CT Scan Findings in Neuroimaging
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Questions and Answers

What is a common characteristic of the hyperdense area seen in CT findings?

  • Biconvex, crescent-shaped appearance (correct)
  • Irregular mass shape
  • Dome-shaped configuration
  • Completely spherical shape

Where is the hyperdense area most likely located in relation to the sutures?

  • Limited to the areas above the midline sutures
  • Confined between the suture lines (correct)
  • Unrestricted by suture lines
  • Encapsulated entirely by the calvarium

What effect might a hyperdense area have on the delineation of brain structures?

  • It diminishes the visibility of ventricles
  • It creates an increased contrast between the brain and calvarium
  • It causes a distortion of cranial shape
  • It may shift the ventricles (correct)

What structure is commonly associated with the draining veins into the superior sagittal sinus?

<p>Pterion region (B)</p> Signup and view all the answers

In the context of CT findings, what may also be observed apart from the hyperdense area?

<p>Skull fracture (B)</p> Signup and view all the answers

What occurs if the temporal lobe herniates through the tentorial notch?

<p>It results in CN III palsy. (D)</p> Signup and view all the answers

What is a possible management procedure when dealing with a herniated temporal lobe?

<p>Burr hole drainage may be required. (B)</p> Signup and view all the answers

What characterizes an ischaemic stroke?

<p>A blockage that prevents blood supply to brain tissue. (D)</p> Signup and view all the answers

What distinguishes a haemorrhagic stroke from an ischaemic stroke?

<p>It occurs due to bleeding in or around the brain tissue. (A)</p> Signup and view all the answers

What may be necessary if a burr hole drainage does not resolve the issue in brain management?

<p>Clipping of an aneurysm. (C)</p> Signup and view all the answers

What type of motor symptoms are observed in pseudo-bulbar palsies?

<p>Upper motor neuron (UMN) symptoms (B)</p> Signup and view all the answers

Which cranial nerves are implicated in Jugular Foramen Syndrome?

<p>CN IX, X, XII (C)</p> Signup and view all the answers

In which part of the brain do cranial nerves III and IV decussate?

<p>Midbrain (A)</p> Signup and view all the answers

How are pain and temperature sensations transmitted in the nervous system?

<p>Along lateral tracts (D)</p> Signup and view all the answers

What are the dorsal columns referred to when they are in the brainstem?

<p>Medial lemnisci (B)</p> Signup and view all the answers

What role does the GPi play in the motor pathway at rest?

<p>Inhibits the thalamus to prevent unwanted movement (B)</p> Signup and view all the answers

Which neurotransmitter is primarily responsible for sending excitatory signals in the basal ganglia pathways?

<p>Glutamate (C)</p> Signup and view all the answers

What is the outcome when the striatum is excited in the direct pathway?

<p>Inhibition of GPi and activation of the thalamus (A)</p> Signup and view all the answers

What happens to the subthalamic nucleus when the GPe is inhibited in the indirect pathway?

<p>It is free to send impulses to the GPi (D)</p> Signup and view all the answers

Which structure modulates the line of communication between the thalamus and the motor cortex?

<p>Globus pallidus internus (GPi) (D)</p> Signup and view all the answers

What is the main function of the direct pathway in the basal ganglia?

<p>To activate muscles based on intention (D)</p> Signup and view all the answers

What is the result of the substantia nigra releasing dopamine onto DA 1 receptors?

<p>It excites inhibitory striatum neurons (D)</p> Signup and view all the answers

Which branch is responsible for the inferior half of the genu within the context of vascular supply to the basal ganglia?

<p>ICA branches (B)</p> Signup and view all the answers

What is a characteristic effect of a midbrain stroke?

<p>Inability to turn eyes up and in (B)</p> Signup and view all the answers

What indicates a lesion in the ophthalmic nerve (CN V1)?

<p>Absent corneal reflex (B)</p> Signup and view all the answers

What is an observed symptom of CN V peripheral nerve damage?

<p>Anaesthesia of the mid-face (D)</p> Signup and view all the answers

In cases of CN V lesion affecting the mandibular nerve, which symptom is expected?

<p>Flaccidity of mastication muscles (D)</p> Signup and view all the answers

Which symptom reflects PNS dysfunction in a midbrain stroke?

<p>Pupil does not constrict to light (A)</p> Signup and view all the answers

What compensatory mechanism occurs due to lack of intorsion in the eye?

<p>Head tilts to unaffected side (C)</p> Signup and view all the answers

Which of the following best describes motor dysfunction due to CN V lesions?

<p>Weakness of mastication muscles (B)</p> Signup and view all the answers

What visual effect represents vertical diplopia in a midbrain stroke?

<p>Higher position of the pupil in affected eye (A)</p> Signup and view all the answers

How does a CN V peripheral lesion impact the sensation of the face?

<p>Unilateral anaesthesia of the forehead (A)</p> Signup and view all the answers

What is a potential outcome of lesions affecting the motor nuclei of CN V?

<p>Muscle weakness of the anterior 2/3 of the tongue (B)</p> Signup and view all the answers

What is the primary cause of peripheral CN VII nerve palsy known as Bell's Palsy?

<p>Acute Idiopathic conditions (B)</p> Signup and view all the answers

Which symptom is NOT associated with supranuclear lesions of CN VII?

<p>Ipsilateral weakness of the forehead (C)</p> Signup and view all the answers

Which of the following is true regarding the presentation of peripheral lesions of CN VII?

<p>Weakness is ipsilateral to the lesion (C)</p> Signup and view all the answers

In the case of a unilateral UMN lesion affecting CN VII, which area shows contralateral weakness?

<p>Mid-face and lower face (D)</p> Signup and view all the answers

What feature distinguishes peripheral CN VII lesions from supranuclear lesions regarding forehead involvement?

<p>Supranuclear lesions spare the forehead (D)</p> Signup and view all the answers

Which of the following symptoms would most likely indicate a central lesion of CN VII?

<p>Weakness of the forehead (D)</p> Signup and view all the answers

Which statement about the jaw deviation in the case of a lesion is correct?

<p>The jaw deviates toward the side of the lesion (A)</p> Signup and view all the answers

What possible symptom might occur as a result of a peripheral CN VII lesion besides facial weakness?

<p>Inability to taste from the anterior tongue (D)</p> Signup and view all the answers

In which condition is the pain experienced most prominently?

<p>Herpes Zoster Infection (C)</p> Signup and view all the answers

Which factor is most likely to be related to the presence of a gag reflex absence in lesions of CN IX or X?

<p>Unilateral cranial nerve lesions (D)</p> Signup and view all the answers

What is a characteristic feature of central lesions of CN VII compared to peripheral lesions?

<p>Contralateral facial weakness (B)</p> Signup and view all the answers

Which of the following is a likely cause of CN IX lesions?

<p>Trauma (B)</p> Signup and view all the answers

What is the typical presentation of a peripheral CN VII lesion?

<p>Ipsilateral facial weakness with eyelid drooping (C)</p> Signup and view all the answers

How would a patient with a peripheral CN VII lesion most likely present?

<p>Inability to close both eyes (A)</p> Signup and view all the answers

What shape characterizes the hyperdense area seen in the CT findings of cranial imaging?

<p>Biconvex (A)</p> Signup and view all the answers

Which feature distinguishes the hyperdense area in CT findings from normal brain anatomy?

<p>It is sharply demarcated. (D)</p> Signup and view all the answers

What does the presence of a skull fracture in conjunction with the hyperdense area typically indicate?

<p>A possible injury to the cortex (C)</p> Signup and view all the answers

How does the hyperdense area affect the ventricle's appearance in cranial imaging?

<p>It may shift their position. (B)</p> Signup and view all the answers

What anatomical feature limits the area of hyperdensity observed in imaging findings?

<p>Suture lines (D)</p> Signup and view all the answers

What is the primary function of pyramidal tracts?

<p>Generation of voluntary movement (D)</p> Signup and view all the answers

How do extrapyramidal tracts differ from pyramidal tracts?

<p>They coordinate voluntary movements without directly initiating them. (D)</p> Signup and view all the answers

Which tract specifically targets the head and neck region?

<p>Corticobulbar tract (A)</p> Signup and view all the answers

What is the role of upper motor neurons (UMNs) in motor pathways?

<p>They transmit impulses to lower motor neurons. (A)</p> Signup and view all the answers

What distinguishes the corticospinal tract from other motor tracts?

<p>It decussates in the medulla before synapsing with lower motor neurons. (D)</p> Signup and view all the answers

What type of headache is characteristic of a subarachnoid hemorrhage?

<p>A thunderclap headache (C)</p> Signup and view all the answers

Which symptom is commonly associated with high blood pressure during a stroke?

<p>Erratic mood swings (D)</p> Signup and view all the answers

What focal deficit might indicate a potential stroke occurrence?

<p>Contralateral hemiparesis (A)</p> Signup and view all the answers

Which of the following is NOT a typical symptom during the presentation of a stroke?

<p>Persistent fever (B)</p> Signup and view all the answers

What could be a sign that the brain is under high pressure during a stroke?

<p>Nausea and vomiting (C)</p> Signup and view all the answers

Which key symptom differentiates a stroke caused by a subarachnoid hemorrhage from other types of strokes?

<p>Thunderclap headache (C)</p> Signup and view all the answers

What symptom is often mistaken for signs of intoxication when a patient is experiencing a stroke?

<p>Erratic mood swings (C)</p> Signup and view all the answers

What is the primary function of the internal carotid arteries in the vascular supply of the CNS?

<p>Supply the cerebrum and parts of the orbit. (C)</p> Signup and view all the answers

Which statement about the development of clots during a stroke is accurate?

<p>Clots are unlikely to develop in low-pressure veins. (D)</p> Signup and view all the answers

Which structure connects the carotid and vertebrobasilar systems in the CNS?

<p>Cerebral Arterial Circle (Circle of Willis) (C)</p> Signup and view all the answers

What occurrence results when an internal carotid artery undergoes a carotid siphon?

<p>It allows for dilation due to a covering membrane. (C)</p> Signup and view all the answers

What is the origin of the vertebral arteries?

<p>Subclavian arteries (C)</p> Signup and view all the answers

Which artery supplies predominantly extracranial structures, with one notable exception?

<p>External carotid artery (B)</p> Signup and view all the answers

What type of anastomosis is formed by the connection of the anterior and posterior arteries in the brain?

<p>Natural circulatory arterial anastomosis (D)</p> Signup and view all the answers

What is one function that the communicating arteries do NOT perform in the CNS?

<p>Facilitate blood passage from one side to another. (C)</p> Signup and view all the answers

How do the vertebral arteries enter the skull?

<p>Through the foramen magnum. (B)</p> Signup and view all the answers

What is the main difference between a transient ischaemic attack (TIA) and a stroke?

<p>A TIA is reversible, while a stroke is not (C)</p> Signup and view all the answers

What condition involves a clot in the cerebral blood vessels typically due to the rupture of an atherosclerotic plaque?

<p>Thrombosis (A)</p> Signup and view all the answers

Which type of haemorrhage occurs when there is bleeding within the brain tissue itself?

<p>Intraparenchymal haemorrhage (B)</p> Signup and view all the answers

Which symptom is typically associated with a transient ischaemic attack (TIA)?

<p>Difficulty speaking (C)</p> Signup and view all the answers

What is the consequence of systemic hypoperfusion in the brain?

<p>Insufficient blood supply to the brain (C)</p> Signup and view all the answers

Which of the following is NOT typically a symptom of a TIA?

<p>Persistent confusion (A)</p> Signup and view all the answers

In cavernous sinus syndrome, what potential cause is indicated by the infection of superficial veins of the face?

<p>Swelling in the cavernous sinus (C)</p> Signup and view all the answers

What is a characteristic feature of cerebral venous sinus thrombosis (CVST)?

<p>Clot located in the dural venous sinuses (A)</p> Signup and view all the answers

What effect on eye movement is associated with a midbrain stroke?

<p>The eyes turn downward and outward (B)</p> Signup and view all the answers

What is a potential outcome of a lesion affecting the ophthalmic nerve (CN V1)?

<p>Absent corneal reflex (D)</p> Signup and view all the answers

Which visual symptom signifies horizontal diplopia?

<p>Inability to abduct the affected eye (D)</p> Signup and view all the answers

What is a symptom associated with a lesion of the maxillary nerve (CN V2)?

<p>Anaesthesia of the mid-face (A)</p> Signup and view all the answers

In the context of CN V lesions, what characterizes motor dysfunction?

<p>Flaccid weakness of mastication muscles (C)</p> Signup and view all the answers

What pupillary reaction is typically observed with PNS dysfunction in a midbrain stroke?

<p>Pupil does not constrict and appears blown out (C)</p> Signup and view all the answers

What compensatory mechanism might occur due to a lack of intorsion in a midbrain stroke?

<p>Head tilting away from the affected side (D)</p> Signup and view all the answers

What is indicated by a sensory loss of the forehead in a CN V lesion?

<p>Lesion of the sensory nuclei (A)</p> Signup and view all the answers

What is a probable outcome of lesions affecting the motor nuclei of CN V?

<p>Ipsilateral flaccid paralysis in mastication (D)</p> Signup and view all the answers

What does 'down and out' eye position indicate in midbrain dysfunction?

<p>Cranial nerve III palsy (D)</p> Signup and view all the answers

Flashcards

Temporal Lobe Herniation

Displacement of the temporal lobe through the tentorial notch, frequently causing compression or injury to cranial nerve III.

CN III Palsy

Paralysis of the oculomotor nerve, often caused by pressure on the nerve, like a herniated temporal lobe.

Ischemic Stroke

Stroke caused by a blocked blood vessel in the brain, reducing blood supply to brain tissue.

Haemorrhagic Stroke

Stroke caused by bleeding in or around the brain tissue.

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Stroke Management (Temporal Herniation)

Treatment for a herniated temporal lobe may involve a burr hole to relieve pressure, or a craniotomy if blood has coagulated.

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Dural venous sinuses

Veins that drain into the superior sagittal sinus.

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CT finding of a hematoma

A well-defined, biconvex (crescent-shaped) hyperdense area between the calvarium and brain, not limited by suture lines.

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Biconvex hematoma

A well-defined, rounded, blood clot shape in a CT scan.

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Hyperdense area

An area in a CT scan that appears brighter than surrounding tissues due to the presence of blood.

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Suture lines

Lines formed where bones of the skull join together.

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Basal Ganglia Direct Pathway

A neural pathway in the brain that allows for wanted movement by facilitating the thalamus's activation of the motor cortex.

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Basal Ganglia Indirect Pathway

A neural pathway in the brain that prevents unwanted movement by inhibiting the thalamus's activation of the motor cortex.

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Striatum

The input region of the basal ganglia.

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Globus Pallidus Internal (GPi)

Output region of the basal ganglia; inhibits the thalamus at rest.

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Subthalamic Nucleus

A nucleus that excites the substantia nigra, part of the indirect pathway.

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Substantia Nigra

Releases dopamine, modulating striatal activity.

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Dopamine (in basal ganglia)

A neurotransmitter that influences the basal ganglia's modulation of movement. It sends excitation signals to the inhibitory neurons in the striatum.

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Motor Cortex and Movement

The motor cortex initiates movement by sending excitatory signals to the striatum in both pathways.

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UMN vs LMN

UMN lesions cause pseudo-bulbar palsies with upper motor neuron symptoms; LMN lesions affect cranial nerves with lower motor neuron symptoms.

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Jugular Foramen Syndrome

A condition involving damage to cranial nerves IX, X, and XII, resulting in a combination of lower motor neuron symptoms.

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Pyramidal Tract: Head and Neck

The part of the pyramidal tract responsible for voluntary movement of the head and neck.

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Decussation of Pyramidal Tract

The point where the pyramidal tract fibers cross over to the opposite side of the body, allowing one side of the brain to control the contralateral side of the body.

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Sensory Pathways: Spinal Cord to Brain

The pathways in the spinal cord and brainstem that carry information about touch, pain, temperature, and proprioception to the brain.

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Cavernous sinus thrombosis

A blood clot in the cavernous sinus, which is a network of veins near the brain. It can cause various complications.

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Midbrain stroke

A stroke that affects the midbrain, a part of the brain responsible for various functions, including eye movement.

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Vertical Diplopia

Double vision where one image appears higher than the other.

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Horizontal Diplopia

Double vision where one image appears to the side of the other.

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"Down and Out" eye turn

A specific eye movement pattern associated with damage to the oculomotor nerve (CN III). The affected eye turns downwards and outwards.

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Ptosis

Drooping of the upper eyelid, often due to weakness or paralysis of the levator palpebrae superioris muscle.

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Pupil constricts to light

The normal response of the pupil to light, where it shrinks in size.

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Blown out pupil

A dilated pupil that does not respond to light, often indicating a serious problem.

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Ophthalmic nerve (CN V1)

The first branch of the trigeminal nerve that provides sensation to the forehead, scalp, and upper face.

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Maxillary nerve (CN V2)

The second branch of the trigeminal nerve that provides sensation to the middle face, including the cheek and upper teeth.

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CN VII Lesion

Damage to the facial nerve (CN VII), which controls facial expressions, taste, and tear production.

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Supranuclear CN VII Lesion

Damage to the upper motor neuron (UMN) pathway of the facial nerve, typically affecting the contralateral (opposite side) lower face.

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Peripheral CN VII Lesion

Damage to the lower motor neuron (LMN) of the facial nerve, affecting the ipsilateral (same side) entire face.

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Forehead Sparing

Preservation of forehead movement in a unilateral UMN lesion of CN VII, because the forehead receives bilateral innervation.

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Bell's Palsy

A common cause of peripheral CN VII palsy, often idiopathic (unknown cause), resulting in facial weakness.

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CN IX Lesion

Damage to the glossopharyngeal nerve (CN IX), affecting taste, swallowing, and the gag reflex.

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CN X Lesion

Damage to the vagus nerve (CN X), impacting swallowing, speaking, and heart rate.

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CN XI Lesion

Damage to the accessory nerve (CN XI), affecting the sternocleidomastoid and trapezius muscles, leading to head and shoulder weakness.

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CN XII Lesion

Damage to the hypoglossal nerve (CN XII), leading to tongue weakness or paralysis, affecting speech and swallowing.

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Bulbar Palsies

Weakness or paralysis of the muscles involved in speech and swallowing, often caused by lesions affecting CN IX, X, XI, and XII.

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Uvula Deviation

A deviation of the uvula towards the healthy side in a CN IX or X lesion, due to weakness on the affected side.

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Tongue Atrophy

A wasting away of the tongue muscles in a CN XII lesion, leading to fasciculations (muscle twitches).

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Gag Reflex

A reflex contraction of the throat muscles elicited by touching the back of the tongue or palate, absent in CN IX or X lesions.

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Jaw Deviation

The jaw deviates towards the side of a CN V (trigeminal) lesion due to unopposed action of the opposite pterygoid muscle.

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Ipsilateral vs. Contralateral

Ipsilateral refers to the same side of the body, while contralateral refers to the opposite side.

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Internal Carotid Artery

An artery that originates from the common carotid artery and supplies blood to the brain. It enters the skull via the carotid canal and then makes two characteristic 90 degree bends called the carotid siphon.

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Vertebral Artery

An artery that branches off from the subclavian artery and supplies blood to the brainstem and cerebellum. It travels through the transverse foramina of the vertebrae before entering the skull through the foramen magnum.

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Basilar Artery

The artery formed by the union of the two vertebral arteries. It runs along the anterior surface of the brainstem and lies on top of the clivus of the cranial base.

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Circle of Willis

A circular network of arteries at the base of the brain that connects the anterior (carotid) and posterior (vertebrobasilar) circulatory systems. It provides an important route for blood to circulate to the brain, even if one of the major arteries is blocked.

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Anterior Communicating Artery

A small artery that connects the anterior cerebral arteries of the two hemispheres. It plays a role in providing a collateral pathway if one of the anterior cerebral arteries is blocked.

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Posterior Communicating Artery

A small artery that connects the internal carotid artery to the posterior cerebral artery. It plays a role in providing a collateral pathway if one of the posterior cerebral arteries is blocked.

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Foramen Magnum

A large opening at the base of the skull through which the spinal cord passes and where the vertebral arteries enter the skull.

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Clivus

The sloping surface at the base of the skull that forms part of the occipital bone. The basilar artery lies on top of the clivus.

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Superior Sagittal Sinus

The largest dural venous sinus, located along the midline of the skull, and receives blood from the brain's surface.

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CT Finding: Subdural Hematoma

A crescent-shaped, hyperdense area on CT scans, located between the dura mater and the brain, often not limited by suture lines.

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What is a key feature of a subdural hematoma on a CT scan?

Subdural hematomas are often not limited by suture lines, meaning they can extend across multiple skull bones.

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Why does a subdural hematoma shift the ventricles?

Because the hematoma is located between the brain and the skull, it exerts pressure on the brain, causing the ventricles to shift or compress.

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CT of Subarachnoid Hemorrhage

This CT scan will show blood in the subarachnoid space, appearing hyperdense (brighter than surrounding tissues).

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Clinical Features of Subarachnoid Hemorrhage

The patient presents with a sudden, intense headache (thunderclap headache), vomiting, and possible fainting. They may have focal deficits like weakness or sensory loss.

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What's the initial presentation of Subarachnoid Hemorrhage?

The initial presentation is marked by a lucid interval, a period of clarity and normalcy, followed by a sudden, acute onset of worsening symptoms.

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Reason for delayed symptoms in Subarachnoid Hemorrhage

The delayed symptoms arise because the vein is under low pressure, allowing a clot to slowly form and build up pressure before causing a neurological event.

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How do you distinguish Subarachnoid Hemorrhage from stroke?

Subarachnoid hemorrhages often cause a 'thunderclap headache', while stroke symptoms may be more gradual and less intense.

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What is the likely outcome of Subarachnoid Hemorrhage?

Subarachnoid Hemorrhages can often lead to a stroke due to the blood clot pressing on the brain.

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How are focal deficits observed in Subarachnoid Hemorrhage?

Focal deficits, like weakness or sensory loss, often appear contralateral (on the opposite side of the body) to the affected area of the brain.

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What is a common symptom in Subarachnoid Hemorrhage?

A common symptom is changes in mood, potentially mistaken for being drunk.

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Pyramidal Tracts

The pyramidal tracts are responsible for voluntary movement. They consist of the corticobulbar tract (controls head and neck) and the corticospinal tract (controls trunk and limbs).

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Corticobulbar Tract

The corticobulbar tract carries signals from the brain to the brainstem, controlling muscles of the head and neck.

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Corticospinal Tract

The corticospinal tract carries signals from the brain to the spinal cord, controlling muscles of the trunk and limbs. It decussates (crosses over) in the medulla, allowing one side of the brain to control the opposite side of the body.

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Extrapyramidal Tracts

Extrapyramidal tracts help coordinate and fine-tune movement, but they cannot initiate movement on their own.

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TIA

A temporary focal neurological deficit caused by ischemia (lack of blood flow) but not infarction (permanent damage). It resolves within 24 hours and is a risk factor for stroke.

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Amaurosis Fugax

A temporary loss of vision in one or both eyes due to a lack of blood supply, often a symptom of a TIA.

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Contralateral Hemiparesis

Weakness or paralysis of one side of the body opposite to the affected brain area, often a symptom of TIA or stroke.

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Cavernous Sinus Syndrome

Swelling and inflammation of the cavernous sinus, a network of veins near the brain, often caused by an infection from the face.

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CVST

Cerebral Venous Sinus Thrombosis: A blood clot in the dural venous sinuses, causing venous congestion.

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Embolism

A blockage in a cerebral blood vessel caused by an embolus (a clot, air bubble, or other material) traveling from elsewhere in the body.

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Thrombosis

A clot forming inside a cerebral blood vessel, often due to atherosclerosis (plaque buildup).

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Systemic Hypoperfusion

Reduced blood flow throughout the body, which can affect the brain and lead to stroke.

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Cavernous Sinus

A network of veins near the brain that drains blood from the face, eyes, and orbit. It's located near the pituitary gland and sphenoid bone.

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Study Notes

Vascular Supply of the CNS

  • The cerebral, cerebellar, and brainstem receive blood from three arteries originating from two sources:
    • Common Carotid (bifurcates at C4)
    • Subclavian Artery
  • The common carotid gives rise to the internal and external carotids
  • Structures supplied by the external carotid artery are predominantly extracranial, with the exception of the middle meningeal artery, which is intracranial.

Arterial Supply to the Cerebrum, Cerebellum, and Brainstem

  • There are two primary systems:
    • Anterior (Carotid): Formed by the right and left internal carotid arteries (ICA). The ICA enters the cranium through the carotid canal, passes over the Foramen Lacerum, and then undergoes two 90° bends (carotid siphon).
    • Posterior (Vertebrobasilar): Formed by the vertebral arteries, which branch from the subclavian arteries. The vertebral arteries run through the transverse foramina of the vertebrae before entering the skull via the Foramen Magnum. They join to form the Basilar artery, traveling along the anterior brainstem surface and resting on the clivus of the occipital bone.
  • The two systems connect via the Circle of Willis. This connection is called a natural circulatory arterial anastomosis.

Circle of Willis

  • Connects the anterior and posterior arterial systems.
  • It's important in case of occlusion as it provides alternative routes for blood flow.

Anterior Cerebral Artery (ACA)

  • Passes underneath the corpus callosum
  • Progresses posteriorly along the superior surface of the corpus callosum
  • Supplies the medial aspect of the parietal lobes, motor cortex for lower limbs, and parts of the basal ganglia (and anterior limb of the internal capsule)

Middle Cerebral Artery (MCA)

  • Passes laterally to the temporal lobe and onto the lateral aspects of the cerebrum
  • Supplied by the internal carotid artery
  • Supplies the temporal lobe, parietal lobe, Broca's and Wernicke's speech areas, and parts of the basal ganglia (and internal capsule).
  • Branches include lateral striate arteries.

Posterior Cerebral Artery (PCA)

  • Terminal branch of the basilar artery
  • Passes posteriorly to the parietal lobe
  • Supplies the occipital lobe (visual cortex)

Important Branches of the Cerebral Arteries

  • Lateral striate arteries from the MCA supply deep brain structures including the basal ganglia, putamen, pallidus, caudate nucleus, and superior half of the internal capsule.
  • Medial striate arteries from the ACA supply deep brain structures.

Choroidal Arteries

  • Supply the choroid plexuses.
  • Anterior supplies the postero-inferior aspect of the internal capsule.
  • Posterior supplies multiple branches

Cerebellar Arteries

  • SCA, AICA, and PICA.

Important Note:

  • The meningeal arteries supply the meninges of the brain, especially the middle meningeal artery, which is a significant source of epidural hemorrhages. They originate as branches of external carotid arteries, and the main meningeal artery is the middle meningeal artery which passes through the foramen spinosum.

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Description

This quiz explores critical aspects of hyperdense areas observed in CT scans, including their characteristics, anatomical relationships to the sutures, and their impact on delineating brain structures. Additionally, it examines the common associations with draining veins and other findings in neuroimaging. Test your knowledge on these essential neuroanatomical concepts!

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