Chapter 45: Chronic Disorders of Neurological Function (Exam 3)

Seizure

Transient neurological event caused by excessive or abnormal neuronal discharges.

Epilepsy

Chronic disease characterized by recurrent seizures requiring lifelong treatment.

Common causes of seizures

Cerebral injury, lesions, metabolic disorders, nutritional disorders, and idiopathic causes.

Epileptogenic focus

Group of hyperexcitable neurons that emit excessive electrical discharges.

Aura

Subjective feeling that a seizure is about to occur.

Common prodrome symptoms of seizures

Headache, lethargy, mood changes, and palpitations.

Main excitatory neurotransmitter

Glutamate.

Main inhibitory neurotransmitter

GABA.

Generalized seizure

Seizure involving the entire brain.

Partial (focal) seizure

Seizure activity limited to one hemisphere.

Simple focal seizure

Focal seizure without loss of consciousness.

Complex focal seizure

Focal seizure with altered consciousness.

Status epilepticus

Continuous seizures without recovery between episodes.

Absence seizure

Brief staring spell usually occurring in children.

Myoclonic seizure

Single or repeated muscle jerks.

Atonic seizure

Drop attack causing sudden loss of muscle tone.

Tonic-clonic seizure

Seizure with loss of consciousness and violent muscle contractions.

Diagnostic test for epilepsy

EEG (electroencephalogram).

Treatment priorities during a seizure

Maintain airway, protect from injury, and document the seizure.

Purpose of anticonvulsants

Reduce neuronal excitation and increase inhibition.

Dementia

Syndrome involving progressive decline in memory and cognitive function.

Most common neurodegenerative dementia

Alzheimer disease.

Most common non-neurodegenerative dementia

Vascular dementia.

Risk factor that increases Alzheimer's risk fourfold

Family history.

Hallmark of Alzheimer's disease

Beta-amyloid plaques and neurofibrillary tangles.

Location of neuronal degeneration in Alzheimer's

Temporal and frontal lobes.

Beta-amyloid plaques

Protein deposits found in Alzheimer's disease.

Neurofibrillary tangles

Abnormal tau protein deposits in neurons.

Neurotransmitter deficiency in Alzheimer's

Acetylcholine.

Early signs of Alzheimer's

Forgetfulness and impaired judgment.

Late signs of Alzheimer's

Loss of ambulation, incontinence, and inability to perform self-care.

Acetylcholinesterase inhibitors used in Alzheimer's

Donepezil, Rivastigmine, and Galantamine.

NMDA receptor antagonist used in Alzheimer's

Memantine (Namenda).

Goal of Alzheimer's medications

Slow disease progression and stabilize cognition.

Parkinson disease

Progressive neurodegenerative disorder causing impaired movement.

Most common cause of Parkinson disease

Idiopathic degeneration of dopaminergic neurons.

Brain structure affected in Parkinson disease

Substantia nigra.

Neurotransmitter deficient in Parkinson disease

Dopamine.

Protein deposits found in Parkinson disease

Lewy bodies.

Lewy bodies are composed of

Alpha-synuclein.

Percentage of dopaminergic cell loss before symptoms appear

75–80%.

Bradykinesia

Slowness of movement.

Classic triad of Parkinson disease

Bradykinesia, rigidity, and resting tremor.

Characteristic gait in Parkinson disease

Shuffling gait with absent arm swing.

Postural abnormality in Parkinson disease

Stooped posture.

Swallowing problem in Parkinson disease

Dysphagia with risk of aspiration.

Primary medication for Parkinson disease

Levodopa plus Carbidopa.

Dopamine agonists used in Parkinson disease

Pramipexole and Ropinirole.

MAOI used in Parkinson disease

Safinamide.

Purpose of Parkinson medications

Increase dopamine activity in the brain.

Cerebral palsy

Group of permanent, nonprogressive disorders affecting motor control.

Causes of cerebral palsy

Prenatal infection, trauma, hypoxia, prematurity, and neonatal hypoglycemia.

Spastic cerebral palsy

Characterized by stiffness and hypertonia.

Ataxic cerebral palsy

Characterized by poor balance and coordination.

Dyskinetic cerebral palsy

Characterized by abnormal involuntary movements.

Characteristic gait of cerebral palsy

Scissored gait.

Treatment for cerebral palsy

Muscle relaxants, anticonvulsants, braces, and surgery.

Hydrocephalus

Abnormal accumulation of cerebrospinal fluid.

Congenital causes of hydrocephalus

Neural tube defects and aqueduct stenosis.

Acquired causes of hydrocephalus

Infection, hemorrhage, and tumors.

Normal pressure hydrocephalus triad

Gait instability, urinary incontinence, and dementia.

Obstructive hydrocephalus

Caused by blockage of CSF flow.

Nonobstructive hydrocephalus

Caused by impaired CSF absorption.

Most common treatment for hydrocephalus

Ventriculoperitoneal shunt.

Alternative surgical treatment for hydrocephalus

Endoscopic third ventriculostomy.

Function of the cerebellum

Coordinates movement and maintains balance.

Symptoms of cerebellar disorders

Ataxia, hypotonia, intention tremor, and gait disturbances.

Multiple sclerosis

Chronic autoimmune demyelinating disease of the CNS.

Population most affected by MS

Young adult women.

Cause of MS

Unknown but thought to involve autoimmune, genetic, and environmental factors.

Pathology of MS

Inflammation and destruction of myelin.

Commonly affected nerves in MS

Optic and oculomotor nerves.

Course of MS

Exacerbations and remissions.

Symptoms of MS

Double vision, weakness, and sensory deficits.

Treatment for MS

Steroids and immune-modifying drugs.

Spina bifida

Defective closure of the neural tube.

Risk factor for spina bifida

Folate deficiency.

Spina bifida occulta

Incomplete vertebral fusion without an external sac.

Sign of spina bifida occulta

Dimple with a tuft of hair.

Meningocele

Protrusion containing only CSF.

Myelomeningocele

Sac containing meninges, CSF, and spinal cord tissue.

Myeloschisis

Exposed neural tissue with permanent paralysis.

Treatment for spina bifida

Surgical repair within 72 hours of birth.

Prevention of neural tube defects

Folic acid supplementation.

ALS

Amyotrophic lateral sclerosis; progressive degeneration of motor neurons.

Other name for ALS

Lou Gehrig disease.

Age group commonly affected by ALS

50–75 years old.

Pathologic hallmark of ALS

Misfolded protein aggregates.

Symptoms of ALS

Muscle wasting, twitching, and weakness.

Body area usually affected first in ALS

Hands and upper extremities.

Most common cause of death in ALS

Respiratory failure.

Functions preserved in ALS

Sensation, cognition, and bowel and bladder control.

Medication that prolongs life in ALS

Riluzole.

Medication that slows functional decline in ALS

Edaravone.

Spinal cord injury (SCI)

Compression or trauma causing damage to the spinal cord.

Most common cause of SCI

Land transportation accidents.

Mechanisms of SCI

Hyperflexion, hyperextension, and compression.

Primary spinal cord injury

Immediate axonal disruption and neuronal death.

Secondary spinal cord injury

Ischemia, edema, and inflammation after injury.

Acute phase of SCI

Begins immediately with trauma and ischemia.