Neuropathology Spot Test

Question 1

What are the macroscopic neuropathological features of patients with multiple systems atrophy?

Answer 1

Macroscopic pathology

• Cortical atrophy
• Cerebellar atrophy
• Shrinkage of the cerebellar peduncles, pons and inferior olivary nuclei
• Pallor of the locus corelues (decline in NA) and substantia nigra (decline in DA).

Question 2

What are the microscopic neuropathological features of patients with multiple systems atrophy?

Answer 2

> Mixed neuronal and glial pathology
Oligodendroglial cytoplasmic inclusions that are immunoreactive to alpha-synuclein (Papp Lantos Bodies)
Neuronal cytoplasmic & nuclear inclusions
Glial neuronal inclusions
Neuropil threads

Question 3

What are the neuropathological hallmarks of corticobasal degeneration?

Answer 3

> Neuronal and glial inclusions that are immunoreactive to tau
Astrocytic plaques
Neuropil threads
Atrophy of the cerebral cortex, deep cerebellar nuclei and substantia nigra.

Question 4

What are the neuropathological hallmarks of progressive supranuclear palsy?

Answer 4

> Neuronal and glial inclusions that are immunoreactive to tau
Tufted astrocytes and coiled oligodendroglial bodies
Atrophy of the basal ganglia, subthalamus and brainstem.

Question 5

What are the hallmarks of meningitis?

Answer 5

> Purulent exudation
Congestive Meningeal vessels
Sulci are obscured by pus

Question 6

What are the hallmarks of meningitis tuberculosis?

Answer 6

> Tubercules (pin point) - suggestive of entry via the choroid plexus and CSF.
White fibrous thickening

Question 7

What are the macroscopic hallmarks meningiomas?

Answer 7

> Rounded masses that arise from the meninges (Cap cells) that compress underlying brain.
May also grow en plaque in which the tumour spreads in a sheet-like fashion along the surface of the dura.
Do not invade the underlying brain tissue
Gross evidence of necrosis and extensive haemorrhage is usually not present.

Question 8

What are the microscopic hallmarks for meningiomas?

Answer 8

Whorled pattern of cell growth with psammoma bodies

Question 9

Why is the septum pellucidum at high risk of injury when rotational forces are applied?

Answer 9

Midline structures are held rigidly by the dura and are at the central point where a rotational force acts. As a result, they are most likely to undergo shearing and tearing when a rotational force becomes applied.

Question 10

What type of haemorrhage is generated by an aneurysm?

Answer 10

SAH

Rupture of the aneurysm can result in extravasation in the subarachnoid space, brain substance or both.

Question 11

How do we treat patients with an aneurysm?

Answer 11

We used to ligate the common carotid artery in order to reduce the pressure in treatment of the aneurysm. But this method is no longer used. We now either clip the aneurysm or start a thrombosis by the use of an endovascular coil to reduce the risk of bleeding.

Question 12

Describe the effects raised intracranial pressure has had on the brain?

Answer 12

Midline deviation
Subfalcine herniation
Transtentorial herniation, with squashing of the ipsilateral cerebellar lobe. Occulomotor nerve compression resulting in pupillary dilatation and impaired ocular movement on the side of the lesion.
Transforaminal hernation of the cerebellar tonsils (coning), leading to the compression of the brainstem and therefore patient death.

Question 13

How do intracerebral haemorrhages present?

Answer 13

> Midline shift
Oedema
Ventricular infiltration
Atrophy of surrounding brain substance

Question 14

How does agenesis of the corpus callosum present radiographically?

Answer 14

> Misshapen lateral ventricles (bat-wing deformity)

>The fibres that form the corpus callosum lie longitudinally to form Probst bundles.

Question 15

How do patients with agenesis of corpus callosum present clinically?

Answer 15

Patients can present with/without mental retardation

Question 16

What 2 types of tissues are involved in an encephalocele?

Answer 16

Neural tissue and scalp tissue

Question 17

What is the more common site for an encephalocele?

Answer 17

Occipital lobe

BUT encephalocele can occur at the from the frontal lobe outwards and downwards (through the ethmoid bone and into the nasal cavity).

Question 18

Describe the classification of FTD?

Answer 18

3R Tauopathy - Pick’s disease
> Knife edge atrophy of the frontotemporal lobes
> Pick bodies, balloon neurons, neuronal loss and gliosis

Tau-negative FTD

• Progranulin mutations - C17
• TARDBP - TDP43 + inclusions - C17
• FUS - ubiquitin positive
• C9orf72

No staining
- Dementia lacking distinct histology (DLDH)

Question 19

What macroscopic and histological changes would be seen in a patient with HD?

Answer 19

Macroscopic changes
- Atrophy of caudate and putamen resulting in ventricular dilatation

Microscopic changes
- Degeneration of medium spiny GABAergic neurons

Histological changes
- Intranuclear inclusions that contain ubiquitin positive Huntingtin proteins

Question 20

What stains are used to stain for myelin?

Answer 20

LFB - Luxol Fast Blue stain

PAS - Periodic Acid-Schiff stain

Question 21

What stains are used to stain for diffuse axonal injury?

Answer 21

> Silver impregnation techniques

> Peroxidases stains for axonally transported proteins e.g. APP and alpha synuclein.

Question 22

A brain specimen contains needle track marks. What procedure could they have potentially carried out?

Answer 22

Chemothalamotomy

Question 23

What is the underlying rationale for chemothalamotomy?

Answer 23

To destroy the tissue within the ventrolateral thalamus by either injecting material into the tissue or by thermocoagulation.

Question 24

How patients with MSA clinically present?

Answer 24

Parkinson’s related symptoms

Cerebellar related symptoms - more common for MSA

Question 25

How do patients with corticobasal degeneration clinically present?

Answer 25

> Rigidity 
> Clumsiness 
> Stiffness
 >Jerking of the arm 
> "Alien Limb"

Question 26

How do patients with progressive supranuclear palsy present?

Answer 26

> Supranuclear palsy

>Postural instability