Movement Disorders Flashcards
Classification of movement disorders
-Hypokinetic
=Parkinsonism
-Hyperkinetic
=Tremor
=Chorea
=Myoclonus
=Dystonia
=Tics
What is chorea?
-Irregular, purposeless movements that flow from one part of the body to another
Clinical features of chorea
-Can be generalised, confined to one body region (orofacial) or one side of the body (hemichorea) (look restless or fidgety)
-Ballism is a severe proximal form of chorea in which there is flinging movements of the affected limbs
=hemiballism due to injury to contralateral subthalamic nucleus (vascular cause)
Causes of chorea
-Genetic (Huntington’s, C9orf72 mutations, Wilson’s, neurocanthocytosis, ataxia telangiectasia)
-Drug-induced (neuroleptics, contraceptive, levodopa)
-Structural lesions (basal ganglia)
-Autoimmune (SLE, antiphospholipid syndrome, encephalitis)
-Infections (HIV)
-Metabolic (thyroid, glucose, sodium, calcium, polycythaemia rubra vera)
-Pregnancy
-Paroxysmal dyskinesia
Chorea treatment
-Tetrabenazine (VMAT 2 inhibitor)
-Dopamine blocking drugs
What is myoclonus?
-Brief, electric shock-like muscle jerks
Clinical features of myoclonus
-Can affect one muscle or groups of muscles
-Sometimes myoclonus causes temporary cessation of muscle activation (negative myoclonus- asterixis in liver failure, lower limbs bouncy legs with sudden loss of muscle tone)
-Muscle activation can arise, from the cortex, subcortical structures (including brainstem), spinal cord/nerve roots/ plexus
Causes of myoclonus
-Genetic (may occur alongside epilepsy, ataxia)
-Neurodegenerative conditions
-Hypoxic brain injury
-Renal or liver failure
-Drug-induced (lithium, carbamazepine)
-Spinal cord/ nerve root/ plexus disorders
-Toxin (lead poisoning)
-Infections (Whipple’s)
-Autoimmune (PERM, paraneoplastic, coeliac)
Treatment of myoclonus
-Clonazepam
-Sodium valproate
-Levetiracetam
-Primidone
What is dystonia?
-Involuntary muscle spasm that leads to sustained abnormal postures of a body part
Clinical features of dystonia
-Can be focal, segmental, multifocal, hemi dystonia, generalised
-Typically mobile rather than fixed
-Due to co-contraction of antagonistic muscles
-Often improved by sensory trick
Causes of isolated dystonia
-Genetic (DYT1, DYT5, DYT6)
-Task-specific (writer-s cramp, musicians’)
-Focal (blepharospasm, cervical dystonia)
Causes of combined dystonia
-Genetic
-Structural brain lesion (basal ganglia)
-Drugs (dopamine blocking)
-Neurodegenerative conditions (PD, PSP, CBD, MSA)
-Functional
-Paroxysmal dyskinesia’s
Treatment of dystonia
-Trihexyphenidyl
-Clonazepam
-Tetrabenazine
-Baclofen
-Botulinum toxin (1)
-Deep brain stimulation (generalised)
What are tics?
-Involuntary, brief, stereotyped movements or vocalisations
Clinical features of tics
-Suppressible followed by flurry of tics, premonitory urge
-Motor can be simple (blinking, shoulder shrugging) or complex (head shaking, touching, kicking)
-Vocal can be simple (cough, grunt) or complex (words)
-Copropraxia/ lalia…
-Stereotypies longer more complex repetitive behaviours (body rocking, hand wringing)
Primary tic disorders
-Childhood onset motor tic
-Tourette’s syndrome
Secondary tic disorders
-Neurodegenerative condition (Wilson’s, Huntington)
-Developmental syndromes (Rett’s syndrome, Lesch-Nyhan)
-Drug-induced (cocaine, amphetamines, methylphenidate)
-Structural lesions (basal ganglia)
-Infection or immune mediated
Treatment for Tics
-Cognitive behavioural therapy
-Clonidine
-Dopamine blocking drugs (aripiprazole)
-Tetrabenazine
What is tremor?
-An involuntary, rhythmic, oscillatory movement of a body part
Structure of a general examination of a tremor
- Assess different tremor components
=Rest (sitting/lying)- cognitive stress (serial 7s)
=Action (postural like arms out and both hands under chin, and kinetic- finger nose test) - Assess impact of tremor
=Writing
=Transferring water between 2 cups
=Spiral drawing - Assess tremor in other body parts
- Complete neurological examination
Functional signs in examination
-Entrainability
=Tremor frequency changes when patient performs motor task with contralateral hand
-Distractibility
=Cessation of tremor when distracted (mental task or contralateral movement)
-Resolution when performing ballistic movements
Describe Essential Tremor
-Bilateral upper limb postural and kinetic tremor
-Bimodal age distribution
-Different from enhanced physiological tremor (which normalises after removal of the provoking factors such as anxiety or caffeine)
-Around half of ET patients have positive family history
-Often alcohol responsive
-Typically worsens over time
-Can involve head, voice and other body parts
Additional signs and tremor features of Parkinsonism
-Bradykinesia and/or rigidity
-Rest tremor (4-7Hz) with or without postural tremor, asymmetric
Additional signs and tremor features of cerebellar syndrome
-Gait ataxia, limb coordination, slurred speech, eye movement disorder
-Intention tremor
Additional signs and tremor features of dystonia
-Abnormal posturing (same or different body part)
-Postural or kinetic tremor, irregular, position-dependent
Additional signs and tremor features of neuropathy
-Weakness, glove and stocking sensory deficits, areflexia
-Mainly postural tremor
Causes of drug-induced tremor
-Neuroleptics (dopamine blocking)
-Anticonvulsants (sodium valproate, phenytoin)
-Lithium
-Amiodarone
-Antidepressants (SSRI, tricyclics)
Metabolic causes of tremor
-Hyperthyroidism
-Renal and liver failure
-Rare:
=Phaeochromocytoma (serum catecholamines)
=Wilson’s disease (copper and caeruloplasmin)
=Neurodegeneration with brain iron accumulation (iron studies)
=Toxins (mercury)
Indications for DAT scan
-Dopamine Transporter imaging= presynaptic dopaminergic deficit
=Drug-induced vs idiopathic PD
=Dystonic tremor vs PD
=Longstanding ET with prominent rest tremor
=PD with prominent functional tremor
Tremor treatments
Essential tremor
=Propranolol, primidone, topiramate, clonazepam
=Deep brain stimulation
=Focussed MR guided ultrasound
PG
=Dopaminergic therapy
Functional tremor
=Neurophysiotherapy
