Essential tremor (ET), also called benign tremor, familial tremor, and idiopathic tremor, is a medical condition characterized by involuntary rhythmic contractions and relaxations of certain muscle groups in one or more body parts of unknown cause. It is typically symmetrical, and affects the arms, hands, or fingers; but sometimes involves the head, vocal cords, or other body parts. Essential tremor is either an action (intention) tremor—it intensifies when one tries to use the affected muscles during voluntary movements such as eating and writing—or it is a postural tremor, which occurs when holding arms outstretched and against gravity. This means that it is distinct from a resting tremor, such as that caused by Parkinson's disease, which is not correlated with movement. Unlike Parkinson's disease, essential tremor may worsen with action.
Parkinsonism is a clinical syndrome characterized by tremor, bradykinesia, rigidity, and postural instability. Both hypokinetic as well as hyperkinetic features are displayed by Parkinsonism. These are the four motor symptoms found in Parkinson's disease (PD) – after which it is named – dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD), and many other conditions. This set of symptoms occurs in a wide range of conditions and may have many causes, including neurodegenerative conditions, drugs, toxins, metabolic diseases, and neurological conditions other than PD.
Dementia with Lewy bodies (DLB) is a type of dementia characterized by changes in sleep, behavior, cognition, movement, and regulation of automatic bodily functions. Memory loss is not always an early symptom. The disease worsens over time and is usually diagnosed when cognitive impairment interferes with normal daily functioning. Together with Parkinson's disease dementia, DLB is one of the two Lewy body dementias. It is a common form of dementia, but the prevalence is not known accurately and many diagnoses are missed. The disease was first described on autopsy by Kenji Kosaka in 1976, and he named the condition several years later.
Single-photon emission computed tomography is a nuclear medicine tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera, but is able to provide true 3D information. This information is typically presented as cross-sectional slices through the patient, but can be freely reformatted or manipulated as required.
Nuclear medicine, or nucleology, is a medical specialty involving the application of radioactive substances in the diagnosis and treatment of disease. Nuclear imaging is, in a sense, radiology done inside out, because it records radiation emitted from within the body rather than radiation that is transmitted through the body from external sources like X-ray generators. In addition, nuclear medicine scans differ from radiology, as the emphasis is not on imaging anatomy, but on the function. For such reason, it is called a physiological imaging modality. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) scans are the two most common imaging modalities in nuclear medicine.
A radioactive tracer, radiotracer, or radioactive label is a synthetic derivative of a natural compound in which one or more atoms have been replaced by a radionuclide. By virtue of its radioactive decay, it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling or radiotracing is thus the radioactive form of isotopic labeling. In biological contexts, experiments that use radioisotope tracers are sometimes called radioisotope feeding experiments.
Iodobenzamide is a pharmaceutical drug used for diagnostic purposes. It is a dopamine antagonist and it can be used by nuclear medicine physicians as a radioactive tracer for SPECT where the radioactive isotope is iodine-123 or iodine-125. The main purpose of a brain study with IBZM is the differentiation of Parkinson's disease from other neurodegenerative diseases such as Lewy Body dementia and multiple system atrophy.
Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by tremors, slow movement, muscle rigidity, and postural instability, autonomic dysfunction and ataxia. This is caused by progressive degeneration of neurons in several parts of the brain including the basal ganglia, inferior olivary nucleus, and cerebellum.
Progressive supranuclear palsy (PSP) is a late-onset neurodegenerative disease involving the gradual deterioration and death of specific volumes of the brain. The condition leads to symptoms including loss of balance, slowing of movement, difficulty moving the eyes, and cognitive impairment. PSP may be mistaken for other types of neurodegeneration such as Parkinson's disease, frontotemporal dementia and Alzheimer's disease. The cause of the condition is uncertain, but involves the accumulation of tau protein within the brain. Medications such as levodopa and amantadine may be useful in some cases.
Parkinson-plus syndromes (PPS) are a group of neurodegenerative diseases featuring the classical features of Parkinson's disease with additional features that distinguish them from simple idiopathic Parkinson's disease (PD). Parkinson-plus syndromes are either inherited genetically or occur sporadically.
Corticobasal degeneration (CBD) is a rare neurodegenerative disease involving the cerebral cortex and the basal ganglia. CBD symptoms typically begin in people from 50 to 70 years of age, and typical survival before death is eight years. It is characterized by marked disorders in movement and cognition, and is classified as one of the Parkinson plus syndromes. Diagnosis is difficult, as symptoms are often similar to those of other disorders, such as Parkinson's disease, progressive supranuclear palsy, and dementia with Lewy bodies, and a definitive diagnosis of CBD can only be made upon neuropathologic examination.
Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is an autosomal dominant neurodegenerative tauopathy and Parkinson plus syndrome. FTDP-17 is caused by mutations in the MAPT gene located on the q arm of chromosome 17, and has three cardinal features: behavioral and personality changes, cognitive impairment, and motor symptoms. FTDP-17 was defined during the International Consensus Conference in Ann Arbor, Michigan, in 1996.
Iodine-123 (123I) is a radioactive isotope of iodine used in nuclear medicine imaging, including single-photon emission computed tomography (SPECT) or SPECT/CT exams. The isotope's half-life is 13.2230 hours; the decay by electron capture to tellurium-123 emits gamma radiation with a predominant energy of 159 keV. In medical applications, the radiation is detected by a gamma camera. The isotope is typically applied as iodide-123, the anionic form.
RTI(-4229)-55, also called RTI-55 or iometopane, is a phenyltropane-based psychostimulant used in scientific research and in some medical applications. This drug was first cited in 1991. RTI-55 is a non-selective dopamine reuptake inhibitor derived from methylecgonidine. However, more selective analogs are derived by conversion to "pyrrolidinoamido" RTI-229, for instance. Due to the large bulbous nature of the weakly electron withdrawing iodo halogen atom, RTI-55 is the most strongly serotonergic of the simple para-substituted troparil based analogs. In rodents RTI-55 actually caused death at a dosage of 100 mg/kg, whereas RTI-51 and RTI-31 did not. Another notable observation is the strong propensity of RTI-55 to cause locomotor activity enhancements, although in an earlier study, RTI-51 was actually even stronger than RTI-55 in shifting baseline LMA. This observation serves to highlight the disparities that can arise between studies.
Ioflupane (123I) is the international nonproprietary name (INN) of a cocaine analogue which is a neuro-imaging radiopharmaceutical drug, used in nuclear medicine for the diagnosis of Parkinson's disease and the differential diagnosis of Parkinson's disease over other disorders presenting similar symptoms. During the DaT scan procedure it is injected into a patient and viewed with a gamma camera in order to acquire SPECT images of the brain with particular respect to the striatum, a subcortical region of the basal ganglia. The drug is sold under the brand name Datscan and is manufactured by GE Healthcare, formerly Amersham plc.
Central nervous system diseases or central nervous system disorders are a group of neurological disorders that affect the structure or function of the brain or spinal cord, which collectively form the central nervous system (CNS). These disorders may be caused by such things as infection, injury, blood clots, age related degeneration, cancer, autoimmune disfunction, and birth defects. The symptoms vary widely, as do the treatments.
Parkinson's disease (PD), or simply Parkinson's, is a long-term neurodegenerative disease of mainly the central nervous system that affects both the motor and non-motor systems of the body. The symptoms usually emerge slowly, and as the disease progresses, non-motor symptoms become more common. Usual symptoms include tremors, slowness of movement, rigidity, and difficulty with balance, collectively known as parkinsonism. Parkinson's disease dementia, falls and neuropsychiatric problems such as sleep abnormalities, psychosis, mood swings, or behavioral changes may also arise in advanced stages.
Kufor–Rakeb syndrome (KRS) is an autosomal recessive disorder of juvenile onset also known as Parkinson disease-9 (PARK9). It is named after Kufr Rakeb in Irbid, Jordan. Kufor–Rakeb syndrome was first identified in this region in Jordan with a Jordanian couple's 5 children who had rigidity, mask-like face, and bradykinesia. The disease was first described in 1994 by Najim Al-Din et al. The OMIM number is 606693.
Iofetamine, brand names Perfusamine, SPECTamine), or N-isopropyl-(123I)-p-iodoamphetamine (IMP), is a lipid-soluble amine and radiopharmaceutical drug used in cerebral blood perfusion imaging with single-photon emission computed tomography (SPECT). Labeled with the radioactive isotope iodine-123, it is approved for use in the United States as a diagnostic aid in determining the localization of and in the evaluation of non-lacunar stroke and complex partial seizures, as well as in the early diagnosis of Alzheimer's disease.
