Harding ataxia | |
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Other names | Early onset cerebellar ataxia with retained reflexes (EOCARR) |
Harding ataxia has an autosomal recessive pattern of inheritance. | |
Specialty | Neurology |
Harding ataxia is an autosomal recessive cerebellar ataxia originally described by Harding in 1981. [1] This form of cerebellar ataxia is similar to Friedreich ataxia including that it results in poor reflexes and balance, but differs in several ways, including the absence of diabetes mellitus, optic atrophy, cardiomyopathy, skeletal abnormalities, and the fact that tendon reflexes in the arms and knees remain intact. [2] This form of ataxia is characterized by onset in the first 20 years, and is less severe than Friedreich ataxia. Additional cases were diagnosed in 1989, [3] 1990, [4] 1991, [5] and 1998. [6]
40 cases were diagnosed in northern Italy between 1940 and 1990. The gene frequency for this autosomal recessive condition was estimated at 1 in 218. [7] In 1989, 16 cases on EOCA were diagnosed in children with a mean onset age of 7.1 [3] In 1990, 20 patients affected by EOCA were studied. It was found that the ataxia of this study's participants affected the pyramidal tracts and peripheral nerves. [4]
Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements, that indicates dysfunction of parts of the nervous system that coordinate movement, such as the cerebellum.
Hereditary spastic paraplegia (HSP) is a group of inherited diseases whose main feature is a progressive gait disorder. The disease presents with progressive stiffness (spasticity) and contraction in the lower limbs. HSP is also known as hereditary spastic paraparesis, familial spastic paraplegia, French settlement disease, Strumpell disease, or Strumpell-Lorrain disease. The symptoms are a result of dysfunction of long axons in the spinal cord. The affected cells are the primary motor neurons; therefore, the disease is an upper motor neuron disease. HSP is not a form of cerebral palsy even though it physically may appear and behave much the same as spastic diplegia. The origin of HSP is different from cerebral palsy. Despite this, some of the same anti-spasticity medications used in spastic cerebral palsy are sometimes used to treat HSP symptoms.
Cerebellar hypoplasia is characterized by reduced cerebellar volume, even though cerebellar shape is (near) normal. It consists of a heterogeneous group of disorders of cerebellar maldevelopment presenting as early-onset non–progressive congenital ataxia, hypotonia and motor learning disability.
Friedreich's ataxia (FRDA) is a rare, inherited, autosomal recessive neurodegenerative disorder that primarily affects the nervous system, causing progressive damage to the spinal cord, peripheral nerves, and cerebellum, leading to impaired muscle coordination (ataxia). The condition typically manifests in childhood or adolescence, with initial symptoms including difficulty walking, loss of balance, and poor coordination. As the disease progresses, it can also impact speech, vision, and hearing. Many individuals with Friedreich's ataxia develop scoliosis, diabetes, and hypertrophic cardiomyopathy, a serious heart condition that is a leading cause of mortality in patients.
Spinocerebellar ataxia (SCA) is a progressive, degenerative, genetic disease with multiple types, each of which could be considered a neurological condition in its own right. An estimated 150,000 people in the United States have a diagnosis of spinocerebellar ataxia at any given time. SCA is hereditary, progressive, degenerative, and often fatal. There is no known effective treatment or cure. SCA can affect anyone of any age. The disease is caused by either a recessive or dominant gene. In many cases people are not aware that they carry a relevant gene until they have children who begin to show signs of having the disorder. Currently, research is being conducted at Universities, such as the University of Minnesota, to elucidate many of the unknown characteristics of the disease.
Sensory ataxia is both a symptom and a sign in neurology. It is a form of ataxia caused not by cerebellar dysfunction but by loss of sensory input into the control of movement.
Cerebellar ataxia is a form of ataxia originating in the cerebellum. Non-progressive congenital ataxia (NPCA) is a classical presentation of cerebral ataxias.
Cerebellar abiotrophy (CA), also called cerebellar cortical abiotrophy (CCA), is a genetic neurological disease in animals, best known to affect certain breeds of horses, dogs and cats. It can also develop in humans. It develops when the neurons known as Purkinje cells, located in the cerebellum of the brain, begin to die off. These cells affect balance and coordination. They have a critical role to play in the brain. The Purkinje layer allows communication between the granular and molecular cortical layers in the cerebellum. Put simply, without Purkinje cells, an animal loses its sense of space and distance, making balance and coordination difficult. People with damage to the cerebellum can experience symptoms like unsteady gait, poor muscle control, and trouble speaking or swallowing.
Frataxin is a protein that in humans is encoded by the FXN gene.
Ramsay Hunt syndrome type 1 is a rare, degenerative, neurological disorder characterized by myoclonus epilepsy, intention tremor, progressive ataxia and occasionally cognitive impairment
Gillespie syndrome, also called aniridia, cerebellar ataxia and mental deficiency, is a rare genetic disorder. The disorder is characterized by partial aniridia, ataxia, and, in most cases, intellectual disability. It is heterogeneous, inherited in either an autosomal dominant or autosomal recessive manner. Gillespie syndrome was first described by American ophthalmologist Fredrick Gillespie in 1965.
Peter Kynaston "PK" Thomas was a Welsh academic neurologist, author, teacher and administrator. From 1974 to 1991 he was Professor of Neurology at the University of London. He was a fellow of University College London and the Royal Society of Medicine, and was the recipient of the Medal of the Association of British Neurologists. Thomas was, at various times, the president of the Association of British Neurologists, the European Neurological Society, and the Peripheral Nerve Society.
Autosomal recessive cerebellar ataxia type 1 (ARCA1) is a condition characterized by progressive problems with movement. Signs and symptoms of the disorder first appear in early to mid-adulthood. People with this condition initially experience impaired speech (dysarthria), problems with coordination and balance (ataxia), or both. They may also have difficulty with movements that involve judging distance or scale (dysmetria). Other features of ARCA1 include abnormal eye movements (nystagmus) and problems following the movements of objects with their eyes. The movement problems are slowly progressive, often resulting in the need for a cane, walker, or wheelchair.
Oculomotor apraxia (OMA) is the absence or defect of controlled, voluntary, and purposeful eye movement. It was first described in 1952 by the American ophthalmologist David Glendenning Cogan. People with this condition have difficulty moving their eyes horizontally and moving them quickly. The main difficulty is in saccade initiation, but there is also impaired cancellation of the vestibulo-ocular reflex. Patients have to turn their head in order to compensate for the lack of eye movement initiation in order to follow an object or see objects in their peripheral vision, but they often exceed their target. There is controversy regarding whether OMA should be considered an apraxia, since apraxia is the inability to perform a learned or skilled motor action to command, and saccade initiation is neither a learned nor a skilled action.
Autosomal dominant cerebellar ataxia (ADCA) is a form of spinocerebellar ataxia inherited in an autosomal dominant manner. ADCA is a genetically inherited condition that causes deterioration of the nervous system leading to disorder and a decrease or loss of function to regions of the body.
Non-progressive congenital ataxia (NPCA) is a non-progressive form of cerebellar ataxia which can occur with or without cerebellar hypoplasia.
Autosomal recessive cerebellar ataxia describes a heterogeneous group of rare genetic disorders with an autosomal recessive inheritance pattern and a clinical phenotype involving cerebellar ataxia.
William Walton Gooddy (1916–2004) was an English neurologist.
Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is an autosomal recessive late-onset heredodegenerative multisystem neurological disease. The symptoms include poor balance and difficulty walking. Chronic cough and difficulty swallowing may also be present. Clinical findings include ataxia, sensory neuropathy, and absence of the vestibulo–ocular reflex. The syndrome was initially described in 2004. In 2019, the cause was identified as biallelic pentanucleotide expansion in the RFC1 gene.
Boucher-Neuhäuser syndrome is a very rare genetic disorder which is characterized by a triad consisting of cerebellar ataxia, chorioretinal dystrophy, and hypogonadism.