Degenerative Diseases of the Nervous System
Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw in Hankey's Clinical Neurology, 2020
Subtypes of PD have emerged based on distinct clinic features. They include: Tremor-dominant: in which tremor is an early and prominent feature. This is often misdiagnosed as essential tremor, and there may be a pathological link between the two disorders. There is a related entity called ‘benign tremulous parkinsonism’ in patients who have prominent rest tremor in the absence of other nontremor signs and gait disorder, and lack of progression.Postural instability with gait difficulty (PIGD): in which patients demonstrate early gait abnormalities; and there is prominent bradykinesia and rigidity (sometimes referred to as ‘akinetic rigid subtype’).Young-onset PD (age < 50).Late-onset PD (age > 50).
Neurologic disorders in pregnancy
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
Essential tremor is the most common movement disorder in the general population and is frequently seen in younger patients. This movement disorder more likely than any others to be encountered by a treating obstetrician. It involves action tremors of the hands, head, voice, and occasionally legs or trunk, and frequently runs in families. The tremor occurs when the patient is using the extremity; however, the head tremor occurs with any upright posture. There is no other impairment of neurologic function or cognition. The disorder follows a benign course and is generally only socially disabling; however, in more severe cases, it can be very difficult to eat or write. The most effective treatment for this disorder involves the use of PMD and propranolol. Other medications have been used with varying success. Given the unclear danger to the fetus of these medications, as well as the benign nature of the disorder, it is probably wise to counsel the mother to take no medication for this condition while she is pregnant or breast-feeding. If the mother’s tremor is so severe that it precludes reasonable normal daily function, the choice of medications should be discussed between the obstetrician and the neurologist to determine which medication is felt to be least likely, at that time, to cause harm to the fetus and most effective for that patient.
Discussions (D)
Terence R. Anthoney in Neuroanatomy and the Neurologic Exam, 2017
As noted in the discussion of Factual Conflicts 1–2, authors disagree as to the effect of volitional movement on the amplitude of essential tremor (or familial tremor). This disagreement may be due, at least in part, to variation in how authors name physical findings. Most authors do not describe additional neurological abnormalities in patients with essential tremor, and at least one claims that no other evidence of neurologic disease is evident in such patients (Chus, p. 195). If these authors believe that no real “pathology” is responsible for essential tremor, then they may tend to ascribe additional neurologic abnormalities found in such patients to the tremor itself. As a probable example, Adams and Victor write that “essential or familial tremor may, in its advanced stages, assume the aspects of a cerebellar or intention tremor” (1985, p. 79). A few authors, however, describe what may be the same phenomena as findings separate from the essential tremor—for example, “Mild cerebellar signs such as ataxia of finger-to-nose test may be present” (G&M, p. 196).6
Post-diagnostic lived experiences of individuals with essential tremor
Published in Disability and Rehabilitation, 2020
Jessica Moore, Fiona J. R. Eccles, Jane Simpson
Essential tremor was once previously viewed as a solely motor disorder but psychological difficulties are increasingly being recognized [10]. Furthermore, quality of life is also found to be impaired for individuals with a diagnosis of essential tremor [11]. In common with other neurological conditions such as Parkinson’s disease [12] the main predictors of quality of life are psychological and psychosocial factors, such as emotional well-being and social withdrawal, rather than illness severity [11]. It has also been found that ability to perform at work, and during leisure activity, impacts upon levels of depression for individuals with essential tremor [13]. As a result of the overlap in essential tremor and Parkinson’s disease, previous research has not only explored the relationship between the two conditions [14] but has also compared quality of life [15]. In particular this comparison identified that individuals with essential tremor experienced more impairment in relation to writing, eating, drinking, embarrassment, and concentration [15] in comparison to individuals with Parkinson’s disease. In addition, individuals with essential tremor were also found to have higher self- ratings of tremor severity in their arms, and drink alcohol more frequently than they would like, compared to individuals with Parkinson’s disease, whereas the latter were noted to have higher levels of speech impairment and higher self-ratings of tremor severity in their legs compared to individuals with essential tremor [15].
Dapagliflozin modulates neuronal injury via instigation of LKB1/p-AMPK/GABAB R2 signaling pathway and suppression of the inflammatory cascade in an essential tremor rat model
Published in Expert Opinion on Therapeutic Targets, 2023
Ahmed S. Kamel, Sama M. Farrag, Heba M. Mansour, Noha N. Nassar, Muhammed A. Saad
Essential tremor (ET), one of the most commonly prevalent neurological diseases, affects nearly 1% of the world’s population, escalating to 4% in those aged above 40; nonetheless, it is misdiagnosed in 30% to 50% of the cases [1]. The latest estimates of ET prevalence stated an incidence of 0.32% that progresses to 2.8% in patients above 80 years [2]. One of the prominent features that signify ET is upper limbs kinetic tremors [3] that spread to different body parts like neck, vocal cords, or jaw [4]. ET was identified as a mono-symptomatic disorder, but as is the case with many neurological diseases, motor inadequacy is accompanied by non-motor cognitive symptoms [5], auditory and olfactory deficits [6], as well as minor ataxia [7]. Recently, many epidemiological studies have noted an increased risk of dementia and Parkinson’s disease among ET patients. In spite of the soaring prevalence, there is no specific diagnostic test or a biomarker for ET [8]. Furthermore, owing to the heterogeneity of clinical manifestations and lack of disease recognition, only a small percentage of ET patients seek medical care [9].
Brain circuits and neurochemical systems in essential tremor: insights into current and future pharmacotherapeutic approaches
Published in Expert Review of Neurotherapeutics, 2018
Sara M Schaefer, Ana Vives Rodriguez, Elan D Louis
Despite the high prevalence of essential tremor (ET), its underlying pathophysiology in not completely understood. The medications that are available for its treatment are few and they are only moderately effective.Dysfunction of T-type calcium channels (T-tCaCs) and/or γ-aminobutyric acid (GABA) biology have been implicated in the pathophysiology of ET.GABAA receptors have multiple different subunits that form pentamers; these subunits are distributed variably throughout the brain. Medications that act at specific subunits can therefore have very different clinical effects. Medications should be considered based on subunit specificity rather than global GABAergic activity.A multifocal or global GABAergic effect may have multiple competing (i.e., self-cancelling) influences within the tremor-generating system, that could limit an overall inhibitory effect and therefore limit the impact on tremor.The medications that are currently used in ET act at many different types of receptors, including many different types of GABA receptors.Looking at the distribution and biology of different types of GABA receptors, we can begin to form hypotheses as to how agonist or antagonist activity at those receptors may impact the entire system.Ultimately, as we form a better understanding of the biochemical and pathophysiological influences in ET, we can aim to design targeted medications that will provide tremorolytic effects without competing effects or marked side effects.
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