Neurological conditions Flashcards
MS
A relapsing and remitting demyelinating disease of the CNS in which episodes of neurological disturbance affect different parts of the CNS at different times.
This disrupts the normal flow of electrical impulses along the nerves, leading to a wide range of symptoms.
MS Epidemiology
Women
Peak age 20-30
MS Patho
Combo of Enviro factors (infections and Vit D deficiency)
and Genetic factors that trigger an abnormal Autoimmune response, whereby immune system attacks myelin which covers neurons causing communication between neurons to breakdown.
Myelin is the fatty tissue which surrounds and protects nerve fibres.
Brain/neurons protected by BBB - only lets certain cells through.
T-cells activated by myelin - change BBB to express more receptors allowing more immune cells to cross BBB.
Type 4 Hypersensitivity reaction (cell mediated response).
Myelin specific T-cells release cytokines which dilate blood vessels allowing more immune cells to cross the BBB and cause damage to the oligodendrocytes (myelinating cells).
Cytokines also attract B-cells + macrophages that engulf and destroy the oligodendrocytes - no myelin to cover neurons creating areas of scarring/plaques. When nerves are damaged this way they cant conduct electrical impulses to and from the brain.
Attacks typically happen in bouts as regulatory T-cells reduce inflammation.
In the early stages of the disease, a complete recovery from an episode of demyelination is the rule =remyelination.
As the disease progresses, recovery is slower and residual deficit remains as axons begin to die. Eventually, extensive axonal death results in irreversible permanent neurological disability.
4 main types of MS
1) Relapsing-remitting (RRMS) - the most common, bouts of autoimmune attacks happening months and years apart e.g. loss of vision followed by improvement but some residual disability remains. This means that with each attack more and more of the CNS becomes irreversibly damaged.
Occurs in bouts due to T-regulatory cells.
2) Secondary progressive (SPMS) - Starts like RRMS but Overtime the immune attack becomes constant causing a steady progression of disability overtime
3) Primary progressive (PPMS) - One constant attack on myelin, steady progression of disability overtime.
4) Progressive - relapsing (PRMS) - one constant attack where bouts are superimposed, disability happens even faster.
1-4 get worse (4 the worst)
MS S&S
Unpredictable, may be mild or severe, short or long lasting - depends on location of the plaques.
Firstly- blurred or double vision, red-green colour distortion, P and loss of vision because of optic neuritis.
Dysarthria - unclear speech - Plaques in the brain stem
Nystagmus - involuntary rapid eye movements - plaques in nerves controlling eye movements
Intention tremor - plaques in motor pathways
Trouble walking - spastic gait
Clonus
Lhermitte sign
Intention tremor
Abducens nerve palsy - medial gaze
Paraesthesia
Others- muscle weakness in peripherals, lack of coordination, spasticity (involuntary inc tone of muscle leading to stiffness and spasm), speech problems, depression, changes in bowel and bladder
Cognitive- lack of concentration, attention, memory, judgement
MS Investigations
Changes to brain patterning can be seen on MRI
Must have had 2 attacks less than 1 month apart. Attack= sudden emergence of symptoms
More than 1 area of damage to CNS myelin
MS Mangement
Options may include medications to control inflammation and slow the progression of the disease
Corticosteroids and immunosuppressants.
Equipment- such as canes, braces or walkers
Rehab activities.
Amyotrophic Lateral Sclerosis
Characterised by the degeneration and loss of motor neurons in the brain, brainstem, and spinal cord.
As the disease progresses, the muscles become progressively weaker, leading to difficulties in speaking, swallowing, breathing, and eventually, total paralysis.
ALS Epidemiology
55-75
Males, as people age the difference between sexes disappears
Race and ethnicity- Caucasians and non-Hispanics
ALS Patho
Genetic mutation (25-40%)
Affects both upper and lower motor neurons- those nerve cells in brain and spinal cord that control voluntary movement
Usually starts in one limb and moves to other limbs and trunk muscles.
Loss of motor neurons in spinal ventral horns, most brainstem motor nuclei and motor cortex
It is progressive
As motor neurons die and degenerate, they stop sending messages to muscles
This causes weakness, fasciculations and atrophy
Eventually all control is lost to initiate and control voluntary movements
ALS S&S
Early- muscle twitches in arm, leg, shoulder, tongue
Muscle cramps
Spasticity of neck muscles
Trouble walking or doing usual daily activities.
Tripping and falling.
Weakness in the legs, feet or ankles.
Hand weakness or clumsiness.
Eventually will not be able to stand or walk
Dysphagia
Dysarthria (speech)
Dyspnoea (breathing)
Unable to maintain weight and nourishment
ALS Investigations
EMG- detects electrical activity of muscle fibres
Nerve conduction study- measures electrical activity of nerves and muscles by assessing nerves ability to send a signal along the nerve or to the muscle
MRI- non-invasive, imagine of brain and spinal cord
ALS Management
There is no cure for ALS, and treatment focuses on managing symptoms, providing supportive care, and improving quality of life.
Riluzole and edaravone
Epilepsy
A recurrent tendency to spontaneous episodes of abnormal electrical activity within the brain which manifest as seizures.
Clinical manifestations range from major motor convulsion to brief period of lack of awareness
Epilepsy Epidemiology
Any age
1% have recurrent
