Due to the condition's rarity, it is frequently misdiagnosed, often as cerebral palsy. This results in patients often living their entire childhood with the condition untreated.

The diagnosis of SS can be made from a typical history, a trial of dopamine medications, and genetic testing. Not all patients show mutations in the GCH1 gene (GTP cyclohydrolase I), which makes genetic testing imperfect.

Sometimes a lumbar puncture is performed to measure concentrations of biopterin and neopterin, which can help determine the exact form of dopamine-responsive movement disorder: early onset parkinsonism (reduced biopterin and normal neopterin), GTP cyclohydrolase I deficiency (both decreased) and tyrosine hydroxylase deficiency (both normal).

In approximately half of cases, a phenylalanine loading test can be used to show decreased conversion from the amino acid phenylalanine to tyrosine. This process uses BH4 as a cofactor.

During a sleep study (polysomnography), decreased twitching may be noticed during REM sleep.

An MRI scan of the brain can be used to look for conditions that can mimic SS (for example, metal deposition in the basal ganglia can indicate Wilson's disease or pantothenate kinase-associated neurodegeneration). Nuclear imaging of the brain using positron emission tomography (PET scan) shows a normal radiolabelled dopamine uptake in SS, contrary to the decreased uptake in Parkinson's disease.

Other differential diagnoses include metabolic disorders (such as GM2 gangliosidosis, phenylketonuria, hypothyroidism, Leigh disease) primarily dystonic juvenile parkinsonism, autosomal recessive early onset parkinsonism with diurnal fluctuation, early onset idiopathic parkinsonism, focal dystonias, dystonia musculorum deformans and dyspeptic dystonia with hiatal hernia.

- Diagnosis - main

- typically referral by GP to specialist Neurological Hospital e.g. National Hospital in London.

- very hard to diagnose as condition is dynamic w.r.t. time-of-day AND dynamic w.r.t. age of patient.

- correct diagnosis only made by a consultant neurologist with a complete 24-hour day-cycle observation(with video/film) at a Hospital i.e. morning(day1)->noon->afternoon->evening->late-night->sleep->morning(day2).

- patient with suspected SS required to walk in around hospital in front of Neuro'-consultant at selected daytime intervals to observe worsening walking pattern coincident with increased muscle tension in limbs.

- throughout the day, reducing leg-gait, thus shoe heels catching one another.

- diurnal affect of condition: morning(fresh/energetic), lunch(stiff limbs), afternoon(very stiff limbs), evening(limbs worsening), bedtime(limbs near frozen).

- muscle tension in thighs/arms: morning(normal), lunch(abnormal), afternoon(very abnormal), evening(bad), bedtime(frozen solid).

- Diagnosis - additional

- lack of self-esteem at school/college/University -> eating disorders in youth thus weight gains.

- lack of energy during late-daytime (teens/adult) -> compensate by over-eating.

Since paroxysmal exercise-induced dystonia is such a rare disorder it makes it difficult to study the disease and find consistencies. Many of the current studies seem to have contradicting conclusion but this is due to the fact that studies are usually limited to a very small number of test subjects. With such small numbers it is hard to determine what is a trend and what is random when in comes to characterizing the disease. Further study is needed to find better diagnostic techniques and treatments for PED. Patients with PED are living a limited lifestyle since simple tasks like walking and exercise are often impossible.

MRI is often done to diagnose PSP. MRI may show atrophy in the midbrain with preservation of the pons giving a "hummingbird" sign appearance.

Sporadic cases may be brought on by minor head injuries and concussions. This was observed in one patient who started experiencing painless dystonia after mild exercise following a concussion. More research still needs to be done to determine how injuries can induce PED, as little is known in this area. Two cases of PED have been associated with insulinomas, after removal of which the symptoms of PED were resolved.

Usually the diagnosis is established on clinical grounds. Tremors can start at any age, from birth through advanced ages (senile tremor). Any voluntary muscle in the body may be affected, although the tremor is most commonly seen in the hands and arms and slightly less commonly in the neck (causing the person's head to shake), tongue, and legs. A resting tremor of the hands is sometimes present. Tremor occurring in the legs might be diagnosable as orthostatic tremor.

ET occurs within multiple neurological disorders besides Parkinson's Disease. This includes migraine disorders, where co-occurrences between ET and migraines have been examined.

Diagnosis is similar, but slightly different for each type of PD. Some types are more understood than others, and therefore have more criteria for diagnosis.

PSP is frequently misdiagnosed as Parkinson's disease because of the slowed movements and gait difficulty, or as Alzheimer's disease because of the behavioral changes. It is one of a number of diseases collectively referred to as Parkinson plus syndromes. A poor response to levodopa along with symmetrical onset can help differentiate this disease from PD. Also, patients with the Richardson variant tend to have an upright or arched-back posture as opposed to the stooped-forward posture of other Parkinsonian disorders, although PSP-Parkinsonism (see below) may show the stooped posture. Early falls are characteristic, especially with Richardson-syndrome.

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.

The guidelines for diagnosing PKD were reviewed and confirmed by Unterberger and Trinka. PKD consists of unexpected forms of involuntary movements of the body. The patient is usually diagnosed sometime before their 20's, and is more likely diagnosed during childhood than early adulthood. Almost all PKD's are idiopathic, but there have been examples of autosomal dominant inheritance as well. Physical examination and brain imaging examinations show normal results, and an EEG shows no specific abnormalities as well. However, the negative synchronous EEG results can be used to prove that PKD is not a sort of reflex epilepsy, but a different disease.

PKD is the most prevalent subtype of paroxysmal dyskinesia, encompassing over 80% of all given PD diagnosis. PKD is more prevalent in boys, usually as high as 3.75:1.

As of 1993 only approximately 30 people with AHC had been described in scientific literature. Due to the rarity and complexity of AHC, it is not unusual for the initial diagnosis to be incorrect, or for diagnosis to be delayed for several months after the initial symptoms become apparent. The average age of diagnosis is just over 36 months. Diagnosis of AHC is not only difficult because of its rarity, but because there is no diagnostic test, making this a diagnosis of exclusion. There are several generally accepted criteria which define this disorder, however other conditions with a similar presentation, such as HSV encephalitis, must first be ruled out. Due to these diagnostic difficulties, it is possible that the commonness of the disease is underestimated.

The following descriptions are commonly used in the diagnosis of AHC. The initial four criteria for classifying AHC were that it begins before 18 months of age, includes attacks of both hemiplegia on either side of the body, as well as other autonomic problems such as involuntary eye movement (episodic monocular nystagmus), improper eye alignment, choreoathetosis, and sustained muscle contractions (dystonia). Finally, patients suffer from intellectual disabilities, delayed development, and other neurological abnormalities. These diagnostic criteria were updated in 1993 to include the fact that all of these symptoms dissipate immediately upon sleeping. Diagnostic criteria were also expanded to include episodes of bilateral hemiplegia which shifted from one side of the body to the other.

Recent criteria have been proposed for screening for AHC early, in order to improve the diagnostic timeline. These screening criteria include focal or unilateral paroxysmal dystonia in the first 6 months of life, as well as the possibility of flaccid hemiplegia either with or separate from these symptoms. Paroxysmal ocular movements should also be considered, and these should include both binocular and monocular symptoms which show in the first 3 months of life.

There is no cure for torsion dystonia. However, there are several medical approaches that can be taken in order to lessen the symptoms of the disease. The treatment must be patient specific, taking into consideration all of the previous and current health complications. The doctor that creates the treatment must have intimate knowledge of the patients’ health and create a treatment plan that covers all of the symptoms focusing on the most chronic areas.

The first step for most with the disorder begins with some form of physical therapy in order for the patient to gain more control over the affected areas. The therapy can help patients with their posture and gain control over the areas of their body that they have the most problems with.

The second step in the treatment process is medication. The medications focus on the chemicals released by neurotransmitters in the nervous system, which control muscle movement. The medications on the market today are anticholinergics, benzodiazepines, baclofen, dopaminergic agents/dopamine-depleting agents, and tetrabenazine. Each medication is started on a low dosage and gradually increased to higher doses as the disease progresses and the side effects are known for the individual.

A more site-specific treatment is the injection of botulinum toxin. It is injected directly into the muscle and works much the same way the oral medications do—by blocking neurotransmitters. The injections are not a treatment for the disease, but are a means to control its symptoms.

A fourth option in the treatment for the symptoms of torsion dystonia is surgery. Surgery is performed only if the patient does not respond to the oral medications or the injections. The type of surgery performed is specific to the type of dystonia that the patient has.

This condition is very rare, only affecting one in two million people. It is more common in females than in males. There are several hundred cases in the United States, 25 known cases in the United Kingdom, and less than that in Australia and New Zealand.

Paroxysmal kinesigenic dyskinesia is diagnosed using a strict set of guidelines. These criteria were studied and confirmed by Bruno et al. in a study of 121 individuals with PKD. The age at onset is between 1 and 20 years old. The attacks of involuntary movements last less than one minute and have a known trigger, usually a sudden voluntary movement. For example, if a PKD patient stands up or begins walking after being sedentary for a period of time, or a person goes from a walk to a run, it can trigger an attack. Persons with PKD do not lose consciousness during attacks and have a full memory of the entire attack. Lastly, people with the disorder have a good response to medication and are usually prescribed anticonvulsants. The study also found that patients with familial PKD exhibit symptoms that follow the diagnostic criteria closely, while sporadic PKD individuals may deviate slightly. Prior to criteria for diagnosis being set out, many patients with PKD were often diagnosed with some form of epilepsy. Many patients also experience an aura, similar to those experienced with epilepsy, preceding their attacks. Some patients describe it as a tingling sensation in the affected limb or “butterflies in their stomach.” Some individuals also have precipitants, such as stress and anxiety, that make it more likely for attacks to occur.

The above diagnostic criteria also set PKD apart from the other paroxysmal dyskinesias, which include paroxysmal nonkinesigenic dyskinesia (PNKD) and paroxysmal exercise-induced dyskinesia (PED). While PKD attacks last less than one minute, PNKD attacks last a few minutes to a few hours, and as the name suggests, the attacks do not occur because of a sudden voluntary movement like PKD. Additionally, PKD can almost always be managed with drug therapy, while PNKD is not as responsive to anticonvulsants. PED, on the other hand, separates itself from PKD in that it is caused by prolonged exercise. Attacks from PED will cease soon after exercise is stopped.

There is no cure for XDP and medical treatment offers only temporary relief. Some authors have reported benzodiazepines and anticholinergic agents in the early stages of the disease. Botulinum toxin injections have been used to relieve focal dystonia. Deep brain stimulation has shown promise in the few cases treated surgically.

A 1969 study of torsion dystonia patients found an average IQ 10 points higher than controls matched for age, sex and ethnic background.

Although essential tremor is often mild, people with severe tremor have difficulty performing many of their routine activities of daily living. ET is generally progressive in most cases (sometimes rapidly, sometimes very slowly), and can be disabling in severe cases.

Meige's is commonly misdiagnosed and most doctors will have not seen this condition before. Usually a neurologist who specializes in movement disorders can detect Meige's. There is no way to detect Meige's by blood test or MRI or CT scans. OMD by itself may be misdiagnosed as TMJ.

The lack of prompt response to anticholinergic drugs in cases of idiopathic Meige's syndrome is important in differentiating it from acute dystonia, which does respond to anticholinergics.

Overall outcomes for AHC are generally poor, which is contributed to by AHC's various diagnostic and management challenges. In the long term, AHC is debilitating due to both the hemiplegic attacks and permanent damage associated with AHC. This damage can include cognitive impairment, behavioral and psychiatric disorders, and various motor impairments. There is, however, not yet any conclusive evidence that AHC is fatal or that it shortens life expectancy, but the relatively recent discovery of the disorder makes large data for this type of information unavailable. Treatment for AHC has not been extremely successful, and there is no cure. There are several drugs available for treatment, as well as management strategies for preventing and dealing with hemiplegic attacks.

Different medications are tried in an effort to find a combination that is effective for a specific person. Not all people will respond well to the same medications. Medications that have had positive results in some include: diphenhydramine, benzatropine and atropine. anti-Parkinsons agents (such as ropinirole and bromocriptine), and muscle relaxants (such as diazepam).

- Anticholinergics

Medications such as anticholinergics (benztropine), which act as inhibitors of the neurotransmitter acetylcholine, may provide some relief. In the case of an acute dystonic reaction, diphenhydramine is sometimes used (though this drug is well known as an antihistamine, in this context it is being used primarily for its anticholinergic role).. See also Procyclidine.

- Baclofen

A baclofen pump has been used to treat patients of all ages exhibiting muscle spasticity along with dystonia. The pump delivers baclofen via a catheter to the thecal space surrounding the spinal cord. The pump itself is placed in the abdomen. It can be refilled periodically by access through the skin. Baclofen can also be taken in tablet form

- Botulin toxin injection

Botulinum toxin injections into affected muscles have proved quite successful in providing some relief for around 3–6 months, depending on the kind of dystonia. Botox or Dysport injections have the advantage of ready availability (the same form is used for cosmetic surgery) and the effects are not permanent. There is a risk of temporary paralysis of the muscles being injected or the leaking of the toxin into adjacent muscle groups, causing weakness or paralysis in them. The injections have to be repeated, as the effects wear off and around 15% of recipients will develop immunity to the toxin. There is a Type A and a Type B toxin approved for treatment of dystonia; often, those that develop resistance to Type A may be able to use Type B.

- Muscle relaxants

Clonazepam, an anti-seizure medicine, is also sometimes prescribed. However, for most, their effects are limited and side-effects like mental confusion, sedation, mood swings, and short-term memory loss occur.

- Parkinsonian drugs

Dopamine agonists: One type of dystonia, dopamine-responsive dystonia, can be completely treated with regular doses of L-DOPA in a form such as Sinemet (carbidopa/levodopa). Although this does not remove the condition, it does alleviate the symptoms most of the time. (In contrast, dopamine antagonists can sometimes cause dystonia.)

Ketogenic Diet

A Ketogenic diet consisting of 70% fats (focusing on medium chain triglycerides and unsaturated fats), 20% protein and 10% carbohydrates (any sugar) has shown strong promise as a treatment for Dystonia.

Prevention of tardive dyskinesia is achieved by using the lowest effective dose of a neuroleptic for the shortest time. However, with diseases of chronic psychosis such as schizophrenia, this strategy must be balanced with the fact that increased dosages of neuroleptics are more beneficial in preventing recurrence of psychosis. If tardive dyskinesia is diagnosed, the causative drug should be discontinued. Tardive dyskinesia may persist after withdrawal of the drug for months, years or even permanently. Some studies suggest that physicians should consider using atypical antipsychotics as a substitute to typical antipsychotics for patients requiring medication. These agents are associated with fewer neuromotor side effects and a lower risk of developing tardive dyskinesia.

Recent studies have tested the use of melatonin, high dosage vitamins, and different antioxidants in concurrence with antipsychotic drugs (often used to treat schizophrenia) as a way of preventing and treating tardive dyskinesia. Although further research is needed, studies reported a much lower percentage of individuals developing tardive dyskinesia than the current prevalence rate for those taking antipsychotic drugs.

Almost all patients respond positively to antiepileptic (anticonvulsant) drugs. One of the drugs most often mentioned in the literature is carbamazepine, and is the most widely used drug for treating PKD. Other anticonvulsants like valproic acid, phenytoin and clonazepam are common alternatives. Other categories of drugs have also been used, such as dopamine affecting drugs like Levodopa or Tetrabenazine. Individuals with the disorder can also modify their behavior to lessen their attacks without the influence of drug therapy. For example, decreasing stress to avoid precipitants can help patients decrease the number of attacks. In addition, avoiding any sudden movements can also prevent an attack. In order to prevent an attack, some individuals use their auras as a warning, while others purposefully perform slow gestures or movements prior to a triggering movement. Many, if not most, individuals end up growing out of the attacks with age, even without medicinal therapy, but some patients will go back to having attacks after a period of remission. In regards to secondary PKD, treatment of the primary condition can lessen the PKD attacks in those individuals.

Protein function tests that demonstrate a reduce in chorein levels and also genetic analysis can confirm the diagnosis given to a patient. For a disease like this it is often necessary to sample the blood of the patient on multiple occasions with a specific request given to the haematologist to examine the film for acanthocytes. Another point is that the diagnosis of the disease can be confirmed by the absence of chorein in the western blot of the erythrocyte membranes.

Spasmodic torticollis is a form of focal dystonia, a neuromuscular disorder that consists of sustained muscle contractions causing repetitive and twisting movements and abnormal postures in a single body region. There are two main ways to categorize spasmodic torticollis: age of onset, and cause. The disorder is categorized as early onset if the patient is diagnosed before the age of 27, and late onset thereafter. The causes are categorized as either primary (idiopathic) or secondary (symptomatic). Spasmodic torticollis can be further categorized by the direction and rotation of head movement.

Although all early reported cases occurred in the Philippines, X-linked dystonia parkinsonism has been diagnosed in the US, Canada, and Germany in people of Filipino descent. The prevalence in the Philippines has been estimated at 1/322,000 and as high as 1/4,000 in the province of Capiz's male population. As x-linked recessive disease, the majority of those affected are males with females generally asymptomatic carriers. In the largest described series, the mean age of onset was 39.7 years, the mean duration of illness was 16 years, and the mean age of death was 55.6 years.

Treatment of tics present in conditions such as Tourette’s syndrome begins with patient, relative, teacher and peer education about the presentation of the tics. Sometimes, pharmacological treatment is unnecessary and tics can be reduced by behavioral therapy such as habit-reversal therapy and/or counseling. Often this route of treatment is difficult because it depends most heavily on patient compliance. Once pharmacological treatment is deemed most appropriate, lowest effective doses should be given first with gradual increases. The most effective drugs belong to the neuroleptic variety such as monoamine-depleting drugs and dopamine receptor-blocking drugs. Of the monoamine-depleting drugs, tetrabenazine is most powerful against tics and results in fewest side effects. A non-neuroleptic drug found to be safe and effective in treating tics is topiramate. Botulinum toxin injection in affected muscles can successfully treat tics; involuntary movements and vocalizations can be reduced, as well as life-threatening tics that have the potential of causing compressive myelopathy or radiculopathy. Surgical treatment for disabling Tourette’s syndrome has been proven effective in cases presenting with self-injury. Deep Brain Stimulation surgery targeting the globus pallidus, thalamus and other areas of the brain may be effective in treating involuntary and possibly life-threatening tics.