Pathophys ch23 chronic neuro disorders Flashcards
What is Hydrocephalus
Excess CSF accumulates within the skull compressing brain tissue and blood vessels
Hydrocephalus in infants
Infant’s head enlarges beyond the normal size as fluid increases
Noncommunicating or obstructive hydrocephalus
flow of CSF through the ventricles is blocked leading to increased back pressure of fluid in the ventricles which gradually enlarge - compressing the blood vessels and brain tissue
Communicating hydrocephalus
absorption of CSF through the subarachnoid villi is impaired - resulting in increased pressure of CSF in the system
Hydrocephalus induced brain damage
The amount of brain damage depends on the rate at which pressure increases and the time that elapses before relief occurs
Hydrocephalus Etiology
- Developmental abnormality
- stenosis of connecting canals
- thickened arachnoid membrane
- tumor, infection, or scar tissue
Hydrocephalus S&S - in neonates
Head enlarges - scalp veins are dilated - shrill cry - etc.
What is Spina bifida
Neural tube defect in which the posterior spinous processes do not fuse
Spina bifida occulta
spinous processes don’t fuse - no herniation
Meningocele
herniation of meninges and CSF form a sac outside
Myelomeningocele
herniation of spinal cord and nerves along with meninges and CSF
Spina bifida Etiology
Combination of genetic and environmental factors
Spina Bifida S&S
Menigocele - visible protruding sac - sensory and motor function impairment below the herniation.
Alpha-fetoprotein levels elevated in maternal blood and amniotic fluid.
What is Cerebral palsy
Group of disorders marked by motor impairment caused by mutations, infection, brain damage occuring during the perinatal period.
3 groups of cerebral palsy motor disabilities
- spastic paralysis
- dyskinetic
- ataxic
Spastic paralysis
damage to the motor cortex or pyramidal tracts causing hyperreflexia
Dyskinetic disease
damage to the extrapyramidal tract - basal nuclei - or cranial nerves resulting in athetoid or choreiform involuntary movement and loss of coordination
Ataxic cerebral palsy
damage to the cerebellum resulting in loss of balance and coordination
Cerebral palsy etiology
- Brain damage or abnormal brain development
- infection, hypoxia, hypoglycemia, trauma
- hypoxia or ischemia is the major cause of brain damage
Cerebral palsy - other areas of disfunction
Additional areas of dysfunction - intelligence - speech - seizures - vision
Seizure disorders
sudden - spontaneous - uncontrolled depolarization of neurons
Seizure disorders classification
Classified by their location in the brain and their clinical features
- generalized seizures (multiple foci or origin)
- partial seizures (single focus origin)
Seizure disorders - neuronal focus
The neurons in the focus are hyperexcitable and have a lowered threshold for stimulation
Seizure disorders - propagation
The focal cells stimulate the surrounding normal cells - spreading the activity
Seizure disorders - etiology
- idiopathic (primary cause)
- congenital disorders
- acquired (secondary)
- head injury, infection, tumor, high fever
Generalized seizures
both hemispheres are affected with loss of consciousness
Absence (petit mal) seizures
brief loss of awareness and sometimes transient facial movements
Tonic-clonic (grand mal) seizures
loss of consciousness and the individual falls to the floor - strong tonic muscle contractions followed by clonic stage when muscles alternately contract and relax
Status epilepticus
recurrent tonic-clonic seizures without full return to consciousness which can lead to severe hypoxia, hypoglycemia, acidosis
Partial seizures
single focus or origin - often in the cerebral cortex
Simple partial or focal seizures
manifested by repeated motor activity or by a sensation such as tingling - memory and consciousness remain
Jacksonian seizure (Partial seizures)
focal motor seizure in which clonic contractions begin in a specific area and spread progressively
Psychomotor seizures - behavioral S&S
Also known as Complex partial or temporal lobe seizures. S&S bizarre behavior - perhaps repetitive and purposeful but inappropriate
Psychomotor seizures - visual S&S
Visual or auditory hallucinations or feelings of deja vu occur
Psychomotor seizures - awareness
Person is unresponsive to people or activities during the seizure
What is Multiple sclerosis (MS)
Progressive demyelination of the neurons of the brain, spinal cord, and cranial nerves
Multiple sclerosis (MS) - pathophsiology
Loss of myelin interferes with conduction of impulses in affected fibers
Multiple sclerosis (MS) - etiology
- Immune inflammatory response in which cells attack neurons (autoimmune disease).
- Genetic and environmental components
Multiple sclerosis (MS) - S&S
S&S - blurred vision - weakness in legs - diplopia - scotoma - dysarthia
What is Parkinson’s disease
Progressive degeneration disorder affecting motor function through loss of extrapyramidal activity
Parkinson’s disease - pathophysiology
A decreased number of neurons in the substantia nigra secrete dopamine
Parkinson’s disease S&S
S&S - tremors in hands - feet - etc. along with muscle rigidity - bradykinesia
What is Amyotrophic lateral sclerosis (ALS)
Progressive degenerative disease affecting both upper motor neurons in the cerebral cortex and lower motor neurons in the brainstem and spinal cord.
Amyotrophic lateral sclerosis (ALS) - spastic pathophysiology
Loss of upper motor neurons leads to spastic paralysis and hyperreflexia
Amyotrophic lateral sclerosis (ALS) - flaccid pathophysiology
Loss of lower motor neurons leads to flaccid paralysis
Amyotrophic lateral sclerosis (ALS) - S&S
S&S - muscle weakness and atrophy - paralysis progressing through body - eventually swallowing and respiration are impaired
What is Myasthenia gravis
Autoimmune disorder that impairs the receptors for acetylcholine at the neuromuscular junction preventing stimulation of the muscles
Myasthenia gravis S&S
S&S - muscle weakness and fatigue in face and eyes - chewing and swallowing become difficult - neck and arm muscles become involved
What is Huntington’s disease
Autosomal-dominant inherited disorder does not manifest until midlife
Huntington’s disease - pathophysiology
Progressive atrophy of the brain occurs with degeneration of neurons in the basal ganglia and the frontal cortex
Huntington’s disease S&S
S&S - mood swings - personality changes - restlessness - choreiform movements progressing to rigidity - akinesia - dementia
Dementia
Progressive chronic disease where cortical function is decreased impairing cognitive function
Dementia - S&S
Behavioral and personality changes are usually present
Alzheimers disease - Pathophysiology
Progressive cortical atrophy and loss of intellectual function
Alzheimers disease - S&S
S&S - loss of memory - lack of concentration etc.
Vascular dementia - etiology
caused by cerebrovascular disease and results from multiple small brain infarctions
Vascular dementia - S&S
S&S - memory loss - apathy - inability to manage daily routine
Creutzfeldt-Jakob disease - etiology
caused by infection by a prion
Creutzfeldt-Jakob disease - S&S
S&S - memory loss - behavioral changes - motor dysfunction
AIDS dementia
HIV invades brain tissue resulting in gradual memory loss and cognitive ability and impaired motor skills
Mental disorders
Dysfunction in the areas of behavior or personality that interferes with the person’s ability to function
Schizophrenia - pathophysiology
Changes in brain - reduced gray matter in the temporal lobe - enlarged ventricles - excessive dopamine secretion - decreased blood flow to the frontal lobes
Schizophrenia S&S
S&S - disorganized thought processes - impaired communication
Depression - what is it?
Classified as mood disorder on the basis of characteristic disorganized emotions
Depression types
Includes unipolar / bipolar disorders and response to a life event
Depression pathophysiology
Results from decreased activity of norepenephrine and serotonin
Depression S&S
S&S - prolonged period of profound sadness marked by hopelessness and an inability to find pleasure in any activity
Describe a Panic disorder
An anxiety disorder which develops when panic attacks are frequent or prolonged
Panic disorder - pathophysiology
An increased discharge of neurons or biochemical abnormalities involving neurotransmitters
Panic disorder S&S
S&S - repeated episodes of intense fear without provocation
What is a Herniated intervertebral disc?
Protrusion of the nucleus pulposus through a tear in the annulus fibrosus into the extradural space
Herniated intervertebral disc pathophysiology
Exerts pressure on the spinal nerve or cord interfering with conduction
Herniated intervertebral disc - how is permanent damage done
Pressure on nerve tissue / blood supply may result in permanent damage
Herniated intervertebral disc - etiology
Etiology - trauma or poor body mechanics
Herniated intervertebral disc S&S
S&S - lumbosacral causes lower back pain that radiates down 1 or 2 legs - cervical causes pain in the neck and shoulder that radiates down the arm
Definition of Amyotrophic lateral sclerosis:
- Amyotrophic = muscle wasting
- Lateral Sclerosis = degenerative hardening of lateral corticospinal tracts
Name two types of hydrocephalus.
- Noncommunicating (or obstructive) hydrocephalus
- Communicating hydrocephalus
Name three categories of spina bifida
- Spina bifida occulta
- Meningocele
- Myelomenigocele
