Approach to Neurological Syndromes Flashcards
General approach
- Localize dysfunction based on signs / sxs
- Diff diagnosis based on location and syndrome time course
- Narrow diff diagnosis based on px risk factors
Cytotoxic edema
Intracellular
Vasogenic edema
Extracellular
Gliosis / astrogliosis / astrocytosis
Astrocytes multiply, get bigger / longer / thicker process and forms a glial scar
Acronym for categories of neuropathology
GIVE MAN MINT
Genetic, idiopathic, vascular, epileptic, mechanical, autoimmune, neoplastic, metabolic, infectious, nutritional, toxic
What are most common areas for vascular NS problems?
Mainly affect brain and retina, rarely SC, and very rarely PNS.
What part of NS do seizures normally effect?
Seizures are mainly a manifestation of the cerebral cortex (gray matter). Rare to see subcortical and brainstem seizures.
In what population are febrile seizures common?
Little kids. Usually outgrow them.
Symptomatic vs idiopathic epilepsy
- Symptomatic epilepsy has identifiable features, such as brain tissue scarring from trauma.
- Idiopathic seizures / epilepsy = recurrent unprovoked seizures w/o known cause.
Things that provoke seizures
Fever, structural brain abnormalities, toxins, metabolites, infections.
Characteristics of absence seizures
- Generalized at onset, but pxs usually can still stand / sit.
- Most common in kids. Usually grow out of it.
- Usually no aura or post-ictal state (snap right into / out of it).
Todd’s paresis / paralysis
AKA postictal paresis/paralysis or “after seizure”
Focal weakness in a part of the body after a seizure. Think of the neurons as being “exhausted”. Usually only lasts a couple minutes.
May be provoked by hyperventilation.
Co-morbidities w/ epilepsy
Mood disorders or cognitive deficits
What change in brain anatomy may occur w/ chronic epilepsy?
Hippocampal sclerosis
Laceration
Torn tissue
Spondylosis
Spinal degeneration, including hernation of discs. May cause compression of SC or roots. Other problems include degeneration / thickening of ligamentum flavum (bind laminae of adjacent vertebrae), facet joints (bone spurs)
Spondylolysis
Defect in pars interarticularis of vertebrae
Spondylolisthesis
Displacement of vertebrae relative to neighbor
What parts of NS are most common to get tumors?
Brain is most common site in NS to get tumors, followed by SC, then PNS
Intra-axial tumor
Located in CNS
Extra-axial tumor
Located in skull / spine, but NOT in CNS. Causes compression.
Meningitis
WBCs
Glucose
Protein
- Usually an elevated WBC count, w/ predominance of neutrophils in bacterial, or lymphocytes for other pathogens.
- Glucose concentration is low in bacterial meningitis. Glucose is normal for other pathogens.
- Protein concentration is high w/ any cause of meningitis (but highest w/ bacterial) due to exudation from circulation as part of normal inflammatory response.
Precautions w/ lumbar puncture
•May cause brain herniation if there is focal mass effect, such as intracranial tumor, by increasing pressure diff b/w cranial and spinal areas. Not true for high pressure that is equally distributed. If focal CNS sxs are present, or if arousal is diminished, cranial imaging is required prior to tap to rule out mass.
When is a lumbar puncture mandatory?
•When there is high clinical suspicion for subarachnoid hemorrhage and imaging is neg. Look for continuous bleeding. Emergency.
Xanthochromia
Yellow tinge caused by RBC breakdown from subarachnoid hemorrhage that has been present for hours.
Carcinomatous meningitis
Metastatic cancer to CSF. Do CSF cytology to diagnose.
EMG changes w/ demyelination
Normal, but contraction is reduced.
EMG changes w/ axonal loss (denervation)
Abnormal. Fibrillation potentials may occur, representing spontaneous APs of myocytes at rest.
When is biopsy required?
- Brain tumors that aren’t obviously metastases
- Autoimmune disorders that cause inflammation of blood vessels, meninges, or brain.
- Polyneuropathies / myopathies
