Tremors/Huntington's Disease/Parkinson’s Disease - Neuro Flashcards
Essential Tremor (ET)
- Most Common movement disorder
- Affects 5-10 million people in US
- Can present in childhood, but increased in >(50-)70 years
- High-frequency tremor (up to 11 Hz)
- Predominantly affects upper extremities
- Typically bilateral and symmetric, but may remain asymmetric
- Improved with alcohol
- Worsened by stress
ET PE Findings
- Impaired coordination in tandem walking
- Disturbances of hearing, cognition, and olfaction in some cases.
- Neurological exam normal except the tremor (in most cases).
- Must differentiate between Parkinson’s Disease (PD)
ET etiology
Not known.
~50% of cases have a positive family history (autosomal dominant pattern)
Treatment of ET
- Reassurance
- Beta blockers
- Propranolol 20-80 mg daily in divided doses
- Contraindicated in bradycardia and asthma
- Hand tremor= most improved, head tremor=often refractory - Primidone
- Start at low dose 12.5 mg gradually increased (125-250 tid) to avoid sedation
- -Beta blockers and Primidone help in about 50% of cases
Types of tremors
- Rhythmic oscillation of a body part due to intermittent muscle contractions.
- Rest tremor-most prominent at rest (Parkinson’s)
- Postural tremor-On assuming a posture (Essential tremor)
- Kinetic tremor-On actively reaching for a target (cerebellar disease)
Huntington’s Disease (HD)
- Progressive, fatal, highly penetrant autosomal dominant disorder characterized by motor, behavioral, and cognitive dysfunction.
- Onset 25-45 (range 3-70)
- 2-8 cases per 100,000 (about 30,000 people in US)
- Average age at death 60 years
- Prevalent in Europe, North/South America, Austrailia, but rare in Asians and African Americans.
HD Pathophysiology
- Prominent neuronal loss and gliosis in the caudate nucleus and putamen
- Similar changes also widespread in cerebral cortex
- Mitochondrial dysfunction demonstrated in the striatum and skeletal muscle of symptomatic and presymptomatic individuals
- Mutant huntington protein=toxic by translocating into the nucleus and interferes with transcriptional upregulation of the proteins.
HD Symptoms
- Rapid, non-patterned, semipurposeful, involuntary choreiform movements.
- Dysarthria, gait disturbance, oculomotor abnormalites
- Early stages= focal or segmental
- Advanced disease=dystonia, rigidity, bradykinesia, myoclonus and spasticity.
HD Complications
-Behavioral and cognitive disturbances; with majority progressing to dementia
-Depression (with suicidal tendencies)
-Aggressive behavior
Psychosis
-NIDDM (non-insulin dependent diabetes)
-Neuroendocrine abnormalities (hypothalamic dysfunction)
HD Treatment
- Mutidisciplinary
- Dopamine-blocking agents (help control chorea)
- Tetrabenazine
- Neuroleptics=NOT rec (like haldol)
- Antidepressants
- Antianxiety drugs
Sydenham’s chorea
-“Saint Vitus Dance”
-Post Group A strep infection
20-30% of patients with ARF (acute rheumatic fever)
-Can occur up to 6 months after the infection.
-More common in females
-Most children <18 years of age
-ACUTE onset (sometimes within hours)
-Chorea (usually affecting all limbs), behavior change, dysarthria, gait disturbance, headache, slowed cognition, facial grimacing, fidgetiness, hypotonia
-Tongue Fasciculations
-Milk sign
Parkinson’s Disease (PD)
- Second most common neurodegenerative disease (exceeded only by Alzheimer’s)
- Affects ~ 1 million persons in US (5 million worldwide)
- Affects men and women of all races, all occupations and all countries
- Mean age of onset is 60 (can occur in 20’s or earlier)
PD clinical features
- resting tremor: rhythmic oscillations usually in the hands or feet and when the muscles are relaxed
- cogwheel rigidity: increased muscle tone that is felt by the examiner as a ratchet like resistance during a passive ROM
- bradykinesia/akinesia: slowness of initiation and performance of both volitional and non-volitional movement
- postural instability/impaired balance: pts may lose balance when standing or when pressure is applied to their back or trunk
- Reduced eye blink (or stare of PD)
- Soft voice (hypophonia)
- Dysphagia (difficulty with or painful swallowing)
- Freezing
Nonmotor features of PD
- Anosmia (decreased or loss of smell)
- Sensory disorders (pain)
- Mood disorders (depression)
- Sleep disturbances
- Autonomic disturbances
- Orthostatic hypotension
- GI disturbances
- Genitoruinal disturbances
- Sexual dysfunction
- Cognitive impairment/Dementia
Etiology of PD
- 85-90% of cases unknown
- Only 15-25% of people have + family hx
- If affected first-degree relative, such as a parent or sibling, have a 4-9% higher chance of developing PD, as compared to the general population
- Parkinson’s has developed at an early age in individuals with mutations in genes for parkin, PINK1, LRRK2, DJ-1, and glucocerebrosidase, among others.
