Nursing Reference: Movement Disorders Slide Transcript
Slide 1: Movement disorders* * Except Parkinsonism and tremor Submitted to AskTheNeurologist.Com in 2007 Author Anon.
Slide 2: What is a Movement disorder? “ A disorder which impairs the regulation of voluntary motor activity without directly affecting strength, sensation or cerebellar function ” • Sometimes also known as “ extrapyramidal disorders” • Many neurologists restrict the term “ extrapyramidal” to refer only to Parkinsonism
Slide 3: Types of abnormal movement • Myoclonus • Ballismus • Chorea • Athetosis • Dystonia • Tics • Tremor ( discussed elsewhere )
Slide 4: Myoclonus •“ sudden, brief, shock-like involuntary movements” • May be caused by active muscle contraction - positive myoclonus • May be caused by inhibition of ongoing muscle activity - negative myoclonus ( eg. Asterixis ) • Generalised - widespread throughout body • Focal / segmental – restricted to particular part of body
Slide 5: Generalised myoclonus • Physiologic - Nocturnal ( usually on falling asleep ) - Hiccups • Essential - Occurs in the absence of other abnormality - Benign and sometimes inherited • Epileptic - Demonstrable cortical source • Symptomatic i.e secondary to disease process - Neurodegenerative eg. Wilson’s disease - Infectious e.g CJD, Viral encephalitis - Toxic e.g. penicillin, antidepressants - Metabolic - anoxic brain damage - hypoglycemia - hepatic failure ( “ asterixis” ) - renal failure - hyponatremia….. And others
Slide 6: Segmental Myoclonus • Can arise from lesions anywhere in the CNS • Can arise from many of the processes that can cause generalised myoclonus • Example is “palatal myoclonus” which arises due to any lesion that interrupts pathway between red nucleus, cerebellum and olivary nucleus.
Slide 7: Treatment of Myoclonus • Valproic acid is drug of choice • May respond to benzodiazepines e.g. clonazepam
Slide 8: Ballismus, Chorea, Athotosis and Dystonia These should NOT be thought of as separate entities amenable to specific definition but rather as a SPECTRUM of movements that blend into one-another WHY?
Slide 9: Because…….. • They often co-exist • Even neurologists may often not be able to agree as to how a particular movement should be classified! • They often ( with some notable exceptions ) have the same significance in terms of aetiology.
Slide 10: The spectrum Ballismus Chorea Athetosis Dystonia Movements become - Less violent / explosive / jerky - Smoother and more flowing - More sustained They differ from tics in that they cannot be suppressed by voluntary control
Slide 11: Ballismus • Violent “flinging” movement of entire limb • Almost always unilateral and therefore use term “ HEMIBALLISMUS” • Involves proximal musculature and is sometimes thought of as a “ proximal unilateral chorea ” • Usually due to a CVA in contralateral subthalamic nucleus
Slide 12: Chorea ( “dance” in Greek) • Rapid irregular muscle jerks • May affect limbs, head, face and tongue • In the limbs chorea refers more to distal movements ( as proximal movements usually called ballismus) • Patients often attempt to conceal involuntary movements by superimposing voluntary movements onto them e.g. an involuntary movement of arm towards face may be adapted to look-like an attempt to look at watch
Slide 13: Athetosis “ changeable” in Greek • Slow, flowing, often twisting movements • Occurs mainly distally ( hands, fingers) • Can also affect face and tongue • Often use term “ choreoathetosis ” due to overlap between syndromes ( chorea referring to less smooth , more jerky movements)
Slide 14: Dystonia • “ condition in which the patient assumes a sustained, abnormal posture or limb position” • Due to co-contraction of agonist and antagonist muscles in part of body • Can be thought of as an athetoid movement that “gets stuck” for a period of time; thus, a patient with choreoathetosis may perform an involuntary movement in which his hand and fingers are twisted behind his head. He may hold this position for a few moments before his hand moves back in front of his body. • The part of the movement when the limb was held, unmoving, in an abnormal position would be considered a dystonia ( may occur alone).
Slide 15: Examples of focal dystonias • Blepharospasm: - involuntary forceful closure of eyes • Torticollis: - Tendency of neck to twist to one side. • Writer’s cramp: - Dystonic posturing of arm when hand used to perform specific tasks e.g. writing, playing piano
Slide 16: Botulinum toxin • Derived from Clostridium botulinum • Prevents pre-synaptic release of Ach vesicles and therefore blocks neuro- muscular junction transmission • May be injected selectively into muscles responsible for focal dystonias, allowing relief for up to several months • Requires expertise; can cause more extensive paralysis than intended.
Slide 17: Causes of Chorea, Dystonia and athetosis • Hereditary • Static Encephalopathy ( Cerebral Palsy ) • Drugs • Cerebrovascular ( ischaemia, haemorrhage ) • Structural lesions ( subthalamic nucleus) • Secondary to medical disorders • Miscellaneous - Sydenham’s chorea - Chorea Gravidarum - Sporadic idiopathic torsion dystonia - Focal dystonias
Slide 18: Hereditary • Huntington’s disease • Wilson’s disease • Neuroacanthocytosis • Hereditary dystonias - idiopathic torsion dystonia - dopa - responsive dystonia
Slide 19: Wilson’s disease • Autosomal recessive defect of copper excretion in which there is defective copper-binding to ceruloplasmin • Leads to copper deposition in: - liver causing cirrhosis - brain ( especially basal ganglia ) leading to movement disorders and other abnormalities - Cornea leading to the appearance of rusty brown “ Kayser-Fleischer rings” around cornea (usually only seen with slit-lamp). • Diagnosis is via low serum ceruloplasmin, increased urinary Cu, liver biopsy ( excessive Cu) and brain MRI changes • Although it is rare it is very important to think-of and diagnose as it is TREATABLE:- Penicillamine is given to chelate the copper and promote excretion.
Slide 20: Idiopathic torsion dystonia • Hereditary and sporadic forms • Variable inheritence • High incidence in Ashkenazi Jews • Onset may be in childhood / adulthood • Affects limbs, trunk, neck, face • Trial of L-dopa usually initiated • Level of disability variable
Slide 21: Dopa-responsive dystonia • Autosomal dominant inheritence • Onset usually in childhood • Girls more severely affected • Some parkinsonian features - rigidity - bradykinesia Low levels of L-Dopa very effective
Slide 22: Drug-induced • Drugs acting on dopaminergic system - Antiparkinsonian - Antipsychotic • Lithium • Phenytoin • Oral contraceptives
Slide 23: Secondary to medical disorders (A SHEEP) • Anoxic brain damage ( post – CPR ) • Systemic lupus erythematosis • Hepatic failure • Endocrine - Thyrotoxicosis - Addisons • Electrolyte - Low Ca, Mg, - High Na • Polycythemia rubra vera
Slide 24: Sydenham’s chorea • Mainly children / adolescents • Complication of previous group A streptococcal infection • Usually no recent history of infection • Acute / subacute onset • May have behavioural problems • Usually remits spontaneously
Slide 25: Chorea gravidarum • Chorea of any cause that begins in pregnancy • May represent recurrence of Sydenham’s chorea. • Most commonly associated with anti- phospholipid syndrome +/- SLE • Usually resolves spontaneously
Slide 26: Tics • Recurrent, sterotyped abnormal movements • May be suppressed voluntarily or with distraction • Voluntary suppression leads to anxiety and a build-up of internal unrest. • Worsen under stress
Slide 27: Summary • Movement disorders are often difficult to define precisely, but have similar differential diagnoses. • They are often a manifestation of a more widespread neurological or internal medical problem. • Other than the specific treatments mentioned, most details of therapy are beyond the scope of this course. • In some cases treatment includes treatment of underlying cause e.g. Wilson’s disease
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