Neurodegenerative Diseases

Neurodegenerative Diseases

These illnesses are characterized by the progressive loss of selected neurons in discrete brain areas, resulting in characteristic disorders of movement, cognition, or both. For example, Alzheimer s disease is characterized by the loss of cholinergic neurons in the nucleus basalis, whereas Parkinson s disease is associated with a loss of dopaminergic neurons in the substantia nigra.

Parkinson s Disease
Parkinsonism is a progressive neurological disorder of muscle movement, characterized by tremors, muscular rigidity, bradykinesia (slowness in initiating and carrying out voluntary movements).

Etiology: The disease is correlated with destruction of dopaminergic neurons in the substantia nigra with a consequent reduction of dopamine actions that are involved in motor control.

Strategy of treatment
Many of the symptoms of parkinsonism reflect an imbalance between the excitatory cholinergic neurons and the greatly diminished number of inhibitory dopaminergic neurons. Therapy is aimed at restoring dopamine in the basal ganglia and antagonizing the excitatory effect of cholinergic neurons, thus reestablishing the correct dopamine/acetylcholine balance.

Drugs Used in Parkinson s Disease
Currently available drugs offer temporary relief from the symptoms of the disorder, but they do not arrest or reverse the neuronal degeneration caused by the disease.



Drugs Used in Parkinson s Disease
Currently available drugs offer temporary relief from the symptoms of the disorder, but they do not arrest or reverse the neuronal degeneration caused by the disease.

Levodopa and carbidopa
Dopamine-receptor agonists
Antimuscarinic agents
Catechol-O-methyltransferase inhibitors
Selegiline and rasagiline

Drugs Used in Alzheimer s Disease
Current therapies are aimed at either improving cholinergic transmission within the CNS or preventing excitotoxic actions resulting from overstimulation of N-methyl-D-aspartic acid (NMDA)-glutamate receptors.

A. Acetylcholinesterase inhibitors
B. NMDA-receptor antagonist