Even though OMA is not always associated with developmental issues, children with this condition often have hypotonia, decreased muscle tone, and show developmental delays. Some common delays are seen in speech, reading and motor development

Most cases of autosomal recessive cerebellar ataxia are early onset, usually around the age of 20. People with this type of ataxia share many characteristic symptoms including:

- frequent falls due to poor balance

- imprecise hand coordination

- postural or kinetic tremor of extremities or trunk

- dysarthria

- dysphasia

- vertigo

- diplopia

- lower extremity tendon reflexes

- dysmetria

- minor abnormalities in ocular saccades

- attention defects

- impaired verbal working memory and visuospatial skills

- Normal life expectancy

Autosomal recessive ataxias are generally associated with a loss of proprioception and vibration sense. Arreflexia is more common in autosomal recessive ataxia than autosomal dominant ataxias. Also, they tend to have more involvement outside of the nervous system. Mutations in subunit of the mitochondrial DNA polymerase (POLG) have been found to be a potential cause of autosomal recessive cerebellar ataxia.

Telangiectasias are widened blood vessels that can develop anywhere on the skin, mucous membranes, whites of the eyes, and even in the brain. Telangiectasias are associated with multiple systemic signs, the most serious of which are unusual sensitivity to ionizing radiation, excessive chromosomal breakage, and a deficiency in the immune system. Ataxia telangiectasia results from defects in the ataxia telangiectasia mutated gene, which can cause abnormal cell death in various places of the body, including brain areas related to coordinated movement of the eyes. Patients with ataxia telangiectasia have prolonged vertical and horizontal saccade latencies and hypometric saccades, and, although not all, some patients show head thrusts.

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.

Onset of symptoms usually occur in early adulthood and is characterized by intention tremor, progressive ataxia, convulsions, and myoclonic epileptic jerks.

Tremors usually affect one extremity, primarily the upper limb, and eventually involve the entire voluntary motor system. Overall, the lower extremity is usually disturbed less often than the upper extremity.

Additional features of the syndrome include: an unsteady gait, seizures, muscular hypotonia, reduced muscular coordination, asthenia, adiadochokinesia and errors with estimating range, direction, and force of voluntary movements. Mental deterioration can occur, however it is rare.

Typically, episodic ataxia presents as bouts of ataxia induced by startle, stress, or exertion. Some patients also have continuous tremors of various motor groups, known as myokymia. Other patients have nystagmus, vertigo, tinnitus, diplopia or seizures.

Unlike ataxias of cerebellar origin, Bruns apraxia exhibits many frontal lobe ataxia characteristics, with some or all present.

- Difficulty in initiating movement

- Poor truncal mobility

- Falls due to minor balance disturbances

- Greatly hindered postural responses

- Characteristic magnetic gait, the inability to raise one's foot off of the floor.

- Wide base, poor balance control when in stance

- Short stride

- En bloc turns

Often patients with frontal lobe ataxia may experience minute cognitive changes that accompany the gait disturbances, such as frontal dementia and presentation of frontal release signs (Plantar reflex). Urinary incontinence may also be present.

Bruns apraxia can be distinguished from Parkinsonian ataxia and cerebellar ataxia in a number of ways. Patients typically afflicted with Parkinsonian ataxia typically have irregular arm swing, a symptom not typically present in frontal ataxia. Walking stride in cerebellar ataxia varies dramatically, accompanied by erratic foot placement and sudden, uncontrolled lurching, not generally characteristic of Bruns apraxia.

Episodic ataxia type-3 (EA3) is similar to EA1 but often also presents with tinnitus and vertigo. Patients typically present with bouts of ataxia lasting less than 30 minutes and occurring once or twice daily. During attacks, they also have vertigo, nausea, vomiting, tinnitus and diplopia. These attacks are sometimes accompanied by headaches and precipitated by stress, fatigue, movement and arousal after sleep. Attacks generally begin in early childhood and last throughout the patients' lifetime. Acetazolamide administration has proved successful in some patients. As EA3 is extremely rare, there is currently no known causative gene. The locus for this disorder has been mapped to the long arm of chromosome 1 (1q42).

Symptoms typically are onset in the adult years, although, childhood cases have also been observed. Common symptoms include a loss of coordination which is often seen in walking, and slurred speech. ADCA primarily affects the cerebellum, as well as, the spinal cord. Some signs and symptoms are:

SCA13 is typified by early onset, mildly progressive cerebellar ataxia with accompanying dysarthria, mental retardation, and nystagmus. Symptoms and age of onset can vary slightly according to the causative mutation.

Dysarthrias are classified in multiple ways based on the presentation of symptoms. Specific dysarthrias include spastic (resulting from bilateral damage to the upper motor neuron), flaccid (resulting from bilateral or unilateral damage to the lower motor neuron), ataxic (resulting from damage to cerebellum), unilateral upper motor neuron (presenting milder symptoms than bilateral UMN damage), hyperkinetic and hypokinetic (resulting from damage to parts of the basal ganglia, such as in Huntington's disease or Parkinsonism), and the mixed dysarthrias (where symptoms of more than one type of dysarthria are present). The majority of dysarthric patients are diagnosed as having 'mixed' dysarthria, as neural damage resulting in dysarthria is rarely contained to one part of the nervous system — for example, multiple strokes, traumatic brain injury, and some kinds of degenerative illnesses (such as amyotrophic lateral sclerosis) usually damage many different sectors of the nervous system.

Ataxic dysarthria is an acquired neurological and sensorimotor speech deficit. It is a common diagnosis among the clinical spectrum of ataxic disorders. Since regulation of skilled movements is a primary function of the cerebellum, damage to the superior cerebellum and the superior cerebellar peduncle is believed to produce this form of dysarthria in ataxic patients. Growing evidence supports the likelihood of cerebellar involvement specifically affecting speech motor programming and execution pathways, producing the characteristic features associated with ataxic dysarthria. This link to speech motor control can explain the abnormalities in articulation and prosody, which are hallmarks of this disorder. Some of the most consistent abnormalities observed in patients with ataxia dysarthria are alterations of the normal timing pattern, with prolongation of certain segments and a tendency to equalize the duration of syllables when speaking. As the severity of the dysarthria increases, the patient may also lengthen more segments as well as increase the degree of lengthening of each individual segment.

Common clinical features of ataxic dysarthria include abnormalities in speech modulation, rate of speech, explosive or scanning speech, slurred speech, irregular stress patterns, and vocalic and consonantal misarticulations.

Ataxic dysarthria is associated with damage to the left cerebellar hemisphere in right-handed patients.

Dysarthria may affect a single system; however, it is more commonly reflected in multiple motor-speech systems. The etiology, degree of neuropathy, existence of co-morbidities, and the individual's response all play a role in the effect the disorder has on the individual's quality of life. Severity ranges from occasional articulation difficulties to verbal speech that is completely unintelligible.

Individuals with dysarthria may experience challenges in the following:

- Timing

- Vocal quality

- Pitch

- Volume

- Breath control

- Speed

- Strength

- Steadiness

- Range

- Tone

Examples of specific observations include a continuous breathy voice, irregular breakdown of articulation, monopitch, distorted vowels, word flow without pauses, and hypernasality.

RHS type 1 is caused by the impairment of a regulatory mechanism between cerebellar and brainstem nuclei and has been associated with a wide range of diseases, including Lafora disease, dentatorubropallidoluysian atrophy, and celiac disease.

Gerstmann syndrome is characterized by four primary symptoms:

1. Dysgraphia/agraphia: deficiency in the ability to write

2. Dyscalculia/acalculia: difficulty in learning or comprehending mathematics

3. Finger agnosia/anomia: inability to distinguish the fingers on the hand

4. Left-right disorientation

Bruns apraxia, or frontal ataxia is a gait apraxia found in patients with bilateral frontal lobe disorders. It is characterised by an inability to initiate the process of walking, despite the power and coordination of the legs being normal when tested in the seated or lying position. The gait is broad-based with short steps with a tendency to fall backwards. It was originally described in patients with frontal lobe tumours, but is now more commonly seen in patients with cerebrovascular disease.

It is named after Ludwig Bruns.

Motor speech disorders are a class of speech disorders that disturb the body's natural ability to speak due to neurologic impairments. These neurologic impairments make it difficult for individuals with motor speech disorders to plan, program, control, coordinate, and execute speech productions. Disturbances to the individual's natural ability to speak vary in their etiology based on the integrity and integration of cognitive, neuromuscular, and musculoskeletal activities. Speaking is an act dependent on thought and timed execution of airflow and oral motor / oral placement of the lips, tongue, and jaw that can be disrupted by weakness in oral musculature (dysarthria) or an inability to execute the motor movements needed for specific speech sound production (apraxia of speech or developmental verbal dyspraxia). Such deficits can be related to pathology of the nervous system (central and /or peripheral systems involved in motor planning) that affect the timing of respiration, phonation, prosody, and articulation in isolation or in conjunction.

Spinocerebellar ataxia type 13 (SCA13) is a rare autosomal dominant disorder, which, like other types of SCA, is characterized by dysarthria, nystagmus, and ataxia of gait, stance and the limbs due to cerebellar dysfunction. Patients with SCA13 also tend to present with epilepsy, an inability to run, and increased reflexes. This cerebellar dysfunction is permanent and progressive. SCA13 is caused by mutations in KCNC3, a gene encoding a voltage-gated potassium channel K3.3. There are two known mutations in this gene causative for SCA13. Unlike many other types of SCA, these are not polyglutamine expansions but, rather, point mutations resulting in channels with no current or altered kinetics.

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.

Degeneration occurs at the cellular level and in certain subtypes results in cellular death. Cellular death or dysfunction causes a break or faulty signal in the line of communication from the central nervous system to target muscles in the body. When there is impaired communication or a lack of communication entirely, the muscles in the body do not function correctly. Muscle control complications can be observed in multiple balance, speech, and motor or movement impairment symptoms. ADCA is divided into three types and further subdivided into subtypes known as SCAs (spinocerebellar ataxias).

Dysarthria is the reduced ability to motor plan volitional movements needed for speech production as the result of weakness/paresis and/or paralysis of the musculature of the oral mechanism needed for respiration, phonation, resonance, articulation, and/or prosody.

In adults, the syndrome may occur after a stroke or in association with damage to the inferior parietal lobule of the dominant (left) side.

In addition to exhibiting the above symptoms, many adults also experience aphasia, which is a difficulty in expressing oneself when speaking, in understanding speech, or in reading and writing.

Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes. In other words, it is a condition in which problems effectively occur with the muscles that help produce speech, often making it very difficult to pronounce words. It is unrelated to problems with understanding language (that is aphasia), although a person can have both. Any of the speech subsystems (respiration, phonation, resonance, prosody, and articulation) can be affected, leading to impairments in intelligibility, audibility, naturalness, and efficiency of vocal communication. Dysarthria that has progressed to a total loss of speech is referred to as anarthria.

Neurological injury due to damage in the central or peripheral nervous system may result in weakness, paralysis, or a lack of coordination of the motor-speech system, producing dysarthria. These effects in turn hinder control over the tongue, throat, lips or lungs; for example, swallowing problems (dysphagia) are also often present in those with dysarthria.

Dysarthria does not include speech disorders from structural abnormalities, such as cleft palate, and must not be confused with apraxia of speech, which refers to problems in the planning and programming aspect of the motor-speech system. Just as the term "articulation" can mean either "speech" or "joint movement", so is the combining form of the same in the terms "dysarthria", "dysarthrosis", and "arthropathy"; the term "dysarthria" is conventionally reserved for the speech problem and is not used to refer to arthropathy, whereas "dysarthrosis" has both senses but usually refers to arthropathy.

Cranial nerves that control the muscles relevant to dysarthria include the trigeminal nerve's motor branch (V), the facial nerve (VII), the glossopharyngeal nerve (IX), the vagus nerve (X), and the hypoglossal nerve (XII). The term is from New Latin, "dys-" "dysfunctional, impaired" and "arthr-" "joint, vocal articulation")

Developmental verbal dyspraxia (DVD), also known as childhood apraxia of speech (CAS) and developmental apraxia of speech (DAS), is when children have problems saying sounds, syllables, and words. This is not because of muscle weakness or paralysis. The brain has problems planning to move the body parts (e.g., lips, jaw, tongue) needed for speech. The child knows what they want to say, but their brain has difficulty coordinating the muscle movements necessary to say those words. The exact cause of this disorder is unknown. Some observations suggest a genetic cause of DVD, as many with the disorder have a family history of communication disorders. There is no cure for DVD, but with appropriate, intensive intervention, people with this motor speech disorder can improve significantly.

The symptoms of SSADH deficiency fall into three primary categories: neurological, psychiatric, and ocular. The most constant features seen are developmental delay, hypotonia and intellectual disability. Nearly half of patients seen manifest ataxia, behavior problems, seizures, and hyporeflexia.

The age of onset ranges from newborn period to 25 years. Problems unique to neonates can include prematurity, lethargy, decreased sucking, respiratory difficulty and hypoglycemia. Gastrointestinal symptoms have been seen primarily in this

population and are usually related to increased feeding.

Ocular problems related to the disorder include strabismus, nystagmus, retinitis, disc pallor, and oculomotor apraxia.

Over half of the patients with SSADH deficiency have seizures. These include absence, tonic clonic, and convulsive status epilepticus. It is unclear whether decreased levels of GABA or elevated levels of GHB are responsible for these seizures but alterations in these neurotransmitters and their receptor binding or neurotransmitter transport is hypothesized to play a role in the pathogenesis of the seizures in this population.

Symptoms associated with SSADH may be mild, moderate or severe and often vary greatly from case to case. The symptoms of SSADH are caused by the accumulation of GHB in the brain and include the following manifestations (Defined as: common, > 70% of patients; frequent 30-70% of patients;unusual, < 30% of patients):

Common manifestations include:

- Delayed gross motor development

- Delayed mental development

- Delayed fine motor skill development

- Delayed speech and language development

- Hypotonia

Frequent manifestations include:

- Seizures

- Hyporeflexia

- Ataxia

- Behavioral problems

- Hyperkinesis

Unusual manifestations include:

- Neonatal problems

- EEG abnormalities

- Psychoses

- MRI or X-ray computed tomography abnormalities

- Oculomotor apraxia

- Microcephaly

- Macrocephaly

- Hyperreflexia

- Somnolence

- Choreoathetosis

- Myopathy

There is substantial variability in the severity of features of A-T among affected individuals, and at different ages. The following symptoms or problems are either common or important features of A-T:

- Ataxia (difficulty with control of movement) that is apparent early but worsens in school to pre-teen years

- Oculomotor apraxia (difficulty with coordination of head and eye movement when shifting gaze from one place to the next)

- Involuntary movements

- Telangiectasia (dilated blood vessels) over the white (sclera) of the eyes, making them appear bloodshot. These are not apparent in infancy and may first appear at age 5–8 years. Telangiectasia may also appear on sun-exposed areas of skin.

- Problems with infections, especially of the ears, sinuses and lungs

- Increased incidence of cancer (primarily, but not exclusively, lymphomas and leukemias)

- Delayed onset or incomplete pubertal development, and very early menopause

- Slowed rate of growth (weight and/or height)

- Drooling particularly in young children when they are tired or concentrating on activities

- Dysarthria (slurred, slow, or distorted speech sounds)

- Diabetes in adolescence or later

- Premature changes in hair and skin

Many children are initially misdiagnosed as having ataxic cerebral palsy. The diagnosis of A-T may not be made until the preschool years when the neurologic symptoms of impaired gait, hand coordination, speech and eye movement appear or worsen, and the telangiectasia first appear. Because A-T is so rare, doctors may not be familiar with the symptoms, or methods of making a diagnosis. The late appearance of telangiectasia may be a barrier to the diagnosis. It may take some time before doctors consider A-T as a possibility because of the early stability of symptoms and signs.

There are three significant features that differentiate DVD/CAS from other childhood speech sound disorders. These features are:

- "Inconsistent errors on consonants and vowels in repeated productions of syllables and words

- Lengthened coarticulatory transitions between sounds and syllables

- Inappropriate prosody, especially in the realization of lexical or phrasal stress"

Even though DVD/CAS is a "developmental" disorder, it will not simply disappear when children grow older. Children with this disorder do not follow typical patterns of language acquisition and will need treatment in order to make progress.

SCA6 is typified by progressive and permanent cerebellar dysfunction. These cerebellar signs include ataxia and dysarthria, likely caused by cerebellar atrophy. Prior to diagnosis and the onset of major symptoms, patients often report a feeling of "wooziness" and momentary imbalance when turning corners or making rapid movements. The age at which symptoms first occur varies widely, from age 19 to 71, but is typically between 43 and 52. Other major signs of SCA6 are the loss of vibratory and proprioceptive sensation and nystagmus.

While most patients present with these severe progressive symptoms, others, sometimes within the same family, display episodic non-progressive symptoms more similar to episodic ataxia. Still others present with symptoms common to both SCA6 and familial hemiplegic migraine.