CNS CPC Year 2: Raised Intracranial Pressure

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Questions and Answers

What is the primary reason for the formation of a bright ring around a lesion on a scan when using contrast agents?

Reduction in lesion size due to vascularization

Contrast accumulation in disrupted blood-brain barrier areas (correct)

Increased blood flow to the center of the lesion

Greater necrosis in the inner area of the lesion

Which symptoms occur as a result of transtentorial uncal herniation?

Altered consciousness and elevated blood pressure

Delayed reflexes and seizures

Ipsilateral pupil dilation and contralateral hemiparesis (correct)

Bilateral pupil dilation and hemiplegia

Which of the following components is NOT part of Cushing's Triad?

Hypotension (correct)

Bradycardia

Irregular respiration

Hypertension

What typically characterizes the inner, darker area of a high grade tumor lesion?

Low vascularization and potential necrosis Signup and view all the answers

What is the primary effect of compression on the third cranial nerve due to transtentorial uncal herniation?

Ipsilateral pupil dilation Signup and view all the answers

What is the primary characteristic of a ring-enhancing lesion observed in brain imaging?

A distinct outer ring of enhanced brightness around a central darker area Signup and view all the answers

Which of the following describes the cause of cytotoxic edema?

Direct injury to neuronal or glial cells causing fluid retention Signup and view all the answers

What is a common symptom of raised intracranial pressure?

Early morning headache with associated nausea Signup and view all the answers

Which pump is primarily affected in cytotoxic edema that disrupts ionic balance in neurons?

Na+/K+ ATPase pump Signup and view all the answers

What does localized cerebral edema suggest in a patient with a brain lesion?

Localized damage possibly related to a mass effect from a lesion Signup and view all the answers

What specific imaging technique is most suitable for evaluating suspected brain tumors?

CT scan followed by MRI with contrast Signup and view all the answers

In the context of secondary brain tumors, what is the significance of a patient's history of systemic malignancy?

It serves as a marker for possible brain metastasis. Signup and view all the answers

Which type of cerebral edema is characterized by normal blood-brain barrier function but dynamic fluid shifts?

Vasogenic edema Signup and view all the answers

What is a key histological feature that can be observed in a biopsy of glioblastoma multiforme?

Vascular proliferation Signup and view all the answers

Which molecular analysis is associated with improving prognosis in gliomas?

MGMT methylation Signup and view all the answers

Identify a characteristic that classifies a tumour as oligodendroglioma.

1p19q co-deletion Signup and view all the answers

What accounts for the poor prognosis associated with histone (H3) mutations in tumors?

Automatically classified as WHO grade IV Signup and view all the answers

Why might a grade I tumour still lead to patient mortality?

Location and surgical risks Signup and view all the answers

What distinguishes a primary brain tumor like meningioma from a glioma?

Arises from meningothelial cells Signup and view all the answers

What is a common treatment strategy for managing brain tumors?

Combination of surgery, radiotherapy, and chemotherapy Signup and view all the answers

Which of these tumors is most likely to metastasize to the brain?

Melanoma Signup and view all the answers

What is the primary consequence of hypoxia or ischemia on cellular function?

Insufficient ATP supply leading to sodium accumulation Signup and view all the answers

Which artery is primarily at risk of injury near the falx cerebri?

Anterior cerebral artery Signup and view all the answers

What characterizes Cushing's triad?

Hypertension, bradycardia, irregular respirations Signup and view all the answers

What is a possible effect of brain herniation on the vascular structures?

Vascular stretching and compression Signup and view all the answers

During transtentorial uncal herniation, which cranial nerve is typically affected, leading to a specific pupil response?

Oculomotor nerve Signup and view all the answers

What is a key clinical sign of increased intracranial pressure associated with uncal herniation?

Altered level of consciousness Signup and view all the answers

What might occur if the perforating vessels in the brainstem are damaged?

Duret haemorrhage Signup and view all the answers

What is a rapid consequence of swelling or mass effects in the area of the uncus?

Immediate signs and symptoms of herniation Signup and view all the answers

Study Notes

CPC CNS CPC Raised Intracranial Pressure

Class: Year 2
Course: CNS CPC
Lecturer: Paul Murray
Date: November 2024

Case History

A 74-year-old man presented to the Emergency Department with a new onset seizure.
Past medical history: lung adenocarcinoma 10 years prior, treated with neoadjuvant chemotherapy and resection.
Examination: drowsy with rhythmic jerking of the right arm.

Four Presenting Features of Brain Tumour

Seizure
Symptoms/signs of raised intracranial pressure (headache, especially early morning, vomiting, coma, papilledema), plus/minus hydrocephalus symptoms.
Focal neurological deficit
Behavioural alteration

Brain Imaging

CT brain followed by MRI brain with contrast.
Ring-enhancing space-occupying lesion with edema.
Ring-enhancing refers to a distinct outer ring or border of enhanced brightness/contrast surrounding a darker central area on imaging. Contrast agent highlights the blood vessels and the outer border of the lesion.

Questions

Cerebral edema categorization: localised (rather than generalised).
One cause of generalised cerebral edema: hypoxia-ischemia.

Presentation of Secondary Brain Tumour

Multiple brain lesions (50% solitary).
History of systemic malignancy.
Mass lesion (e.g., lung) – check CXR.

Cellular Level Cerebral Edema

Vasogenic edema: Normal blood-brain barrier disrupted, increased vascular permeability, fluid escapes from intravascular to intercellular compartments (e.g., trauma).
Cytotoxic edema: Increase in intracellular fluid secondary to cellular injury (e.g., neuronal, glial, endothelial), like hypoxia-ischemia. [Sodium/Potassium pump failure due to insufficient ATP.]

Consequences of Raised Intracranial Pressure and Herniation

Diagram showing herniation types, structures affected (e.g., brain stem, midline shift, tentorial notch distortion, subfalcine/transtentorial herniation of the cingulate gyrus).

Complications of Brain Herniation

Vascular stretching and compression due to brain movement within the skull.
- Anterior cerebral artery (ACA): supplies blood to frontal lobes, vulnerable near the falx cerebri.
- Posterior cerebral artery (PCA): supplies occipital and temporal lobes, vulnerable near the tentorium cerebelli.
- Perforating vessels in brainstem: small, deep arteries supply blood to brainstem, damage can lead to devastating bleeding areas (e.g., Duret hemorrhage).

Transtentorial Uncal Herniation

Uncus (medial temporal lobe) herniates over the tentorium cerebelli.
Clinical signs: Pupillary changes (ipsilateral dilated pupil), altered level of consciousness (drowsiness to stupor/coma), and Cushing's triad (hypertension, bradycardia, irregular respiration)
Significant and potentially life-threatening.

Biopsy of the Ring-enhancing Lesion in the Motor Cortex

Four main diagnostic possibilities:
- Metastatic carcinoma
- Primary brain tumour
- Infection
- Negative/non-diagnostic biopsy

Biopsy Appearance

Densely cellular glioma with mitoses, vascular proliferation and necrosis. GFAP positivity.
No gland formation.
Diagnosis: Glioblastoma multiforme.
Other techniques for more accurate diagnostic/prognostic information: available?

Molecular Information Impacts on Diagnosis and Prognosis

Molecular analysis table showing BRAF gene fusion/mutation, IDH1/2 mutation, 1p/19q co-deletion, MGMT methylation, Histone (H3) mutation, and their respective impacts on diagnosis and prognosis.

Interphase FISH

FISH probes showing TP73 [1p36], ABL2 [19q25], D19S221 [19p13], EHD2 [19q13] used for visualising chromosomal deletions and co-deletions (1p/19q).

Chromosomal Microarray

Diagram showing chromosomal microarray results with highlighting of the 1p and 19q co-deletion.

Why Might a Grade I Tumour Cause Death?

Location: Difficulty accessing and high morbidity associated with surgery, especially deep/brainstem location.

How Are Patients With Brain Tumours Managed?

Gross total resection
Radiotherapy
Chemotherapy
Combinations of the above
Palliation
Seizure control

Fill in the Blanks

Glioma: primary brain tumour arising from glial cells (astrocytes, oligodendrocytes, ependyma).
Most common malignant glioma in adults: Glioblastoma.
Most common benign primary brain tumour: Meningioma (arising from meningothelial cells in meninges).
Meningioma prognosis: Good.
Tumour most likely to metastasize to the brain: Melanoma (with lung and breast primaries as frequent metastatic occurrences).

Contrast Agents in Brain Imaging

Contrast agents highlight the "ring" of a lesion, where blood-brain barrier is disrupted in areas of infection, tumour, inflammation.
Inner, darker area in usually poorly vascularized and necrotic in severe tumours.

Transtentorial Herniation (detailed)

Medial temporal lobe (especially the uncus) herniates through the tentorial notch.
Key clinical triad of "blown" pupil, hemiplegia, and coma.
Compression of CN III (ipsilateral oculomotor nerve) leads to dilated pupil.
Compression of cerebral peduncles causes hemiplegia.
Midbrain reticular formation distortion leads to loss of consciousness; coma possible.

Cushing's Triad

Clinical syndrome of increased intracranial pressure and impending brain herniation: Hypertension (increased blood pressure for perfusion), Bradycardia (slowed heart rate), Irregular respiration (abnormal breathing patterns due to brainstem compression).

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Description

This quiz focuses on a case involving a 74-year-old man who presented with seizures and symptoms suggesting raised intracranial pressure. The case studies the clinical features, imaging findings, and underlying conditions related to brain tumors. Test your understanding of critical brain tumor presentations in this CNS CPC Year 2 quiz.