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Different types of ataxia:
- congenital ataxias (developmental disorders)
- ataxias with metabolic disorders
- ataxias with a DNA repair defect
- degenerative ataxias
- ataxia associated with other features.
Clinical diagnosis is conducted on individuals with age onset between late teens and late forties who show the initial characteristics for the recessive autosomal cerebellar ataxia.
The following tests are performed:
- MRI brain screening for cerebellum atrophy.
- Molecular genetic testing for SYNE-1 sequence analysis.
- Electrophysiologic studies for polyneurotherapy
- Neurological examination
Prenatal diagnosis and preimplantation genetic diagnosis (PGD) can be performed to identify the mothers carrying the recessive genes for cerebellar ataxia.
A diagnosis of Friedreich's ataxia requires a careful clinical examination, which includes a medical history and a thorough physical exam, in particular looking for balance difficulty, loss of proprioception, absence of reflexes, and signs of neurological problems. Genetic testing now provides a conclusive diagnosis. Other tests that may aid in the diagnosis or management of the disorder include:
- Electromyogram (EMG), which measures the electrical activity of muscle cells,
nerve conduction studies, which measure the speed with which nerves transmit impulses
- Electrocardiogram (ECG), which gives a graphic presentation of the electrical activity or beat pattern of the heart
- Echocardiogram, which records the position and motion of the heart muscle
- Blood tests to check for elevated glucose levels and vitamin E levels
- Magnetic resonance imaging (MRI) or computed tomography (CT) scans, tests which provide brain and spinal cord images that are useful for ruling out other neurological conditions
Diffuse, symmetric white matter abnormalities were demonstrated by magnetic resonance imaging (MRI) suggesting that Behr syndrome may represent a disorder of white matter associated with an unknown biochemical abnormality.
Diagnosis is suspected clinically and family history, neuroimaging and genetic study helps to confirm Behr Syndrome.
The diagnosis of A-T is usually suspected by the combination of neurologic clinical features (ataxia, abnormal control of eye movement, and postural instability) with telangiectasia and sometimes increased infections, and confirmed by specific laboratory abnormalities (elevated alpha-fetoprotein levels, increased chromosomal breakage or cell death of white blood cells after exposure to X-rays, absence of ATM protein in white blood cells, or mutations in each of the person’s ATM genes).
A variety of laboratory abnormalities occur in most people with A-T, allowing for a tentative diagnosis to be made in the presence of typical clinical features. Not all abnormalities are seen in all patients. These abnormalities include:
- Elevated and slowly increasing alpha-fetoprotein levels in serum after 2 years of age
- Immunodeficiency with low levels of immunoglobulins (especially IgA, IgG subclasses, and IgE) and low number of lymphocytes in the blood
- Chromosomal instability (broken pieces of chromosomes)
- Increased sensitivity of cells to x-ray exposure (cells die or develop even more breaks and other damage to chromosomes)
- Cerebellar atrophy on MRI scan
The diagnosis can be confirmed in the laboratory by finding an absence or deficiency of the ATM protein in cultured blood cells, an absence or deficiency of ATM function (kinase assay), or mutations in both copies of the cell’s ATM gene. These more specialized tests are not always needed, but are particularly helpful if a child’s symptoms are atypical.
There is no known prevention of spinocerebellar ataxia. Those who are believed to be at risk can have genetic sequencing of known SCA loci performed to confirm inheritance of the disorder.
In diagnosing autosomal dominant cerebellar ataxia the individuals clinical history or their past health examinations, a current physical examination to check for any physical abnormalities, and a genetic screening of the patients genes and the genealogy of the family are done. The large category of cerebellar ataxia is caused by a deterioration of neurons in the cerebellum, therefore magnetic resonance imaging (MRI) is used to detect any structural abnormality such as lesions which are the primary cause of the ataxia. Computed tomography (CT) scans can also be used to view neuronal deterioration, but the MRI provides a more accurate and detailed picture.
There is no known prevention of spinocerebellar ataxia. Those who are believed to be at risk can have genetic sequencing of known SCA loci performed to confirm inheritance of the disorder.
MJD can be diagnosed by recognizing the symptoms of the disease and by taking a family history. Physicians ask patients questions about the kind of symptoms relatives with the disease had, the progression and harshness of symptoms, and the ages of onset in family members.
Presymptomatic diagnosis of MJD can be made with a genetic test. The direct detection of the genetic mutation responsible for MJD has been available since 1995. Genetic testing looks at the number of CAG repeats within the coding region of the MJD/ATXN3 gene on chromosome 14. The test will show positive for MJD if this region contains 61-87 repeats, as opposed to the 12-44 repeats found in healthy individuals. A limitation to this test is that if the number of CAG repeats in an individual being tested falls between the healthy and pathogenic ranges (45-60 repeats), then the test cannot predict whether an individual will have MJD symptoms.
Neuroimaging like MRI is important. However, there was considerable intrafamilial variability regarding neuroimaging, with some individuals showing normal MRI findings. Early individual prognosis of such autosomal recessive cerebellar ataxias is not possible from early developmental milestones, neurological signs, or neuroimaging.
The clinical diagnosis is backed up by investigative findings. Citrulline level in blood is decreased. Mitochondrial studies or NARP mtDNA evaluation plays a role in genetic diagnosis which can also be done prenatally.
Because OMS is so rare and occurs at an average age of 19 months (6 to 36 months), a diagnosis can be slow. Some cases have been diagnosed as having been caused by a virus. After a diagnosis of OMS is made, an associated neuroblastoma is discovered in half of cases, with median delay of 3 months.
The interictal EEG pattern is usually normal.
In terms of a cure there is currently none available, however for the disease to manifest itself, it requires mutant gene expression. Manipulating the use of protein homoestasis regulators can be therapuetic agents, or a treatment to try and correct an altered function that makes up the pathology is one current idea put forth by Bushart, et al. There is some evidence that for SCA1 and two other polyQ disorders that the pathology can be reversed after the disease is underway. There is no effective treatments that could alter the progression of this disease, therefore care is given, like occupational and physical therapy for gait dysfunction and speech therapy.
There is currently no cure for SCA 6; however, there are supportive treatments that may be useful in managing symptoms.
There are five sub-types of MJD that are characterized by the age of onset and range of symptoms.
The sub-types illustrate a wide variety of symptoms that patients can experience. However, assigning individuals to a specific sub-type of the disease is of limited clinical significance.
- Type I is distinguished by arrival between the ages of 10 and 30 and represents approximately 13% of individuals. It usually has fast development and severe rigidity and dystonia.
- Type II is the most common sub-type (approximately 57% of individuals with MJD ) and typically begins between 20 and 50 years of age . It has an intermediate progression and causes symptoms that include spasticity, exaggerated reflex responses and spastic gait, ataxia and upper motor neuron signs.
- Type III MJD has a slow progression. Patients typically have an onset between the ages of 40 and 70 and represent approximately 30% of MJD patients. Symptoms include muscle twitching, tingling, cramps, unpleasant sensations such as numbness, pain in the feet, hands and limbs and muscle atrophy. Nearly all patients experience a decline in their vision such as blurred vision, double vision, inability to control eye movements, and loss of capability to distinguish color. Some patients also experience Parkinsonian symptoms.
- Type IV is distinguished by Parkinsonian symptoms that respond particularly well to levodopa treatment.
- Type V appears to resemble Hereditary Spastic Paraplegia; however, more research is needed to conclude the relationship between Type V MJD and hereditary spastic paraplegia.
Brain MRI shows vermis atrophy or hypoplasic. Cerebral and cerebellar atrophy with white matter changes in some cases.
Arts syndrome should be included in the differential diagnosis of infantile hypotonia and weakness aggravated by recurrent infection with a family history of X-linked inheritance. Sequence analysis of PRPS1, the only gene associated with Arts syndrome, has detected mutations in both kindreds reported to date. Arts syndrome patients were also found to have reduced levels of hypoxanthine levels in urine and uric acid levels in the serum. In vitro, PRS-1 activity was reduced in erythrocytes and fibroblasts.
RG2833, a histone deacetylase inhibitor developed by Repligen, was acquired by BioMarin Pharmaceutical in January 2014. The first human trials with this compound began in 2012.
Horizon Pharma's development plan of interferon gamma-1B for treatment of FA was given fast track designation by the Food and Drug Administration in 2015.
In its trials released in December 2016, however, the results showed no improvements over placebo in patients.
Recurrent sinus and lung infections can lead to the development of chronic lung disease. Such infections should be treated with appropriate antibiotics to prevent and limit lung injury. Administration of antibiotics should be considered when children and adults have prolonged respiratory symptoms (greater than 7 days), even following what was presumed to have been a viral infection. To help prevent respiratory illnesses from common respiratory pathogens, annual influenza vaccinations should be given and pneumococcal vaccines should be administered when appropriate. Antibiotic treatment should also be considered in children with chronic coughs that are productive of mucous, those who do not respond to aggressive pulmonary clearance techniques and in children with muco-purulent secretions from the sinuses or chest. A wet cough can also be associated with chronic aspiration which should be ruled out through proper diagnostic studies, however aspiration and respiratory infections are not necessarily exclusive of each other. In children and adults with bronchiectasis, chronic antibiotic therapy should be considered to slow chronic lung disease progression.
Culturing of the sinuses may be needed to direct antibiotic therapy. This can be done by an Ear Nose and Throat (ENT) specialist. In addition, diagnostic bronchoscopy may be necessary in people who have recurrent pneumonias, especially those who do not respond or respond incompletely to a course of antibiotics.
Clearance of bronchial secretions is essential for good pulmonary health and can help limit injury from acute and chronic lung infections. Children and adults with increased bronchial secretions can benefit from routine chest therapy using the manual method, an a cappella device or a chest physiotherapy vest. Chest physiotherapy can help bring up mucous from the lower bronchial tree, however an adequate cough is needed to remove secretions. In people who have decreased lung reserve and a weak cough, use of an insufflator-exsufflator (cough-assist) device may be useful as a maintenance therapy or during acute respiratory illnesses to help remove bronchial secretions from the upper airways. Evaluation by a Pulmonology specialist however, should first be done to properly assess patient suitability.
Children and adults with chronic dry cough, increased work of breathing (fast respiratory rate, shortness of breath at rest or with activities) and absence of an infectious process to explain respiratory symptoms should be evaluated for interstitial lung disease or another intrapulmonary process. Evaluation by a Pulmonologist and a CT scan of the chest should be considered in individuals with symptoms of interstitial lung disease or to rule other non-infectious pulmonary processes. People diagnosed with interstitial lung disease may benefit from systemic steroids.
FXTAS can be diagnosed using a combination of molecular, clinical, and radiological findings. In order for individuals to acquire FXTAS, they must first be permutation carriers, having between 55-200 CGG trinucleotide repeat expansion of the FMR1 gene. A definite, probable, or possible diagnosis of FXTAS can be assigned based on a clinician's confidence based on combined clinical or radiological findings in conjunction with the molecular permutation.
Clinical findings are divided into major and minor symptoms. Major symptoms include intention tremor and gait ataxia. Minor symptoms such as parkinsonism, short-term memory deficit, and executive function decline can further contribute to a diagnosis of FXTAS. Radiological findings are similarly divided into major and minor categories. As patients with FXTAS can have distinct brain scans from other movement disorders, a scan showing white matter lesions of the middle cerebellar peduncle is a major finding that can be attributed to FXTAS. Overall or generalized brain tissue atrophy and cerebral white matter lesions can also be minor indicators for a diagnosis.
For a definite diagnosis to be made, a major radiological finding and one major clinical finding must be present. Probable diagnosis can be made off either a major radiological finding and a minor clinical finding or two major clinical findings alone. The possible category for diagnosis can be made with a minor radiological finding and a major clinical finding.
The severity and prognosis vary with the type of mutation involved.
Acute Cerebellar ataxia is a diagnosis of exclusion. Urgent CT scan is necessary to rule out cerebellar tumor or hemorrhage as cause of the ataxia; however in acute cerebellar ataxia, the CT will be normal. CSF studies are normal earlier in the course of disease. Later on CSF shows moderate elevation of proteins.
Supportive treatment is the only intervention for acute cerebellar ataxia of childhood. Symptoms may last as long as 2 or 3 months.
There is no known definitive cure for OMS. However, several drugs have proven to be effective in its treatment.
Some of medication used to treat the symptoms are:
- ACTH has shown improvements in symptoms but can result in an incomplete recovery with residual deficits.
- Corticosteroids (such as "prednisone" or "methylprednisolone") used at high dosages (500 mg - 2 g per day intravenously for a course of 3 to 5 days) can accelerate regression of symptoms. Subsequent very gradual tapering with pills generally follows. Most patients require high doses for months to years before tapering.
- Intravenous Immunoglobulins (IVIg) are often used with varying results.
- Several other immunosuppressive drugs, such as cyclophosphamide and azathioprine, may be helpful in some cases.
- Chemotherapy for neuroblastoma may be effective, although data is contradictory and unconvincing at this point in time.
- Rituximab has been used with encouraging results.
- Other medications are used to treat symptoms without influencing the nature of the disease (symptomatic treatment):
- Trazodone can be useful against irritability and sleep problems
- Additional treatment options include plasmapheresis for severe, steroid-unresponsive relapses.
The National Organization for Rare Disorders (NORD) recommends FLAIR therapy consisting of a three-agent protocol involving front-loaded high-dose ACTH, IVIg, and rituximab that was developed by the National Pediatric Myoclonus Center, and has the best-documented outcomes. Almost all patients (80-90%) show improvement with this treatment and the relapse rate appears to be about 20%.
A more detailed summary of current treatment options can be found at Treatment Options
The following medications should probably be avoided:
- Midazolam - Can cause irritability.
- Melatonin - Is known to stimulate the immune system.
- Also, see for more details