19. Neurological Disorders Flashcards
What is amyotrophic lateral sclerosis (ALS)?
ALS is a progressive neurodegenerative disease of the upper and lower motor neurons due to degeneration of lateral cotricospinal tracts, which will eventually lead to muscle failure
How does ALS present?
Progressive muscle weakness, hyperreflexia (due to upper motor neuron involvement), muscle fasciculations (due to lower motor neuron involvement), and atrophy
Maxillofacial implications of ALS
Dysphagia (pharyngeal muscle weakness) leading to aspiration risk (bulbar nuclei involvement), tongue weakness with fasciculations, sialorrhea due to inability to handle secretions.
What is Alzheimer’s Disease?
A neurodegenerative disease characterized by the progressive loss of cortical neurons and the formation of amyloid plaques and intraneuronal neurofibrillary tangles
- Progressive loss of neurons eventually leads to a relative deficiency in cortical acetylcholine transmission (resulting from loss of neurons in the nucleus basalis)
Dose of sedative-hypnotics should be reduced by ___% in alzeheimer disease patients
30%
What is Parkinson’s Disease?
Neurodegenerative disease characterized by classic triad of bradykinesia, rigidity, and resting (pill-rolling tremor) caused by progressive loss of dopaminergic neurons in the pars compacta of the substantia nigra in the basal ganglia.
What is the pathophysiology of Parkinson’s disease?
Depletion of dopamine –> diminished inhibition of neurons in the extrapyramidal motor system –> unopposed stimulation by acetylcholine –> tremors of Parkinsonism.
Treatment of Parkinson’s disease
Goal to increase concentration of dopamine in the basal ganglia.
- Carbidopa-levodopa (Sinemet). Levodopa is a dopamine precursor that is combined with the decarboxylase inhibitor, carbidopa, which prevents peripheral conversion of levodopa to dopamine, thereby optimizing the amount of levodopa that can enter the CNS.
What drugs are used in early Parkinson’s disease that delay the need for levodopa treatment?
Selegiline, rasagiline (Type B Monoamine Oxidase Inhibitors) MAO-B inhibitors
Anticholinergics and antihistamines are also used to antagonize the effects of acetylcholine
What are the options for Parkinson’s patients who fail medical treatment?
Surgical treatment: thalamotomy, pallidotomy, or implantation of deep brain stimulator
What is Multiple Sclerosis?
MS is an inflammatory demyelinating disease of the CNS marked by discrete episodes of neurological dysfunction, termed relapses, followed by periods of remission.
- Demyelination preferentially occurs in the periventricular areas of the brain, due to autoimmune processes involving T and B autoreactive cells.
- Symptoms = visual disturbances, gait disturbance, ascending paresis, limb paresthesias, trigeminal neuralgia.
Diagnosis of MS
MRI with gadolinium (to demonstrate demyelination in the CNS)
CSF analysis will show increased intrathecal synthesis of IgG
What is a seizure?
A sudden onset of abnormal, highly synchronous discharges of neurons
Phases of seizures
Ictus (seizure itself)
Ictal phase (period of time during seizure)
Postictal phase (the time after the seizure)
Interictal phase (the time in between seizures)
What is epilepsy?
Epilepsy is a chronic disorder defined as recurrent seizures resulting from congenital or acquired factors in the cerebral cortex (e.g. cerebral scar, malformation, tumor, abnormal gene expression).
- Requires 2 separate unprovoked seizures
