Chapter 14: Nervous System Disorders

Vocabulary-based flashcards covering nervous system anatomy, stroke mechanisms, seizure types, and neurodegenerative disorders such as Parkinson's, ALS, and Alzheimer's.

Frontal lobe

Responsible for personality, judgment, voluntary movement, and expressive speech.

Parietal lobe

Brain region that processes sensation.

Temporal lobe

Brain region that supports hearing, language, and memory.

Occipital lobe

Brain region that processes vision.

Reticular activating system (RAS)

The system responsible for maintaining alertness.

Aphasia

Impaired ability to speak, understand, read, or write because of damage to the brain's language areas.

Expressive or Broca Aphasia

Difficulty producing words while understanding language remains intake, caused by damage to the frontal lobe.

Receptive or Wernicke Aphasia

Condition where a person speaks fluently but the words may not make sense, caused by damage to the temporal-parietal region.

Global Aphasia

Severe impairment in both understanding and producing language due to extensive damage involving both major language areas.

Cushing triad

A late and dangerous sign of increased ICP consisting of increased systolic BP/widened pulse pressure, bradycardia, and irregular respirations.

Papilledema

Blurred vision caused by pressure transmitted to the optic nerve.

Bitemporal hemianopia

Loss of lateral vision from both visual fields, often associated with pituitary tumors.

Ataxia

Loss of coordination and balance problems typically associated with cerebellum or brainstem manifestations.

Transient Ischemic Attack (TIA)

A temporary interruption of blood flow that causes stroke symptoms which resolve within minutes, leaving no permanent infarction.

Thrombotic stroke

The most common type of stroke, occurring when a clot forms in a cerebral artery, usually over atherosclerotic plaque.

Embolic stroke

A stroke where a clot travels from another location to block a cerebral artery.

Hemorrhagic stroke

A stroke caused by the rupture of a cerebral blood vessel, resulting in high ICP and potential herniation.

Ischemic stroke

A broad category including thrombotic and embolic strokes that account for about $87\%$ of strokes.

Penumbra

The surrounding tissue of an infarcted central area in an ischemic stroke that may be saved with rapid treatment.

Apraxia

Difficulty planning movements, often seen in left frontal and parietal strokes.

Shingles

Reactivation of varicella-zoster virus producing a painful, blistering rash in a dermatomal pattern.

Ptosis

A drooping eyelid.

Agnosia

The inability to recognize everyday objects.

Contralateral

A term referring to the opposite side.

Dysarthria

Difficulty pronouncing words.

Paraplegia

Paralysis of the lower half of the body.

Photophobia

Increased sensitivity to light.

Quadriplegia

Paralysis of all four limbs.

Ipsilateral

A term referring to the same side.

Hemiplegia

Paralysis of one side of the body.

Glioma

A brain tumor originating in neurologic cells.

Contusion

Bruising of the brain.

Absence or Petit Mal Seizure

A brief staring episode usually lasting less than $20\,\text{seconds}$ without major collapse or postictal confusion.

Prodromal signs

Nonspecific changes such as irritability or headache occurring hours or days before a seizure.

Aura

A specific sensation that occurs immediately before or at the beginning of a seizure.

Tonic Phase

A phase of a seizure where the body becomes stiff and the person loses consciousness.

Clonic Phase

A phase of a seizure characterized by repetitive rhythmic jerking.

Parkinson's Disease

A disorder caused by the degeneration of dopamine-producing neurons in the substantia nigra.

Bradykinesia

Slowness of movement, characteristic of Parkinson's Disease.

Lewy bodies

Abnormal structures containing alpha-synuclein that may be present in Parkinson's Disease.

Amyotrophic Lateral Sclerosis (ALS)

A progressive, fatal disease involving degeneration of upper and lower motor neurons, resulting in muscle atrophy and respiratory failure.

Myasthenia Gravis

An autoimmune disorder where antibodies target ACh receptors, causing fluctuating muscle weakness that improves with rest.

Huntington's Disease

An autosomal dominant mutation involving an expanded $CAG$ repeat in the $HTT$ gene, leading to chorea and cognitive decline.

Beta-amyloid plaques

Typical brain changes in Alzheimer's Disease found between neurons.

Tau neurofibrillary tangles

Typical brain changes in Alzheimer's Disease found inside neurons.