Issues with Nervous System Flashcards
(19 cards)
Migraines
Aura due to dysfunction of ion channels causing cortical depolarisation (excitation) followed by hyperpolarisation
Neurotransmitters such as serotonin and dopamine may be involved (inhibitors may be used to help)
Headache associated with vasodilation of extracranial vessels may be related to hypothalamic activity
Activation of trigeminovascular system likely important
Blood proteins
Tension headaches
Most common type of headache (42%)
Not fully understood (not muscle tension, but anxiety can contribute)
Women are twice as likely to experience
Pain presents as dull, tight or pressure
Pain is constant & generalised
No associated symptoms, such as nausea
Women are twice as likely to experience
Cluster headaches
Cause unknown
Possible abnormal hypothalamic activity
Cluster lasts weeks to months
Headaches usually daily
1 or several attacks can occur within 24 hrs
Lasts 15 minutes to 3 hours
Often woken at night (1-2 hours after going to bed)
Severe unilateral periorbital pain with autonomic features, flushing/swelling, eye red
Risk factors
More frequent in men, onset usually in 3rd decade, smoking, ↑ ETOH
Tinnitus
Involved auditory & non-auditory systems
*Abnormal neuronal activity in auditory complex
*Ringing or other noises not due to external sound
*Can cause fatigue, sleep disturbances, concentration, memory & mental health issues
*Experienced by 15-20% of population
Temporal arteritis (Giant cell arteritis)
*Inflammation affecting medium & large sized arteries around head
*Genetic
*Environmental
*Severe & frequent headaches
*Pain/tenderness over temples
*Jaw pain when eating or talking
*Visual disturbances
*Risk factors
*Polymyalgia rheumatic (5-15% - but almost 50% the other way around, age, sex, ethnicity
Ménière’s disease
*Abnormality of endolymph (in m labyrinth of inner ear)
*Episodes of vertigo
*Tinnitus
*Sense of pressure in ear
*Hearing loss
Labyrinthitis (acute vestibular failure)
*Inflammation of labyrinth
*Usually due to viral or bacterial infection
*Self limiting
*Dizziness
*Hearing loss
*Vertigo
*Risk factors
Viral infection, allergies, smoking, ↑ ETOH, head injury, vascular disorder, immune disorder, medications, age
Benign paroxysmal positional vertigo
*Occurs when otoconia move into semicircular canals
*Disrupts flow of endolymph
*Otoconia move & stimulate cilia causing vertigo
*Most common inner ear disorder
*Symptoms
*Dizziness, light-headedness, balance issues, nausea, vomiting, blurred vision, nystagmus
Macular degeneration
Late-onset, neurodegenerative retinal disease
2 types - Dry & wet
*Dry -parts of the macula get thinner with age and tiny clumps of protein (drusen) grow.
*Wet -abnormal blood vessels grow under the retina. These vessels may leak blood or other fluids, causing scarring of the macula
Acute vs Chronic Stress
- Acute - normal physiological response to event or situation
- Stress response system has not evolved
- Chronic – prolonged activation of stress response system
- Ongoing elevated cortisol → levels reduced immune response & ↑ inflammation
- ↑heart rate, blood pressure, respiratory rate, muscle tension
- low energy, low mood, sleep disturbances, MSK, change in appetite, difficulty focusing
- Can lead to hypertension, heart disease, obesity, metabolic syndrome, type 2 diabetes, arthritis, addiction, mood disorders
- Embracing vs elimination stress
- Stress resilience
Adrenal fatigue
- Not to be confused with adrenal insufficiency
- Controversial topic
- Not a recognised medical condition in orthodox medicine
- But do recognise that a correlation between hypocortisolism & some disease states
- Standard blood tests only look at extreme underproduction or overproduction of hormone levels
- Syndrome rather than disease
- Sub-clinical syndrome
- Failure of adrenals or failure in communication system?
Insomnia
Repeated difficulty with sleep onset, maintenance, duration or quality despite adequate opportunity & results in daytime impairment
- Prevalence 7.9% in UK (2012)
- Many different models proposed
- Hyperarousal – physiological & cognitive
- Genetics
- Molecular mechanisms
- Specific brain regions
- NREM sleep instability
- Behavioural & cognitive
Chronic fatigue syndrome (Myalgic Encephalomyelitis)
- Unexplained, profound fatigue
- Cognitive dysfunction
- Impairment of daily function
- Last for more than 6 months
- Pathogenesis unknown
- Immune dysfunction
- Hormone regulation
- Metabolism
- Oxidative stress response
- Estimated minimum prevalence 0.2% (UK, 2011
Fibromyalgia
Neurosensory disorder characterized in part by abnormalities in pain processing by CNS
- Lower threshold of pain & other stimuli
- Biochemical, metabolic & immunoregulatory abnormalities
Signs & symptoms
* Persistent (>3 month) wide spread pain
* Stiffness
* Fatigue
* Cognitive impairments
* Sleep disturbance
* Mood disorders
* IBS
* Prevalence of 5.4% in UK (2016)
neurodegenerative disease
Neurodegenerative disease: umbrella term for disorders characterized by progressive degeneration of neurones/neuronal cell loss.
Has distinct patterns in different disorders, depending on areas affected.
Neurones cannot undergo cell division –if the cell body is damaged, they die
Neurones are functional unit of nervous system and conduct impulses throughout
Affect central nervous system (CNS) – brain and spinal cord
Hallmark is neuroinflammation
Progressive –poor long term outcomes and limited treatments
Challenging to diagnose –often exclusion of other conditions
Causes often unclear and/or multifactorial
Multiple sclerosis
- Chronic inflammatory condition of the central nervous system, affecting both the brain and spinal cord, immune mediated
- Progressive demyelination of neurones in the brain, spinal cord and cranial nerves (Hubert, 2023)
- Common -1.2/1000 in UK (Jarman& Vivekananda, 2021)
- Commonest disabling disease affecting young people (Dobson & Giovannini, 2019)
Motor Neurone Disease
Progressive degenerative disease affecting upper motor neurons in cerebral cortex (causes spastic paralysis and hyperreflexia) and lower motor neurons in brain and spinal cord (causes flaccid paralysis with decreased muscle tone and reflexes).
- No indication of inflammation.
- Reasons for cell death unknown
- Sensory neurons, memory and cranial nerves to eye muscles not affected.
- Occurs in diffuse and asymmetric pattern, proceeds without remission
- No specific diagnostic tests.
Dementia
- Dementia is a syndrome – includes:
Progressive cognitive impairment (e.g. language, numeracy, logical thinking, ability to learn, motor coordination) due to decreasing cortical function
Particular impact on short term memory (also progressive) but can include confusion with long term memory
Behavioural and psychological symptoms that impair social and daily functioning. (Hubert, 2023)
- How is it different to normal memory loss due to age? Normal memory loss still allows people to function independently, although they may need reminders or prompts (Hubert, 2023)
- What about mild cognitive impairment? MCI is minor loss of cognitive function affecting daily life to some extent but not severely. May progress onto dementia. (Alzheimer’s Society, 2022
Parkinsons
- Unknown aetiology
- Progressive degenerative changes in dopaminergic neurones in in substantia nigra in the basal ganglia (responsible for fine- tuning voluntary movements)
- Presence of Lewy bodies (tangles of α- synuclein and ubiquitin) which spread from lower brainstem to midbrain to cortex
- ~70% dopaminergic nigrostriatal cells lost by the time symptoms occur
- Dopamine is an inhibitory neurotransmitter - excitation and inhibition becomes imbalanced
