Acute Dystonia
- "Long-lasting contraction or spasm of musculature
develops secondary to the use of antipsychotic medication.
- Acute dystonia typically subsides
spontaneously within hours after onset.
Common Dystonias |
- Torticollis (lateral neck rotation)
- Retrocollis (neck extension)
- Limb torsion
- Forced jaw closing (trismus) or opening
- Tongue protrusion
- Opisthotonus (extension of head, neck, and paraspinal muscles in an
arch)
- Oculogyric crisis (forceful eye deviation).
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- Usually emerge within 0–7 days
- Pathophysiology
- Abnormalities in dopamine–acetylcholine balance -
(cholinergic antagonists and dopaminergic agonists improve the dystonia in many patients)
- Epidemiology
- 2 to 12% of patients -
conventional antipsychotic medication
- Risk factors include
- high-potency conventional antipsychotics, e.g. haloperidol
- Young age, male sex, and a prior dystonic
reaction.
- Clinical features
- Abnormal positioning of the head and neck in
relation to the body (e.g., retrocollis, torticollis)
- Spasms of the jaw muscles (trismus, gaping,
grimacing)
- Impaired swallowing (dysphagia), speaking,
or breathing (laryngeal–pharyngeal spasm,
dysphonia)
- Thickened or slurred speech due to hypertonic
or enlarged tongue (dysarthria, macroglossia)
tongue protrusion or tongue dysfunction
- Eyes deviated up, down, or sideward
(oculogyric crisis)
- Abnormal positioning of the distal limbs or
trunk
- Treatment
- Standard treatment is anticholinergic agent- equivalent of 2 mg of benztropine or 50 mg of diphenhydramine/promethazine.
- In case of laryngeal or pharyngeal dystonias with
airway compromise, repeated dosing of medication should
occur at shorter intervals until resolution is achieved.
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Parkinsonism
- A condition characterized by Parkinsonian
signs or symptoms (resting tremor, muscle rigidity, and
bradykinesia/akinesia) that develop in association with the use of an
antipsychotic medication.
- Most commonly associated with use of Dopamine Receptor Antagonists.
- Pathophysiology
- Blockade of postsynaptic
dopamine (D2 ) receptors in the corpus striatum.
- Epidemiology
- 5 to 90%, depending on the use of first-generation
antipsychotics, high-potency FGAs and associated medical and
neurological disorders.
- Clinical features include:
- Parkinsonian tremor (i.e., a coarse, rhythmic,
resting tremor with a frequency between 3
and 6 cycles per second, affecting the limbs,
head, mouth, or tongue)
- Parkinsonian muscular rigidity (i.e., cogwheel
rigidity or continuous “lead-pipe” rigidity)
- Akinesia (i.e., a decrease in spontaneous
facial expressions, gestures, speech, or body
movements)
- Differential diagnosis include:
- Major depressive disorder
- Catatonia
- Negative symptoms
of schizophrenia
- Treatment
- Milder cases do not require treatment, reassurance that condition will improve as patient will tolerate the drug over time.
- Decrease the dose of antipsychotic to the lowest effective
dose for the patient.
- Low dose anticholinergic - benztropine/trihexyphenidyl
- Treat with atypical
antipsychotics.
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Akathisia (“inability to sit”)
- Definition
: “A subjective feeling of restlessness and an
intensely unpleasant need to move occurring secondary to antipsychotic
treatment”.
- Usually emerge with in 7–14 days of starting antipsychotics therapy.
- Pathophysiology
- Excessive noradrenergic activity (the efficacy of beta-adrenergic blockers in improving some cases of akathisia)
- Mesocortical dopaminergic neurons that innervate the
prefrontal cortex seem to be resistant to depolarization induced by
long-term antipsychotic treatment.
- Epidemiology
- Occur in 20–75% of patients treated with conventional agents.
- Clinical features
- Subjective complaints of restlessness
- Fidgety movements or swinging of the legs
- Rocking from foot to foot while standing
- Pacing to relieve restlessness
- Inability to sit or stand for at least several minutes
- Differential Diagnosis
- Primary psychiatric disorders presenting with
agitation, such as depression, mania, anxiety, schizophrenia, dementia,
delirium, substance intoxication/withdrawal, and attention-defi
cit/hyperactivity disorder.
- Restless legs syndrome (RLS)
- Treatment
- Beta-blocker propranolol - often considered first-line treatment
- Benzodiazepines - clonazepam and Lorazepam
- Anticholinergic agents – benztropine
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Tardive Dyskinesia
- Definition:
- "A syndrome
consisting of abnormal, involuntary, choreoathetoid
movements typically involve the mouth, face, limbs, and trunk caused by
long-term treatment with antipsychotic medication.
- Pathophysiology
- hypotheses
- Striatal dopamine receptor supersensitivity as
a compensatory reaction to prolonged dopamine receptor blockade.
- Damage to gamma-aminobutyric acid
(GABA)-containing striatal neurons.
- Long-term antipsychotic use may
produce toxic free radicals that damage striatal neurons
and result in persistent TD.
- Reduced levels
of brain-derived neurotrophic factor (BDNF) and elevated
serum homocysteine.
- Epidemiology - (after starting antipsychotics)
- 5% after 1 year
- 18.5% after 4 years
- 40% after 8 years
- Clinical Features
- Involuntary movements of the tongue, jaw, trunk,
or extremities have developed in association with
the use of neuroleptic medication.
- Choreiform movements (i.e., rapid, jerky,
nonrepetitive)
- Athetoid movements (i.e., slow, sinuous,
continual)
- Rhythmic movements (i.e., stereotypies)
- Differential Diagnosis
- Sydenham’s chorea
- Huntington’s disease
- Conversion disorder and
malingering
- Hyperthyroidism
- Complications
- Emotional distress
- Dental problems
- Respiratory alkalosis
- Treatment
- Atypical
antipsychotics may improve the condition
- Clozapine
may be effective in reducing TD in patients with existing
TD
- Vitamin
E (alpha-tocopherol) has some efficiency
- Abnormal Involuntary Movement Scale (AIMS) may be used to monitor progress of the treatment.
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Scales & Instruments
Simpson-Angus Rating Scale for Extrapyramidal Side Effects
- The Simpson-Angus scale was developed to monitor the effects of antipsychotic drugs.
- It has 10 items, each of which is rated on an item-specific, five-point severity scale ranging from 0 to 4.
- Scores are reported as the mean on all 10 items, with 0.3 considered the upper limit of normal.
- It is focused on parkinsonian symptoms, -rigidity,includes one akathisia item.
- It can be administered by trained lay raters.
- Good psychometric properties have been reported.
Abnormal Involuntary Movement Scale (AIMS)
- developed to measure dyskinetic symptoms in patients taking antipsychotic drugs.
- 12 items, on five-point severity scale ranging from 0 to 4.
- Total scores are not generally reported. Instead, changes in global severity and individual areas can be monitored over time.
- Ten items cover the movements themselves, divided into
sections rating global severity and those related to specific body
regions; two items concern dental factors that can complicate the
diagnosis of dyskinesia.
- In the presence of extended neuroleptic exposure and the
absence of other conditions causing dyskinesia, mild dyskinetic
movements in two areas or moderate movements in one area suggest a
diagnosis of tardive dyskinesia.
- The scale can be administered by trained raters.
- It can be completed in under 10 minutes.
- Good psychometric properties have been reported.
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References
-
Miyamoto S, Merrill DB, Lieberman JA, Fleischacker WW, Marder SR. Antipsychotic Drugs. In Psychiatry,
Third Edition. Edrs. Allan Tasman, Jerald Kay, Jeffrey A. Lieberman,
Michael B. First and Mario Maj.John Wiley & Sons, Ltd, 2008.
- Daniel DG, Igan MF, Wolf SS. Neuropsychiatric Aspects of Movement Disorders. In Comprehensive
Textbook of Psychiatry , Vol 7 , Kaplan HI and Saddock BJ (eds). Williams & Wilkins , Baltimore, MD, USA .
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