Neuro Part 2 Flashcards
What is the pathophysiology of Parkinsons Disease?
- Progressive degenerative disorder characterised by neuronal loss in brainstem and basal ganglia of the brain, leading to disorders of movement.
- Loss of dopaminergic neurones in substantia nigra leads to inadequate dopamine transmission
- Can lead to lewy body formation in affected neurones
What is the triad of fx seen in PD?
- Resting tremor - 4-6 Hz resting tremor
- Muscular Rigidity
- Bradykinesia
What are some of the signs + sx of PD?
- Unilateral Tremor: Pill rolling tremor: 4-6 Hz (4-6 times a second)
- Bradykinesia: movements get slower and smaller.
- “Cogwheel” Rigidity
- Shuffling gait: they can only take small steps when walking
- Hypomimia: reduced facial movements and facial expressions
- Micrographia
- Autonomic dysfunction: postural hypotension, constipation, urinary frequency/urgency, dribbling of saliva
- Neuropsychiatric complications: depression, dementia, psychosis, sleep disturbance, Cognitive impairment and memory problems
What are some of the differences between the PD tremor and benign essential tremor
What features form the diagnostic criteria for PD
Three or more required for diagnosis of definite Parkinson’s disease in combination with step one:
- Unilateral onset
- Rest tremor present
- Progressive disorder
- Persistent asymmetry affecting side of onset most
- Excellent response (70-100%) to levodopa
- Severe levodopa-induced chorea
- Levodopa response for 5 years or more
- Clinical course of ten years or more
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What is parkinsonism?
Parkinsonism – bradykinesia + rigidity NO tremor
What medications are used for the mx of PD?
- Levodopa - synthetic dopamine (SE: dyskinesias. dystonia, chorea, athetosis **, nausea, hallucinations, psychosis, low BP)
- Peripheral decarboxylase inhibitors. (stops levodopa being broken down in the body before entering brain): carbidopa and benserazide
- Combination:
- Co-benyldopa (levodopa and benserazide)
- Co-careldopa (levodopa and carbidopa)
-
COMT Inhibitors: entacapone: Inhibitors of catechol-o-methyltransferase (COMT) which metabolises levodopa in both the body and brain.
- Taken with levodopa to slow its breakdown (extend duration)
- Dopamine Agonists: Bromocryptine., pergolide, Carbergoline - mimic dopamine in the basal ganglia and stimulate the dopamine receptors
- Monoamine Oxidase-B Inhibitors: Selegiline, Rasagiline - Monoamine oxidase enzymes break down neurotransmitters such as dopamine, serotonin and adrenaline.
What are the fx of benign essential tremor
- Fine tremor
- Symmetrical
- More prominent on voluntary movement
- Worse when tired, stressed or after caffeine
- Improved by alcohol
- Absent during sleep
How is benign essential tremor mx’d?
There is no definitive treatment for benign essential tremor
Medications:
- Propranolol
- Primidone (a barbiturate anti-epileptic medication)
What muscles does CNVII innervate?
- Face: Muscles of facial expression
- Ear: nerve to stapedius in the inner ear and the posterior digastric, stylohyoid and platysma muscles in the neck.
- Taste: Sensory: anterior 2/3 of the tongue.
- Tear: Parasympathetic: it provides the PS to the submandibular and sublingual salivary glands and the lacrimal gland (stimulating tear production).
What are the different causes of LMN and UMN facial nerve lesions?
What is Bell’s Palsy? How is it mx’d?
- Idiopathic unilateral LMN facial nerve palsy.
- The peak incidence is 20-40 years and the condition is more common in pregnant women.
- Mx: if in 72h of presenting symptoms: prednisolone
- 50mg for 10 days
- 60mg for 5 days followed by a 5-day reducing regime of 10mg a day
-
Other: lubricating eye drops
- Exposure keratopathy: urgent opthalmological review
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What are the sx of Bell’s palsy?
- LMN facial nerve palsy - forehead affected
- Post-auricular pain (may precede paralysis)
- Altered taste
- Dry eyes
- Hyperacusis
What is Ramsay Hunt Syndrome? What is its mx?
- Varicella zoster virus (VZV).
- Unilateral LMN facial palsy (like Bells)
- Presentation: painful and tender vesicular rash in the ear canal, pinna and around the ear on the affected side. This rash can extend to the anterior 2/3 of the tongue and hard palate
- Mx: in 72h: Prednisolone and Aciclovir
What are some of the cause of bilateral facial nerve palsies?
- Sarcoidosis
- Guillain-Barre syndrome
- Lyme disease
- Bilateral acoustic neuromas (neurofibromatosis T2)
What is MS?
- Chronic and progressive condition that involves demyelination (plaques) of the myelinated neurones in the CNS. This is caused by an inflammatory process involving the activation of immune cells against the myelin
- Typically presents in young adults (under 50 years) and is more common in women.
- Symptoms tend to improve in pregnancy and in the postpartum period.