Neuro 2 Flashcards
What are the adult brain tumors
Glioblastoma multiforme (astrocytes) Meningioma (arachnoid cells) Schwannoma (Schwann cells) Oligodendroglioma (oligodendrocytes) Hemangioblastoma Pituitary adenoma
What are the child brain tumors
Pilocytic astrocytoma (astrocytes)
Medulloblastoma (cerebellum)
Ependymoma (surrounding ventricles)
Craniopharyngioma (Rathke’s pouch)
Location of Broca’s area
Inferior frontal gyrus
Location of Wernicke’s area
Posterior section of superior temporal gyrus
What is Gerstmann syndrome
Lesion of dominant parietal cotex
Causes: agraphia (inability to write), acalculia (inability to calculate), finger agnosia (inability to distinguish fingers), left-right disorientation
Anatomy that may cause weakness
o Motor cortex o Pyramidal tract (e.g. corticospinal tract) o Extrapyramidal tract (e.g. basal ganglia) o Cerebellum o Spinal cord o Lower motor neurons o Neuromuscular junction disease o Muscular weakness
In which aphasia is repetition affected?
Broca’s, Wernicke’s, and conduction
So it is affected in the cortical aphasias, but not in the precortical aphasias
Describe path of dorsal column/medial lemniscus
♣ Processes fine touch, pressure, vibration, and proprioception
♣ First order neurons (dorsal column) have cell bodies in dorsal root ganglion or cranial nerve ganglion and ascend ipsilaterally to the nucleus gracilis (lower body) or nucleus cuneatus (upper body) in the medulla
♣ In the medulla they synapse on second order neurons which then cross the midline
♣ Second order neurons (now called the medial lemniscus) ascend to the contralateral thalamus (VPL) where they synapse on 3rd order which ascend to the somatosensory cortex and synapse on 4th order
Describe path of spinothalamic tract
♣ Processes pain, temperature, and light touch (crude touch?)
♣ First order neurons have cell bodies in dorsal horn (of gray matter) and synapse on thermoreceptors and nociceptors in the skin
♣ First order nerves synapse on second order in the dorsal horn of the spinal cord, where the second order cross the midline at the anterior white commissure and ascend to the contralateral thalamus (VPL) when second order synapse on third order which ascend to somatosensory cortex and synapse on fourth order
Describe path of corticospinal tract
♣ UMN from motor cortex descend to pyramid in the medulla
♣ Axons cross to contralateral side in the caudal medulla and descend via lateral cortico-spinal tract
♣ Enter the spinal cord at lateral white column and travel to the anterior grey horn
♣ Synapse to LMN (alpha motor neuron) which then exits via ventral spinal root to innervate muscle
Where is lesion in conductive aphasia
Arcuate fasciculus
Describe glioblastoma multiforme
• Malignant tumor of astrocytes GFAP (+)
• Found in cerebral hemispheres and may cross corpus callosum – “butterfly lesion”
• Pseudopalisading – tumor surrounding central necrosis
o THINK:
♣ Pseudopallisading looks like a star = astrocyte
♣ Central area is necrotic/dead so this must be an old people tumor – astocyte tumor of adults = glioblastoma multiforme
Describe meningioma
- Benign tumor of arachnoid cells
- Most often occurs near surfaces of brain
- Extra-axial (external to brain parenchyma) and may have a dural attachment (“tail”)
- May present with seizures
- Histology shows whorled pattern and Psammoma bodies
Describe hemangioblastoma
- Tumor of the CNS that originates from vascular origin
- Associated with Von-Hippel Lindau syndrome (increased risk of bilateral renal cell carcinoma)
- Can produce erythropoietin secondary polycythemia
Describe Schwannoma
- Benign tumor of Schwann cells S-100 (+)
- Most frequently involved CN VIII (loss of hearing and tinnitus)
- Bilateral vestibular schwannomas seen in neurofibromatosis-2
Describe Oligodendroglioma
- Most often in frontal love
* “Fried egg” appearance (round nuclei with clear cytoplasm)