Neuropathology Flashcards
Describe the difference in location of white vs grey matter in the human brain and spinal cord:
- The human brain has grey matter (primary neurons) within the cortical layer on the outside of the brain as well as some deep grey matter. White matter comprised of myelinated axons is found within the centre of the brain
- The spinal cord has grey matter (primary neurons) on the inside (divided into a ventral and dorsal horn) and white matter located on the periphery
Describe the gross pathology of a brain with Alzheimer’s disease:
- Significant atrophy of the brain tissue due to loss of neurons and their synaptic connections
- Gryi of grey matter considerably smaller and deepening of sulci
- Compensatory enlargement of ventricles filled with CSF to fill space and balance intracranial pressure
What specific symptoms are linked to neurodegeneration in the:
- Cortex
- Basal ganglia
- Spino-cerebellar region
- Motor neurons
- Cortex
- Dementia - Basal ganglia
- Movement disorders - Spino-cerebellar region
- Ataxia (abnormal gait) - Motor neurons
- Upper and lower motor neuron signs (rigidity and paralysis)
Describe the gross pathology of a brain with Huntington’s Disease:
- Total atrophy of the caudate nuclei within the basal ganglia of the brain (essential for initiating movement)
What are examples of acquired spinal cord diseases vs inherited spinal cord diseases?
Acquired spinal cord disorders:
- MS (inflammatory disease)
- Poliomyelitis
- Tabes Dorsalis (syphilitis myelopathy)
- Vitamin B12 deficiency
Inherited spinal cord dieases:
- Spinocerebellar ataxias
- Motor neuron disease
- Spinal muscular atrophy
Are primary brain tumours more common in adults or children?
Are they idiopathic?
- Primary brain tumours are more common in children (particulary medulloblastomas and pilocytic astrocytomas)
- Accounts for 20% of childhood cancers
- Primary brain tumors are idiopathic
What is the most common type of primary brain tumour?
Gliomatas are the most common form of primary brain tumour (50%)
- Of these astrocytomas are the most common (75%)
Which forms of brain tumour are highly vascular?
Which forms are not vascular?
Vascular:
- Glioblastomas (form necrotic and haemorrhagic cores)
- Meningioma
- Medulloblastoma
- Metastatic carcinomas
Not vascular:
1. Low grade diffuse astrocytoma
What are symptoms of low grade vs high grade tumours?
Low grade:
- long history of poorly controlled seizures
High grade:
- Brief history of headaches, nausea and vomiting and localising signs
Describe a meningioma:
- Derived from epithelial cells of the meninges
- Common (15%) type of intracranial tumour
- Cause an increase in intracranial pressure
- Vast majority are slow growing (benign)
- Good survivibility
Describe an astrocytoma:
- Derived from neural stem cells that differentiate down astrocytoma lineage
- Most common form of primary brain tumour (75% of gliomatas)
- Causes raised intracranial pressure and focal neurological sign
- Low grade tumours usually evolve into high grade tumours
- Anaplastic have 4-5 years survival
- Pilocytic astrocytomas seen in the cerebellum of children have excellent diagnosis
Describe a glioblastoma:
- A highly malignant astrocytic tumour that grows rapidly
- Incidence greatest at 65 years
- Characterised by necrotic hemorrhagic masses in the core the tumour
- Aggressive growth can lead to non-communicating hydrocephalus
- Can form from a lower-grade astrocytoma
- Median survival time of 10 months
What are the generalised symptoms of CNS tumours?
- Due to rise in intracranial pressure:
1. Headaches and vomiting
2. Oculomotor nerve compression leading to palsy of the eye/fixed dilated pupil
3. Generalised epileptic fits
4. Dizziness
5. Papilledema (oedema of the optic nerve head) which causes clouding/blurring of vision
6. Progressive bradycardia and arterial hypertension
What are the location specific symptoms of CNS tumours:
- Prefrontal Lobe:
- Vague psychiatric signs
- Loss of appreciation of consequences of actions
- Generalised convulsions - Precentral gyrus:
- Causes Jacksonian epilepsy (rhythmic seizures beginning with face and progressing down body)
- Dysphasia - Parietal lobe:
- Jacksonian epilepsy of sensory type
- Disturbances in sensation
- Spatial disorientation
- Apraxia (difficulty with motor planning to perform tasks)
- Agnosia (cannot interpret sensations)
- Hemaniopoa (blindness in half of visual field - Occipital lobe:
- Visual hallucinations
- Hemianopia (blindness in half of visual field - Temporal lobe:
- Visual, auditory, gustatiry and olfactory hallucinations
- Amnesic periods
- Dream states
- Memory upsets
- Automatic behaviour
What is a feature of the positioning of secondary malignancies in the CNS?
- Usually present in multiple sites in the brain
- Most common form of CNS lesion in adults- specifically malignant melanoma
