Diagnosis of MSA can be challenging because there is no test that can definitively make or confirm the diagnosis in a living patient. Clinical diagnostic criteria were defined in 1998 and updated in 2007. Certain signs and symptoms of MSA also occur with other disorders, such as Parkinson's disease, making the diagnosis more difficult.

Both MRI and CT scanning frequently show a decrease in the size of the cerebellum and pons in those with cerebellar features. The putamen is hypodense on T2-weighted MRI and may show an increased deposition of iron in Parkinsonian form. In cerebellar form, a "hot cross" sign has been emphasized; it reflects atrophy of the pontocereballar fibers that manifest in T2 signal intensity in atrophic pons.

A definitive diagnosis can only be made pathologically on finding abundant glial cytoplasmic inclusions in the central nervous system.

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

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.

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.

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.

Diagnosis requires a neurological examination and neuroimaging can be helpful.

BVVL can be differentially diagnosed from similar conditions like Fazio-Londe syndrome and amyotrophic lateral sclerosis, in that those two conditions don't involve sensorineural hearing loss, while BVVL, Madras motor neuron disease, Nathalie syndrome, and Boltshauser syndrome do. Nathalie syndrome does not involve lower cranial nerve symptoms, so it can be excluded if those are present. If there is evidence of lower motor neuron involvement, Boltshauser syndrome can be excluded. Finally, if there is a family history of the condition, then BVVL is more likely than MMND, as MMND tends to be sporadic.

Genetic testing is able to identify genetic mutations underying BVVL.

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 importance of correctly recognizing progressive muscular atrophy as opposed to ALS is important for several reasons.

- 1) the prognosis is a little better. A recent study found the 5-year survival rate in PMA to be 33% (vs 20% in ALS) and the 10-year survival rate to be 12% (vs 6% in ALS).

- 2) Patients with PMA do not suffer from the cognitive change identified in certain groups of patients with MND.

- 3) Because PMA patients do not have UMN signs, they usually do not meet the "World Federation of Neurology El Escorial Research Criteria" for “Definite” or “Probable” ALS and so are ineligible to participate in the majority of clinical research trials such as drugs trials or brain scans.

- 4) Because of its rarity (even compared to ALS) and confusion about the condition, some insurance policies or local healthcare policies may not recognize PMA as being the life-changing illness that it is. In cases where being classified as being PMA rather than ALS is likely to restrict access to services, it may be preferable to be diagnosed as "slowly progressive ALS" or "lower motor neuron predominant" ALS.

An initial diagnosis of PMA could turn out to be slowly progressive ALS many years later, sometimes even decades after the initial diagnosis. The occurrence of upper motor neurone symptoms such as brisk reflexes, spasticity, or a Babinski sign would indicate a progression to ALS; the correct diagnosis is also occasionally made on autopsy.

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.

Physiotherapy intervention aims to improve balance and gait of OPCA patients, by stimulating neuroplastic changes in the atrophied neural structure. A challenge-oriented treatment program has previously been shown to be beneficial for individuals with ataxia from OPCA. The treatment program was composed of repetitive training with task challenges (e.g. obstacle course) and/or novel motor skills acquisition over a 12-week period under the supervision of a physiotherapist. Task challenges were progressed only when the patient showed mastery of a task.

Overground harness systems may be used to allow OPCA patients to challenge their balance without chance of falling. Furthermore, home exercise programs and/or aquatic exercises are used to allow more repetitions to facilitate balance learning. Treatment programs should be frequently monitored and adjusted based on a patient's progress. Outcome measures such as the Berg Balance Scale, Dynamic Gait Index and activities-specific balance confidence scales are useful to assess patient’s progress over time.

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.

There is no known cure for MSA and management is primarily supportive.

Ongoing care from a neurologist specializing in "movement disorders" is recommended as the complex symptoms of MSA are often not familiar to less-specialized health care professionals.

One particularly serious problem, the drop in blood pressure upon standing up (with risk of fainting and thus injury from falling) often responds to fludrocortisone, a synthetic mineralocorticoid. Another common drug treatment is midodrine (an alpha-agonist). Non-drug treatments include "head-up tilt" (elevating the head of the whole bed by about 10 degrees), salt tablets or increasing salt in the diet, generous intake of fluids, and pressure (elastic) stockings. Avoidance of triggers of low blood pressure (such as hot weather, alcohol, and dehydration) are crucial.

Hospice/homecare services can be very useful as disability progresses.

Levodopa (L-Dopa), a drug used in the treatment of Parkinson's disease, improves parkinsonian symptoms in a small percentage of MSA patients. A recent trial reported that only 1.5% of MSA patients experienced a less than 50% improvement when taking levodopa, and even this was a transient effect lasting less than one year. Poor response to L-Dopa has been suggested as a possible element in the differential diagnosis of MSA from Parkinson's disease.

A November, 2008 study conducted in Europe failed to find an effect for the drug riluzole in treating MSA or PSP.

PMA is a diagnosis of exclusion, there is no specific test which can conclusively establish whether a patient has the condition. Instead, a number of other possibilities have to be ruled out, such as multifocal motor neuropathy or spinal muscular atrophy. Tests used in the diagnostic process include MRI, clinical examination, and EMG. EMG tests in patients who do have PMA usually show denervation (neurone death) in most affected body parts, and in some unaffected parts too.

It typically takes longer to be diagnosed with PMA than ALS, an average of 20 months for PMA vs 15 months in ALS/MND.

There is currently no cure for SCA 6; however, there are supportive treatments that may be useful in managing symptoms.

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.

Olivopontocerebellar atrophy is hereditary, but has an unknown genetic basis. There are two forms:

A few non-hereditary diseases formerly categorized as olivopontocerebellar atrophy have been reclassified as forms of multiple system atrophy as well as to four hereditary types, that have been currently reclassified as four different forms of spinocerebellar ataxia:

Three dimensional (3D) T1W, Axial, coronal, sagittal imaging is excellent for differentiation between gray matter and white matter acquisition of high-resolution anatomic information.T2W, Axial and coronal imaging for acquisition of high-resolution anatomic information; delineation of cortex, white matter, and gray matter nuclei. Diffusion tensor, axial imaging is used for evaluation of white matter microstructural integrity, identification of white matter tracts. CISS, axial + MPR imaging for evaluation of cerebellar folia, cranial nerves, ventricles, and foramina. Susceptibility weighted axial scan for Identification and characterization of hemorrhage, blood products, calcification, and iron accumulation.

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.

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.

There is no cure for spinocerebellar ataxia, which is currently considered to be a progressive and irreversible disease, although not all types cause equally severe disability.

In general, treatments are directed towards alleviating symptoms, not the disease itself. Many patients with hereditary or idiopathic forms of ataxia have other symptoms in addition to ataxia. Medications or other therapies might be appropriate for some of these symptoms, which could include tremor, stiffness, depression, spasticity, and sleep disorders, among others. Both onset of initial symptoms and duration of disease are variable. If the disease is caused by a polyglutamine trinucleotide repeat CAG expansion, a longer expansion may lead to an earlier onset and a more radical progression of clinical symptoms. Typically, a person afflicted with this disease will eventually be unable to perform daily tasks (ADLs). However, rehabilitation therapists can help patients to maximize their ability of self-care and delay deterioration to certain extent. Researchers are exploring multiple avenues for a cure including RNAi and the use of Stem Cells and several other avenues.

On January 18, 2017 BioBlast Pharma announced completion of Phase 2a clinical trials of their medication, Trehalose, in the treatment of SCA3. BioBlast has received FDA Fast Track status and Orphan Drug status for their treatment. The information provided by BioBlast in their research indicates that they hope this treatment may prove efficacious in other SCA treatments that have similar pathology related to PolyA and PolyQ diseases.

In addition, Dr. Beverly Davidson has been working on a methodology using RNAi technology to find a potential cure for over 2 decades. Her research began in the mid-1990s and progressed to work with mouse models about a decade later and most recently has moved to a study with non-human primates. The results from her most recent research "are supportive of clinical application of this gene therapy". Dr. Davidson along with Dr. Pedro Gonzalez-Alegre are currently working to move this technique into a Phase 1 clinical trial.

Finally, another gene transfer technology discovered in 2011 has also been shown by Dr. Davidson to hold great promise and offers yet another avenue to a potential future cure.

Hereditary spastic paraplegias can be classified based on the symptoms; mode of inheritance; the patient’s age at onset; the affected genes; and biochemical pathways involved.

Physical therapists can assist patients in maintaining their level of independence through therapeutic exercise programmes. One recent research report demonstrated a gain of 2 SARA points (Scale for the Assessment and Rating of Ataxia) from physical therapy. In general, physical therapy emphasises postural balance and gait training for ataxia patients. General conditioning such as range-of-motion exercises and muscle strengthening would also be included in therapeutic exercise programmes. Research showed that spinocerebellar ataxia 2 (SCA2) patients with a mild stage of the disease gained significant improvement in static balance and neurological indices after six months of a physical therapy exercise training program. Occupational therapists may assist patients with incoordination or ataxia issues through the use of adaptive devices. Such devices may include a cane, crutches, walker, or wheelchair for those with impaired gait. Other devices are available to assist with writing, feeding, and self care if hand and arm coordination are impaired. A randomised clinical trial revealed that an intensive rehabilitation program with physical and occupational therapies for patients with degenerative cerebellar diseases can significantly improve functional gains in ataxia, gait, and activities of daily living. Some level of improvement was shown to be maintained 24 weeks post-treatment. Speech language pathologists may use both behavioral intervention strategies as well as augmentative and alternative communication devices to help patients with impaired speech.

The clinical course of BVVL can vary from one patient to another. There have been cases with progressive deterioration, deterioration followed by periods of stabilization, and deterioration with abrupt periods of increasing severity.

The syndrome has previously been considered to have a high mortality rate but the initial response of most patients to the Riboflavin protocol are very encouraging and seem to indicate a significantly improved life expectancy could be achievable. There are three documented cases of BVVL where the patient died within the first five years of the disease. On the contrary, most patients have survived more than 10 years after the onset of their first symptom, and several cases have survived 20–30 years after the onset of their first symptom.

Families with multiple cases of BVVL and, more generally, multiple cases of infantile progressive bulbar palsy can show variability in age of disease onset and survival. Dipti and Childs described such a situation in which a family had five children that had Infantile PBP. In this family, three siblings showed sensorineural deafness and other symptoms of BVVL at an older age. The other two siblings showed symptoms of Fazio-Londe disease and died before the age of two.