Lecture 1 and 2: Neuropathology Flashcards
What are some clinical signs associated with cerebrum/forebrain
Ataxia, behavioral changes, seizures, head-pressing, circling, blindness
What are some clinical signs associated with midbrain/cerebellum/brainstem
Ataxia, hypermetria, hypertonicity, head tilt, circling, nystagmus, tremors, cranial nerve deficits
What are some clinical signs associated with Spinal cord
Paralysis/paresis, weakness, spasticity
What is a coup injury and what does it involve
Occurs on same side and can involve soft tissue, skull fracture, dural or subdural hematomas
What is a contrecoup injury and what does it involve
Injury on opposite side of injury that can cause hemorrhage and edema
What is a concussion
Head injury leading to loss of consciousness without gross evidence of injury
What is a contusion
Head injury that results in hemorrhage, +/- tearing of brain parenchyma, +/- skull fracture
What wrong
Subdural hemorrhage
Why are skull fractures dangerous
Act as FB or mechanism for laceration of neurological tissue it surrounds
What wrong
vertebral fracture
What occurs as a result of a hematoma
Space occupying lesion that will increase ICP leading to compression or herniation
Where does the cerebellum herniate through and why is it life threatening
Herniates through foramen magnum and life threatening because it compresses on respiratory centers within the brainstem
What wrong
Cerebellar herniation through foramen magnum
What do these images show
left: normal intervertebral disc
Right: degenerated disc, chalky nucleus pulposus
Intervertebral discs can herniate into spinal cord causing ___, ___, and ___
Hemorrhage, edema and necrosis
what wrong
Herniated disc
What is type 1 disc herniation (who gets it, acute or chronic, what herniates)
Chondrodystrophic breeds (dachshunds, frenchies), acute onset of clinical signs due to herniation of nucleus pulposus
What is type 2 disc herniation (who gets it, acute or chronic, what herniates)
More common in our large breed dogs
Gradual onset of clinical signs
Annulus fibrosis herniates
What is a major consequence of spinal cord trauma
Hemorrhagic myelomalacia
What is hemorrhagic myelomalacia
Ascending and/or descending hemorrhage and necrosis within the cord
How do animals with hemorrhagic myelomalacia present
Ascending or descending paralysis and sensory deficits within 12-24hrs after spinal cord injury
What is one reason/ location that can make myelomalacia life threatening
Lesion near phrenic nerve will cause suffocation because innervates diaphragm
What wrong
Hemorrhagic myelomalacia
What wrong
hemorrhagic myelomalacia
What is a stroke
Sudden onset of focal neurological deficits due to intracranial vascular event caused by local ischemia
What is the most common cause of stroke
Infarction- thrombosis
Which infarction is acute vs chronic
Left: acute (red to black)
Right: chronic (golden-brown, shrunken/depressed)
How do cats with feline ischemic encephalopathy present
Ataxia, circling, seizures, blindness, postural deficits
What does lesion from
FIE look like
Asymmetrical/ unilateral ischemic necrosis and atrophy of cerebral cortex that is supplied by middle cerebral artery
What artery is occluded with FIE
Middle cerebral artery
What is cause of FIE
Vascular disorder as a result of
1. Cardiomyopathy—> thrombosis
2. Parasite migration—> cuterebra
What this
FIE
What is fibrocartilaginous emboli (FCE)
Specific form of infarction caused by degenerative intervertebral disc material that extruded into spinal blood vessels to the parenchyma of spinal cord causing infarction
What this
FCE
What age and breeds are typically associated with CNS neoplasms
Older dogs, brachycephalic breeds
Brachycephalic breeds tend to get what specific CNS tumor
Gliomas
What is the one brain tumor that can be seen in young or in-utero animals
Medulloblastoma
What are some signs of CNS neoplasia
Seizures, depression, temperament changes, propulsive gait, blindness
What is the number one type of CNS tumor in dogs and cats
Meningioma
What are the 3 meninge layers
- Dura
- Arachnoid
- Pka mater
The arachnoid matter and pia mater are called ___
Leptomeninges
The pia matter is present in the __which is in the ventricles
Choroid plexus
Where are meningiomas located
Brain, spinal cord and intraventricular possible due to pia in choroid plexus
Are meningiomas benign or malignant
Benign but space occupying that cause damaging compression
What is gross appearance of meningioma
Discrete, firm to rubbery mass with meningeal attachment
What this
meningioma
Although meningiomas do not infiltrate underlying structures they cause ___to tissues beneath them
Compression
What is the 2nd most common brain tumor in dogs
Gliomas- astrocytomas and oligodendroglioma
What are gemistocytes
Astrocytes that respond to injury by increasing their cytoplasm
What are Alzheimer’s type 2 astrocytes and what are they associated with
Clusters of astrocytic nuclei that are swollen and clear
Associated with hepatic and renal encephalopathy
What are these
Gemistocytes
What is the function of oligodendrocytes
Form myelin wheat around axons in CNS
What cell is responsible for myelinating axons in PNS
Schwann cells
Are glial tumors malignant or benign
Malignant
Where are astrocytomas typically located
Cerebrum- especially temporal lobe
What this
astrocytomas
Where are olgiodendrogliomas located
Cerebrum- frontal lobe
What is the gross appearance of oligodendroglioma
Pink to gray, soft and gelatinous tumors
What this
oligodendroglioma
What is the appearance of oligodendroglioma on histology
Fried egg
What does this histology indicated
Oligodendroglioma
What sex are oligodendroglioma more prevalent in
Males
What is the main function of microglia
Phagocytosis
What is the third most common type of CNS tumors in dogs
Choroid plexus epithelial derived tumors- papilloma, carcinoma, adenoma
What cells do choroid plexus derive from
Epithelial cells
Where is the choroid plexus located
Lateral ventricle
What is the function of choroid plexus
Produce CSF
Where is the most common location for choroid plexus tumor
4th ventricle
How do animals with choroid plexus tumors present
Vomiting, positional nystagmus, head tilt, and tetraparesis
What type of tumors are these based on location
choroid plexus tumors
What is a major sequela of choroid plexus tumors
Hydrocephalus due to ventricular obstruction
Identify layers of cerebellar cortex 1-6
- Leptomeninges
- External granular cell layer
- Molecular layer
- Purkinje cell layer
- Granular cell layer
- White matter
What are medulloblastomas composed of
Undifferentiated cells of neural tube
Where and who do medulloblastomas occur in
Cerebellum of young animals, most commonly in calves
Where do medulloblastomas arise from
External granular cell layer
What is gross appearance of medulloblastomas
Gray masses in cerebellum
Necropsy of young dog- What this
Medulloblastoma
What is method of metastatic spread to CNS
Hematogenous
What is pattern of metastatic neoplasia in CNS
Multifocal, embolic pattern
What are the most common metastatic neoplasia in dog CNS
Hemangiosarcoma and melanoma
What are your 2 differentials
- Hemangiosarcoma
- Melanoma
What type of cancer
lymphoma
What cells are known to cause peripheral nervous system neoplasia
- Perineural cells
- Fibroblasts
- Schwann cells
What are the benign peripheral nerve sheath tumors
- Schwannoma- Schwann cell
- Neurofibroma- Schwann cell and perineural cells
What are malignant peripheral nerve sheath tumors called
Just peripheral nerve sheath tumors
What this
Peripheral nerve sheath tumor of spinal nerves
What this
peripheral nerve sheath tumor of brachial plexus
What are neurofibromatosis and who gets them and where
Syndrome inc cattle which single or multiple peripheral nerve sheath tumors develop at following sites
- heart
- brachial plexus
- mediastinum and intercostal nerves
Ribs from cow what is top differential
Neurofibromatosis
