Movement Disorders Overview and Parkinson's Disease

Movement Disorders - General Overview

• Pyramidal tract initiates movement, weakness results from dysfunction
• Extrapyramidal tract coordinates/modifies movement, disorders from basal ganglia problems
• Basal ganglia: group of nuclei deep in the brain; includes caudate nucleus, putamen, subthalamic nuclei, globus pallidus (external/internal), substantia nigra (compacta/reticulate)
• Involved in movement of trunk, extremities, extra-ocular muscles, cognition, and emotion.
• Sometimes includes cerebral cortex

Parkinsonism

• Syndrome of clinical features, mainly caused by Parkinson's disease
• Cardinal features: (1) bradykinesia—main feature, (2) resting tremor—most common initial feature, (3) postural instability—recurrent falls, clinically diagnosed by a pull test, (4) rigidity.

Parkinson's Disease

• Progressive neurodegenerative disease, affecting 100-200 per 100,000 people over 40, common age onset in 60s
• Loss of dopaminergic neurons in substantia nigra pars compacta
• Early onset if presents before 50
• Levodopa-induced dyskinesias (combination of chorea and dystonia) develop over time with higher doses

Clinical Presentation

• Bradykinesia, often with resting tremor

Red Flags Suggesting Diagnosis Other Than Parkinson's

• Early dementia
• Early postural instability
• Early hallucinations/psychosis (low doses)
• Ocular signs (impaired vertical gaze)
• Pyramidal tract signs not explained by prior stroke or spinal cord issues
• Early autonomic symptoms
• Prominent motor apraxia
• Alien limb phenomenon
• Truncal symptoms more than appendicular symptoms
• Marked symmetry early in disease

Tremor

• Most common movement disorder, involuntary rhythmic oscillation
• Resting, action, postural, kinetic
• Position-specific, task-specific
• Essential and Parkinsonian tremor have different characteristics

Essential Tremor

• Isolated tremor syndrome, bilateral upper limb action tremor (postural and kinetic)
• At least 3 years, with/without in other locations (head, voice).
• Improves with alcohol, not parkinsonism
• AD, with absence of neurological signs

Dystonia

• Movement disorder-sustained/intermittent muscle contractions
• Abnormal, often repetitive movements/postures, sometimes tremulous
• Often initiated or worsened by voluntary muscle action
• Sensory trick often accompanies
• Stereotyped

Chorea

• Non-goal-directed, rapid movements involving multiple body parts
• Random, erratic amplitude with high individual variability
• Not suppressed by volition
• Neurological conditions like Huntington's disease and drugs such as levodopa cause this

Myoclonus

• Briefest hyperkinetic movement
• Shock-like movements, positive/negative myoclonus
• Sudden muscle contractions or pauses in tone
• Can be spontaneously occurring or during movement
• May be provoked by external stimuli like touch or sound

Tics

• Unwanted, non-goal-directed, discrete muscle movements, repetitive, patterned, inter/intra-individual variability
• Severity can range
• Associated with premonitory sensory phenomena; sometimes suppressed by volition
• Motor or phonic types, simple or complex movement

Tourette's Syndrome

• Neuropsychiatric disorder, motor/phonic tics, diagnosed before age 18.
• Often associated with ADHD and OCD

Wilson's Disease

• Young-onset movement disorder, AR
• Impaired intracellular copper transporter function causing copper accumulation in liver, brain, cornea
• Clinical features: liver, neurologic, psychiatric—may present with any movement disorder.
• Diagnosis: Reduced serum ceruloplasmin with/without Kayser-Fleischer rings.

Sydenham Chorea

• Acute rheumatic fever
• Most common form of acquired chorea in children (5-13 years old)
• Onset 1-8 months after infection (Group A beta-hemolytic streptococcus)

This quiz covers the key concepts of movement disorders with a focus on Parkinson's disease. Participants will learn about the anatomy of the pyramidal and extrapyramidal tracts, the role of the basal ganglia, and the hallmark features of Parkinsonism. Ideal for students studying neurology or related fields.