Home About us Contact
|
Home About us Contact | ||
|
|
||
Essential Tremor (essential + tremor)
Selected AbstractsA preliminary look at the percentage of patients with Restless Legs Syndrome who also have Parkinson Disease, Essential Tremor or Tourette Syndrome in a single practiceJOURNAL OF SLEEP RESEARCH, Issue 4 2003Arthur S. Walters No abstract is available for this article. [source] Midbrain SERT in degenerative parkinsonisms: A 123I-FP-CIT SPECT study,MOVEMENT DISORDERS, Issue 12 2010Francesco Roselli MD Abstract SPECT imaging is widely used for the differential diagnosis of degenerative parkinsonisms by exploiting the high affinitiy of the radiotracer 123I-FP-CIT for the dopamine transporter. Reduced levels of DAT are found in Parkinson Disease (PD), Dementia with Lewy Bodies (DLB), and Progressive Supranuclear Palsy (PSP) compared to in Essential Tremor (ET) and Healthy Controls (HC). However, the extent of the neurodegenerative process may extend beyond nigrostriatal system. We have exploited the affinity of the same radiotracer 123I-FP-CIT for the serotonin transporter to investigate SERT levels in the midbrain of patients with PD, DLB, PSP, and ET compared to HC. Using MRI images as anatomical templates for midbrain uptake quantification, we found a mild decrease in SERT levels in PD compared to ET and HC, with marked inter-individual variability; on the other side, PSP and DLB patients displayed markedly reduced to undetectable levels of SERT, respectively. These findings show that the neurodegenerative process affects serotoninergic neurons in parkinsonisms, with much more severe involvement in DLB than in PD patients, despite the comparable loss of striatal DAT. SERT-dependent 123I-FP-CIT uptake may allow a more comprehensive assessment of neurochemical disturbances in degenerative parkinsonisms and may have a value for differential diagnosis. © 2010 Movement Disorder Society [source] Program: Twenty Third Annual Symposium on Etiology, Pathogenesis, and Treatment of Parkinson's Disease and Other Movement DisordersMOVEMENT DISORDERS, Issue 12 2009Article first published online: 11 SEP 200 The symposium will consist of two keynote speakers and peer-reviewed platform and poster presentations designed to communicate recent research advances, including new pharmacological and non-pharmacological treatment options, in the field of Parkinson's disease, Huntington disease, ataxia, dystonia, myoclonus, Tourette's syndrome, Essential Tremor and other movement disorders thereby enhancing patient care. Professionals in neurology and related disciplines as well as practitioners, psychologists, educators, and researchers are invited to attend. The gaps in clinical practice we wish to address are the unmet needs pertaining to the translational and clinical evaluation, along with the care and treatment of patients and families affected by Parkinson's disease and other movement disorders. At the conclusion of this session, participants should be able to: 1) Identify and describe by scholarly review, oral presentation and group discussion the current research into the diagnosis, prevention and treatment of Parkinson's disease (PD) and Essential Tremor (ET) which may be relevant to current treatment or which may lead to the development of further research protocols; 2) Distinguish and assess the important advances in research and clinical treatments relating to Parkinson's disease and Essential Tremor in terms of available treatment options or new methodologies for clinical research; 3) Explain new pharmacological and non-pharmacological treatment options available for Parkinson's disease and other movement disorders in connection with their clinical practice or with regard to further clinical research methods; 4) Interpret the mechanisms (genetic, environmental, pathophysiology, neurobiology) linked to Parkinson's disease and other movement disorders when assessing Parkinson's disease or other movement disorder patients or when developing new research protocols; and 5) Employ diagnostic approaches and tools available for assessing Parkinson's disease and Essential Tremor when diagnosing new patients or when conducting clinical research. [source] Quality of life in a random sample of community dwelling older patients with essential tremorACTA NEUROLOGICA SCANDINAVICA, Issue 5 2007H. V. Nguyen Study Objective,,, Nested case-control study aimed to assess the quality of life of community dwelling participants aged 65 years or over with newly diagnosed Essential Tremor (ET). Methods and Results,,, Thirty-two participants with newly diagnosed ET and 32 age and gender matched controls were administered the Rand-SF36 quality of life questionnaire. Medical co-morbidities were also assessed in the two groups. Results,,, Participants with ET had significantly lower scores in the physical function, role limitation because of physical function, role limitation as a result of emotional problem, pain, and energy/vitality subscales of the Rand-SF36 when compared with controls. Conclusions,,, Older patients with newly diagnosed ET have poorer quality of life than their community dwelling counterparts without ET. [source] DRD3 Ser9Gly variant is not associated with essential tremor in a series of Italian patientsEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2008C. Vitale Background: Essential tremor (ET) is the most common movement disorder worldwide. Three susceptibility loci on chromosomes 3q13, 2p24.1, and 6p23 have been reported, but no causative genes were found. The Ser9Gly variant of dopamine D3 receptor (DRD3) receptor was found associated to ET in a French and US population. Methods: A case,control study to evaluate the association between the Ser9Gly variant and ET was performed in a cohort of 116 Italian patients with familial ET and in 158 normal controls. Results: No significant difference in allele and genotype frequencies was found between the two groups. Conclusions: These results do not support an association between DRD3 Ser9Gly and susceptibility to ET in Italian patients. [source] Essential tremor , Neurodegenerative or nondegenerative disease towards a working definition of ET,MOVEMENT DISORDERS, Issue 14 2009Günther Deuschl MD Abstract Essential tremor (ET) is a syndrome of tremor in posture and movement, but recent studies have revealed additional cerebellar motor disturbances, cognitive disturbances, personality changes, hearing loss, and olfactory deficits. Even dementia and shortened life expectancy were found in one cohort. Recent postmortem studies have found limited Lewy body pathology in some patients and Purkinje cell loss with torpedoes and Bergmann gliosis in others. These findings have led to the hypothesis that ET is a syndrome produced by at least two neurodegenerative diseases with more widespread clinical consequences than previously appreciated. We review the evidence for and against this hypothesis and conclude that studies purporting to support this hypothesis have failed to control for age-associated comorbidities, depression, medications, and other confounding factors. We propose the alternative hypothesis that abnormal neuronal oscillation is the fundamental abnormality in ET, and the well-documented cerebellar signs and symptoms, the controversial non-motor signs, and even the cerebellar pathology of ET could be caused by this oscillation. A major problem for many studies is the lack of a diagnostic gold standard. Lacking such a standard, we propose a subclassification of ET into three categories: hereditary ET, sporadic ET, and senile ET, which we believe will help researchers resolve many of the controversies in this field. © 2009 Movement Disorder Society [source] Posturographic analysis of balance control in patients with essential tremorMOVEMENT DISORDERS, Issue 2 2006Marco Bove PhD Abstract Essential tremor (ET) is a common movement disorder causing an important functional disability. ET is generally regarded as a monosymptomatic disorder, but additional signs may be present. We analyzed postural sway in 19 patients with classic ET and in 19 sex- and age-matched normal controls (NC) to uncover possible abnormalities of balance control. Static posturography was performed with eyes open (EO) and closed during quiet stance and during performance of mental calculation or motor sequence of thumb opposition to the other fingers. No significant differences of center of foot pressure (COP) parameters were observed between patients and controls during quiet standing. Visual deprivation induced a similar worsening of postural sway in both groups. Concomitant performance of a cognitive or motor task did not affect COP area, whereas COP path was significantly modified by the cognitive task in both groups. In all EO conditions, the COP path was significantly lower in NC than in ET, but such offset was related only to the group of ET patients with head tremor. This study demonstrates that balance control is only minimally affected in ET, although patients with head involvement and longer disease duration tend to present a reduced postural stability. The "dual-task effect" is less important in ET than in Parkinson's disease patients. © 2005 Movement Disorder Society [source] Essential tremor is a monosymptomatic disorderMOVEMENT DISORDERS, Issue 4 2002Rodger J. Elble MD [source] Essential tremor: A heterogenous disorderMOVEMENT DISORDERS, Issue 4 2002Joseph Jankovic MD [source] Cognition in essential tremor: should we worry about progressive cognitive decline?EUROPEAN JOURNAL OF NEUROLOGY, Issue 10 2010E. Tolosa No abstract is available for this article. [source] A clinical maneuver to increase tremor differentiation between Parkinson disease and essential tremorEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2010R. Mazzocchio No abstract is available for this article. [source] Alzheimer's disease, Parkinson's disease and essential tremor: three common degenerative diseases with shared mechanisms?EUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2010E. D. Louis No abstract is available for this article. [source] Paraoxonase 1 (PON1) polymorphisms and risk for essential tremorEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2010E. García-Martín Background:, The polymorphic enzyme human serum paraoxonase 1 (PON1), encoded by the gene PON1 (chromosome 7q21.3), plays a major role in the metabolism of organophosphorus compounds. We investigated the possible association between the PON1 genotype and allelic variants of the polymorphisms Leu55Met and Glu192Arg, and the risk for essential tremor (ET). Methods:, We studied the frequency of the PON1 genotypes and allelic variants in 201 patients with ET and 220 healthy controls using a PCR-RLFP method. Results:, The frequencies of the PON1 genotypes and allelic variants of the polymorphisms Leu55Met and Gln192Arg did not differ significantly between patients with ET and controls. These polymorphisms were unrelated with the age of onset of ET. Conclusions:,PON1 polymorphisms are not related with the risk for ET. [source] How are we doing with the treatment of essential tremor (ET)?EUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2010Persistence of patients with ET on medication: data from 528 patients in three settings Background:, The pharmacological treatment of essential tremor (ET) is not optimal. There are only two first-line medications and troublesome side effects are common. It is not uncommon for patients to simply stop taking medication. Yet, no published data substantiate or quantify this anecdotal impression. Objectives:, To determine, amongst patients with ET who were prescribed medication for tremor, what proportion are still taking medication and what proportion have stopped? Methods:, Five hundred and twenty-eight patients with ET from three distinct study settings (clinical, brain donors, population) were interviewed. Results:, A clear pattern that emerged across settings was that the proportion of patients with ET who had stopped medication was sizable and consistently similar (nearly one-third): 31.4% (clinical), 24.3% (brain donors), 30.0% (population), 29.8% (overall). A similarly high proportion of cases with severe tremor had stopped their medication: 31.9% (clinical), 36.4% (brain donors). For the four most commonly used medications (propranolol, primidone, diazepam, topiramate), one-half or more of the treated patients had stopped the medication; amongst the less commonly used medications, the proportion who stopped was even higher. Conclusions:, Nearly one of every three patients with ET who had been prescribed medication for tremor had discontinued pharmacotherapy. Even more revealing was that a similar proportion of cases with severe tremor had stopped medication. These data make tangibly evident that there is a sizable population of patients with ET who are untreated and disabled, and underscore the inadequacy of current pharmacotherapeutic options for this common neurological disease. [source] Another connection between essential tremor and Parkinson's disease?EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2010E. D. Louis No abstract is available for this article. [source] DRD3 Ser9Gly variant is not associated with essential tremor in a series of Italian patientsEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2008C. Vitale Background: Essential tremor (ET) is the most common movement disorder worldwide. Three susceptibility loci on chromosomes 3q13, 2p24.1, and 6p23 have been reported, but no causative genes were found. The Ser9Gly variant of dopamine D3 receptor (DRD3) receptor was found associated to ET in a French and US population. Methods: A case,control study to evaluate the association between the Ser9Gly variant and ET was performed in a cohort of 116 Italian patients with familial ET and in 158 normal controls. Results: No significant difference in allele and genotype frequencies was found between the two groups. Conclusions: These results do not support an association between DRD3 Ser9Gly and susceptibility to ET in Italian patients. [source] Shared Mechanisms and Comorbidities in Neurologic and Psychiatric DisordersHEADACHE, Issue 2001Stephen D. Silberstein MD Migraine may be comorbid with several other neurologic and psychiatric conditions, including mood disorders (eg, depression, anxiety, panic disorder), epilepsy, stroke, and essential tremor. Comorbidity presents physicians with opportunities and challenges for both diagnosis and treatment. All diseases must be considered, and therapeutic strategies may need to be modified to avoid potential drug interactions. Comorbidities also may provide clues to the pathophysiologies and any shared mechanisms of the two disorders. Longitudinal studies have demonstrated a bidirectional influence between migraine and major depression, but not between migraine and other severe headache. Migraine is strongly and consistently associated with panic disorder. The risk of migraine in epilepsy is increased particularly in individuals with head trauma, partial seizures, and a positive family history of migraine. The influence is bidirectional. There is also growing evidence of an association between migraine and stroke, particularly among women of childbearing age and individuals who experience migraine with aura. Lastly, a bidirectional association between migraine and essential tremor also exists. These findings suggest that migraine, major depression, epilepsy, and essential tremor share one or more common etiologies. Clinicians should be mindful of them as they design treatment strategies, and also should consider the use of a single pharmacologic agent that is effective for all conditions. [source] Eccrine squamous syringometaplasia mimicking a herpetic infectionINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 6 2006Vicent Alonso MD A 69-year-old woman with a history of hypertension and essential tremor was diagnosed with a Burkitt-like diffuse large-cell lymphoma. She received chemotherapy with cyclophosphamide, vincristine and adriamycin (HyperCVAD). Ten days after starting the second cycle of chemotherapy (HyperCVAD), she presented with well-defined, intense, erythematous macules which coalesced to form a symmetric diffuse erythema located on the upper back. Later, the lesions progressed and affected the lower back and perineal areas, extending to the groin. In a few days, a gradual diminution of the erythema was seen, with subsequent development of postinflammatory gray-brownish hyperpigmentation. On the lower back, there were also superficial erosions. Some asymptomatic, closely grouped, gray papules, vesicles, and blisters were found in the groin, resembling the typical lesions of herpetic infection (Fig. 1). Two biopsies of the groin and one of the upper back were performed, and were processed for histopathologic and microbiologic study. Figure 1. Closely grouped gray papules, vesicles, and blisters on the groin mimicking a herpetic infection The histopathologic study showed epidermal hyperplasia with acanthosis and papillomatosis. In both biopsies, eccrine ducts covered by mature squamous epithelium were found in the reticular dermis (Fig. 2a,c). In the sample from the groin, an intracorneal bulla was found. Numerous normal isolated cornified cells were seen within the lumen of the bulla (Fig. 2d). An inflammatory mononuclear infiltrate was also present in a periductal and perivascular distribution. No multinucleation, ground-glass nuclei, or peripheral margination of chromatin were found. Therefore, no morphologic evidence of herpes virus infection was present. Figure 2. Low (a), medium (b), and high (c) magnification showing epidermal hyperplasia and squamous syringometaplasia involving dermal eccrine ducts. (d) Medium power magnification of the intracorneal bulla (hematoxylin and eosin staining; a, ×40; b, ×100; c, ×400; d, ×100) Cultures and serologic analyses for herpes simplex virus (HSV) 1 and 2, varicella zoster virus (VZV), and cytomegalovirus (CMV) were negative. The lesions were treated with topical corticosteroids, with a good response in a few days. [source] Acute febrile neutrophilic dermatosis (Sweet's syndrome) with nodular episcleritis and polyneuropathyINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 2 2002Taizo Kato MD A 56-year-old Japanese housewife presented with multiple erythematous lesions in association with ocular hyperemia and pain in the right upper and lower extremities, including the hands and feet. These symptoms were preceded by a sore throat with persistent fever higher than 38.5 °C for about 1 week. Dermatologic examination showed tender, dull-red, erythematous lesions, measuring 1,2 cm in diameter, located predominantly on the forehead, cheeks, auricular region, neck, forearm, hands, and feet. A biopsy specimen obtained from an erythematous lesion on the right forearm revealed prominent edema in the papillary dermis and remarkable inflammatory cell infiltration throughout the entire dermis (Fig. 1). The infiltrate predominantly consisted of neutrophils and nuclear dust without signs of vasculitis. In routine examination, the leukocyte count was 15,000/mL (normal range, 4000,8000/mL) with severe neutrophilia (80%). The C-reactive protein (CRP) level was 17.65 mg/dL (normal range, < 0.5 mg/dL) and the anti-streptolysin (ASLO) level was 611 IU/mL (normal range, < 166 IU/mL). In human leukocyte antigen (HLA) testing, HLA-A2, -B39, -B35, -Cw2, and -Cw7 were positive, and HLA-B51, -B54, and -Cw1 were negative. Figure Figure 1 . Histologic picture showing a dermal infiltrate of neutrophils Ocular hyperemia was caused by episcleritis forming a nodule and surrounding congestion of the superficial episcleritic vessels at the central portion of the sclera (Fig. 2). The patient suffered from pain once an hour, continuing for about 3 min, at the lateral portion of the right upper and lower extremities, as well as the right small finger. Neurologic examination demonstrated moderate or slight muscle weakness in the extremities. Hand grasping powers were 9 and 7 kg on the right and left, respectively. The patient was right-handed. Dysesthesia and paresthesia were also observed on the hands and feet. The deep tendon reflexes were preserved, however, even in the distal portion of the upper and lower limbs. In addition, essential tremor localized to the neck was recognized. Magnetic resonance imaging did not show any episodes of transient abnormal signal intensity in the central nervous system. Figure 2. Nodular episcleritis (right eye). Telangiectasia of winding vessels with nodular elevation was observed at the upper portion of the sclera The patient was treated with prednisolone (initial dose of 30 mg/day) and intravenous injection of cefazolin sodium (2 g/day for 5 days). Almost complete regression of the ocular and neurologic manifestations, as well as the skin lesions, was achieved in 2 weeks. Prednisolone was reduced gradually and suspended after 4 weeks. Leukocyte and neutrophil counts, CRP, and ASO returned to normal on suspension of therapy. Slight paresthesia remained in the right small finger even after stopping steroid. There was no recurrence at follow-up 6 months later. [source] The pharmacology and epidemiology of post-market surveillance for suicide: the case of gabapentinJOURNAL OF PHARMACEUTICAL HEALTH SERVICES RESEARCH, Issue 2 2010Jill E. Lavigne Abstract Objectives, To describe the challenges in measurement of suicidal thoughts and behaviours and any causal relationship to prescription drug exposures. Recent US Food and Drug Administration (FDA) investigations of potential provocation of suicidal ideation and behaviour have led to black-box warnings of suicidal thoughts and behaviour on drugs ranging from smoking cessation to urinary incontinence agents. We describe the challenges faced in studying the effects of specific drug exposures on suicidal thoughts and behaviours using gabapentin (Neurontin) as an example because it has been implicated by the FDA as a drug that may induce suicidal thoughts or behaviours, offers more than 20 diverse indications including several known to be associated with an increase in suicide risk, and derives its clinical effect from 2 divergent mechanisms. Key findings, Gabapentin has two primary mechanisms: GABAergic neurotransmission and interruption of sodium and calcium channels. An increase in GABAergic neurotransmission is expected to improve anxiety and essential tremor, but to have no effect on pain, specifically migraine and neuropathic pain. Improvements in pain after gabapentin exposure are likely the result of the interruption of calcium and sodium channels. Neither mechanism is expected to affect bipolar disorder or schizophrenia, serious mental illnesses associated with a risk of suicide. Conclusions, These two independent mechanisms are expected to have mutually exclusive effects on a wide range of indications, only some of which are associated with increased risk of suicide. This very complexity and heterogeneity may present fertile ground for research aimed at not only improving our understanding of drug action, but also at expanding our knowledge of suicidal thoughts and behaviours. [source] Functional correlates of lower cognitive test scores in essential tremor,MOVEMENT DISORDERS, Issue 4 2010Elan D. Louis MD Abstract Although motor features have been the defining element of essential tremor (ET), lower neurocognitive test scores are increasingly being recognized. However, the clinical correlates, if any, of these lower test scores remain largely unexplored. The aim of this study was to determine whether cognitive test scores in ET have any functional correlates. The Modified Mini Mental Status Examination (MMSE), Katz Activities of Daily Living (ADL) scale and Lawton Instrumental (I) ADL scale were administered to 95 cases. The Katz ADL score (rho = 0.26, P = 0.01) and Lawton IADL score (rho = 0.32, P = 0.001) were correlated with MMSE scores, such that poorer cognitive performance indicated greater dysfunction. Furthermore, cognitive test scores were a better predictor of functional disability than was tremor severity. Poorer cognitive performance in ET was associated with greater functional deficit. Cognition should enter the clinical dialog with ET patients as an issue of clinical significance. © 2010 Movement Disorder Society [source] Evaluation of a screening instrument for essential tremorMOVEMENT DISORDERS, Issue 7 2008Delia Lorenz MD Abstract To evaluate a screening instrument for essential tremor (ET) consisting of a seven-item questionnaire and a spiral drawing. A total of 2,448 Danish twins aged 70 years or more and a second sample aged 60 years or more (n = 1,684) from a population-based northern German cross-sectional study (PopGen ET) were screened for ET. Inclusion criteria were a previous diagnosis of ET, a positive answer to two or more questions of the questionnaire or a spiral rating >4 (range of scale 0,9). Three hundred thirteen of 380 positively screened and 321 negatively screened subjects were clinically examined. Definite or probable ET was diagnosed in 104 patients, possible in 86 and other tremors in 98 patients. The sensitivity of the screening instrument was 70.5%, the positive predictive value was 64.9%, the specificity was 68.2%, and the negative predictive value was 73.5%. Tremor severity correlated significantly with higher spiral scores and more positive items. More patients were identified by spiral drawing in all tremor groups. The interrater and intrarater reliability for spirals ranged from 0.7 to 0.8 using intraclass coefficient. A cluster analysis revealed that the questionnaire can be reduced to three items, about uncontrollable tremor in any body part, tremor while drinking or pouring and other family members with tremor, without loosing efficacy. We present an easy to use and reliable screening instrument that is effective to identify patients with ET but not able to exclude patients with other tremor forms. © 2008 Movement Disorder Society [source] Secondary social anxiety in hyperkinesiasMOVEMENT DISORDERS, Issue 5 2008Erguvan Tugba Ozel-Kizil MD Abstract This is a comparison study that is aimed to investigate and compare the frequency and severity of secondary social anxiety disorder (SAD) in patients with hyperkinesias, which is associated with a significant sense of disfigurement and compromised social interaction. Patients with hemifacial spasm (n = 20), cervical dystonia (n = 20), and essential tremor (n = 20) were evaluated by SCID-I, Liebowitz Social Anxiety Scale, Hamilton Anxiety and Depression Rating Scales, and Sheehan Disability Scale. The DSM-IV H criterion excluding social anxiety related to a medical condition was disregarded for the diagnosis of secondary SAD. The control group (n = 60) consisted of matched healthy subjects. The frequency of the diagnosis and severity of symptoms were compared and associations with sociodemographic and clinical factors were explored. There was no difference between three patient groups in terms of the frequency or the severity of secondary SAD. Younger age and depressive symptoms were associated with the severity of secondary SAD, while severity or duration of the movement disorder or social disability was not. This study revealed a high frequency of secondary SAD in hyperkinesias, emphasizing the need for psychiatric assessment, especially for younger and depressed patients, who seem to be at greater risk. © 2007 Movement Disorder Society [source] Paradoxes of functional neurosurgery: Clues from basal ganglia recordingsMOVEMENT DISORDERS, Issue 1 2008Peter Brown MD Abstract Deep brain stimulation (DBS) can be remarkably effective in treating movement disorders such as Parkinson's disease, dystonia, and essential tremor. Yet these effects remain essentially unexplained, even paradoxical. Equally challenging is the fact that DBS of motor targets in the basal ganglia appears to reverse abnormalities of movement without any obvious deleterious effects on remaining aspects of movement. Here, we explore the extent to which the noisy signal hypothesis might help solve some of these apparent paradoxes. Essentially the hypothesis, first tentatively advanced by Marsden and Obeso (1994), suggests that disease leads to a pattern of basal ganglia activity that disrupts local and distant function and that surgery acts to suppress or override this noisy signal. Critical to the success this theory is that different disease phenotypes are associated with different patterns of noisy signal, and we survey the evidence to support this contention, with specific emphasis on different types of pathological synchronization. However, just as DBS may suppress or override noisy signals in the basal ganglia, it must equally antagonize any remaining physiological functioning in these key motor structures. We argue that the latter effect of DBS becomes manifest when baseline motor performance is relatively preserved, i.e., when pathological activity is limited. Under these circumstances, the deleterious effects of DBS are no longer obscured by its therapeutic actions in suppressing noisy signals. Whether true, oversimplified or simply incorrect, the noisy signal hypothesis has served to focus attention on the detailed character of basal ganglia discharge and its variation with disease and therapy. © 2007 Movement Disorder Society [source] Dual task interference in psychogenic tremorMOVEMENT DISORDERS, Issue 14 2007Hatice Kumru MD Abstract Psychogenic tremor (PT) is visually indistinguishable from voluntarily mimicked tremor. Healthy volunteers have difficulties with carrying out simultaneously two tasks due to the phenomenon known as dual task interference. Therefore, performing voluntary rhythmic movements would be a burden for carrying out fast ballistic movements with the contralateral hand. We hypothesized that, similarly to healthy volunteers performing rhythmic movements, patients with PT should show the effects of dual task interference, and this may distinguish them from patients with other types of tremor. We studied 6 patients with PT, 9 with Parkinson's disease (PD) and predominantly unilateral tremor, 11 with essential tremor (ET), and 10 normal volunteers (NV) mimicking tremor. They were requested to perform a unilateral simple reaction time task (SRT) to a visual imperative signal in two different conditions: at rest (rSRT) and during contralateral hand tremor (tSRT). Reaction time was significantly longer in tSRT than in rSRT in PT and in NV groups (P < 0.01 for both groups). However, no significant differences were observed between rSRT and tSRT in PD and ET. The delay of unilateral tSRT with respect to rSRT suggests an effect of tremorlike oscillatory movements on reaction time that is consistent with the concept of dual-task interference in NV or PT patients but not in PD or ET. These observations may be useful in the evaluation of psychogenic movement disorders. © 2007 Movement Disorder Society [source] Genetic analysis of SCA 2 and 3 repeat expansions in essential tremor and atypical ParkinsonismMOVEMENT DISORDERS, Issue 13 2007Eng-King Tan MD Abstract Anecdotal reports suggest that patients with spinocerebellar ataxia (SCA 2) patients can present with postural tremor with ataxia. We determined the prevalence of SCA2 and SCA3 mutations in a cohort of ET and atypical Parkinsonism patients. A total of 277 subjects comprising of 177 ET and 100 atypical Parkinsonism were examined. We identified one positive case of SCA3 among those who were diagnosed with ET, yielding a prevalence of 0.5%, but a zero prevalence among our atypical Parkinsonism patients. No study subjects carried an abnormal SCA2 repeat expansion. Our study highlights that SCA3 can present initially with ET symptoms, expanding the spectrum of genetic diseases that can be associated with ET-like phenotype. Routine screening for SCA2 and SCA3 in ET and atypical Parkinsonism patients may not be cost effective. However, in the long-term follow-up of patients who present with an ET phenotype, clinicians should be vigilant for other neurological signs, which may be point to an alternate diagnosis. © 2007 Movement Disorder Society [source] Interest in participating in clinical research: A study of essential tremor patientsMOVEMENT DISORDERS, Issue 1 2007Elan D. Louis MD Abstract Enrolling essential tremor (ET) patients in clinical research can be challenging. Investigators can maximize recruitment by targeting patient subgroups with greater interest in participation. Nothing has been published on factors that are associated with higher levels of interest in participation. The objective of this study was to identify factors associated with higher levels of interest in participating in clinical research on ET. A total of 149 ET patients were questioned about level of interest in participating in future research. Two questions were used, although one was of primary interest. Interest was rated from 0 to 10 (maximal). Data were collected on demographic factors, family history, and tremor-related disability. Tremor severity was assessed. The mean level of interest was 8.0 ± 2.3. Level of interest was not related to age of tremor onset, tremor duration, tremor severity, extent of tremor-related disability, or use of tremor medication. Level of interest was related to family history of tremor (P < 0.05), concern that other family members might develop tremor (P < 0.05), >2 versus 0 live births in women (P < 0.05), the view that the tremor worsens with age (P < 0.05), and presence of head tremor (P = 0.05). A variety of factors were identified that were associated with greater interest in participating in clinical research. These observations should be assessed in additional patient samples. Investigators may use our observations to identify and target patients for clinical trials and other research. © 2006 Movement Disorder Society [source] Alzheimer's disease and essential tremor finally meetMOVEMENT DISORDERS, Issue 11 2007Rodger J. Elble MD [source] Silas Weir Mitchell's essential tremorMOVEMENT DISORDERS, Issue 9 2007Elan D. Louis MD Abstract Silas Weir Mitchell (1829,1914) is recognized as an important American neurologist. Biographers refer in brief to a tremor. The objective of this review was to characterize Mitchell's tremor using handwriting samples, to examine handwriting samples of family members to determine whether this tremor was familial, and study Mitchell's allusions to tremor in personal, scientific, and fictional writings. Primary sources were the Papers of S. Weir Mitchell, College of Physicians of Philadelphia, and Mitchell's scientific and fictional writings. Mitchell's early handwriting was tremor-free yet, by 1873, the writing was tremulous. Handwriting in the 1880s and 1890s shows clear oscillations of moderate-amplitude. By the first decade of the 20th century, his handwriting was virtually illegible. Letters written by two siblings, his mother, and maternal grandfather also reveal tremor. Tremor was not prominent in Mitchell's personal or scientific writings and Mitchell referred to tremor in only 4 of 27 fictional writings In conclusion, Mitchell had a familial action tremor that began when he was in his early 40's and worsened considerably with age. The likely diagnosis was essential tremor. Curiously, Mitchell rarely alluded to tremor in personal writings and tremor was not prominently featured in his scientific or fictional works. © 2007 Movement Disorder Society [source] Treatment of essential tremor with the barbiturate t2000 (1,3-dimethoxymethyl-5,5-diphenyl-barbituric acid)MOVEMENT DISORDERS, Issue 5 2007Calvin Melmed MD Abstract The effect of the barbiturate T2000 (1,3-dimethoxymethyl-5,5-diphenyl-barbituric acid; DMMDPB) on essential tremor, given in twice daily doses of 400 and 300 mg, was assessed in two brief, randomized, placebo-controlled, parallel-group, double-blinded, single-center trials in 12 and 22 patients, respectively. These trials represent the first clinical use of T2000 for a specific indication. The primary endpoint was the change in the mean scores of the treated and control groups based on the Fahn-Tolosa-Marin tremor scale. In the first study of 12 patients treated with 400 mg or placebo twice daily for 14 days, the mean change from baseline at day 14 was 19.3 (P < 0.0001) in the treated group and 9.0 (P = 0.0121) in the control group. Using a two-factor mixed ANOVA model to evaluate within group and between group changes, the effect of T2000 was significantly different from that of the placebo group (P = 0.03). In the second study of 22 patients treated with 300 mg of T2000 or placebo twice daily for 20 days, statistically significant changes were seen in treated patients compared to baseline, but the ANOVA model did not demonstrate a significant treatment effect of T2000 compared to placebo. When the treated groups from each study are compared, the 800-mg daily group is significantly different from the 600-mg daily group (P = 0.02). Some treated patients in each study, but no placebo patients, experienced marked improvement. These results support further evaluation of T2000 in the treatment of essential tremor. © 2006 Movement Disorder Society [source] | ||||||||||