Sandifer syndrome is not typically life-threatening and the prognosis is typically good.

In affected individuals presenting with the ICCA syndrome, the human genome was screened with microsatellite markers regularly spaced, and strong evidence of linkage with the disease was obtained in the pericentromeric region of chromosome 16, with a maximum lod score, for D16S3133 of 6.76 at a recombination fraction of 0. The disease gene has been mapped at chromosome 16p12-q12.This linkage has been confirmed by different authors. The chromosome 16 ICCA locus shows complicated genomic architecture and the ICCA gene remains unknown.

Successful treatment of the associated underlying disorder, such as GORD or hiatus hernia, may provide relief.

Infantile convulsions and choreoathetosis (ICCA) syndrome is a neurological genetic disorder with an autosomal dominant mode of inheritance. It is characterized by the association of benign familial infantile epilepsy (BIFE) at age 3–12 months and later in life with paroxysmal kinesigenic choreoathetosis. The ICCA syndrome was first reported in 1997 in four French families from north-western France and provided the first genetic evidence for common mechanisms shared by benign infantile seizures and paroxysmal dyskinesia. The epileptic origin of PKC has long been a matter of debates and PD have been classified as reflex epilepsies.Indeed, attacks of PKC and epileptic seizures have several characteristics in common, they both are paroxysmal in presentation with a tendency to spontaneous remission, and a subset of PKC responds well to anticonvulsants. This genetic disease has been mapped to chromosome 16p-q12. More than 30 families with the clinical characteristics of ICCA syndrome have been described worldwide so far.

Surgery, such as the denervation of selected muscles, may also provide some relief; however, the destruction of nerves in the limbs or brain is not reversible and should be considered only in the most extreme cases. Recently, the procedure of deep brain stimulation (DBS) has proven successful in a number of cases of severe generalised dystonia. DBS as treatment for medication-refractory dystonia, on the other hand, may increase the risk of suicide in patients. However, reference data of patients without DBS therapy are lacking.

CRPS can occur at any age with the average age at diagnosis being 42. It affects both men and women; however, CRPS is three times more frequent in females than males.

CRPS affects both adults and children, and the number of reported CRPS cases among adolescents and young adults has been increasing, with a recent observational study finding an incidence of 1.16/100,000 among children in Scotland.

The specific molecular mechanism that underpins this movement disorder is not well known. However, most researchers suggest that it follows an autosomal dominant genetic inheritance pattern in which mutations in certain genes give rise to structural abnormalities in nervous system networks responsible for voluntary skeletal muscle movement, which, in turn, result in the functional movement abnormalities seen in patients. Despite being autosomal dominant, it is important to note that the disease has variable expressivity. That is, patients who have inherited a mutated dominant allele, along with their genetically affected parent, can be symptomatic or asymptomatic for CMM disorder. The genes that currently have evidence to be associated with CMM disorder include "DCC" (deleted in colorectal carcinoma), "DNAL4" (dynein axonemal light chain 4), and "RAD51 (recombination protein A)".

"DCC" encodes a receptor for "NTN1" (netrin-1), a protein thought to be responsible for axon guidance and neuronal cell migration during development. A mutation of this gene (including nonsense, splice site mutation, insertions, frameshift) has been identified as a possible cause for CMM disorder. Experiments in mice also support the claim that CMM disorder is associated with genetic mutations in "DCC". "Kanga" mice, lacking the P3 intracellular domain of the "DCC" receptor, show a hopping gait, moving their hind legs in a strictly paired fashion, as do kangaroos.

"DNAL4" encodes a component of dynein motor complex in commissural neurons of the corpus callosum. In contrast to "DCC", "DNAL4" is thought to have a recessive inheritance pattern for the CMM disorder. In CMM disorder patients, researchers found splice site mutations on "DNAL4", which caused skipping of exon 3, and thereby omission of 28 amino acids from "DNAL4" protein. This mutant "DNAL4" protein, in turn, could lead to faulty cross-hemisphere wiring, resulting in CMM.

"RAD51" maintains genome integrity by repairing DNA double-strand breaks through homologous recombination. "RAD51" heterozygous mutations, specifically premature termination codons, have been found in many CMM disorder patients through genome-wide linkage analysis and exome sequencing. In a mouse model, researchers also found "RAD51" products in corticospinal tract axons at the pyramidal decussation. They therefore suggest that "RAD51" might be a gene that, when haploinsufficient, causes CMM disorder in humans.

Despite identification of three prospective genes, no genotype-phenotype correlations have yet been found. That is, the severity of clinical signs and symptoms does not correlate with the type of genetic variant. Mutations in the above genes account for a total of about 35 percent of cases. Mutations in other genes that have not been identified likely account for the other cases of this disorder.

Congenital mirror movement disorder (CMM disorder) is a rare genetic neurological disorder which is characterized by mirrored movement, sometimes referred to as associated or synkinetic movement, most often in the upper extremity of the body. These movements are voluntary intentional movements on one, ipsilateral, side of the body that are mirrored simultaneously by involuntary movements on the contralateral side.

The reproduction of involuntary movement usually happens along the head-tail axis, having a left-right symmetry. For example, if someone were to voluntarily make a fist with their left hand, their right hand would do the same. In most cases, the accompanying contralateral involuntary movements are much weaker than the ipsilateral voluntary ones, although the extent and magnitude of the mirrored movement vary across patients. This disorder has not yet been found to be associated with any other neurologic disease or cognitive disability, and currently, no cures nor means to improve signs or symptoms have been found.

The congenital mirror movements begin in infancy and persist throughout the patient’s life, often with very little improvement, or deterioration. Consequently, patients who do suffer from this movement disorder have serious difficulty carrying out tasks that require manual dexterity or precision, such as playing a two handed musical instrument or typing on a keyboard, for their whole lives. Patients also often experience discomfort or pain in the upper limbs due to prolonged use of the same muscles. Therefore, quality of life can be severely hampered.

CMM disorder’s prevalence in the world is thought to be less than 1 in 1 million people. Because of its rarity, researchers suggest that some mildly affected individuals may never be diagnosed. It is important not to confuse congenital mirror movement disorders, a rare genetically based neurologic disease, with acquired mirror movement disorders that present themselves during one’s lifetime due to other reasons (stroke for example).

Good progress can be made in treating CRPS if treatment is begun early, ideally within three months of the first symptoms. If treatment is delayed, however, the disorder can quickly spread to the entire limb, and changes in bone, nerve, and muscle may become irreversible. The prognosis is not always good. Johns Hopkins Hospital reports that 77% of sufferers have spreads from the original site or flares in other parts of the body. The limb, or limbs, can experience muscle atrophy, loss of use, and functionally useless parameters that require amputation. RSD/CRPS will not "burn itself out", but if treated early, it is likely to go into remission. Once one is diagnosed with Complex Regional Pain Syndrome, the likelihood of it resurfacing after going into remission is significant. It is important to take precautions and seek immediate treatment upon any injury.

Almost all cases of synkinesis develop as a sequel to nerve trauma (the exception is when it is congenitally acquired as in Duane-Retraction Syndrome and Marcus Gunn phenomenon). Trauma to the nerve can be induced in cases such as surgical procedures, nerve inflammation, neuroma

, and physical injury.

One form of treatment that has produced a more integrated body awareness is mirror therapy, in which the individual who denies that the affected limb belongs to their body looks into a mirror at the limb. Patients looking into the mirror state that the limb does belong to them; however body ownership of the limb does not remain after the mirror is taken away.

It has been suggested that damage to the posterior cerebral regions (temporoparietal junction) of the cortex may play a significant role in the development of somatoparaphrenia. However, more recent studies have shown that damage to deep cortical regions such as the posterior insula and subcortical structures such as the basal ganglia, the thalamus and the white matter connecting the thalamus to the cortex may also play a significant role in the development of somatoparaphrenia. It has also been suggested that involvement of deep cortical and subcortical grey structures of the temporal lobe may contribute to reduce the sense of familiarity experienced by somatoparaphrenic patients for their paralyzed limb.

The direct cause and pathophysiological basis of RMD is still unknown and can occur in children and adults of perfect or non-perfect health. Rare cases of adult RMD have developed due to head trauma, stress, and herpes encephalitis. Familial cases have been reported suggesting there may be some genetic aspect to the disorder; however, to date, this explanation has not been directly tested. As familial incidence rate is still relatively low, it is believed that behavioral aspects may play a larger role in RMD than family history and genetics. Many sufferers report no family history of the disorder. Another theory suggests that RMD is a learned, self-stimulating behavior to alleviate tension and induce relaxation, similar to tic movements.

An alternative theory suggests that the rhythmic movements help develop the vestibular system in young children, which can partially explain the high prevalence of RMD in infants. It has been seen that children who have underdeveloped vestibular systems benefit from performing RMD-like movements which stimulate the vestibular system

Rhythmic Movement Disorder (or RMD) is a neurological disorder characterized by involuntary (however may sometimes be voluntary), repetitive movements of large muscle groups immediately before and during sleep often involving the head and neck. It was independently described first in 1905 by Zappert as jactatio capitis nocturna and by Cruchet as rhythmie du sommeil. The majority of RMD episodes occur during NREM sleep, although REM movements have been reported. RMD is often associated with other psychiatric conditions or mental retardation. The disorder often leads to bodily injury from unwanted movements. Because of these incessant muscle contractions, patients’ sleep patterns are often disrupted. It differs from Restless Legs Syndrome in that RMD involves involuntary muscle contractions before and during sleep while Restless Legs Syndrome is the urge to move before sleep. RMD occurs in both males and females, often during early childhood with symptoms diminishing with age. Many sufferers also have other sleep related disorders, like sleep apnea. The disorder can be differentially diagnosed into small subcategories, including sleep related bruxism, thumb sucking, hypnagonic foot tremor, and rhythmic sucking, to name a few. In order to be considered pathological, the ICSD-II requires that in the sleep-related rhythmic movements should “markedly interfere with normal sleep, cause significant impairment in daytime function, or result in self-inflicted bodily injury that requires medical treatment (or would result in injury if preventive measures were not used)”

Synkinesis is the result from miswiring of nerves after trauma. This result is manifested through involuntary muscular movements accompanying voluntary movements. For example, voluntary smiling will induce an involuntary contraction of the eye muscles causing the eye to squint when smiling. Most commonly involved are facial muscles and the extraocular muscles, rarely the hands are performing mirror movements.

Causes are diverse and include nerve trauma with improper healing, or nerve degeneration, as in the course of Parkinson´s disease. In congenital cases, mutations of genes involved in nerve growth, specifically axonal growth have been found. Rarely, it is part of syndromes with neuroendocrine problems such as Kallman syndrome.

The prognosis is usually good with normal intelligence and lifespan. Treatment depends on the cause, but is largely conservative with facial retraining or mime therapy, if needed, while Botox and surgery are used as last resort.

Dysmetria is often found in individuals with multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and persons who have suffered from tumors or strokes. Persons who have been diagnosed with autosomal dominant spinocerebellar ataxia (SCAs) also exhibit dysmetria. There are many types of SCAs and though many exhibit similar symptoms (one being dysmetria), they are considered to be heterogeneous. Friedreich’s ataxia is a well-known SCA in which children have dysmetria. Cerebellar malformations extending to the brainstem can also present with dysmetria.

Paroxysmal kinesigenic dyskinesia has been shown to be inherited in an autosomal dominant fashion. In 2011, the PRRT2 gene on chromosome 16 was identified as the cause of the disease. The researchers looked at the genetics of eight families with strong histories of PKD. They employed whole genome sequencing, along with Sanger sequencing to identify the gene that was mutated in these families. The mutations in this gene included a nonsense mutation identified in the genome of one family and an insertion mutation identified in the genome of another family. The researchers then confirmed this gene as the cause of PKD when it was not mutated in the genome of 1000 control patients. Researchers found PRRT2 mutations in 10 of 29 sporadic cases affected with PKD, thus suggests PRRT2 is the gene mutated in a subset of PKD and PKD is genetically heterogeneous. The mechanism of how PRRT2 causes PKD still requires further investigation. However, researchers suggest it may have to do with PRRT2's expression in the basal ganglia, and the expression of an associated protein, SNAP25, in the basal ganglia as well.

Patients with severe forms of MJD have a life expectancy of approximately 35 years. Those with mild forms have a normal life expectancy. The cause of death of those who die early is often aspiration pneumonia.

There is a group called myoclonic dystonia where some cases are hereditary and have been associated with a missense mutation in the dopamine-D2 receptor. Some of these cases have responded well to alcohol.

Other genes that have been associated with dystonia include CIZ1, GNAL, ATP1A3, and PRRT2. Another report has linked THAP1 and SLC20A2 to dystonia.

Paroxysmal kinesigenic choreathetosis (PKC) also called paroxysmal kinesigenic dyskinesia (PKD) is a hyperkinetic movement disorder characterized by attacks of involuntary movements, which are triggered by sudden voluntary movements. The number of attacks can increase during puberty and decrease in a person's 20s to 30s. Involuntary movements can take many forms such as ballism, chorea or dystonia and usually only affect one side of the body or one limb in particular. This rare disorder only affects about 1 in 150,000 people with PKD accounting for 86.8% of all the types of paroxysmal dyskinesias and occurs more often in males than females. There are two types of PKD, primary and secondary. Primary PKD can be further broken down into familial and sporadic. Familial PKD, which means the individual has a family history of the disorder, is more common, but sporadic cases are also seen. Secondary PKD can be caused by many other medical conditions such as multiple sclerosis (MS), stroke, pseudohypoparathyroidism, hypocalcemia, hypoglycemia, hyperglycemia, central nervous system trauma, or peripheral nervous system trauma. PKD has also been linked with infantile convulsions and choreoathetosis (ICCA) syndrome, in which patients have afebrile seizures during infancy (benign familial infantile epilepsy) and then develop paroxysmal choreoathetosis later in life. This phenomenon is actually quite common, with about 42% of individuals with PKD reporting a history of afebrile seizures as a child.

Dysmetria () refers to a lack of coordination of movement typified by the undershoot or overshoot of intended position with the hand, arm, leg, or eye. It is a type of ataxia. It is sometimes described as an inability to judge distance or scale.

Hypermetria and hypometria refer, respectively, to overshooting and undershooting the intended position.

Mirror-touch synesthesia is a rare condition which causes individuals to experience the same sensation (such as touch) that another person feels. For example, if someone with this condition were to observe someone touching their cheek, they would feel the same sensation on their own cheek. Synesthesia, in general, is described as a condition in which a stimulus causes an individual to experience an additional sensation. Synesthesia is usually a developmental condition; however, recent research has shown that mirror touch synesthesia can be acquired after sensory loss following amputation.

Hemiplegia is not a progressive disorder, except in progressive conditions like a growing brain tumour. Once the injury has occurred, the symptoms should not worsen. However, because of lack of mobility, other complications can occur. Complications may include muscle and joint stiffness, loss of aerobic fitness, muscle spasms, bed sores, pressure ulcers and blood clots.

Sudden recovery from hemiplegia is very rare. Many of the individuals will have limited recovery, but the majority will improve from intensive, specialised rehabilitation. Potential to progress may differ in cerebral palsy, compared to adult acquired brain injury. It is vital to integrate the hemiplegic child into society and encourage them in their daily living activities. With time, some individuals may make remarkable progress.

Dejerine–Sottas disease, also known as Dejerine–Sottas syndrome, Dejerine–Sottas neuropathy, progressive hypertrophic interstitial polyneuropathy of childhood and onion bulb neuropathy (and, "hereditary motor and sensory polyneuropathy type III" and "Charcot–Marie–Tooth disease type 3"), is a hereditary neurological disorder characterised by damage to the peripheral nerves and resulting progressive muscle wasting. The condition is caused by mutations in a various genes and currently has no known cure.

The disorder is named for Joseph Jules Dejerine and Jules Sottas, French neurologists who first described it.

The most common acquired causes of chorea are cerebrovascular disease and, in the developing world, HIV infection - usually through its association with cryptococcal disease.

Sydenham's chorea occurs as a complication of streptococcal infection. Twenty percent (20%) of children and adolescents with rheumatic fever develop Sydenham's chorea as a complication. It is increasingly rare, which may be partially due to penicillin, improved social conditions, and/or a natural reduction in the bacteria ( Streptococcus ) it has stemmed from. Psychological symptoms may precede or accompany this acquired chorea and may be relapsing and remitting. The broader spectrum of paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection can cause chorea and are collectively referred to as PANDAS.

Chorea gravidarum refers to choreic symptoms that occur during pregnancy. If left untreated, the disease resolves in 30% of patients before delivery but, in the other 70%, it persists. The symptoms then progressively disappear in the next few days following the delivery.

Chorea may also be caused by drugs (commonly levodopa, anti-convulsants and anti-psychotics).

Other acquired causes include systemic lupus erythematosus, antiphospholipid syndrome, thyrotoxicosis, polycythaemia rubra vera, transmissible spongiform encephalopathies and coeliac disease.