Increased Prevalence of Non-motor Symptoms in Essential Tremor

REM sleep behavior disorder and Prodromal Parkinson's Disease in patients with Essential Tremor

Several studies suggested the presence of non-motor symptoms in Essential Tremor (ET), including REM sleep behavioral disorder (RBD). RBD is an essential criterion for Prodromal Parkinson's Disease (PPD), suggesting a link between ET and PD. Our objective was to assess the prevalence and features of ET patients with RBD and PDD. RBD was diagnosed by questionnaire screening, followed by polysomnography. PPD risk factors and prodromic markers were assessed with a structured protocol. Patients were characterized regarding tremor features. ET patients with RBD (ET-RBD) and PPD (ET-PPD) were compared to patients without RBD (ET-nonRBD) and without PPD (ET-nonPPD), respectively. ET-RBD patients were also compared with a group of isolated RBD (iRBD) regarding PPD features. We assessed a total of 64 ET patients. Five (8.3 %) and 4 (6.3 %) had criteria for RBD and PPD, respectively. ET-RBD patients did not differ from ET-nonRBD except for a higher prevalence of PPD. There were no significant differences between ET-RBD and iRBD (n = 12) groups. ET-PPD had a higher prevalence of positive DaT-Scans and RBD compared to ET-nonPPD. Three ET-RBD patients had PPD and 3 ET-PPD had RBD. Both RBD and PPD are more frequent in ET patients than in general aged population but not related with specific tremor features. ET-RBD patients did not differ significantly from iRBD patients, a group prone to develop PD. These data suggest a link between ET and PD and are in accordance with studies showing an increase incidence of lewy-body pathology and PD in ET populations.

[The influence of parasomnia on clinical and functional characteristics of extrapyramidal disorders]

OBJECTIVE

To compare clinical and functional features of the essential tremor (ET) and Parkinson's disease (PD) with- or without rapid eye movement (REM) sleep behavior disorder (RBD).

MATERIAL AND METHODS

Sixty patients with PD and 52 patients with ET were examined. Cognitive functions, anxiety, asthenia and depression, autonomic disorders and sleep disorders were assessed with scales and questionnaires. All patients underwent polysomnography (PSG). Based on the results of PSG, patients were divided by the presence or absence of parasomnia, known as REM sleep behavior disorder.

RESULTS

Patients with PD and ET suffering from RBD were more likely to be overweight, more likely to develop cognitive impairment, obstructive sleep apnea, and emotional disorders. In addition, presence of RBD has adverse effects on the sleep structure. The profile of memory, attention, psychoemotional and sleep disorders in patients with PD and ET had common features, which suggests that it is RPBDH that affects the change in the clinical picture.

CONCLUSION

Presence of RBD aggravates non-motor manifestations of such extrapyramidal diseases as PD and ET. On the one hand it helps to predict the course of the disease, on the other hand let us suspect RBD when we see non-motor symptoms worsening.

Sleep Disorders in Patients with Essential Tremor

PURPOSE OF THE REVIEW

Patients diagnosed with essential tremor (ET) report frequent sleep complaints. This review focuses on the main findings of studies addressing sleep features in patients diagnosed with ET, updating previously reported information. Bad quality of sleep and excessive daytime somnolence are very frequent in patients with ET, although the effects of the drugs used for the therapy of ET could contribute to these complaints. REM sleep behavior disorder, restless legs, insomnia, and nocturia are frequent complaints as well. There is a lack of studies addressing polysomnographic features of ET.

Non-motor symptoms in essential tremor, akinetic rigid and tremor-dominant subtypes of Parkinson's disease

Objectives

To compare non-motor symptoms (NMSs) among patients with essential tremor (ET), Parkinson’s disease (PD) subtypes (akinetic-rigid type (ART) and tremor-dominant type (TDT)), and healthy controls.

Patients and methods

This retrospective study included 129 participants, 72 PD (33 PD-ART, 33 PD-TDT, and 6 Mixed), 29 ET patients, and 28 controls. PD patients were assessed by the unified Parkinson’s disease rating scale (UPDRS), Hoehn, and Yahr scale (H&Y), while ET patients were evaluated by the Fahn Tolosa Marin Tremor Rating Scale. All subjects were evaluated by non-motor symptoms scale (NMSS) for NMSs and Beck depression inventory (BDI) for depression.

Results

PD subtypes groups, ET, and controls were age and gender-matched. Compared to controls, all PD, PD subtypes, and ET showed significantly worse most of NMSs (p<0.001) and depression. Compared to ET, all PD and PD-ART had significantly worse gastrointestinal (p = 0.002), urinary symptoms (p = 0.001, p = 0.003) and depression (p = 0.002) and PD-TDT worse depression, while ET patients showed worse memory/attention than PD subtypes. Total NMSS of ET is highly correlated to depression and moderately to tremor severity and age of onset, while total of NMSS is highly correlated to depression, disease severity, and disability.

Conclusion

The current study demonstrated several comparable domains of NMSs of PD subtypes and ET, except worse gastrointestinal and urinary symptoms among PD-ART. Identifying different NMSs profiles is important for predicting, better assessing, and tailoring management of ET and PD subtypes.

Quantitative REM Sleep without Atonia in Parkinson's Disease and Essential Tremor

Background

Rapid eye movement (REM) sleep behavior disorder (RBD) occurs occasionally in essential tremor (ET), but polysomnographic REM sleep without atonia (RSWA) analyses have been sparse.

Objective

To characterize the amount and distribution of polysomnographic RSWA, the electrophysiologic substrate of RBD, in patients with Parkinson's disease (PD) and ET.

Methods

We analyzed quantitative RSWA in 73 patients: PD (23), ET (23), and age-sex-matched controls (27). None had dream-enactment behavior history or received antidepressants. Phasic, tonic, "any," and phasic-burst duration RSWA measures were calculated in the submentalis (SM) and anterior tibialis (AT) muscles. The automated REM atonia index (RAI) was also determined. Statistical analysis was performed by Kruskal-Wallis rank-sum and Mann-Whitney tests.

Results

SM phasic RSWA was significantly greater for PD than ET patients and controls (12.5% ± 12.8% vs. 4.9% ± 6.7%, 3.9% ± 2.6%), as was SM "any" (13.54% ± 14.30% vs. 5.2% ± 7.6%, 4.2% ± 2.6%). RAI was significantly lower in PD than in ET and controls (0.78 ± 0.23 vs. 0.92 ± 0.09 vs. 0.90 ± 0.17, P ≤ 0.005), but no different between ET and controls. AT phasic and "any" RSWA was similar between the 3 groups. ET and control RSWA was similar in all measures. Two ET patients (8.7%) had SM RSWA similar to PD patients.

Conclusions

Elevated SM RSWA distinguished PD from ET in patients without dream-enactment symptoms and occurs frequently in PD patients, and in isolated tremor suggests underlying synucleinopathy. Prospective studies will further validate these findings.

Prodromal Markers of Parkinson's Disease in Patients With Essential Tremor

Background: Essential tremor (ET) is manifested as an isolated syndrome of bilateral upper limb action tremor. Parkinson's disease (PD) is the second most common neurodegenerative disease, with typical motor symptoms of bradykinesia, rigidity, and resting tremor. ET-PD describes the new-onset of PD in ET patients. Recently, numerous studies on epidemiology, genetics, pathology, clinical features, and neuroimaging studies are challenging the idea that ET is an isolated disease, suggesting that patients with ET have the tendency to develop PD. Methods: In this review article, we collected recent findings that reveal prodromal markers of PD in patients with ET. Results: Substantia nigra hyperechogenicity serves as a prodromal marker for predicting the development of PD in patients with ET and provides a reference for therapeutic strategies. Additional potential markers include other neuroimaging, clinical features, heart rate, and genetics, whereas others lack sufficient evidence. Conclusion: In consideration of the limited research of PD in patients with ET, we are still far from revealing the prodromal markers. However, from the existing follow-up studies on ET patients, Substantia nigra hyperechogenicity may enable further exploration of the relationship between ET and PD and the search for pathogenesis-based therapies.

Essential tremor vs idiopathic Parkinson disease: Utility of transcranial sonography

Substantia nigra (SN) hyperechogenicity measured by transcranial sonography (TCS) is a promising biomarker for Parkinson disease (PD). The aim of this study was to explore the diagnostic accuracy of SN hyperechogenicity (SN) for differentiating PD from essential tremor (ET). A total of 119 patients with PD, 106 ET patients and 112 healthy controls that underwent TCS from November 2016 to February 2019 were included in this single-center retrospective case-control study. Two reviewers who were blinded to clinical information independently measured the SN by TCS imaging. The diagnostic sensitivity, specificity, and accuracy of TCS imaging were evaluated between the PD and healthy controls and between patients with PD and ET. Interrater agreement was assessed with the Cohen κ statistic. TCS imaging of the SN allowed to differentiate between patients with PD and ET with a sensitivity (91.6% and 90.8%) and specificity (91.5% and 89.6%) for readers 1 and 2, respectively. Interobserver agreement was excellent (к = 0.87). In addition, measurement of the SN allowed to differentiate between patients with PD and healthy subjects with a sensitivity (91.6% and 90.8%) and specificity (88.4% and 89.3%) for readers 1 and 2, respectively. Interobserver agreement was excellent (к = 0.91). Measurement of SN on TCS images could be a useful tool to distinguishing patients with PD from those with ET.

The Relationship Between Serum Uric Acid Levels and Clinical Features in Essential Tremor

Introduction

In this study, we aimed to investigate the effect of uric acid on the disease, its severity and progression in ET patients with partially co-clinical features with Parkinson's disease (PD).

Methods

Serum UA levels of 87 consecutive ET patients were measured and were matched according to age and sex with 87 healthy controls. Fahn-Tolosa-Marin scale was used for the severity of tremor. Sociodemographic characteristics, type of ET, duration of disease, and treatment modalities were evaluated.

Results

The mean uric acid level was calculated as 4.986±2.1458 mg/dL and 6.004±1.523 mg/dL in the patient and control groups, respectively (p≤0.005). The blood UA level of patients with sporadic (n: 61) ET was found to be lower than the familial ET (n: 26) (p≤0.005). The tremor severity of the family ET patients was lower than the sporadic ET. (n: 61) (p≤0.005). The mean blood UA level (4.429±1.216 mg/dL) in the patients with high total tremor severity scores (n: 48) was found lower than in the patients with low total tremor severity scores (n: 39) (5.673±2.106 mg/dL) (P=0.000). The serum UA level was significantly lower in the patients whose disease duration longer than 5 years than in patients whose duration of the disease was shorter than 5 years. 5.732±1.240 for ≥5 years; 6.438±0.286≤5 years) (P=0.001).

Conclusion

We hypothesize that as a result of high antioxidant properties of high serum uric acid levels, it is a biomarker that can show disease risk and progression in patients with ET as well as PD.

REM-Sleep Behavior Disorder in Patients With Essential Tremor: What Is Its Clinical Significance?

Objective: REM sleep behavior disorder (RBD) is an important risk factor for the dementia development and for the deterioration of autonomic functions in patients with Parkinson's Disease. RBD has also been reported in patients with Essential Tremor (ET). However, its clinical significance in ET remains still unknown. We aimed to investigate clinical, neuropsychological and cardiac autonomic scintigraphic differences between ET patients with and without RBD.

Methods: To assess RBD symptoms, RBD Single-Question has been administered in a cohort of 55 patients with a clinical diagnosis of ET. Patients with clinical RBD underwent polysomnography (PSG) confirmation. All patients completed a battery of neuropsychological assessment of memory, executive function, attention, language, and visuospatial function. Cardiac MIBG scintigraphy was performed in order to measure the cardiac autonomic innervation.

Results: Ten ET patients (18%) had a PSG-confirmed RBD (ET^RBD+). Compared to ET patients without RBD (ET^RBD−), significantly reduced scores on memory domain tests such as Rey auditory verbal learning test immediate recall (p = 0.015) and Rey auditory verbal learning test delayed recall (p = 0.004) and phonemic fluency test (p = 0.028) were present in ET^RBD+. By contrast, no other significant clinical difference has emerged from the comparison between two ET groups. Similarly, ET^RBD+ patients have cardiac MIBG tracer uptake in the normal value range as occurred in those with ET^RBD−.

Conclusions: This study improves the knowledge on clinical significance of RBD symptoms in ET patients. Our preliminary findings demonstrate that presence of RBD in ET is associated with neurocognitive impairment, but not with cardiac autonomic dysfunction. Further longitudinal studies are needed to investigate whether ET patients with RBD will develop a frank dementia over the time.

Essential Tremor and Parkinson's Disease: Exploring the Relationship

Background

There is longstanding controversy surrounding the possible link between essential tremor (ET) and Parkinson's disease (PD). Inconsistent and unreliable diagnostic criteria may in part account for some of the difficulties in defining the relationship between these two common movement disorders.

Methods

References for this systematic review were identified using PubMed with the search terms "essential tremor" AND "Parkinson's disease" with articles published in English between 1960 and September 2018 included.

Results

In this review we provide evidence that some patients diagnosed with ET have an increased risk of developing PD years or decades after onset of action tremor. There are several still unresolved questions about the link between the two disorders including lack of verifiable diagnostic criteria for the two disorders and marked overlap in phenomenology. Here we review clinical, epidemiologic, imaging, pathologic, and genetic studies that address the ET-PD relationship. Several lines of evidence support the association between ET and PD, including overlapping motor and non-motor features, relatively high prevalence of rapid eye movement sleep behavior disorder (26-43%) in ET patients, increased prevalence of PD in patients with longstanding antecedent ET, increased prevalence of ET in family members of patients with PD, and the presence of Lewy bodies in the brains of some ET patients (15-24%).

Discussion

There is a substantial body of evidence supporting the association between ET and PD within at least a subset of patients, although the nature and possible pathogenic mechanisms of the relationship are not well understood.

Probable REM-Sleep Behavior Disorder and Dysautonomic Symptoms in Essential Tremor

Background

Non-motor symptoms can be present in essential tremor (ET). We intend to assess the frequency of rapid eye movement (REM) sleep behavior disorder (RBD) and dysautonomic symptoms in ET patients and evaluate the differences between patients with ET and RBD (ET-RBD and ET without RBD [ET-nonRBD]).

Methods

All ET patients were contacted by telephone. Autonomic symptoms were assessed using the Scales for Outcomes in Parkinson's Disease-Autonomic (SCOPA-AUT) questionnaire, and RBD symptoms with the RBD screening questionnaire (RBDSQ) using ≥5 as a cut-off for probable RBD (pRBD).

Results

From 92 ET patients contacted, 53 (55% female) were included. The mean age at assessment was 73.6±19 years, and the average disease duration was 19.9±17.3 years. Fourteen patients (26.4%) had pRBD and 52 (98.1%) reported at least one autonomic symptom, the most prevalent being urinary symptoms (96%). The ET-RBD group had higher SCOPA-total and thermoregulatory scores than ET-nonRBD patients (13.9±9.6 vs. 7.7±5.1, p=0.017 and 2.5±2.0 vs. 0.9±1.6, p=0.001). There were no other differences between groups.

Discussion

Our results suggest that pRBD is common in ET, and its presence is associated with dysautonomic symptoms. As these symptoms are known to be prodromal symptoms of Parkinson's disease (PD), we question if this patient subgroup has a higher risk of developing a synucleinopathy.

Motor and Non-motor Features: Differences between Patients with Isolated Essential Tremor and Patients with Both Essential Tremor and Parkinson's Disease

BACKGROUND

Patients with essential tremor (ET) who develop Parkinson's disease (PD) (i.e., ET→PD) may differ with respect to motor features (MFs) and non-motor features (NMFs) from patients with isolated ET. Few studies have assessed this issue.

METHODS

In this retrospective chart review, we analyzed data on MFs and NMFs of 175 patients, including 54 ET→PD and 121 ET, actively followed in the Athens University 1st Neurology Department.

RESULTS

Significantly more ET→PD than ET patients reported asymmetric tremor at ET onset (68.5% vs. 14.9%, p<0.001). Significantly more ET than ET→PD patients had head tremor (43.5% vs. 13.2%, p<0.001) and cerebellar signs (41.3% vs. 9.3%, p<0.001). More ET than ET→PD patients reported hearing impairment (65.3% vs. 28.3%, p<0.001) and restless legs syndrome (34.8% vs. 3.7%, p<0.001). Conversely, a larger proportion of ET→PD than ET patients reported rapid eye movement behavior disorder (51.9% vs. 10.0%, p<0.001), constipation (67.9% vs. 36.4%, p<0.001), and olfactory dysfunction (83.3% vs. 36.4%, p<0.001).

DISCUSSION

The subset of ET→PD patients may have distinct MFs and NMFs that should be assessed further for the possible predictive value for the emergence of PD.

Transcranial sonography and the pocket smell test in the differential diagnosis between parkinson's disease and essential tremor

The aim of this study was to determine the specificity and sensitivity of transcranial sonography (TCS) and the Pocket Smell Test (PST) in differing Parkinson's disease from essential tremor. The results were compared with the dopamin transporter scan (DaTSCAN) findings. Based on the DaTSCAN finding we formed a group of patients with essential tremor (51 patients) and a group with the Parkinson's disease (59 patients). The control group consisted of 26 healthy one. To evaluate the olfactory dysfunction the PST was used, whereas by TCS the substantia nigra hyperechogenicity was marked. The sensitivity and specificity of each diagnostic method was statistically calculated. In confirming Parkinson's disease the specificity of TCS was 88.2 % and the sensitivity 94.9 %. The specificity of PST was 80.4 % whereas the sensitivity was 74.6 %. TCS and PST should be performed to evaluate which patients need to be examined by DaTSCAN.