Neurological Disorders I

What mechanism causes irreversible brain damage due to brain ischemia?

cell swelling, decreased brain pH, elevated potassium levels, and excessive neurotransmitter release, resulting in neuronal damage.

Define excitotoxicity.

process by which excessive stimulation of neurons by neurotransmitters, particularly glutamate, leads to neuronal cell damage and death.

Which brain regions control consciousness?

The brainstem, thalamus, and cerebral cortex are key regions that control consciousness.

What are the main characteristics of a coma?

lack of wakefulness and awareness; the patient cannot be awakened and does not respond to stimuli.

What defines a vegetative state?

wakefulness without awareness; the patient may have sleep-wake cycles but shows no purposeful responses.

What is Locked-in Syndrome?

patient is fully conscious but cannot move or communicate due to paralysis of nearly all voluntary muscles.

What occurs during REM sleep?

increased brain activity, vivid dreaming, and temporary muscle paralysis, while the body is in a state of arousal.

Name some causes of increased intracranial pressure.

brain tumors, hemorrhage, traumatic brain injury, and infections such as meningitis.

What are some signs and symptoms of increased intracranial pressure?

headache, vomiting, altered consciousness, and papilledema due to pressure on the brain.

What are the consequences of increased intracranial pressure?

brain herniation, permanent neurological damage, and death.

What is spastic paralysis?

stiff and awkward movements due to damage in the motor cortex or pathways.

What is dyskinesia?

involuntary movements resulting from damage in the basal ganglia.

What are hallmark signs of Autism Spectrum Disorder (ASD)?

difficulties in social interaction, communication challenges, and repetitive behaviors.

Which brain regions are affected in ASD?

amygdala (emotion regulation), prefrontal cortex (social behavior), and cerebellum (motor control).

What are the main characteristics of ADHD?

inattention, hyperactivity, and impulsivity, often linked to dysregulation of dopamine and norepinephrine neurotransmitters.

Why are stimulants used to treat ADHD?

They increase the levels of neurotransmitters like dopamine and norepinephrine, improving attention and focus despite seeming counterintuitive.

What are the unique effects of left hemisphere brain damage?

Loss of logical thinking ability, analytical skills, and communication skills.

What are the unique effects of right hemisphere brain damage?

Impaired appreciation of music and art, along with behavioral problems.

What are some causes of brain injury?

Ischemia, trauma, tumors, infection, and neurodegenerative diseases.

What is hypoxic injury?

A condition where the brain lacks oxygen.

What is ischemic injury?

A condition where the brain lacks oxygen, glucose, and is unable to clear waste.

What happens to cellular ATP levels during brain ischemia?

They decrease after 4-5 minutes

What is excitotoxicity?

excessive glutamate leads to excessive calcium influx, resulting in cell swelling and necrosis.

What determines the level of consciousness?

The cerebral cortex and reticular activating system in the brainstem.

What are some signs of decreased consciousness?

Lethargy, confusion/disorientation, memory loss, obtundation, and stupor.

What characterizes a coma?

The most serious impairment in consciousness where the patient lacks both awareness and wakefulness.

What is the Glasgow Coma Scale used for?

To assess the level of consciousness based on eye opening, verbal response, and motor response.

What score on the Glasgow Coma Scale indicates a coma?

A score between 3-8.

What is locked-in syndrome?

A condition where the patient is aware and capable of thinking but is paralyzed and unable to communicate.

What is a vegetative state?

A condition of diffuse brain damage with loss of awareness and mental capabilities, but brainstem function remains intact.

What is brain death?

The irreversible end of all brain activity, with no response to pain or reflexes.

What is increased intracranial pressure (ICP)?

A condition where the skull is rigid and nonexpandable, leading to decreased brain perfusion and neuronal death.

What can cause increased intracranial pressure?

Increased blood volume, increased CSF volume, and increased brain volume due to masses or edema.

What are the general signs of increased intracranial pressure?

Decreasing level of consciousness, headache, vomiting, increasing blood pressure, papilledema, and fixed and dilated pupils.

What is brain herniation?

Displacement of brain tissue from its normal position, which can lead to neuronal death.

What are the motor manifestations resulting from brain damage?

Spastic paralysis, dyskinetic disease, and loss of coordination.

What characterizes spastic paralysis?

Damage to the pyramidal tracts or motor cortex, leading to hyperreflexia.

What characterizes dyskinetic disease?

Damage to the extrapyramidal tract or basal ganglia, resulting in choreiform involuntary movements and loss of coordination.

What is ataxia?

Damage to the cerebellum characterized by loss of balance and coordination.

What are general causes of congenital neurological disorders?

Genetics, necrosis, perinatal injury, infections, toxins, mechanical trauma, hemorrhage, hypoglycemia, ischemia, and elevated bilirubin levels.

What is hydrocephalus?

A condition where excess cerebrospinal fluid (CSF) accumulates in the skull, leading to compression of brain tissue and cerebral blood vessels.

What are the main causes of hydrocephalus?

Increased CSF production, decreased CSF reabsorption, and obstruction of CSF clearance.

What are the signs and symptoms of hydrocephalus in neonates?

Head enlargement, lethargy, irritability, difficulty feeding, and a high-pitched cry when picked up or moved.

What is spina bifida?

A group of neural tube defects resulting from incomplete closure of the vertebral arch, leading to herniation of the meninges and spinal cord.

What is the most common location for spina bifida?

The lumbar region.

What are the potential treatments for spina bifida?

Surgical repair, which can now be performed in utero, along with physical therapy and assistive equipment post-repair.

What is cerebral palsy (CP)?

A group of disabilities resulting from brain injury perinatally, affecting motor, sensory, and cognitive functions.

What are common symptoms of cerebral palsy?

Delay in motor development, abnormal muscle tone, persistence of early reflexes, and potential intellectual and communication deficits.

What is the hallmark characteristic of Autistic Spectrum Disorder (ASD)?

Impaired social interaction.

What are some signs of ASD?

Failure to respond to name, lack of eye contact, inability to understand social cues, and restricted repetitive behaviors.

What are common co-morbid conditions associated with ASD?

Seizures, ADHD, gastrointestinal disorders, and tics.

What are the main neurotransmitters implicated in ADHD?

Dopamine (DA) and norepinephrine (NE).

What are the characteristics of ADHD?

Inattentiveness, impulsivity, and hyperactivity, leading to poor performance in school and work.

What are common treatments for ADHD?

Stimulants like amphetamine and amphetamine-like drugs (e.g., Ritalin) that increase levels of DA and NE in the synapse.

What is the pathophysiology of ADHD?

Decreased cortical surface area, decreased cerebellar volume, and defects in dopamine receptor genes.

What factors may contribute to the etiology of ASD?

Unknown causes, strong genetic components, immune dysfunction, advanced parental age, and maternal medication use.

What is kernicterus?

Neurotoxicity caused by free (unconjugated) bilirubin in the brain, often due to elevated bilirubin levels in newborns.

What are the treatment options for autism?

Therapies such as Applied Behavior Analysis (ABA), speech therapy, occupational therapy, and management of co-morbid conditions.

What is the significance of the immature blood-brain barrier (BBB) in newborns?

It makes babies more susceptible to neurotoxic effects, such as those from elevated bilirubin levels.

What is the role of physical therapy in treating cerebral palsy?

To provide individualized therapy and support for motor development and functional abilities.

What are the potential consequences of untreated hydrocephalus in neonates?

Permanent brain damage leading to major physical and intellectual disabilities.

What is the relationship between spina bifida and anencephaly?

Both are neural tube defects, with anencephaly being the absence of cerebral hemispheres and superior cranial vault.

What are the potential environmental factors linked to ASD?

Toxic exposures and maternal medication use, though vaccines and thimerosal have no evidence linking them to ASD.

What is the impact of maternal medication use on ADHD?

Certain medications, such as SSRIs and antiepileptics, have been associated with an increased risk of ADHD.

What are the effects of damage to the right hemisphere of the brain?

Deficiencies may include issues with spatial awareness, emotional regulation, and non-verbal communication.

What are the effects of damage to the left hemisphere of the brain?

Deficiencies may include problems with language, analytical thinking, and logical reasoning.

How does ischemia differ from hypoxia?

Ischemia refers to reduced blood flow to an area, while hypoxia refers to reduced oxygen availability regardless of blood flow.

What is the ischemic cascade?

A series of biochemical events triggered by ischemia that can lead to cell death, involving calcium influx and excitotoxicity.

What role does calcium play in excitotoxicity?

Calcium influx into neurons during excitotoxicity can activate destructive enzymes and lead to cell death.

What is the function of the reticular activating system?

It regulates consciousness, arousal, and sleep-wake cycles.

What are the different levels of consciousness?

Levels include coma, vegetative state, locked-in syndrome, and brain death.

Define confusion.

A state of disorientation regarding time, place, or identity.

Define lethargy.

A state of sluggishness, inactivity, and lack of energy.

What is obtundation?

A state of reduced alertness and responsiveness.

Define stupor.

A state of near-unconsciousness where the individual can only be aroused with vigorous stimulation.

What are the symptoms of increased intracranial pressure?

Symptoms may include headache, nausea, vomiting, altered consciousness, and visual disturbances.

What is papilledema?

Swelling of the optic disc due to increased intracranial pressure.

What is decerebrate posturing?

An abnormal body posture indicating severe brain injury, characterized by extension of the arms and legs.

Differentiate between spastic paralysis and ataxia.

Spastic paralysis is characterized by stiff and awkward movements due to muscle tightness, while ataxia is characterized by lack of coordination and balance.

What causes hydrocephalus?

It forms due to an imbalance between the production and drainage of cerebrospinal fluid, leading to increased intracranial pressure.

What are common signs of autism spectrum disorders (ASD)?

Signs may include difficulties with communication, social interactions, and repetitive behaviors.

What co-morbid conditions are often associated with ASD?

Conditions may include anxiety disorders, ADHD, and sensory processing disorders.

What anatomical changes are observed in ADHD?

Changes may include reduced size of certain brain regions, such as the prefrontal cortex and basal ganglia.