neurological conditions + pharmacology COPIED Flashcards
Name five major neurodegenerative diseases characterised by progressive loss of neuronal function
Parkinson disease (PD)
Huntington disease (HD)
Alzheimer disease (AD)
Multiple sclerosis (MS)
Amyotrophic lateral sclerosis (ALS)
Three characteristics of PD
- resting tremor
- rigidity (inability to initiate movements)
- bradykinesia (slowness of movement)
Components of the basal ganglia
(interconnected subcortical nuclei)
striatum (caudate and putamen)
substantia nigra
globus pallidus
subthalamus
Apart from activities such as walking, what else is the basal ganglia involved with?
procedural memory
eg. driving a car
Key neuronal pathophysiology in PD
There is a degeneration of inhibitory dopaminergic neurons leading to a relative excess of cholinergic activity.
Therefore drugs can inhibit cholinergic activity or increase dopamine levels.
How does Levodopa work?
levodopa is taken up by dopaminergic neurons in the striatum and it is converted to dopament by LAAD.
Therefore this drug increases dopamine levels.
NB. As disease progresses and more dopaminergic neurons are lost, the conversion of levodopa to dopamine declines.
What is Myasthenia Gravis caused by?
an antibody against AChR
(acetylcholine receptor)
autoimmune disease; antibodies that block or destroy nicotinic acetylcholine receptors at the junction between the nerve and muscle.
This prevents nerve impulses from triggering muscle contractions
Symptoms of myasthenia gravis
The most commonly affected muscles are those of the eyes, face, and swallowing.
It can result in double vision, drooping eyelids, trouble talking, and trouble walking.
Onset can be sudden.
Those affected often have a large thymus gland
- eyes, throat and limbs affected. Worse for exercise.
Treatment of myasthenia gravis
Acetylcholinesterase inhibitors such as neostigmine and pyridostigmine.
Immunosuppressants, such as prednisone or azathioprine, may also be used
Symptoms of Parkinson’s
Higher tone. Cogwheel wrist
micrographia
Lack of facial expression
Dementia with later stages
Festinating gait
What are ergot alkaloids?
Ergoline derivatives are used clinically for the purpose of vasoconstriction (5-HT1 receptor agonists—ergotamine) and in the treatment and alleviation of migraines (used with caffeine) and Parkinson’s disease (bromocriptine - D2 receptor agonist and D1 receptor antagonist)
Symptoms of Huntington’s Disease
(hereditary disorder)
- degeneration of aminobutyric acid (GABA) neurons in the striatum.
mutation in the huntingtin gene, which results in the production of a toxic form of the huntingtin protein that attacks the neurons.
- dancelike movements of the limbs (choreoathetoid movements)
- rhythmic movements of the tongue and face
- mental deterioration that leads to personality disorders
- psychosis, dementia
- Symptoms usually start in 30s
Treatment of Huntington’s Disease
symptoms are consistent with excessive dopaminergic activity,
therefore drugs that block dopamine receptors (eg. haloperidol)
Diazepam potentiates GABA and thus help to reduce movements. Efficacy of benzodiazepines declines with disease progression.
Symptoms of encephalitis
- focal/ diffuse neurological signs
- fever, headache, psychiatric symptoms & seizure
- alteration in consciousness
What common virus can cause encephalitis (70% mortality rate)
herpes simplex
