Neuroimaging in Nuclear Medicine
Michael Ljungberg in Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
In another common neurodegenerative disorder, Parkinson´s disease (PD), clumps of protein called Lewy bodies (protein aggregates dominated by α-synuclein) accumulate inside neurons. Like in AD and FTD, neurons producing acetylcholine degenerate in PD. However, the hallmark of PD is loss of dopamine-producing nerve cells. In particular, dopamine-producing neurons located in the substantia nigra (see section 13.1.1) are affected. These cells normally produce lots of dopamine that is released in the striatum, regulating movements, but is also important in cognitive function. The typical movement symptoms of PD, Parkinsonism (i.e. slowness of movement, muscular stiffness/rigidity, balance impairment, and resting tremor) are largely associated with the loss of dopamine, and treatment with dopamine-like drugs (e.g. L-dopa) substitute for the loss of neurotransmitter and improve symptoms through action on the dopamine receptors. Parkinsonism may be seen in other conditions not associated with dopamine loss. Hereditary tremor, for example, is a relatively common neurological condition that may sometimes resemble early Parkinson’s disease, but is not a neurodegenerative disease and should not be treated with anti-Parkinson drugs (i.e. dopaminergic agents). Parkinsonism is also seen in so-called atypical Parkinson syndromes (Multisystem atrophy, Progressive supranuclear palsy, and Corticobasal syndrome). These are far less common, but share the loss of dopamine in the striatum with PD. However, in these diseases, also the dopamine receptors are lost, and therefore dopaminergic treatment is usually not helpful.
MPTP-Induced Parkinsonism
W. R. Wayne Martin in Functional Imaging in Movement Disorders, 2019
In 1983, Langston and colleagues described four patients who developed irreversible signs of parkinsonism after intravenous injections of a substance later found to contain MPTP.7 Clinically, these patients had signs and symptoms of parkinsonism including tremor, bradykinesia, and rigidity. The symptoms occurred within 4 to 14 days after the initiation of drug administration and the effects progressed for a few days after the drug was stopped.7 The patients improved clinically with the administration of dopamine agonists and developed side effects similar to those seen in patients with end-stage Parkinson’s disease. Pathological studies of a subject who had taken MPTP were reported to show destruction of the substantia nigra with neuromelanin within microglial cells and a structure that resembled a Lewy body.10
Anticholinergic and Neuroleptic Drugs
Frank A. Barile in Barile’s Clinical Toxicology, 2019
Acute dystonic reactions appear in 95% of patients, predominantly young males, within 4 days of initiation of therapy or as dosage increases. In contrast, akathisia affects mostly elderly patients in early treatment (the first 60 days) and subsides with lower dosage. Parkinsonism develops within 10 weeks of therapy and affects 90% of patients, although it is reversible at lower doses. It is important to note that the risk of developing a tardive disorder, and the likelihood that it will become irreversible, increases with the duration of treatment and with the total cumulative dose of neuroleptic drug. As neuroleptic agent is withdrawn, dopamine activity increases, and tardive dyskinesia emerges. The effect is probably due to upregulation of dopamine receptors in the corpus striatum, especially with chronic neuroleptic treatment. Neuroleptic malignant syndrome (NMS) is a potentially fatal idiosyncratic complication occurring in 2% of patients on antipsychotic therapy. It is an extreme EPS reaction resulting from excessive antidopaminergic activity. Precipitating factors include abrupt withdrawal of antiparkinson dopamine agonist drugs (L-dopa) or anticholinergic medication, or a rapid increase in the dose of neuroleptics. Meningitis and anticholinergic poisoning mimic NMS and must be ruled out.
The inter-relationship between various non-motor symptoms and with habitual physical activity in Parkinsonism: a scoping review protocol
Published in Physical Therapy Reviews, 2022
Amanda Still, Leigh Hale, Prasath Jayakaran
Parkinsonism is a group of disorders characterised by the presence of bradykinesia with rigidity or tremor [1,2]. Neurodegenerative processes are the most common cause of Parkinsonism disorders, such as idiopathic Parkinson’s disease (PD) and atypical Parkinsonism disorders (APDs) [2,3]. APDs include multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration, and dementia with Lewy bodies. PD and APDs have distinct pathophysiology but are commonly misdiagnosed, particularly in the early stages of the disease, due to symptom overlap [2,4]. PD is the most prevalent of these disorders, which has had a more than two-fold increase in global prevalence in the last two decades [5]. The current global prevalence of PD is estimated to be 6.1 million [5], and epidemiological research projects this to increase by approximately 770,000 by 2040 [6]. APDs account for approximately 10% of neurodegenerative causes, with a collective prevalence of approximately 0.4% (400 per 100,000 persons) [3,7]. Although APDs are less common, they are usually associated with a more rapid disease progression and a shorter lifespan [2].
Smart ankle bracelet-laser device to improve gait and detect freezing of gait in Parkinsonism patients: a case series
Published in Assistive Technology, 2022
Chompoonuch Ratanasutiranont, Kwan Srisilpa, Pichet Termsarasab, Peeraya Ruthiraphong
Four Parkinsonism patients with FOG who met the inclusion criteria were recruited into the study. The inclusion criteria were as follows: 1) diagnosis of parkinsonism by a neurologist; 2) ability to walk at least 10 meters with or without a gait aid; 3) no medication adjustment in the past 3 months; 4) history of FOG based on a score of 2 (occasional freezing when walking) or 3 (frequent freezing when walking, occasional falls as a result of freezing) on item 14 (freezing when walking) of the Unified Parkinson’s Disease Rating Scale (UPDRS). The exclusion criteria were as follows: 1) unable to see the laser line; 2) other neurological disorders; 3) unable to communicate or understand how to use the device. One participant was excluded from the study because they did not experience FOG during the test because of the white coat effect.
Assessing and treating conversations with partners in Parkinson’s disease: A scoping review of the evidence
Published in International Journal of Speech-Language Pathology, 2022
Ramishka Thilakaratne, Andrea M. Loftus, Naomi Cocks
Idiopathic (of unknown origins) Parkinson’s disease (PD) is the second most common neurodegenerative disorder, with a prevalence rate of 0%–3% of the population in industrialised countries (Tysnes & Storstein, 2017). Parkinsonism refers to a group of neurological disorders that share the cardinal motor symptoms of PD, such as tremor, slowed movement, postural instability, and rigidity (Aminoff, Greenberg, and Simon, 2005). As it is often difficult to differentiate between the disorders, they are grouped together under the umbrella term of Parkinsonism. Included in this grouping are Progressive Supranuclear Palsy, Multiple System Atrophy, Lewy-Body Dementia, Corticobasal Degeneration, Vascular Parkinsonism, and Drug-Induced Parkinsonism. The heterogeneous nature of PD, coupled with the overlap with other neurological disorders, often means that research studies are not PD specific and may include those diagnosed with Parkinsonism.
Related Knowledge Centers
- Syndrome
- Tremor
- Hypokinesia
- Spasticity
- Balance Disorder
- Parkinson's Disease
- Dementia With Lewy Bodies
- Parkinson's Disease Dementia
- Neurodegenerative Disease
- Toxin