CNS Disorders

Question 1

Mechanisms of pathogenesis in the CNS

Answer 1

• Altered gene expression
• Abnormal protein-protein interactions
• Other molecular mediators

All mechanisms result in region-specific neuronal/ synaptic dysfunction and cell death

Question 2

Cerebral cortex

Answer 2

Involved in planning & execution of motor activity as well as conscious awareness

The most common neurological problems in this area are due to trauma, stroke, tumour or neurodegeneration

Question 3

Basal ganglia

Answer 3

Involved in motor function and emotion

Dysfunction of the basal ganglia leads to involuntary movement (Parkinson’s disease, Huntington’s disease)

Question 4

Hypothalamus

Answer 4

Controls the homeostatic functions of the body

Question 5

Thalamus

Answer 5

Relays sensory and motor signals

Question 6

Limbic system

Answer 6

Unique to mammals, involved in self-preservation functions

Dysfunction of the limbic system leads to dementia, anxiety, affective disorders and psychosis

Question 7

Cerebellum

Answer 7

Co-ordinates movement

Question 8

Depression

Answer 8

An affective disorder that interferes with daily life and normal functioning

Causes = genetic, environmental (stress)

Symptoms = persistent negative emotions, difficulty concentrating, fatigue

Treatment = antidepressants, talking therapies

Question 9

Schizophrenia

Answer 9

A loss of contact with reality, leading to psychotic episides

Causes = alcohol, tumours, dementia, neurodegenerative disorders

Symptoms = postive (delusions)/ negative (anhedonia)

Treatment = antipsychotic drugs

Question 10

Tourette syndrome

Answer 10

A neurological disorder characterised by uncontrolled outbursts of speech/movement

Cause = unknown

Symptoms = repetitive involuntary movements and vocalisations

Treatment = none

Question 11

Epilepsy

Answer 11

Abnormal neuronal signalling, leading to seizures

Causes = illness, brain trauma, neurotransmitter imbalance

Symptoms = convulsions, muscle spasms, loss of conciousness

Diagnosis = electroencephalogram

Treatment = antiepileptic drugs, surgery

Question 12

Traumatic brain injury

Answer 12

Sudden trauma causing damage to the brain

Symptoms = loss of conciousness, headache, dizziness, memory problems, nausea, vomiting, confusion

Treatment = prevention of further injury, surgery

Question 13

CNS tumours

Answer 13

Abnormal tissue growths (benign or malignant) which place pressure on the brain and impair function

Symptoms = headaches, seizures, nausea, vomiting

Treatment = surgery, radiotherapy, chemotherapy

Question 14

Spinal cord injury

Answer 14

Sudden traumatic blow to the spine causing fracture/dislocation of vertebrae

This can disrupt the neuronal signalling pathway

Can result in full recovery or paralysis

Complications = chronic pain, bladder dysfunction

Treatment = rehabilitation programmes

Question 15

Hydrocephalus

Answer 15

Excessive accumulation of cerebrospinal fluid, putting pressure on brain tissue

Causes = abnormal dilation of ventricles (due to a congenital defect or trauma)

Symptoms = headache, vomiting, lethargy, changes in personality

Question 16

Metabolic disorders

Answer 16

Causes = nutritional deficiencies, metal toxins

Symptoms = direct CNS damage, secondary CNS pathology

Question 17

Dementia

Answer 17

Significant impairment of intellectual functioning

Causes = medications, tumours, age

Symptoms = loss of ability to solve problems, language impairment, memory loss

Question 18

Alzheimer’s Dementia

Answer 18

The most common form of dementia

Symptoms = progressive cognitive impairment

Causes = genetics, age

Treatment = none to slow progression, cholinesterase inhibitors

Question 19

Pick’s disease

Answer 19

Frontotemporal dementia, very rare

Symptoms = changes in behaviours, language disturbance

Memory remains intact

Treatment = none

Question 20

Multi-infarct dementia

Answer 20

Causes = multiple strokes leading to damaged brain tissue

Symptoms = confusion, short-term memory problems

Treatment = none

Question 21

Parkinson’s disease

Answer 21

A motor system disorder

Causes = loss of dopaminergic neurons in the substantia nigra

Symptoms = tremor, rigidity

Treatment = L-dopa

Question 22

Huntington’s disease

Answer 22

A motor system disorder

Cause = genetically programmed brain degeneration

Symptoms = uncontrolled movements, loss of intellectual faculties, emotional disturbance

Treatment = pharmacology to control symptoms

Question 23

Narcolepsy-cataplexy

Answer 23

Cause = loss of hypocretins/orexins and neurotransmission

Symptoms = excessive daytime sleepiness, cataplexy, direct transition from wakefulness to REM sleep

Treatment = wake-promoting drugs

Question 24

Cerebral aneurysm

Answer 24

Dilation/bulging of part of the wall of an artery in the brain

Symptoms =

• Unruptured; loss of feeling, vision problems
• Ruptured: severe headache, nausea, vomiting, loss of consciousness

Treatment = restore respiration, reduce pressure in brain, surgery

Question 25

Meningitis/encephalitis

Answer 25

Inflammatory disease of the membranes surrounding the brain or spinal cord Cause = bacteria or viral infections Symptoms = high fever, severe headache, stiff neck, nausea, vomiting, confusion Treatment = antibiotics/ antivirals

Question 26

Creutzfeldt-Jakob disease

Answer 26

Degenerative fatal brain disorder Cause = altered forms of the protein prion Diagnosis = autopsy Treatment = none

Question 27

Kuru

Answer 27

A fatal brain disorder occurring in New Guinea Cause = ritualistic cannibalism Symptoms = unsteady gait, tremor, slurred speech, behavioural changes

Question 28

Multiple sclerosis

Answer 28

Demyelinating condition Cause = unknown Symptoms = blurred vision, muscle weakness, speech impairment, tremor Treatment = none

Question 29

Aging

Answer 29

There is an age-related decline in cognitive functions caused by oxidative stress Symptoms = memory loss