Week 3 - Movement disorders Flashcards
What symptoms are associated with upper motor neuron damage?
Muscle weakness / stiffness
+ muscle tone
+ stretch reflexes
What symptoms are associated with lower motor neuron damage?
Muscle weakness
Decreased muscle tone
Inhibited stretch reflexes
Spontaneous firing
What is aphasia?
What are the two types?
Disruption of speech
Broca’s = failure to formulate
Wernicke’s = failure to comprehend
What are the 4 stages of motor neuron disease?
What occurs in each?
Amyotrophic lateral sclerosis - degeneration of MNs
Primary lateral sclerosis - slow corticospinal tract degeneration
Pseudobulbar palsy - corticobulbar tract degeneration (facial paralysis)
Progressive muscular atrophy - degeneration of LMNs
What is multiple sclerosis and what are the symptoms?
Autoimmunity against myelin
Leg tingling, fatigue, balance issues, blurred vision, dysphagia
What are 4 ways of measuring sleep?
- Polysomogram
- Electro-encephalogram
- Electro-myogram
- Electro-oculogram
What are the stages of sleep?
- REM
- Non-REM 1
- Non-REM 2
- Non-REM 3
Why do we sleep?
- Reset body
- Tau accumulates in brain during day and is cleared during sleep
- Tau forms tangles if it accumulates
What happens to the body during sleep deprivation?
- Increased sleep propensity
- Decreased glucose metabolism
- Increased tau
- Mood changes
- High level cognitive functioning
- Perceptual changes
- Increase in risky behaviours
What are the 3 types of insomnia?
Transient = 2-3 days
Short-term = < 1 month
Long-term = undewrlying psychiatric illness
What is the circadian rhythm?
- Controlled by suprachiasmatic nucleus in hypothalamus
- Melatonin produced when its dark, inducing tiredness
- SCN releases cortisol in daylight, causing wakefulness
What is the role of ACh in sleep?
Active during wakefulness and REM
What is the role of NA in sleep?
Generates arousal
What is the role of histamine in sleep?
Promotes wakefulness
What is the role of 5HT in sleep?
Promotes wakefulness and supresses REM
What is the role of DA in sleep?
Exerts potent wake promoting effects
What causes restless leg syndrome?
- Dopamine dysfunction
- Genetics
- Medications
- Chronic illness
- Vitamin deficiency
- Pregnancy
- Sleep deprivation
What drugs are used to treat sleep disorders?
- Benzodiazepines
- Antihistamines
- Sedative antidepressants
- Valerian
- Melatonin receptor antagonists
- Z drugs (bind to benzodiazepine binding sites)
WHat is executive function?
Description of psychological processes underlying flexible goal directed behaviour
What are the causes of Huntington’s disease?
- Genetics
- Autosomal dominant on chromosome 4
- Trinucleotide repeat disorder
- HD gene codes for Huntingtin protein (HTT)
What are the clinical features of Huntington’s disease?
- Chorea, dystonia, dysarthria, dysphagia
- Dementia of frontal lobe, loss of empathy, lack of insight, loss of verbal fluency
- Depression, anxiety, psychosis
- High metabolic rate, weight loss
How is Huntington’s managed?
- Dopamine blockers for chorea
- Psychiatric medications
- Speech and swallowing assessments
- Fortified diet
- Feeding tube?
What triplet repeat causes Huntington’s?
CAG
What is anticipation in regards to triplet repeats?
When triplet repeats become unstable
Therefore more likely to expand
Therefore increased chance of developing condition
What is the parent of origin effect for maternal transmission?
- Larger CTG expansion occurs only on maternal transmission
- Female carriers more likely to have children with expanded gene
What is the parent of origin effect for paternal transmission?
- Large CAG expansion repeats occur almost only on paternal transmission
- Male carriers more likely to have children with expanded gene
What is incomplete penetrance?
When not everyone who inherits the mutation develops the disease
WHat are the 2 types of stroke and their subtypes?
- Ischaemic
- Thrombotic
- EMbolic
- Lacunar occlusion
- Large vessel occlusion
- Haemorrhagic
- Intracerebral
- Subarachnoid
What are the symptoms of a haemorrhagic stroke?
- Thunderclao headache
- Seizures
- Nausea
- Unilateral weakness
What are the symptoms of a anterior circulatory stroke?
- Hemiplegia
- Hemisensory loss
- Hemianopia
- Dysphasia
- Aphasia
What are the symptoms of a posterior circulatory stroke?
- Bilateral sensory deficits
- Dis-conjugate eye movement
- Cerebellar dysfunction
- Isolated hemianopia
What happens in a lacunar infarction?
- Small stroke in penetrating arteries
- Clinically silent
- Motor hemiplegia syndrome
How do you treat a haemorrhagic stroke?
- Pain management
- Surgery
- Lower BP
How do you treat an ischaemic stroke?
- Thrombolysis with alteplase within 3 hours
- Thrombectomy within 6 hours
What are the penumbra and core of a stroke?
Penumbra = area of potentially salvageable tissue
Core = irreversibly damaged tissue
What happens during excitotoxicity stage of stroke?
- Failure of ion pumps
- Cell depolarisation
- Na+, Ca2+, H2O influxe
- K+ efflux
- GLutamate release and receptor activation
What happens in the later stages of a stroke cellularly?
- Microglia, astrocytes, blood vessels
- BBB breakdown
- Influx of leukocytes
When do strokes lead to dementia?
When there is major vascular cognitive impairment
How do the basal ganglia and cerebellum assist one another for movement?
Basal ganglia:
- Receives sensory and motor cortical information
- Plans movement
Cerebellum:
- Assists with dynamic coordination of movement, balance, and posture
What is the basal ganglia?
- Group of subcortical greay matter structures
- Plan movement to cortex via thalamus
- Prevents unwanted movement
- Injury = involuntary movements
- Caudate nucleus, lentiform nucleus (putamen + globus pallidus), substantia nigra, subthalamic nucleus
What is the role of the striatum?
- Receives input from glutamatergic afferents and dopaminergic afferents
- Composed of 90% inhibitory GABAergic medium spiny neurons
What are upper motor neurone disorders?
- Stroke
- Multiple sclerosis
- Amyotrophic lateral sclerosis
What are lower motor neuron disorders?
- Peripheral neuropathy
- Myasthenia gravis
What is Parkinson’s disease?
- Neurodegeneration of extrapyramidal system
- Poor movement, rigidity, mask like expression, tremor
- Depression, dementia, endocrine dysfunction in late stages
- Loss of striatal dopamine
- Loss of pigmented neurons in substantia nigra
How do you treat Parkinson’s disease?
- Dopamine replacement therapy
- Dopamine agonists
- Drugs preventing dopamine metabolism
- Muscarinic receptor antagonists
What are the causes of Parkinson’s disease?
- Oxidative stress
- Immediate relative with disease
- Genetic
- Drug-induced neurodegeneration
- Drug-induced
- Viral encephalitis
What is Huntington’s disease?
Disorder affecting basal ganglia
Loss of GABA but not dopamine
ENlarged lateral ventricles
Reduced putamen and caudate nucleus
What is tourettes and how is it treated?
- Altered basal ganglia function
- Dopamine receptor antagonists = treatment
