Hematomas, Herniations, And Hemorrhages Flashcards
Most common cerebral herniation pattern
Subfalcine herniation (falx herniation)
Location of falx herniation
Displacement of brain beneath free edge of falx cerebri due to increased intracranial pressure
Structures directly involved in tentorial herniation
Uncus
Midbrain
Location of tentorial herniation (specifically uncal herniation)
Herniation of medial temporal lobe from middle into posterior fossa across tentorial opening
Uncus of temporal lobe is forced into gap between midbrain and edge of tentorium
Location of tonsillar herniation
Cerebellar tonsils move downward through foramen magnum, possible compression of lower brainstem and upper cervical SC
Boundaries of epidural hemorrhage
Dura and surrounding skull bone
Boundaries of subdural hematoma
Blood accumulates between inner layer of dura mater and arachnoid mater
Boundaries of subarachnoid hemorrhage
Blood accumulates between arachnoid mater and pia mater
Cause/location of external hydrocephalus
Accumulation of CSF causing increase in volume in subarachnoid space (little to no ventricular dilation)
Cause of internal hydrocephalus
CSF produced in ventricular system does not drain into subarachnoid space
Location of internal hydrocephalus
Ventricle(s) proximal to obstruction
- obstruction in interventricular foramen —> 3rd ventricle choroid plexus ependyma
- obstruction in cerebral aqueduct —> midbrain astrocytoma
- median and lateral apertures —> arnold chiari malformation or dandy-walker cyst
Cause of communicating hydrocephalus
Obstruction of narrow space between the tentorial notch and midbrain, usually due to adhesions or fibrosis in subarachnoid spaces from inflammation, cerebral edema, or uncal herniation
Location of communicating hydrocephalus
Ventricles and infratentorial space
Result of damage to dorsal root of SC
Diminished tone and reflexes
Result of damage to posterior columns of SC
Ipsilateral loss of proprioceptive and 2-point tactile discrimination below the lesion
Effect of damage to LSTT region of spinal cord
Contralateral loss of pain and temperature sensations 2 sensory dermatomes below lesion
Effects of damage of lateral reticulospinal tract of SC
Horner’s syndrome above T1
Incontinence
Deficits associated with lesion in anterior white commissure
Bilateral analgesia (usually of upper limbs)
Effect of lesions of anterior horn of SC
LMN paralysis/paresis
Effect of damage to lateral corticospinal tract (LCST) of SC
Ipsilateral UMN paralysis/paresis below lesion
What CN is commonly affected in ALS?
Hypoglossal n.
What disease often mimics ALS?
Lyme disease
Diminished tone and reflexes may indicate damage to what area of the SC?
Dorsal roots
Ipsilateral loss of proprioceptive and 2-point tactile discrimination below the lesion may indicate damage to what area of the SC?
Posterior columns
Contralateral loss of pain and temperature sensations 2 sensory dermatomes below lesion may indicate damage to what area of the SC?
LSTT
Horner’s syndrome (if above T1) and/or incontinence may indicate damage to what area of the SC?
Lateral reticulospinal tract
Bilateral analgesia (usually of upper limbs) may indicate damage to what area of the SC?
Anterior white commissure
LMN paralysis/paresis may indicate damage to what area of the SC?
Anterior horn
Ipsilateral UMN paralysis/paresis below the lesion may indicate damage to what area of the SC?
Lateral corticospinal tract
