Neuropathology :)

Neuralation happens in week [blank_start]3[blank_end] of embryonic development. The brain, the spinal cord, [blank_start]central[blank_end] [blank_start]canal[blank_end] and [blank_start]ventricles[blank_end] all originate from the neural tube. Meanwhile the [blank_start]sensory[blank_end] ganglia of the spinal and cranial nerves, the [blank_start]autonomic[blank_end] ganglia, and [blank_start]Schwann[blank_end] cells are all from the [blank_start]neural[blank_end] [blank_start]crest[blank_end] cells.

A patient presents with a headache, nausea and vomiting, cognitive difficulty, sleepiness, seizures, balance and gait disturbances, visual abnormalities, and incontinence. An MRI scan is performed and this showed dilated lateral ventricles and dilated third ventricles. What is the most likely diagnosis

A patient has loss of sensation to pain and temperature on their right side. The patient can’t sense vibration on the left side and seems to fall towards the left. There is a loss of motor function of their left upper limb and lower limbs. What is the most likely diagnosis?

A 70 years old woman presents with a painful rash on her forehead as shown below in the diagram. What is the most likely diagnosis

A patient has a lesion on the right optic tract. What would be the presenting complaint of the patient?

A patient presents with loss of sensation and strength on the right side of their face and their right upper limb. The patient can still wrinkle their forehead. What is the most likely diagnosis?

Which of the following is false about the blood supply of the brain?

What is true regarding the Sonic Hedgehog (SHH) signalling molecule?

Fill in the chart describing primary and secondary divisions of the neural chord and what they give arise to:

[blank_start]Holoprosencephaly[blank_end] is a cephalic disorder in which the [blank_start]prosencephalon[blank_end] fails to give rise to two hemispheres. The child could be born with [blank_start]cyclopia[blank_end] (one eye-- like a cyclops.) Mutations in the gene encoding for the [blank_start]SHH[blank_end] protein can cause this condition.

[blank_start]Cerebellar[blank_end] signs are ipsilateral but [blank_start]cerebral[blank_end] signs are contralateral.

What are cerebellar signs?

The post central gyrus is the sensory cortex.

What is this known as? Which 3D model is for what?

Vasculature: [blank_start]Internal[blank_end] [blank_start]carotids[blank_end] give rise to [blank_start]anterior[blank_end] and [blank_start]middle[blank_end] cerebral arteries [blank_start]Vertebral[blank_end] arteries give rise to two [blank_start]posterior[blank_end] arteries, the [blank_start]cerebellar[blank_end] artery, and the [blank_start]basilar[blank_end] artery (trunk for the Circle of Willis.)

Fill in the vessels supplying each of the shaded parts.

Blood vessel occlusions in the brain can present differently: If the anterior cerebral artery becomes blocked, there will be a loss of strength and sensation in the [blank_start]lower[blank_end] part of the body. If the middle cerebral artery becomes blocked, there will be a loss of strength and sensation in the [blank_start]upper[blank_end] parts of the body. If the posterior Cerebral Artery becomes blocked, there will be [blank_start]visual[blank_end]/sensory defects with little to no motor loss. Most notably, there will be [blank_start]homonymous[blank_end] [blank_start]Hemianopia[blank_end].

Parkinsonism involved impaired functionality of the basal ganglia.

What is true regarding the basal ganglia?

Cranial Nerves 2 and 3: Optic nerve: Visual [blank_start]acuity[blank_end] Visual fields and Pupillary [blank_start]afferent[blank_end] reflux Oculomotor nerve is an [blank_start]efferent[blank_end] pupillary reflex.

In the optic chiasm, both temporal and nasal fibers cross over.

Label the types of optic lesions:

Partial optic nerve lesion (lesion within the [blank_start]optic[blank_end] nerve): Causes [blank_start]ipsilateral[blank_end] [blank_start]scotoma[blank_end]. 2. Complete optic nerve lesion: [blank_start]Blindness[blank_end] in that eye. 3. Optic chiasm lesion: [blank_start]Bitemporal[blank_end] [blank_start]hemianopia[blank_end] 4. Optic tract lesion: [blank_start]Homonymous[blank_end] [blank_start]hemianopia[blank_end] 5. Meyer’s loop: PITS ([blank_start]Parietal[blank_end] [blank_start]Inferior[blank_end], [blank_start]Temporal[blank_end] [blank_start]superior[blank_end]) (temporal pathway) lesion: [blank_start]Homonymous[blank_end] upper [blank_start]quadrantanopia[blank_end]. 6. Optic radiation lesion: [blank_start]Homonymous[blank_end] [blank_start]hemianopia[blank_end] 7. Visual cortex lesion: [blank_start]Homonymous[blank_end] [blank_start]hemianopia[blank_end] 8. Bilateral macula cortex lesion: [blank_start]Bilateral[blank_end] [blank_start]central[blank_end] scotomas

Which cranial nerve does not control eye movement?

Eye Movement pneumonic: (SO4LR6)3: [blank_start]Superior[blank_end] [blank_start]oblique[blank_end] is by trochlear (4) [blank_start]lateral[blank_end] [blank_start]rectus[blank_end] is by abducens (6) Everything else is [blank_start]oculomotor[blank_end] (3)

Label the parts of the trigeminal cranial nerve (5)

The trigeminal's ONLY motor function is mastication.

Which condition, which has a rash that never crosses the midline, is shown below? (center button) What is is most often caused by? (top left button)

[blank_start]Decussation[blank_end] is the crossing from one side of the central nervous system to the other

Major sensory pathways: [blank_start]Dorsal[blank_end] [blank_start]columnar[blank_end] (Medial Lemniscus) and [blank_start]Spinothalamic[blank_end] Tract.

Major motor pathways The upper motor neurones: [blank_start]Corticospinal[blank_end] (pyramidal) and [blank_start]Corticobulbar[blank_end] tracts.

Based on the location of decussation, which diagram is for which spinal tract? NOTE: 1st diagram: majority decussates at medulla, but not always

Finish the diagram regarding different types of sensory perception (answers in alphabetical order)

The spinal cord ends at level [blank_start]L1[blank_end]/[blank_start]2[blank_end]. The lower [blank_start]lumbar[blank_end] and [blank_start]sacral[blank_end] nerves travel down to exit at their corresponding level, forming the [blank_start]cauda[blank_end] [blank_start]equina[blank_end]. While an [blank_start]epidural[blank_end] can be done at any level, spinal anesthesia should be done below this level.

How CSF flows: 1. Arachnoid [blank_start]granulations[blank_end] --> 2. [blank_start]Lateral[blank_end] ventricles--> 3. Foramen of [blank_start]Monroe[blank_end]--> 4. [blank_start]Third[blank_end] ventricle--> 5. [blank_start]Cerebral[blank_end] [blank_start]Aqueduct[blank_end]--> 6. [blank_start]Fourth[blank_end] Ventricle--> 7. [blank_start]Median[blank_end] and lateral [blank_start]apertures[blank_end]--> 8. [blank_start]Subarachnoid[blank_end] space

What is of clinical significance regarding spinal tracts?

In Multiple sclerosis, there is damage to the [blank_start]posterior[blank_end] [blank_start]column[blank_end] which leads to a loss of [blank_start]proprioception[blank_end] in the hands and fingers.

 [blank_start]Syringomyelia[blank_end] is the expansion of the [blank_start]central[blank_end] [blank_start]canal[blank_end] which leads to [blank_start]spinothalamic[blank_end] tract damage as the [blank_start]crossing[blank_end] axons are damaged. The presentation is: loss of [blank_start]pain[blank_end] and [blank_start]temperature[blank_end] detection in the upper limbs.

In Amyotrophic [blank_start]Lateral[blank_end] Sclerosis, the [blank_start]Corticospinal[blank_end] tracts are damaged (upper motor neuron lesions) as well as [blank_start]Ventral[blank_end] [blank_start]Motor[blank_end] neurons (lower motor neuron lesions.)

[blank_start]Brown[blank_end] – [blank_start]Sequard[blank_end] Syndrome is the hemisection of the spinal cord. Ipsilateral to the lesion, the presentation is: [blank_start]Upper[blank_end] [blank_start]motor[blank_end] neuron signs due to damage to the corticospinal tract Loss of [blank_start]proprioception[blank_end] due to damage to the dorsal column-medial lemniscus tract Contralateral to the lesion, the presentation is: Loss of [blank_start]pain[blank_end] and [blank_start]temperature[blank_end] due to damage to the spinothalamic tract

If there is cord transection, there is bilateral motor and sensory loss below the affected level

What does not play a role in balanced, upright posture?

The [blank_start]Romberg[blank_end] test is a test of the body's sense of positioning ([blank_start]proprioception[blank_end]), which requires functioning of the [blank_start]dorsal[blank_end] [blank_start]columns[blank_end] of the spinal cord. A patient who has a problem with proprioception can still maintain balance by using [blank_start]vestibular[blank_end] [blank_start]function[blank_end] and [blank_start]vision[blank_end]. The standing patient is asked to close his or her eyes. A [blank_start]loss[blank_end] of [blank_start]balance[blank_end] is interpreted as a positive finding.

What is true regarding the meninges?

The [blank_start]anterior[blank_end] branch of the middle meningeal artery runs under the [blank_start]pterion[blank_end], which is the region where the frontal, parietal, temporal, and [blank_start]sphenoid[blank_end] bones fuse. It is located on the side of the skull, just [blank_start]behind[blank_end] the temple. This artery runs through the [blank_start]foramen[blank_end] [blank_start]spinosum[blank_end]. Trauma to this vessel is the easiest and most common way for one to get a [blank_start]epidural[blank_end] hematoma.

Usually, Epidural hemorrhages are arterial but subdural hemorrhages are venous.

Which of these do not cause subdural hematomas?

Violent shaking of a baby will lead to bridging arteries to tear and a subdural hemorrhage may happen.

WHAT TYPE OF HEMORRHAGE IS EACH CT SCAN DEPICTING?

What is this CT showing? What is the arrow specifically pointing to?

What is the CT showing? What causes this?

The [blank_start]Monro[blank_end]-[blank_start]Kellie[blank_end] doctrine states that three things exist within the fixed dimensions of the skull: [blank_start]blood[blank_end], cerebrospinal fluid, and the brain. An increase in any one component must lead to a [blank_start]decrease[blank_end] in one (or both) of the other components, otherwise the [blank_start]intracranial[blank_end] pressure will increase. If the pressure is severe enough, this can lead to [blank_start]herniation[blank_end] of brain tissue out of the skull. If this occurs at the brainstem, it can lead to [blank_start]coma[blank_end] or even brain [blank_start]death[blank_end].

[blank_start]Cerebellar[blank_end] [blank_start]tentorium[blank_end]: is an extension of the [blank_start]dura[blank_end] mater that separates the cerebellum from the inferior portion of the [blank_start]occipital[blank_end] lobes.

[blank_start]Falx[blank_end] [blank_start]cerebri[blank_end] is a strong, arched fold of [blank_start]dura[blank_end] mater that descends vertically in the [blank_start]longitudinal[blank_end] [blank_start]fissure[blank_end] between the cerebral hemispheres. It is narrow in front, where it is attached to the [blank_start]crista[blank_end] galli of the ethmoid; and broad behind, where it is connected with the upper surface of the [blank_start]tentorium[blank_end] cerebelli.

Falx cerebelli projects downward from the tentorium cerebelli to separate the two cerebellar hemispheres.

Increased stretching or tension of the dura of tentorium cerebelli and above will be detected as pain by which cranial nerve?

Ventricles are hollow.

CSF is acts as a cushion for the brain's [blank_start]cortex[blank_end], providing basic mechanical and [blank_start]immunological[blank_end] protection to the brain inside the skull. It also impacts cerebral autoregulation of cerebral [blank_start]blood[blank_end] [blank_start]flow[blank_end].

What is true?

[blank_start]Wernicke's[blank_end] dysphasia (AKA [blank_start]receptive[blank_end] [blank_start]aphasia[blank_end]) is when one can speak fluently but cannot comprehend nor speak comprehensively. Because the patient is [blank_start]unaware[blank_end] of this, the prognosis is poor. [blank_start]Broca's[blank_end] dysphasia (AKA [blank_start]expressive[blank_end] [blank_start]aphasia[blank_end]) is when one can fully comprehend but has difficulty replying/speaking. They are often very frustrated and recovery is [blank_start]not[blank_end] fully capable. [blank_start]Writing[blank_end] is also affected.