neurological disorders Flashcards
multiple sclerosis
=a potentially disabling disease of the brain and spinal cord (central nervous system). the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body
causes: your immune system mistakenly attacking the brain and nerves. It’s not clear why this happens but it may be a combination of genetic and environmental factors.
symptoms: Numbness or weakness in one or more limbs that typically occurs on one side of your body at a time, Tingling, Electric-shock sensations that occur with certain neck movements, especially bending the neck forward (Lhermitte sign), Lack of coordination, Unsteady gait or inability to walk, Partial or complete loss of vision, usually in one eye at a time, often with pain during eye movement, Prolonged double vision, Blurry vision, Vertigo, Problems with sexual, bowel and bladder function, Fatigue, Slurred speech, Cognitive problems, Mood disturbances
risk factors: 20-40 YOA, women, family history, certain infections, white people, low vitamin D, genes, obesity, other autoimmune diseases, smoking
patho: MS refers to the plaques that form in the CNS combined with inflammation, demyelination, axonal injury and axonal loss. These plaques are found in the brain and spinal cord, essentially in the white matter around the ventricles, optic nerves and tracts, corpus callosum, cerebellar peduncles, long tracts and subpial region of the spinal cord and brainstem, but also in the gray matter
amyotrophic lateral sclerosis
=a nervous system disease that affects nerve cells in the brain and spinal cord. ALS causes loss of muscle control. The disease gets worse over time.
symptoms: Trouble walking or doing usual daily activities, Tripping and falling, Weakness in the legs, feet or ankles, Hand weakness or clumsiness, Slurred speech or trouble swallowing, Weakness associated with muscle cramps and twitching in the arms, shoulders and tongue, Untimely crying, laughing or yawning, Thinking or behavioral changes.
causes: 10% of people is genetic. rest is idiopathic
risk factors: genetics, 60-80. 75+ risk increases, men, smoking, environmental toxin exposure, military service
patho: ALS causes both groups of motor neurons to gradually deteriorate and then die. When motor neurons are damaged, they stop sending messages to the muscles. As a result, the muscles can’t function.loss of motor neurons in the spinal ventral horns, most brainstem motor nuclei and motor cortex
pain physiology
pain is a sensation that occurs when nociceptors (pain receptors) come into contact with painful stimulants
nociceptive pathway= peripheral level: noxious stimuli, nociceptor detection and transduction. spinal segmental level: peripheral nerve fibres (a-delta and c-fibres), spinal cord (pain pathways, dorsal horn synapses), supraspinal level (supraspinal structures (thalamus, midbrain/ pons/ medulla, basal ganglia), cortical level: somatosensory cortex and limbic system
types of pain= nociceptive pain: no nervous system lesion or inflammation–> stimulant dependent pain evoked by high intensity stimuli. physiological and clinically relevant stimuli
inflammatory pain: active inflammation–> spontaneous and stimulus dependent pain. sensory amplification evoked by low and high instensity stimuli. clinically relevant stimuli
neuropathic pain: nervous system lesion or disease–> marked neuroimmune response. spontaneous and stimulus dependent pain. sensory amplification evoked by low and high intensity stimuli. maldaptive and commonly persistant–> abnormal amplification maintained independent of lesion/ disease
epilepsy
=a common neurological disorder that affects the brain caused by frequent seizures. Seizures are bursts of electrical activity in the brain that temporarily affect how it works.
focal seizure–> abnormal activity in just one area of your brain
generalised seizures–> all areas of the brain
causes: Genetics, Previous head trauma (car accidents), Brain abnormalities (brain tumours, stroke), Infections (meningitis, HIV), Prenatal injury (poor nutrients from mother), Developmental disorders (autism)
patho: Seizures are paroxysmal manifestations of the electrical properties of the cerebral cortex. A seizure occurs when there is a sudden imbalance between the excitatory and inhibitory forces within the network of cortical neurons in favour of a sudden onset net excitation.
risk factors: Age (common in children and older adults), Family history, Head injuries, Stroke and other vascular diseases (leads to brain damage), Dementia, Brain infections (meningitis, causes inflammation in the brain and spinal cord), Seizures in childhood
s&s: depends on which part of brain is affected. Uncontrollable jerking and shaking (known as a ‘fit’), Losing awareness and staring blankly into space, Becoming stiff, Strange sensations, such as a ‘rising’ feeling in the tummy and unusual tastes or smells, and a tinging feeling in your arms or legs, Collapsing, Psychological symptoms such as fear, anxiety or deja vu
patho: A seizure can be conceptualized as occurring when there is distortion of the normal balance between excitation (E) and inhibition (I) in the brain. This E/I imbalance can result from an alteration at many levels of brain function, from genes and subcellular signaling cascades to widespread neuronal circuits. The factors that alter E/I balance can be genetic or acquired.
parkinson’s
= brain disorder that causes unintended or uncontrollable movements, such as shaking, stiffness, and difficulty with balance and coordination
causes/ risk factors: a loss of nerve cells in the part of the brain called the substantia nigra.
combination of genetics (runs in the family) and environmental factors (pesticides and herbicides used in farmingand traffic or industrial pollution).
symptoms: develop gradually
tremour (often starting in hand or arm and occurs when limb is at rest), slowness of movement (bradykinesia), muscle stiffness (rigidity) can result in painful muscle cramps (dystonia), balance problems, loss of sense of smell, nerve pain, urinary problems, excessive sweating, difficulty swallowing, depression and anxiety, mild cognitive impairment, dementia
patho: Nerve cells in this part of the brain are responsible for producing a chemical called dopamine.
Dopamine acts as a messenger between the parts of the brain and nervous system that help control and co-ordinate body movements.
If these nerve cells die or become damaged, the amount of dopamine in the brain is reduced.
This means the part of the brain controlling movement cannot work as well as normal, causing movements to become slow and abnormal.
