Neuropathology Flashcards
What are the roles of these cells:
- Oligodendrocytes
- Ependyma
- Microglia
- Wrap around axons forming myelin sheath
- Line the ventricular system
- Serve as a fixed macrophage system (originate from bone marrow)
What must you consider in an elderly patient with symptoms suggestive of dementia?
A vitamin deficiency
What occurs when neurons are subjected to hypoxia?
- Activation of glutamate receptors results in uncontrolled calcium entry into cells
- Cannot metabolise glucose anaerobically
What is the most important histopathological indicator of CNS injury?
Gliosis
- Astrocyte hyperplasia and hypertrophy
- Nucleus enlargement
- Cytoplasmic enlargement
What are ependymal granulations?
Irregularities on the ventricular surface due to proliferation of astrocytes following ependymal cell disruption
What range of diastolic BP’s can the brain autoregulate its blood flow?
50 - 130 mmHg
What symptoms are typical in an anterior cerebral artery occlusion?
- Contralateral sensory loss in foot & leg
- Paresis of arm & foot, sparing of thigh & face
What symptoms are typical in a middle cerebral artery occlusion?
- Hemiparesis (one sided muscle weakness)
- Hemisensory loss
- Aphasia/dysphasia
- Apraxia (inability to perform actions)
What form of visual defect occurs following insult to the occipital lobe?
Homonymous hemianopia with macular sparing
What symptoms are typical following insult to the cerebellum?
- Ataxia (loss of control of body movements)
- Nystagmous
- Intention tremor
- Pendular reflexes (dampened, non-brisk)
Which cells are most sensitive to ischaemia?
Neurons (more so than glial cells)
What is the definition of a stroke?
Sudden disturbance of cerebral function of vascular origin that causes death or lasts over 24 hours
What is the most common cause of a spontaneous subarachnoid haemorrhage?
Rupture of a saccular aneurysm (Berry aneurysm)
What symptoms would make you suspect a subarachnoid haemorrhage?
- Abrupt onset
- Severe headache
- Vomiting
- Loss of conciousness
What are lacunar infarcts that occur in hypertension within the brain?
Small cavities up to 10mm diameter found in the basal ganglia, thalamus and pons of elderly patient’s brains
What are some common symptoms that MS complain of?
- Visual/speech disturbances
- Parasthesia
- Spasticity of one or more of the extremities
- Gait abnormalities
Why does the external appearance of the brain normally look normal in MS?
Is a disease of the white matter which is a deep structure within the brain
Describe the plaques seen in:
- Acute MS
- Chronic MS
- Appear yellow/brown, ill-defined edges which blend into surrounding WM
- Grey/brown, well-demarcated in WM situated around lateral ventricles
What are some pathological changes that occur in the brain of an Alzheimer’s patient?
- Cortical atrophy
- Widening of sulci
- Narrowing of gyri
- Dilatation of ventricles
(Brainstem and cerebellum unaffected)
What are the hallmarks of Dementia with Lewy bodies?
Hallucinations and fluctuating levels of attention
What are the pathological features of dementia with Lewy bodies?
- Degeneration of the substansia nigra (as seen in Parkinson’s)
- Remaining nerve cells contain Lewy bodies
- Cortical areas degenerate (as seen in Alzheimer’s)
Which protein is detected following immunochemical stain in dementia with Lewy bodies?
Ubiquitin
What inheritance pattern does Huntington’s follow and which gene is affected?
- Autosomal dominant
- Huntingtin gene on chromosome 4p
What are the clinical features of Huntington’s disease?
Triad of emotional, cognitive and motor disturbances
