B14-Neurological Disorders Flashcards
Tumor
A mass of cells whose growth is uncontrolled and that serves no useful function.
Malignant tumor
A cancerous (literally, “harm-producing”) tumor; lacks a distinct border and may metastasize.
Benign tumor
(bee nine) A noncancerous (literally, “harmless”) tumor; has a distinct border and cannot metastasize.
metastasis
(meh tass ta sis) The process by which cells break off of a tumor, travel through the vascular system, and grow elsewhere in the body.
Glioma
(glee oh mah) A cancerous brain tumor composed of one of several types of glial cells.
Tumor-initiating cell
Cells that originate from transformations of neural stem cells, rapidly proliferate, and give rise to a glioma
Meningioma
(men in jee oh ma) A benign brain tumor composed of the cells that constitute the meninges.
Seizure disorder
The preferred term for epilepsy.
Convulsion
A violent sequence of uncontrollable muscular movements caused by a seizure.
Partial seizure
A seizure that begins at a focus and remains localized, not generalizing to the rest of the brain.
Generalized seizure
A seizure that involves most of the brain, as contrasted with a partial seizure, which remains localized.
Simple partial seizure
A partial seizure, starting from a focus and remaining localized, that does not produce loss of consciousness.
Complex partial seizure
A partial seizure, starting from a focus and remaining localized, that produces loss of consciousness.
tonic-clonic seizure
A generalized convulsive seizure that includes a tonic phase of rigidity followed by a clonic phase of jerky movements.
aura
A sensation that precedes a seizure; its exact nature depends on the location of the seizure focus
tonic phase
The first phase of a tonic-clonic seizure, in which all of the patient’s skeletal muscles are contracted.
clonic phase
The phase of a tonic-clonic seizure in which the patient shows rhythmic jerking movements.
absence
A type of seizure disorder often seen in children; characterized by periods of inattention, which are not subsequently remembered; also called petit mal seizure.
status epilepticus
A condition in which a patient undergoes a series of seizures without regaining consciousness.
hemorrhagic stroke
A cerebrovascular accident caused by the rupture of a cerebral blood vessel.
ischemic stroke
A cerebrovascular accident caused by occlusion of a blood vessel.
thrombus
A blood clot that forms within a blood vessel, which may occlude it.
embolus (emm bo lus)
A piece of matter (such as a blood clot, fat, or bacterial debris) that dislodges from its site of origin and occludes an artery; in the brain, an embolus can lead to a stroke.
fetal alcohol syndrome
A birth defect caused by ingestion of alcohol by a pregnant woman; includes characteristic facial anomalies and faulty brain development.
phenylketonuria (PKU) (fee nul kee to new ree uh)
A hereditary disorder caused by the absence of an enzyme that converts the amino acid phenylalanine to tyrosine; the accumulation of phenylalanine causes brain damage unless a special diet is implemented soon after birth.
Tay-Sachs disease
A heritable, fatal, metabolic storage disorder; lack of enzymes in lysosomes causes accumulation of waste products and swelling of cells of the brain.
Down syndrome
A disorder caused by the presence of an extra twenty-first chromosome, characterized by moderate to severe mental retardation and often by physical abnormalities.
Transmissible spongiform encephalopathy
A contagious brain disease whose degenerative process gives the brain a spongelike appearance; caused by accumulation of misfolded prion protein.
prion (pree on)
A protein that can exist in two forms that differ only in their three-dimensional shape; accumulation of misfolded prion protein is responsible for transmissible spongiform encephalopathies.
sporadic disease
A disease that occurs rarely and is not obviously caused by heredity or an infectious agent.
caspase
A “killer enzyme” that plays a role in apoptosis, or programmed cell death.
Lewy body
Abnormal circular structures with a dense core consisting of a-synuclein protein; found in the cytoplasm of nigrostriatal neurons in people with Parkinson’s disease.
a-synuclein
A protein normally found in the presynaptic membrane, where it is apparently involved in synaptic plasticity. Abnormal accumulations are apparently the cause of neural degeneration in Parkinson’s disease.
toxic gain of function
Said of a genetic disorder caused by a dominant mutation that involves a faulty gene that produces a protein with toxic effects.
parkin
A protein that plays a role in ferrying defective or misfolded proteins to the proteasomes; mutated parkin is a cause of familial Parkinson’s disease.
loss of function
Said of a genetic disorder caused by a recessive gene that fails to produce a protein that is necessary for good health.
proteasome
An organelle responsible for destroying defective or degraded proteins within the cell.
ubiquitin
A protein that attaches itself to faulty or misfolded proteins and thus targets them for destruction by proteasomes.
internal division of the globus pallidus (GP)
A division of the globus pallidus that provides inhibitory input to the motor cortex via the thalamus; sometimes stereotaxically lesioned to treat the symptoms of Parkinson’s disease.
deep brain stimulation (DBS)
A surgical procedure that involves implanting electrodes in a particular region of the brain and attaching a device that permits the electrical stimulation of that region through the eletrodes.
Huntington’s disease
An inherited disorder that causes degeneration of the basal ganglia; characterized by progressively more severe uncontrollable jerking movements, writhing movements, dementia, and finally death.
huntingtin (htt)
A protein that may serve to facilitate the production and transport of brain-derived neurotrophic factor. Abnormal huntingtin is the cause of Huntington’s disease.
dementia (da men sha)
A loss of cognitive abilities such as memory, perception, verbal ability, and judgment; common causes are multiple strokes and Alzheimer’s disease.
Alheimer’s disease
A degenerative brain disorder of unknown origin; causes progressive memory loss, motor deficits, and eventual death.
amyloid plaque
An extracellular deposit containing a dense core of B-amyloid protein surrounded by degenerating axons ad dendrites and activated microglia and reactive astrocytes.
B-amyloid (AB) (amm i loyd)
A protein found in excessive amounts in the brains of patients with Alzheimer’s disease.
neurofibrillary tangle (new row fib ri lair y)
A dying neuron containing intracellular accumulations of twisted protein filaments that formerly served as the cell’s internal skeleton.
tau protein
A protein that normally serves as a component of microtubules, which provide the cell’s transport mechanism.
B-amyloid precursor protein (APP)
A protein produced and secreted by cells that serves as the precursor for B-amyloid protein.
secretase (see cre tayss)
A class of enzymes that cut the B-amyloid precursor protein into smaller fragments, including B-amyloid.
presenilin (pree sen ill in)
A protein produced by a faulty gene that causes B-amyloid precursor protein to be converted to the abnormal short form; may be a cause of Alzheimer’s disease.
apolipoprotein E (ApoE) (ay po lye po proh teen)
A glycoprotein that transports cholesterol in the blood and plays a role in cellular repair; presence of the E4 allele of the apoE gene increases the risk of late-onset Alzheimer’s disease.
amyotrophic lateral sclerosis (ALS)
A degenerative disorder that attacks the spinal cord and crainial nerve motor neurons.
encephalitis (en seff a lye tis)
An inflammation of the brain; caused by bacteria, viruses, or toxic chemicals.
herpes simplex virus (her peez)
A virus that normally causes cold sores near the lips but that can also cause brain damage.
acute anterior poliomyelitis (poh lee oh my a lye tis)
A viral disease that destroys motor neurons of the brain and spinal cord.
rabies
A fatal viral disease that causes brain damage; usually transmitted through the bite of an infected animal.
meningitis (men in jy tis)
An inflammation of the meninges; can be caused by viruses or bacteria.
