Neuro (Core Qs & Others) Flashcards
At which intervertebral disc level does the conus medullaris typically terminate?
L1-L2
What is the upper limit of the diameter of a normal filum terminale?
2mm
The filum terminale extends from the conus medullar is to the _____
Periosteum of the coccyx
CN I (sensory)
Olfactory: smell
CN II (sympathetic)
Optic: sight
CN III (motor)
Oculomotor: eyeball movement, pupillary light reflex
CN IV (parasympathetic)
Trochlear: eyeball movement
CN V (sensory, sympathetic, motor)
V1: ophthalmic
V2: maxillary
V3: mandibular
CN VI (motor)
Abducens: eyeball movement
CN VII (sympathetic)
Facial: taste (anterior 2/3 of tongue), facial expressions, salivary and lacrimal glands
CN VIII (sensory)
Vestibulocochlear: hearing and baalnce
CN IX (sensory, motor, parasympathetic)
Glossopharyngeal: sensation of posterior 1/3 tongue, parotid salivary gland
CN X (motor, parasympathetic, sympathetic)
Vagus: swallowing, heart rate, GI peristalsis, sweating
CN XI (motor)
Accessory: sternocleidomastoid (head turning), trapezius (shoulder shrugging)
CN XII (motor)
Hypoglossal: most muscles of the tongue
Which CN exists through the cribiform plate?
CN I Olfactory
Which CN exists through the optic canal?
CN II Optic
Which CN exists through the superior orbital fissure?
CN III Oculomotor
CN IV Trochlear
CN V(v1) Ophthalmic
CN VI Abducens
Which CN exists through foramen rotundum?
CN V(v2) Trigeminal (maxillary)
Which CN exists through foramen ovale
CN V(v3) Trigeminal (mandibular)
Which CN exists through the internal acoustic meatus?
CN VII Facial
CN VIII Vestibulocochlear
Which CN exists through the jugular foramen?
CN IX Glossopharyngeal
CN X Vagus
CN XI Accessory
Which CN exists through the hypoglossal canal?
CN XII Hypoglossal
With spinal cord contusion and/or edema, what are the different types?
From best prognosis to the worst:
Cord edema only
Cord edema and contusion
Cord contusion only
Spinal cord compression requires what kind of referral?
A neuro-surgical emergency, requires decompression
Cauda equina syndrome is the compression of _____
Spinal nerve roots, past the conus medullaris
There are many causes of spinal cord compression, what are some common ones?
Intervertebral disc
Spondylophytes
Trauma
Tumors
What is the most common cerebellarpontine angle mass in adults?
Acoustic schwannoma (CN VIII vestibulocochlear nerve) accounts for approximately 80%
Aside from acoustic schwannoma, what are some other common masses of the cerebellarpontine angle?
Meningioma
Trigeminal schwannoma
Facial nerve schwannoma
Ependymoma
What is intraspinal hemorrhage? (Aka hematomyelia)
Hematoma within the spinal cord, can occur during trauma
If a hematomyelia is present without trauma, what should be considered?
Underlying lesion of the spinal cord
What are some causes of intraspinal hemorrhage (hematomyelia)?
Vascular malformation Intramedullary tumor Cavernous hemangioma Spinal cord metastasis Coagulopathies Radiation therapy
Where is the foramen spinosum located?
Posterior-lateral to the foramen ovale
What exists out of the foramen spinosum?
Middle meningeal artery
Middle meningeal vein
Nervus spinosus (usually)
What is the most common cause of neurogenic arthropathy (aka Charcots joints) in the shoulder and/or upper extremity?
Syringomyelia
What portion of the spine is the most common location for a syringomyelia?
C2-T9 region but may descend to the conus medullaris
What are 3 congenital causes of syringomyelia?
Chiari malforrmation
Klippel-Feil syndrome
Myelomeningocele
What is the most common population for viral meningitis?
Children and young adults,
< 1 years old and between 5-10 years old
What is the classic presentation of viral meningitis?
Fever
Neck stiffness
Brudzinski sign (+)
Are there neurological dysfunction associated with viral meningitis?
No, neurological dysfunction is not a feature
Which virus is responsible for the majority of cases of viral meningitis?
Enterovirus (90%) Other viruses include: Poliovirus Echovirus HPV Herpes simplex Epstein Barr virus Cytomegalovirus
Acute transverse myelitis (ATM) is an inflammatory condition that affects both halves of the spinal. This is associated with what changes?
Motor, sensory, and autonomic dysfunctions that rapidly progresses
What is the peak age for acute transverse myelitis?
10-19 years old and 30-39 years old
Clinical symptoms for ATM presents within hours/days, they include the following
Para/tetraparesis (limb weakness)
Sensory impairment
Sphincter dysfunction
Approximately what percentage of people with ATM will recover with no sequelae?
Approximately 1/3 of patients will recover with no sequelae
1/3 will have moderate permanent disability
1/3 will have severe permanent disability
What are the MRI findings of acute transverse myelitis?
Variable enlargement of cord
T1 isointense/hypointense
T2 poorly delineated hyperintense
What is the most common type of multiple sclerosis (MS)?
Classic/Charcot type
MS is the _____ most common cause of neurological impairment
Second most common cause after trauma
What is the peak age for MS to present?
35 years old
Usually presents between adolescence to 6th decade
Is there a strong gender predilection for MS?
Females > males (2:1)
What are some classic clinical features of MS?
Optic neuritis Internuclear ophthalmoplegia (often bilateral) Trigeminal neuralgia Diplopia Vertigo Ataxia and gait disturbances Limb sensory loss Lhermitte sign (+): electric shock sensation on neck flexion Urinary incontinence
Which pattern of MS is the most common type?
Relapse-remitting (70%)
What are the 3 pathological stages for MS lesions?
Early acute stage:
Active myelin breakdown
Plaque appears pink/swollen
Subacute stage:
Plaque is paler (“chalky”)
Abundant macrophages
Chronic Stage: Inactive plaque/gliosis Little/no myelin breakdown Gliosis with associated volume loss Appearance is gray/translucent
The “Dawsons finger” sign is associated with what pathology?
Multiple sclerosis
For intracranial involvement in MS, what are some differential diagnosis to consider?
CNS fungal infection
Mucopolysacchridosis
Susac syndrome
Antiphospholipid syndrome
For spinal involvement in MS, what are some differential diagnosis to consider?
Acute transverse myelitis
Infection
Spinal cord tumors (eg. astrocytomas)
Acute disseminated encephalomyelitis (ADEM) is demyelination of _____
Demyelination of white matter
ADEM typically follows _____
Typically follows a viral infection/vaccination
What part of the grey matter is typically involved with ADEM?
Basal ganglion
What is the typical age range for ADEM?
Children/adolescents usually < 15 years old
Symptoms of ADEM are more systemic rather than focal, including the following
Fever
Headache
Decreased consciousness (lethargy to coma)
Seizure
If treated, what percentage of patients with ADEM make a complete recovery without sequelae?
50-60%, this is the most common result
What percentage of patients with ADEM recovery but with sequelae?
20-30% of patients will have persisting sequelae, most commonly seizures
Multiple benign peripheral nerve sheath tumors (neurofibromas) are strongly associated with which disease?
Neurofibromatosis type I
What percentage of spinal neurofibromas are localized intraneural lesions?
90%
Majority of them are sporadic and solitary
What are the normal components of a spinal neurofibroma?
Schwann cells
Fibroblasts
Collagen fibers
Schwannomas are encapsulated while neurofibromas are _____
Not encapsulated
They infiltrate between nerve fascicles
Primarily affecting superficial cutaneous nerves
The “target” sign is seen with what condition?
Hyperintense rim seen on MRI due to central area of collagen. Seen with neurofibromas
The “fascicular” sign is seen with what condition?
Neurofibromas, demonstrating multiple, small ring-like structures
Neurofibromas are slow growing and often asymptomatic but can cause remodeling of adjacent bone. That often includes the following
Widening of neural foramen
Thinning of pedicle
Posterior vertebral body scalloping
What is the most common nerve sheath tumor of the spine?
Spinal schwannoma
Where do spinal schwannomas typically arise?
Usually from nerve roots
What is the most common intradural extramedullary lesion?
Meningioma (25-30%)
What is the second most common intradural extramedullary lesion?
Schwannoma (15-50%)
What percentage of spinal shwannomas are sporadic and solitary?
90%
What condition is associated with multiple spinal schwannomas?
Neurofibromatosis type II
What is the most common location for spinal schwannomas?
Cervical and lumbar spine
What is the peak age for spinal meningiomas?
Between the 6th and 8th decade
Is there a gender predilection for spinal meningiomas?
Strong females > males predilection in adults
What are some risk factors associated with spinal meningiomas?
Increased ionizing radiation
Prior trauma
What condition is strongly associated with multiple spinal meningiomas?
Neurofibromatosis type II
Where in the spine is the most common location for meningiomas?
Thoracic spine
The “dural tail” sign associated with spinal meningiomas is seen in what percentage of patients?
60-70% of patients, caused by thickened dura
What is the most common spinal cord tumor overall in adults?
Spinal ependymoma
A spinal ependymoma is a considered a _____ cell tumor
Glial cell tumor
Ependymomas arise from the which 2 locations?
Ventricles of the brain
Central canal lining of the spinal cord
What is the most common location for an ependymoma?
Posterior fossa (60%)
Followed by:
Supratentorium (30%)
Spine (10%)
There is an increased coincidence of epnedymomas with what condition?
Neurofibromatosis type II
MRI findings of an ependymoma include the following
T1 isointense/hypointense T2 hyperintense Peritumoral edema (60%) "Cap" sign from hemorrhage may be present
What is the most common spinal cord tumor in children?
Spinal astrocytoma
What is the second most common spinal cord tumor overall?
Spinal astrocytoma
Astrocytomas account for what percentage of intramedullary tumors?
40%
Astrocytomas account for what percentage of pediatric intramedullary tumors?
60%
What underlying condition is associated with an increased chance of developing spinal astrocytomas?
Neurofibromatosis type I
Astrocytomas arise from what kind of cells?
Astrocytic glial cells
Astrocytomas are characterized by hypercellularity as well as absence of surrounding _____
Absence of surrounding capsule
What are the 2 most common locations for spinal astrocytomas?
Thoracic spine (67%) Cervical spine (49%)
Spinal astrocytomas will typically span multiple vertebral segments, this causes the following findings
Thin pedicles and/or lamina
Posterior body scalloping
Hemangioblastoma is the _____ most common intramedullary spinal tumor
3rd most common
Spinal hemangiomblastomas are rarely seen in children, the peak age range is what?
4th decade
Spinal hemangioblastomas consists of what?
Large stromal cells
Packed between blood vessles
If multiple spinal hemangioblastomas are present, a strong association to which condition is suspect?
Von Hippel Lindau syndrome
What are the 2 most common locations for spinal hemangioblastomas?
Thoracic cord (50%) Cervical cord (40%)
What percentage of spinal hemangioblatomas are sporadic?
80%
Tarlov cysts (aka perineural cyst) are defined as what?
CSF filled dilations of nerve root sheath
Located at dorsal root ganglion
Extradural in location
What kind of underlying condition is associated with Tarlov cysts?
Connective tissue disorders:
Marfans syndrome
Ehlers Danlos
Sjogren syndrome
What are the most common locations for Tarlov cysts?
Lower lumbar spine
Sacrum
On MRI, Tarlov cysts have the following appearance
T1 hypointense
T2 hyperintense
No enhancement with contrast
Arachnoid cysts are relatively common and benign. They can be located at which 2 locations?
Intracranial or within spinal cord
Imaging features of arachnoid cysts are as follows
Well defined
Imperceptible wall
Follows CSF patterns
Arachnoid cysts are seen with increased frequency in which type of underlying condition?
Mucopolysacchridosis
What is the most common location for arachnoid cysts?
Middle cranial fossa (50-60%)
Can cause widening of the Sylvian fissure
What is the second most common location for arachnoid cysts?
Retrocerebellar (30-40%)
An intracranial epidermoid cyst is an uncommon congenital cyst caused by the following
Inclusion of ectodermal elements during neural tube closure
Intracranial epidermoid cyst has a thin capsule made up of _____
Squamous epithelium
What is the most common location for an epidermoid cyst?
Intradural (90%) Cerebellarpontine angle (40-50%)
Image findings for an epidermoid cyst includes the following
Lobulated lesion
Fill and expand CSF spaces
Exert gradual mass effect (slow growing)
Displacement of vertebral artery from pons
What is the Currarino triad?
Anorectal anomalies
Sacral anomalies
Presacral mass
What are the presacral masses that are associated with the Currarino triad?
Anterior sacral meningocele (most common)
Mature teratoma (common)
Dermoid/epideroid cyst (rare)
Which 2 CN originate from the cerebrum?
CN I: olfactory
CN II: optic
Which 2 CN originate from the midbrain?
CN III: oculomotor
CN IV: trochlear
Which 4 CN originate from the pons?
CN V: trigeminal
CN VI: abducens
CN VII: facial
CN VIII: vestibulocochlear
Which 4 CN originate from the medulla oblongata?
CN IX: glossopharyngeal
CN X: vagus
CN XI: accessory
CN XII: hypoglossal
What is the definition of benign multiple sclerosis (MS)?
Defined as remaining functional for > 15 years
Accounts fo 15-50% of MS patients
What is a common diagnostic criteria system used for MS?
McDonald diagnostic criteria
Susac syndrome (aka SICRET syndrome) stands for what?
Small infarctions of cochlear, retinal, encephalic tissues
What is the most common population to be affected by Susac syndrome?
Young-middle aged females
What triad is seen with Susac syndrome?
Acute/subacute encephalopathy
Bilateral sensorineural hearing loss
Branch retinal arterial occlusions
Acute/subacute encephalopathy in Susac syndrome leads to the following?
Memory impairment Confusion Behavioral disturbances Headaches Psychosis
on MRI images for Susac syndrome, low signal T1 lesions known as “black holes” and high signal T2 lesions known as “snowball” lesions are seen in which stage of the disease?
Chronic stage of Susac syndrome
Sjorgren syndrome affects which 2 glands?
Lacrimal glands
Salivary glands
After rheumatoid arthritis, what is the second most common autoimmune disease?
Sjorgren syndrome
What is the gender predilection for Sjorgren syndrome?
Females > males (9:1)
What is the typical age range for presentation of Sjorgren syndrome?
40-50 years old
What are some clinical features of Sjorgren syndrome?
Bilateral parotid gland enlargement
Dryness of mucous membranes of mouth (xerostomia)
Keratoconjunctivitis sicca (dryness)
Describe the MRI findings of the parotid glands in Sjorgren syndrome
“Salt and pepper” appearance
“Honeycomb” appearance
Fat deposits
What is a possible malignancy that is associated with Sjorgren syndrome?
Development of malignant lymphoma
The temporal bone consists of which 5 parts?
Squamous Mastoid Petrous Tympanic Styloid process
The mandible bone consists of which parts?
Body Ramus Coronoid process Mandibular notch Condylar process
Chronic small vessel disease is more common in those with which 2 underlying disease?
Alzheimer disease
Lewy body disease
Chronic smell vessel disease is also known as what other name?
Leukoaraiosis (diffuse white matter changes)
Histologically in chronic small vessel disease, what do the lesions show?
Atrophy of axons
Decreased myelin
Diffuse axonal injury (DAI) aka traumatic axonal injury is caused by what kind of forces?
Shearing focus
Typically rotational acceleration forces
What location does DAI have a predilection for?
Gray/white matter junction
Especially the corpus callosum
Severe cases involve the brainstem
The absence of imaging findings do not exclude DAI, MRI findings include the following
Surrounding edema will increase during first few days
Some lesions may be non-hemorrhagic
Lesions are hyperintense on FLAIR
What are 2 complications associated with DAI?
Herniation
Hydrocephalus
Months following the original trauma, DAI patients demonstrate _____ brain volume
Decreased brain volume
Clinical findings for DAI include the following
Loss of consciousness at the time of the accident
Long post traumatic coma
Arachnoiditis is the inflammation of what 2 structures/spaces?
Meninges and subarachnoid space
Arachnoiditis of the cauda equine is known as what?
Spinal/lumbar adhesive arachnoiditis
Clinical presentation for arachnoiditis includes the following
Leg pain
Sensory changes
Motor changes
Arachnoiditis with impaired CSF can cause what condition in the spinal cord?
Syringomyelia
Causes of arachnoiditis includes the following
Infections
Inflammatory such as hemorrhagic and iatrogenic
MRI appearance of arachnoiditis includes the following
Most easily seen at lumbar region: cauda equina
Nerve roots adhere together
Nerve roots may also adherer to theca
What are the different types of arachnoiditis seen at the cauda equina?
Type I:
Nerve roots clumped together and distorted
Type II:
Nerve roots adhere to the theca
“Empty theca” sign
Type III:
Nerve roots and theca clumped together
Becomes a single soft tissue mass
Occasionally ossification can occur at the cauda equina due to arachnoiditis, what is this called?
Arachnoiditis Ossificans
Cortical contusions is often a differential diagnosis to consider for which condition?
Diffuse axonal injury (DAI)
Cortical contusions (aka cerebral hemorrhagic contusion) is a type of _____ hemorrhage
Intracerebral hemorrhage
Cortical contusions can occur anywhere but the predilections are as follows
Anterior cranial fossa floor
Temporal pole
Coup and coutrecoup pattern
What is the most common cause for cortical contusions?
Motor vehicle accidents
What is the MRI appearance of cortical contusions?
T1: hyperintense
T2: hypointense
In cases of acute transverse myelitis (ATM), what percentage of patients will demonstrate a normal MRI?
40%
Lesions can occur anywhere along the spinal cord for acute transverse myelitis but what is the most common location?
Thoracic spine (usually spanning 3-4 segments)
Most frequent areas to check for cortical contusions that resulted from a coup and coutrecoup pattern is where?
Temporal pole
Inferior surface of frontal lobe
Subdural hemorrhage (SDH) aka subdural hematoma is located where?
Within the dura space, between the dura and arachnoid
What is the main cause of subdural hemorrhage?
Main cause is due to trauma
Subdural hemorrhage is seen in all age groups
Infants: suspected abuse
Young adults: vascular lesions, motor vehicle accidents
Elderly: falls
Some common clinical symptoms associated with subdural hemorrhage includes the following
Commonly coexist with cerebral contusions
Severely depressed cognitive state ( 65-80%)
Pupillary abnormalities (40%)
Potts disease is another name what condition?
Tuberculosis causing osteomyelitis and diskitis at the spine
What is the most common musculoskeletal location for tuberculosis?
Spine
What is the typical location for Potts disease?
Lower thoracic spine
Upper lumbar spine
Early radiographic findings of Potts disease includes the following
Decreased vertebral body height
Irregular endplates
Paraspinal collections
What are some common radiographic findings of Potts disease?
Typically sub-ligamentous involvement beneath ALL
Posterior elements are usually spared
Often involves multilevel
Irregularity of anterior vertebral bodies
Spondylodiskitis is infection that involves the intervertebral disc and adjacent vertebral bodies. What is the most common age range?
Pediatric
Older patients > 50 years old
Low back pain is present in what percentage of patients with spondylodiskitis?
90%
Risk factors that are associated with spondylodikitis includes the following
Remote infection Spinal instrumentation/trauma IV drug users Immunocompromised individuals Long term steroid use Organ transplant Malnutrition Cancer
What is the most common location for spondylodiskitis?
Lumbar spine
What is the most common distribution of spondylodikitis?
Single level (65%)
Multiple contiguous levels (20%)
Multiple non-contiguous levels (10%)
What is the most common organism that causes spondylodikitis?
Staph. aureus
Those with spondylodikitis can present with normal radiographs for how long?
2-4 weeks
