (PD) biomarker. There are conflicting reports regarding accuracy of α-synuclein in different tissues and biofluids as a PD biomarker, and the within-subject anatomical distribution of α-synuclein is not well described. The Systemic Synuclein Sampling Study (S4) aims to address these gaps in knowledge. The S4 is a multicenter, cross-sectional, observational study evaluating α-synuclein in multiple tissues and biofluids in PD and healthy controls (HC). OBJECTIVE: To describe the baseline characteristics of the S4 cohort and safety and feasibility of this study. METHODS: Participants underwent motor and non-motor clinical assessments, dopamine transporter SPECT, biofluid collection (cerebrospinal fluid, saliva, and blood), and tissue biopsies (skin, sigmoid colon, and submandibular gland). Biopsy adequacy was determined based on presence of adequate target tissue. Tissue sections were stained with the 5C12 monoclonal antibody against unmodified α-synuclein. All specimens were acquired and processed in a standardized manner. Adverse events were systematically recorded. RESULTS: The final cohort consists of 82 participants (61 PD, 21 HC). In 68 subjects (83%), all types of specimens were obtained but only 50 (61%) of subjects had all specimens both collected and evaluable for α-synuclein. Mild adverse events were common, especially for submandibular gland biopsy, but only 1 severe adverse event occurred. CONCLUSION: Multicenter tissue and biofluid sampling for α-synuclein is feasible and generally safe. S4 will inform understanding of the concurrent distribution of α-synuclein pathology and biomarkers in biofluids and peripheral nervous system in PD.

Botulinum toxin type A for treating voice tremor.

BACKGROUND: Voice tremor, like spasmodic dysphonia and other tremor disorders, may respond to botulinum toxin type A injections. OBJECTIVE: To evaluate the safety and efficacy of botulinum toxin type A injections as treatment for voice tremor. DESIGN: A randomized study of 3 doses of botulinum toxin type A with 6 weeks of follow-up. SETTING: A single-site tertiary care center. PARTICIPANTS AND METHODS: Thirteen subjects (11 women, 2 men; mean age, 73 years) with voice tremor and no spasmodic dysphonia or head, mouth, jaw, or facial tremor were entered into this study. Patients received 1.25 U (n = 5), 2.5 U (n = 5), or 3.75 U (n = 3) of botulinum toxin type A in each vocal cord. All patients were evaluated at baseline and postinjection at weeks 2, 4, and 6. MAIN OUTCOME MEASURES: The primary outcome measure was the patient tremor rating scale, with secondary measures including patient-rated functional disability, response rating scale, independent randomized tremor ratings, and acoustical measures. RESULTS: All patients at all dose levels noted an effect from the injection. The mean time to onset of effect was 2.3 days (range, 1-7 days). For all patients combined, mean tremor severity scale scores (rated by patients on a 5-point scale) improved 1.4 points at week 2, 1.6 points at week 4, and 1.7 points at week 6. Measures of functional disability, measures of the effect of injection, independent ratings of videotaped speech, and acoustic measures of tremor also showed improvement. The main adverse effects at all doses were breathiness and dysphagia. CONCLUSION: Voice tremor improves following injections of botulinum toxin type A.

The 'yips' in golf: a continuum between a focal dystonia and choking.

The definition of the 'yips' has evolved over time. It is defined as a motor phenomenon of involuntary movements affecting golfers. In this paper, we have extended the definition to encompass a continuum from the neurologic disorder of dystonia to the psychologic disorder of choking. In many golfers, the pathophysiology of the 'yips' is believed to be an acquired deterioration in the function of motor pathways (e.g. those involving the basal ganglia) which are exacerbated when a threshold of high stress and physiologic arousal is exceeded. In other golfers, the 'yips' seems to result from severe performance anxiety. Physically, the 'yips' is manifested by symptoms of jerks, tremors or freezing in the hands and forearms. These symptoms can result in: (i) a poor quality of golf performance (adds 4.9 strokes per 18 holes); (ii) prompt use of alcohol and beta-blockers; and (iii) contribute to attrition in golf. Golfers with the 'yips' average 75 rounds per year, although many 'yips'-affected golfers decrease their playing time or quit to avoid exposure to this embarrassing problem. While more investigation is needed to determine the cause of the 'yips', this review article summarises and organises the available research. A small study included in this paper describes the 'yips' phenomenon from the subjective experience of 'yips'-affected golfers. The subjective experience (n = 72) provides preliminary support for the hypothesis suggesting that the 'yips' is on a continuum. Based on the subjective definitions of 72 'yips'-affected golfers, the 'yips' was differentiated into type I (dystonia) and type II (choking). A theoretical model provides a guide for future research on golfers with either type I or type II 'yips'.