Differential Diagnosis Of Essential Tremor Research Articles

Evaluation of Cardiovascular Autonomic Nervous System in Essential Tremor and Tremor Dominant Parkinson's Disease.

(1) Background: The differential diagnosis of essential tremor (ET) and tremor-dominant Parkinson's disease (TDPD) can be challenging. Only a few studies have investigated the autonomic nervous system (ANS) in ET. However, some of these suggested that heart rate variability (HRV) might be useful in the differential diagnosis. (2) Methods: Demographic and clinical data, including medications and comorbidities, were collected from 15 TDPD patients, 19 ET patients, and 20 healthy controls. Assessment with the SCOPA-AUT questionnaire, 5 min HRV analysis in time and frequency domains, and evaluation of orthostatic hypotension (OH) with tilt test were performed. (3) Results: There were no significant differences between all groups on the SCOPA-AUT questionnaire. PD patients had OH more frequently and a larger drop in systolic blood pressure (SBP) during the tilt test than ET patients and controls. HRV was affected in PD, but not in ET and controls. Power in the low frequency band, the standard deviation of all normal RR intervals and SBP drop were potentially useful in differential diagnosis with AUCs of 0.83, 0.78, and 0.83, respectively. (4) Conclusions: Cardiovascular ANS dysfunction was present in TDPD, but not in ET and controls. HRV analysis and assessment of SBP drop may be potentially useful in the differential diagnosis of ET and TDPD.

Neuromelanin-Sensitive Magnetic Resonance Imaging as a Measure for Differential Diagnosis of Essential Tremor and Parkinson's Disease.

We sought to evaluate whether the neuromelanin-sensitive magnetic resonance imaging (NM-MRI) features of the substantia nigra (SN) have utility in the differential diagnosis of Parkinson's disease (PD) and essential tremor (ET). This study enrolled 23 patients with PD, 20 patients with ET, and 18 healthy participants. All subjects underwent clinical examination, motor and cognitive assessments, and NM-MRI scans. The area and contrast-to-noise ratio (CNR) values of SN were defined according to NM-MRI images. Then, receiver operating characteristic (ROC) analysis was conducted to characterize the diagnostic power of the SN area and CNR values of SN. Compared with ET and control groups, the PD group showed a significant reduction of the area of SN (P = 0.003, PD vs. ET; P = 0.001, PD vs. control) and in the SN to midbrain area ratio in the same layer (P = 0.006, PD vs. ET; P = 0.005, PD vs. control). The SN area had a sensitivity of 65% and a specificity of 87% for distinguishing ET from PD, with an area under the curve (AUC) of 0.7630 and a Youden index of 0.5200, whereas the ratio of the SN area to midbrain area in the same layer had a sensitivity of 60% and a specificity of 87% for distinguishing ET from PD, with an AUC of 0.7478 and a Youden index of 0.4700. Compared with the ET group, the mean CNR value of the SN and the respective CNR values of the three subregions were all weakened in the PD group, and only the CNR in the middle part was significantly different from the control group (P = 0.006). The sensitivity of the CNR value of the middle part of the SN for differentiating ET from PD was 65%, the specificity was 87%, the AUC was 0.7500, and the Youden index was 0.5200.Based on our findings, we conclude that NM-MRI can improve diagnostic accuracy in PD and can be used as a specific and sensitive potential diagnostic biomarker for PD.

Neuronal intranuclear inclusion disease tremor-dominant subtype: A mimicker of essential tremor.

The GGC repeat expansion in the NOTCH2NLC gene has been identified as the genetic cause of neuronal intranuclear inclusion disease (NIID). Recently, this repeat expansion was also reported to be associated with essential tremor (ET). However, some patients with this repeat expansion, initially diagnosed with ET, were eventually diagnosed with NIID. Therefore, controversy remains regarding the clinical diagnosis of these expansion-positive patients presenting with tremor-dominant symptoms. This study aimed to clarify the clinical phenotype in tremor-dominant patients who have the GGC repeat expansion in the NOTCH2NLC gene. We screened for pathogenic GGC repeat expansions in 602 patients initially diagnosed with ET and systematically re-evaluated the clinical features of the expansion-positive probands and their family members. Pathogenic GGC repeat expansion in the NOTCH2NLC gene was detected in 10 probands (1.66%). Seven of these probands were re-evaluated and found to have systemic areflexia, cognitive impairment, and abnormal nerve conduction, which prompted a change of diagnosis from ET to NIID. Three of the probands had typical hyperintensity in the corticomedullary junction on diffusion-weighted imaging. Intranuclear inclusions were detected in all four probands who underwent skin biopsy. The NIID tremor-dominant subtype can be easily misdiagnosed as ET. We should take NIID into account for differential diagnosis of ET. Systemic areflexia could be an important clinical clue suggesting that cranial magnetic resonance imaging examination, or even further genetic testing and skin biopsy examination, should be used to confirm the diagnosis of NIID.

Эссенциальный тремор - не просто тремор (обзор литературы)

Essential tremor is one of the most common movement disorders. The nature of this disease is not fully understood. It was believed that this pathology manifests itself only by tremor, and symptoms such as depression, anxiety and apathy in patients with essential tremor can only be regarded as a reaction to the presence of tremor. Cognitive impairment is a concomitant pathology that can occur in the elderly, which accounts for a more frequent onset of the disease. But is it really so Purpose of the study. To study the literature data to identify the presence in patients with essential tremor of such signs that can be attributed to the group of "non-motor" symptoms. Material and methods. In order to study the literature data, a search was carried out in the Web of Science, PubMed databases. During the search, all articles published since 2000 were examined and the following terms were used in combination with "essential tremor": "non-motor symptoms", "anxiety", "depression", "apathy", "cognitive impairment", "sleep disorders", "hearing impairment", "hyposmia". The main search terms were studies based on the study of patients with essential tremor: meta-analyzes, original studies, retrospective and cohort studies. Results and discussion. It can be unambiguously argued that symptoms such as anxiety, depression, apathy and cognitive, hearing and smell dysfunctions are characterised to the patients with essential tremor. The first three manifestations were attributed to the response to the presence of tremor. And cognitive functions, hearing and smell dysfunctions was considered a concomitant pathology, which occurs quite often in old age, which accounts for a more frequent onset of the disease. But in reality, everything is not so simple. The literature data, which began to appear over the past 20 years, make it clear that the previously mentioned clinical manifestations may well be regarded as "non-motor" symptoms of essential tremor. Conclusion. Nowadays neurologists are increasingly faced with the problem of differential diagnosis of essential tremor. Despite the fact that everything was very simple and clear on the diagnosis of this disease, in recent years more and more data have appeared in favor of the fact that essential tremor is a heterogeneous disease that manifests not only by tremor. But this is also a disease, which, due to its heterogeneity of pathophysiology, can give great variability in the clinical picture. Keywords: essential tremor, nonmotor symptoms, anxiety, depression, cognitive impairnment, dementia.

Neural Representations of the Voice Tremor Spectrum.

Voice tremor is a common movement disorder that manifests as involuntary oscillations of laryngeal muscles, leading to rhythmic alterations in voice pitch and loudness. Differential diagnosis of essential tremor of voice (ETv) is often challenging and includes dystonic tremor of voice (DTv), which is characterized by irregular, isometric contractions of laryngeal muscles during dystonic activity. Although clinical characteristics of voice tremor are well described, the pathophysiology underlying its heterogeneous phenomenology remains limited. We used a multimodal approach of functional magnetic resonance imaging for assessment of brain activity during symptomatic speech production, high-resolution magnetic resonance imaging for the examination of cortical thickness and gray matter volume, and diffusion-weighted imaging for evaluation of white matter integrity to identify disorder-specific neural alterations and their relationships with the symptomatology of ETv and DTv. We found a broad overlap between cortical alterations in ETv and DTv, involving sensorimotor regions responsible for the integration of multisensory information during speech production, such as primary sensorimotor, inferior/superior parietal, and inferior temporal cortices. In addition, ETv and DTv showed unique patterns of abnormalities in regions controlling speech motor preparation, which were localized in the cerebellum in ETv and the premotor cortex, insula, and superior temporal gyrus in DTv. Neural alterations in superior parietal and inferior temporal cortices were correlated with ETv severity, whereas changes in the left premotor cortex were associated with DTv severity. Our findings point to the pathophysiological spectrum underlying ETv and DTv and favor a more heterogeneous rather than dichotomous diagnostic classification of these voice tremor disorders. © 2020 International Parkinson and Movement Disorder Society.

Combined Visualization of Nigrosome-1 and Neuromelanin in the Substantia Nigra Using 3T MRI for the Differential Diagnosis of Essential Tremor and de novo Parkinson's Disease.

Differentiating early-stage Parkinson's disease (PD) from essential tremor (ET) remains challenging. In the current study, we aimed to evaluate whether visual analyses of neuromelanin-sensitive magnetic resonance imaging (NM-MRI) combined with nigrosome-1 (N1) imaging using quantitative susceptibility mapping (QSM) in the substantia nigra (SN) are of diagnostic value in the differentiation of de novo PD from untreated ET. Sixty-eight patients with de novo PD, 25 patients with untreated ET, and 34 control participants underwent NM-MRI and QSM. NM and N1 signals in the SN on MR images were visually evaluated using a 3-point ordinal scale. Receiver operating characteristic (ROC) analyses were performed to determine the diagnostic values of the visual ratings of NM and N1. The diagnostic values of the predicted probabilities were calculated via logistic regression analysis using the combination of NM and N1 visual ratings, as well as their quadratic items. The proportions of invisible NM and invisible N1 were significantly higher in the PD group than those in the ET and control groups (p < 0.001). The sensitivity/specificity for differentiating PD from ET was 0.882/0.800 for NM and 0.794/0.920 for N1, respectively. Combining the two biomarkers, the area under the curve (AUC) of the predicted probabilities was 0.935, and the sensitivity/specificity was 0.853/0.920 when the cutoff value was set to 0.704. Our findings demonstrate that visual analyses combing NM and N1 imaging in the SN may aid in differential diagnosis of PD and ET. Furthermore, our results suggest that patients with PD exhibit larger iron deposits in the SN than those with ET.

Brain SPECT imaging in the differential diagnosis of essential tremor and Parkinson's disease - case report

Brain SPECT imaging in the differential diagnosis of essential tremor and Parkinson's disease - case report

Mini Review: linkages between essential tremor and Parkinson’s disease?

Essential tremor (ET) and Parkinson’s disease (PD) are two of the most common movement disorders. Tremors are the primary symptoms of ET and of some PD patients, the two are often mistaken for each other. Especially since there are no available differentiate tests for the tremor of ET or PD, the early diagnoses mainly based on clinical assessments of medical symptoms, family and medication history, and examination by physicians. There is increasing evidence suggesting an association between ET and PD, such as a similar tremor frequency, overlapping resting tremors (a typical PD tremor), postural tremors (mainly in ET patients) in both ET and PD patients, and many ET patients develop PD later in life. Although it is difficult to make a differential diagnosis of ET and tremor-dominant PD based on clinical assessment, recent developments of objective measurements, such as brain imaging, neuropathology, and genetic analysis, has opened a helpful window for distinguishing ET from PD. In this mini review, we included literatures of ET and PD studies and discussed various advanced methods for differential diagnosis between ET and PD such as neuroimaging, genetic markers, tremor intensity and frequency, and drug-responses.

Erratum to: Comparison of two neural network classifiers in the differential diagnosis of essential tremor and Parkinson’s disease by 123I-FP-CIT brain SPECT

Erratum to: Comparison of two neural network classifiers in the differential diagnosis of essential tremor and Parkinson’s disease by 123I-FP-CIT brain SPECT

Comparison of two neural network classifiers in the differential diagnosis of essential tremor and Parkinson’s disease by 123I-FP-CIT brain SPECT

To contribute to the differentiation of Parkinson's disease (PD) and essential tremor (ET), we compared two different artificial neural network classifiers using (123)I-FP-CIT SPECT data, a probabilistic neural network (PNN) and a classification tree (ClT). (123)I-FP-CIT brain SPECT with semiquantitative analysis was performed in 216 patients: 89 with ET, 64 with PD with a Hoehn and Yahr (H&Y) score of ≤2 (early PD), and 63 with PD with a H&Y score of ≥2.5 (advanced PD). For each of the 1,000 experiments carried out, 108 patients were randomly selected as the PNN training set, while the remaining 108 validated the trained PNN, and the percentage of the validation data correctly classified in the three groups of patients was computed. The expected performance of an "average performance PNN" was evaluated. In analogy, for ClT 1,000 classification trees with similar structures were generated. For PNN, the probability of correct classification in patients with early PD was 81.9±8.1% (mean±SD), in patients with advanced PD 78.9±8.1%, and in ET patients 96.6±2.6%. For ClT, the first decision rule gave a mean value for the putamen of 5.99, which resulted in a probability of correct classification of 93.5±3.4%. This means that patients with putamen values >5.99 were classified as having ET, while patients with putamen values <5.99 were classified as having PD. Furthermore, if the caudate nucleus value was higher than 6.97 patients were classified as having early PD (probability 69.8±5.3%), and if the value was <6.97 patients were classified as having advanced PD (probability 88.1%±8.8%). These results confirm that PNN achieved valid classification results. Furthermore, ClT provided reliable cut-off values able to differentiate ET and PD of different severities.

Diffusion tensor MRI changes in cerebellar structures of patients with familial essential tremor

The aim of our study was to investigate the microstructural integrity of brain regions functionally involved in the tremor loop in patients with familial essential tremor (FET), using diffusion tensor imaging (DTI). Twenty-five patients with FET, 15 patients with Parkinson disease (PD), and 15 healthy subjects were studied. DTI was performed to measure fractional anisotropy (FA) and mean diffusivity (MD) in various regions of interest: red nucleus, dentate nucleus (DN), cerebellar white matter, middle (MCP) and superior cerebellar peduncle (SCP), and ventrolateral thalamus. In patients with FET, FA values in the DN (median 0.19, range 0.13-0.23) were reduced (p < 0.001) compared with patients with PD (median 0.37, range 0.32-0.58) and healthy controls (median 0.36, range 0.33-0.40). In patients with FET, FA was also reduced (p = 0.003) and MD values increased (p < 0.001) in the SCP compared with patients with PD and healthy controls. Among patients with FET, those with longer disease duration showed FA values in the DN lower than those with shorter disease duration (p = 0.018). Patients with FET could be completely distinguished from both patient with PD and healthy controls using FA values of the DN alone. Neuroimaging evidence of microstructural changes consistent with neurodegeneration was found in the dentate nucleus (DN) and SCP of patients with familial essential tremor. This suggests that neurodegenerative pathology of cerebellar structures may play a role in essential tremor. Further studies are needed to assess the role of fractional anisotropy and mean diffusivity changes in DN and SCP in the differential diagnosis of essential tremor and Parkinson disease, which may present similar clinical signs at the onset of disease.

Single photon-emission computed tomography imaging in early Parkinson’s disease

Current diagnostic criteria for Parkinson’s disease (PD) rely on the presence of motor signs, but it is now evident that they require months or years to become clinically manifest. By contrast, initial manifestations of PD may involve several nonmotor domains, such as cognition, mood, smell or sleep, and their recognition is critical if one is aiming for early diagnosis to provide neuroprotection. In this context, imaging tracers are gaining relevance as they are increasingly recognized as biological markers of disease progression. In this review, we will discuss the role of single photon-emission computed tomography imaging in the early phases of PD and in the differential diagnosis of essential tremor and atypical parkinsonism. We will also discuss the role of imaging of monoaminergic nondopamine systems to assess nonmotor features.

Cost‐effectiveness of123I‐FP‐CIT SPECT in the differential diagnosis of essential tremor and Parkinson's disease in Italy

Economic evaluation (Italian NHS perspective) modeling (123)I-FP-CIT SPECT (DaTSCAN) compared to clinical judgment alone for differentiating essential tremor (ET) from Parkinson's Disease (PD). A 5-year Markov model was constructed to assess the cost-effectiveness of (123)I-FP-CIT SPECT to differentiate ET from PD in patients referred to a movement disorder specialist in Italy. Published data and a double-round, Delphi panel of 12 specialists populated the model. Effectiveness was expressed as the projected Years on potentially beneficial therapy (PBTYs). Costs were expressed in Euros (2005 values). The model suggests that over 5 years, the "current" diagnostic pathway generated an average of 2.3 PBTYs/patient at an estimated cost of 8,864 euros. (123)I-FP-CIT SPECT generated an average of 4.1 PBTYs/patient at an estimated cost of 8,422 euros, which represented an additional 1.8 PBTYs at a cost saving of 442 euros/patient (341 euros when discounted at 5%). The estimated cost-effectiveness of (123)I-FP-CIT SPECT is under 1,000 euros per PBTY gained when the underlying disease prevalence is high (55-70%), and cost-saving at prevalence under 55%. (123)I-FP-CIT SPECT is likely to be regarded as economically advantageous to differentiate ET from PD, increasing time on potentially beneficial therapy at a lower overall cost to the healthcare system.

Familial cortical tremor with epilepsy

We report here on a Japanese family in which five members in three generations developed non-progressive adult onset cortical tremor and epilepsy. Other than tremulous movements resembling essential tremor, the neurologic findings were unremarkable. Electrophysiologic studies revealed giant somatosensory evoked potentials (SEPs), enhanced long latency reflexes (C-reflex), and positive premovement cortical potentials, recorded by jerk-locked averaging, indicating cortical reflex myoclonus. The seizures were sporadic in nature and easily controlled by the anticonvulsants. The tremor also responded well to anticonvulsants such as clonazepam or sodium valproate, but not to beta-blockers. This dominantly inherited disorder should be considered in the differential diagnosis of essential tremor.