Movement disorder

ChoreaChorea is derived from the Greek word ‘choreia’ meaning a dance. are rapid, purposeless, irregular, jerky movements that seem to flow randomly from one part of the body to another.

Causes Chorea has many causes which can be simply divided into inherited and acquired :

1-Inherited causesHuntington’s diseaseWilson’s disease

2-Acquired causes

StrokeDrug induced:(Levodopa and other dopaminergic drugs, Antipsychotic drugs, Oral contraceptives, Phenytoin)Chorea gravidarum(during pregnancy)ThyrotoxicosisSystemic lupus erythematosus/antiphospholipid syndromePost-infective Sydenham’s chorea

Huntington’s diseaseHuntington’s disease (HD) is a slowly progressive autosomal dominant neurodegenerative disorder and the most important inherited cause of chorea discovered by George Huntingtonin 1872. In 1993, the causative gene defect was identified as a CAG triplet repeat expansion mutation in the HD gene on chromosome 4. Onset is usually in adult life with a mean age of about 40 years It progresses inexorably, with death occurring 15–20 years from HD.Clinical features Motor featuresSubtle motor abnormalities seen early in the disease include general restlessness, abnormal eye movements, and fidgety movements of fingers, hands and toes during stress or when walking. Also Dysarthria.

Cognitive featuresCognitive abnormalities are variable but universal in HD. The key cognitive abnormalities seen are impaired executive function with poor planning and judgment, disorganized actions.

Psychiatric featuresPsychiatric symptoms are common, particularly depression and anxiety. Irritability is also very common and some patients become aggressive.

InvestigationMRI imaging to exclude strokeWilson screen(Serum caeruloplasmin, serum copper ,Urinary copper level and KF ring)Pregnancy testAnti-dsDNA,ANA Thyroid function testsAntistreptolysin O (ASO) titre

TreatmentNo intervention currently slows or halts the degenerative process.Drug used to treat choreaChorea usually responds to treatment with dopamine receptor blockers or dopamine depleting agents:.

dopamine receptor blockers eg.,Olanzapine,Risperidone,Quetiapine Dopamine-depleting agents eg.Reserpine,TetrabenazineBenzodiazepines eg. Clonazepam Drugs Used to Treat Depression and irritability in Huntington’s Disease:Selective serotonin reuptake inhibitors eg.FluoxetineTricyclic anti depressants eg.Nortriptyline

Sydenham’schorea (SC):One of the major manifestations of rheumatic fever, appears months after the index streptococcal infection in children with rheumatic fever,The usual clinical picture of SC is the insidious development of choreic movements in a girl during childhood or adolescence. The chorea evolves over weeks, then recedes within 6 months .Treatment: is valproicacid .

Dystoniais a disorder marked by the presence of involuntary, sustained muscle contractions causing abnormal postures. Pain may accompany the motor symptoms of dystonia.

Classification of DystoniaBody Distribution Focal: single body regionSegmental: contiguous body regionsGeneralized: both legs and at least one other body regionMultifocal: noncontiguous body regionsHemidystonia: involving one half of the body

EtiologyPrimary: Dystonia is only sign; may be sporadic or inheritedSecondary: Dystonia occurring associated with a defined etiology or associated with other neurologic abnormalities

Primary dystoniaYoung onset dystonia (before the age of 26 years) most commonly manifests with limb onset dystonia, followed by subsequent generalization In severe cases, patients can suffer disabling postural deformities and was referred to in the older literature as dystonia musculorum deformans or Oppenheim’s dystonia It has an autosomal dominant inheritance. This condition is more common in Ashkenazi Jewish, with a possible founder in Eastern Europe about 3 centuries ago.

Focal DystoniasThese are the most common forms of dystonia. They typically present in the fourth to sixth decades and affect women more than men. The major types are blepharospasm—dystonic contractions of the eyelids with increased blinking that can interfere with reading, watching TV, and driving.Oromandibular dystonia (OMD)Cervical dystonia—dystonic contractions of neck muscles causing the head to deviate to one side (torticollis), in a forward direction (anterocollis), or in a backward direction (retrocollis). task-specific dystonia such as handwriting (writer's cramp), playing a musical instrument (musician's cramp)

Secondary DystoniasThese develop as a consequence of drugs or other neurologic disorders eg: Wilson disease ,levodopa,meticlopromide etc...

Investigation:MRI of brain and cervical spin Wilson screen eg(serum copper ,serum ceruloplasmin ,KF ring)Genetic study

Treatment Treatment of dystonia are:treatment of a primary underlying condition is available eg: Wilson's diseaseanticholinergics (e.g., trihexyphenidyl)Baclofen(muscle relaxant)Clonazepam (bezodiazepin)Tetrabenazine(dopamin depleting drug)Botulinum toxin has become the preferred treatment for patients with focal dystoniaDBS of the pallidum can provide dramatic benefits for patients with primary dystonia.

Oculogyric crisisIs the name of a dystonic reaction to certain drug or medical condition .the term "oculogyric " refer to rotating of eyeballs also crisis associated with backwards and lateral flexion of the neck ,widely opened mouth, toungue protrusion and agitation Causes :some eg:•Neuroleptic drugs eg: olanzapin•Metoclopramid and domperidon

Treatment •antimuscarinic eg:procyclidin ,benzatropin•diphenhydramine•diazepam

TicBrief, repeated, stereotyped muscle contractions that are often suppressible. Can be simple and involve a single muscle group or complex and affect a range of motor activities.

Tourette's Syndrome (Ts)

TS is a neurobehavioral disorder named after the French neurologist Georges Gilles de la Tourette, It predominantly affects males, TS is characterized by multiple motor tics often accompanied by vocalizations (phonic tics). Associated behavioral disturbances include anxiety, depression, attention deficit hyperactivity disorder, and obsessive-compulsive disorder.

TreatmentPatients with mild disease often only require education and counseling (for themselves and family members). Drug treatment is indicated when the tics are disabling and interfere with quality of life. Therapy is generally initiated with the alpha-agonist eg: clonidine and Guanfacine also atypical antipsychotic can be used ,the DBS(deep brain stimulation) is going on .

Hemifacial spasmThis is a benign, usually painless but often distressing condition, characterized by unilateral, involuntary, irregular tonic or clonic contractions of muscles supplied by the facial nerve. It is now generally accepted that hemifacial spasm is usually caused by extrinsic compression of the root entry zone of the facial nerve, generally by vascular structures such.

as the vertebral or basilar arteries or their branches .Drug treatment with carbamazepine, gabapentin, clonazepam and baclofen are rarely very effective and seldom result in resolution of symptoms Botulinum toxin injection into affected muscles is now the first line for those patients who want treatmentSurgical decompresion.

HemiballismusHemiballismus is a violent form of chorea composed of wild, flinging, large-amplitude movements on one side of the body. Proximal limb muscles tend to be predominantly affected. The movements may be so severe as to cause exhaustion, dehydration, local injury, and in extreme cases, death. The most common cause is a partial lesion (infarct or hemorrhage) in the subthalamic nucleus (STN).

AthetosisSlow, distal, writhing, involuntary movements with a propensity to affect the arms and hands.causes :the same as chorea.