Multiple sclerosis, infections and toxins Flashcards
Incidence of MS
30-80 per 100000 in Canada
Prevalence of MS in the world
depends on where you grew up and not where you live; more prevalent in countries with higher socioeconomic status and less prevalent in countries with warmer climates
Definition of MS
an autoimmune demyelinating (i.e. immune system attacks white matter) disease
Defining feature of MS
neurological episodes varying in time and space with a background of progressive decline
Groups vulnerable to MS
2-3x more common in females and 5x risk in those who have siblings with MS
Peak of onset and disability of MS
onset peaks in 30s-50s while disability peaks in 60s
Symptoms experienced during acute episodes in MS
focal weakness, paresthesias, monocular vision loss, diplopia, dysphagia, dysarthria, ataxia, bladder dysfunction
Chronic impairments in MS
fatigue, gait instability, focal spasticity, cognitive slowing, attention and memory problems, executive dysfunction
Paresthesias
tingling sensation caused by sensory change
Diplopia
double vision or seeing two images of a single object
Dysphagia
difficulty swallowing
Pathophysiology of MS
immunopathologic mechanism wherein lymphocytes and macrophages in immune system attack myelin on axons, forming new lesions along with old lesions in glial scar tissue
5 brain structures most affected in MS
cortex (periventricular), optic nerves, brainstem, spinal cord, cerebellum
How does epstein-barr virus cause MS?
increase in NfL, a protein found in blood and a biomarker of white matter damage, after EBV infection
2 ways to diagnose MS
detecting symptomatic lesions separated in time and space through MRI of brain and spinal cord; cerebrospinal fluid (spinal tap)
Course of MS
possibly years between initial minor symptom and progression
Most common prognosis or pattern of MS
relapsing-remitting with an average of 1-2 attacks per year
3 treatments for MS
corticosteroids for acute attacks; anti-CD20 monoclonal antibodies or MS-specific drugs to regulate immune system (e.g. alemtuzumab, ocrelizumab); EBV-specific therapies
2 kinds of bacterial infections
bacterial meningitis and brain abscess
Bacterial meningitis
inflammatory reaction in the meninges (layer between the brain and skull) leading to fever, headache, stiff neck
Brain abscess
accumulation of pus (ring enhancement in MRI) in the brain that typically starts due to an infection in the nose/sinus
Treatments for bacterial infections
antibiotics
4 types of viral infections
viral meningitis (almost never fatal), herpes simplex encephalitis, HIV, prion diseases
Herpes simplex encephalitis
attacks the medial-temporal lobe (bilateral) that leads to memory problems and personality changes; often misdiagnosed as psychosis
Prion diseases (e.g. Creutzfeldt-Jakob disease)
a rare viral infection that one can get from eating infected meat but is typically idiopathic; leads to the most rapid progression of dementia (weeks-months)
5 hypothesized pathophysiologies of SARS-CoV-2
neuroinflammation with antibody production; factors of susceptibility (e.g. genetics); limited presence of spike protein or viral particles; damaged blood vessels; unexplainable neuronal injury
Unresolved questions about neuropsychiatric effects of COVID-19
weak/inconsistent relationship with disease severity; symptoms and impairments not unique to COVID; symptoms without anosmia (loss of smell); pre-illness psychosocial risk factors
4 kinds of toxins
alcohol, recreational drugs, poisons and venoms, heavy metals
Wernicke-Korsakoff’s Encephalopathy
excessive alcohol consumption leads to poor diet, nutrition (thiamine) deficiency, memory problems (e.g. episodic, retrograde amnesia, confabulation, except for procedural)
Anoxic brain injury
prevents oxygen from binding to red blood cells and getting into the brain
