neuro patho Flashcards
Normal range of ICP
7-15 mmHG
What am I most worried about in a patient with raised ICP?
Tonsillar herniation -> compression of brainstem -> cardiopulmonary arrest (if medulla is compressed)
**Most common cause of epidural haemorrhage
Traumatic head injury causing rupture of middle meningeal artery
Name some features of epidural haemorrhage I would expect to see
On CT scan, there is biconvex (lens-shaped) hematoma.
Patient experiences lucid intervals of consciousness because pressure buildup is slow, patient likely asymptomatic in the early stages and develop a sudden onset of raised ICP when cortex gets compressed.
**Most common cause of subdural haemorrhage
Bridging veins tearing due to age related brain atrophy.
This causing an increase in space between brain and skull, larger distance and more tension is placed on bridging veins.
What will I see on a CT scan with subdural haemorrhage?
Crescent shaped hematoma
**Most common cause of subarachnoid haemorrhage
Berry aneurysm involving the Circle of Willis
**Most common cause of intracerebral haemorrhage
HYPERTENSION!!!
Name the clinical sign that if patient presents with it, i immediately suspect subarachnoid haemorrhage
Thunderclap headache
What 2 conditions is berry aneurysm -> SAH associated with?
Polycystic kidney disease
Aortic coarctation
What protein is Alzheimer’s associated with?
Beta amyloid proteins -> amyloid plaques
Which part of the brain is most affected in Alzheimer’s? What happens to the brain in general?
Temporal lobe
Brain will atrophy
Clinical manifestations of Alzheimer’s
Dementia
Progressive cognitive decline (difficulty pronouncing words - dysarthria, difficulty completing task on their own)
Progressive motor decline
What protein and hormone is Parkinson’s associated with?
Lewy bodies and dompamine.
Loss of nerve cells from substantia nigra -> reduced dopamine to basal ganglia
Which part of the brain is most affected in Parkinson?
Substantia nigra
Clinical manifestations of Parkinson’s
**Cog wheel rigidity - consistent resistance to movements
** Resting tremor
Bradykinesia - slowed movement
Freezing of gait
What is Huntington’s disease?
Autosomal dominant disease associated with the accumulation of Huntington proteins
Results in degeneration and atrophy of the dorsal striatum.
Patient will have motor dysfunction, cognitive decline and personality changes.
Optic nerve lesion
Monocular blindness
Centre of optic chiasm lesion
Bitemporal hemianopia
Lateral optic chiasm lesion
Ipsilateral nasal hemianopia
Optic tract or LGN of thalamus lesion
Contralateral homonymous hemianopia
Optic radiation/primary visual cortex
Contralateral homonymous hemianopia with macular sparing
Meyer’s loop + which lobe affected?
Temporal lobe
Homonymous quadrantanopia
What is macular sparing and why?
The visual cortex/macula receives dual blood supply from the MCA and PCA. Hence, even if there is a stroke, blood supply will never be 100% compromised -> some degree of central visual field will be retained.
Pituitary tumour is associated with
Central optic chiasm compression; bitemporal hemianopia - loss of both peripheral visions
NF type 2 is associated with
Cataracts at young age; hearing loss; schwannomas
Meningioma
What type of brain tumour is more common in AIDS/HIV/immunocompromised patients?
Lymphoma
Most common brain tumour in children
Medulloblastoma
Pilocytic astrocytoma
Brain infections: if bacterial, it is likely (type) and caused by (organism)
Meningitis, neissera meningitis
Brain infections: if viral, it is likely (type) and caused by (organism)
Encephalitis, herpes simplex virus
Brain infections: if fungal, it is likely (type) and caused by (organism)
Patient is immunocompromised, cryptococcosis
Brain infections: patients with AIDs is more likely to have a brain infection caused by _
Toxoplasmosis
What are the 2 unique symptoms of meningitis?
Neck stiffness
Photophobia (sensitivity to light)
Name congenital brain infections (hint: TORCH)
Toxoplasmosis
Others: varicella zoster, syphilis, parvovirus b19
Rubella
Cytomegalovirus
Herpes
3 types of congenital CNS malformations and give an example of each
Neural tube defect:
- Spina bifida
- Hydrocephalus
Forebrain abnormalities
- Polymicrogyria
- Holoprosencephaly
- Anencephaly
- Lissencephaly
Posterior fossa anomalies
- Dandy walker - enlarged
- Arnold chiari - small
What 2 conditions is holoprosencephaly associated with?
Trisomy 13
Maternal diabetes
In autopsy, the cut surface of patient’s brain showed intracerebral petechial. What top 2 causes do I suspect?
Fat embolism
Malaria
Vitamin B1 (thiamine) deficiency can result in
Wernicke’s encephalopathy
- Psychotic symptoms + ophthalmoplegia
Vitamin B12 (folate) deficiency can result in
Peripheral neuropathy accompanied by megaloblastic anaemia
Wernicke’s encephalopathy is caused primarily by
Vitamin B1 thiamine deficiency
Chronic alcoholism can affect the brain as it causes _
Cerebellar atrophy -> dysfunction
Wernicke-korsarkoff’s syndrome (amnesia, invented memories - confabulation, ophthalmoplegia)
Histologically, what will I see in the brain of a patient who had a stroke?
- Foamy macrophages
- Oedematous fluids
- Reactive gliosis (increased number of astrocytes)
- ** LOSS OF GREY WHITE MATTER DIFFERENTIATION
SAH is associated with
Polycystic kidney disease and aortic coarctation
If patient’s brain has petechial haemorrhage, what are the top 2 causes?
Fat embolism
Malaria
Glioblastoma on CT scan looks like?
Butterfly lesion
Medulloblastoma is the most common form of brain cancer in _
Children
Name the pathogen that is the most common cause of meningitis
Neissera meningitis
Is hypertension a cause of SAH?
No!!! Hypertension is the most common cause of INTRACEREBRAL HAEMORRHAGE
But SAH is a extracerebral haemorrhage!!
Which artery in the Circle of Willis is the most prone to aneurysm?
Anterior communicating artery
Describe the microscopic changes of the brain after an infarction
12h: Neurons become red, there is oedema
Reactive gliosis (increase number of astrocytes)
Foamy macrophages
Describe the gross apperance of the brain following an infarction
Within the first 48h, the brain will be pale, swollen and there will be an indistinct grey-white matter junction
In the next 2-10 days, the brain becomes gelatinous and friable.
After 10 days, the area of infarct becomes a liquid filled cavity (liquefactive necrosis).
Patient has an acute onset of hemiparesis and hemisensory loss, specifically in her right leg only.
She says that her face and upper limb feel okay but she has lost total sensation of her right leg.
I suspect that she is having a stroke.
What artery in the brain is likely occluded?
Anterior cerebral artery
Patient complains that she has suddenly lost sensation in one side of her arms and legs.
She is also observed to have facial drooping.
I suspect that she is having a stroke.
What artery in the brain is likely occluded?
Middle cerebral artery
Patient complains of sudden loss of vision and is experiencing hemiparesis and hemisensory loss in one side of her body.
I suspect that she is having a stroke.
What artery in the brain is likely occluded?
Posterior cerebral artery
_ is the MOST COMMON opportunistic CNS infection in patients with AIDS
Toxoplasmosis
Most common fungal infection causing meningitis in patients with AIDS
Cryptococcus
Name some congenital CNS infections
Toxoplasmosis
Others - varicella zoster, syphilis, parvovirus b19
Rubella
Cytomegalovirus
Herpes simplex virus 2
What are the 3 types of CNS malformations?
- Neural tube defect
- Forebrain abnormalities
- Posterior fossa abnormalities
Maternal diabetes is associated with what type of CNS congenital malformation?
Incomplete separation of cerebral hemispheres across midline (looks connected)
= Holoprosencephaly
Baby has one eye - cyclopia
Lewy bodies is seen in what type of neurodegenerative disease?
Parkinson
Dizziness, greying vision points towards
Syncope
Patient has symptoms only in the ipsilateral half of his face.
Where is the lesion? And what is this condition called?
LMN
Bell’s palsy -> lesion to facial nerve CN7
Patient has symptoms only in the contralateral lower half of his face.
Where is the lesion?
UMN
Define apraxia
Inability to carry out movements/perform learned actions upon command
Define aphasia
Impairment of speech; inability to comprehend and/or produce speech
Define ataxia
Lack of muscle control or coordination of voluntary movements, such as walking or picking up objects
Define neuralgia
Severe, shooting pain that occurs due to a damaged or irritated nerve
Define myalgia
Painful sensation evolving from muscle tissue
