Diseases Test 1 Flashcards
Craniorachischisis
Failure of a significant portion of the neural tube to close resulting in exposure of the malformed neural tissue along back of head and body
Anencephaly or Merocephaly
Failure of the Rostral Neuropore to close
Spina Bifida
Failure of the caudal neuropore to close.
Three forms:
- ) Spina Bifida Occulta malformant spinal canal; fauns hair
- ) Meningiocele - Bulge canal in back with CSF only
- ) Myelomeningiocele - Bulge in back with nervous tissue in cele. Most severe.
Linked to low folic acid intake during pregnancy.
Syringomyelia
Tubular cavitation of the spinal cord – generally cervical/upper thoracic
Pathogenesis unknown
Neural deficits begin w/ loss of pain and temp. sensation over shoulders and upper arms. Can grow and move downward.
Holoprosencephaly
Forebrain does not divide into two hemispheres; leads to death and often single eye.
Hydrocephalus
Dialation of ventricles due to CSF overproduction, obstruction of flow or failure of CSF reabsorbtion.
Dandy-Walker Malformation
Partial or complete absence of cerebellar vermis.
Arnold-Chiari Malformation
Cerebellum drops down. Can range from asymptomatic to lack of cerebellar development.
Prenatal alcohol exposure
Marked decrease in child brain development w/ fetal alcohol syndrome. Thought to be due to alcohol interfering w/ migration of axons, so connections do not happen properly. May lack corpus callosum.
Waardenburg Syndrome
Neural crest did not migrate properly. Melanocyte abnormalities.
Hirschsprung Disease or congenital megacolon
Due to failure of neural crest cells t o migrate into the colon - most common in rectum and sigmoid.
Parasympathetic ganglia do not form, so normal peristalsis does not occur
Fecal retention with ballooning of the colon and abdomen.
Wernicke-Korsakoff syndrome
Vit B1/ Thiamine deficiency doesn’t allow transketolases in Pentose Phosphate Pathway to function limiting NADPH production, 5 carbon sugars, and glutathione production.
Destruction of mamillary bodies.
Symptoms: “Can of beer” Alcoholics (unless in developing world), Present with confusion, no formation of new memories, and confabulation.
Berry Aneurysms
Occur at the bifurcations in the circle of willis. Most common site is bifurcation of the anterior communicating artery. Rupture cal lead to hemorrhagic stroke/ subarachnoid hemmorrhage.
Epidural Hematoma
Rupture of middle meningeal artery often secondary to fracture of temporal bone. Lucid interval. Rapid expansion under systemic arterial pressure –> transtentorial herniation, CN III palsy.
CT Shows “biconvex disk” not crossing suture lines. Can cross falx, tentorium.
Neurosurgery emergency
Subdural hematoma
Rupture of bridging veins. Slow venous bleeding (less pressure = hematoma develops over time) with delayed symptoms. Acute (hours) or chronic (months)
Seen in elderly individuals, alchoholics, blunt trauma, shaken baby.
CT - crescent-shaped hemorrhage that crosses suture lines. Gyri are preserved, since pressure is equally distributed. Cannot cross falx, tentorium.
Subarachnoid hemorrhage
Rupture of an aneurysm (usually berry aneurysm) or an AVM.
Patients complain of “worst headache of my life”
Bloody or yellow (xanthochrompic) spinal tap. 2-3 days afterward, there is a risk of vasospasm due to blood breakdown products, which irritate vessels (treat with calcium channel blockers)
Neurosurgical emergency
Normal Pressure Hydrocephalus
“Wet, wobbly, and wacky.” Doesn’t result in increased subarachnoid space volume. Expansion of ventricles distorts the fibers of the corona radiata and leads to the clinical triad of dementia, ataxia, and urinary incontinence.
Very important to rule out for dementia vs. AD because normal pressure hydrocephalus is reversible.
Communicating hydrocephalus
Decreased CSF absorption by arachnoid villi, which can lead to increased intracranial pressure, papilledema, and herniation.
(e.g. arachnoid scarring post meningitis)
Obstructive (non-communicating) hydrocephalus
Caused by structural blockage of CSF circulation within the ventricular system.
(e.g. tumor or stenosis of the aqueduct of sylvius.)
Hydrocephalus ex vacuo
Appearance of increased CSF in atrophy (i.e. AD, advanced HIV, Pick’s disease) Intracranial pressure is normal; triad is not seen.
Multiple Sclerosis
Autoimmune inflammation and demyelination of CNS. Patients can present with optic neuritis (sudden loss of vision), MLF syndrome (internuclear opthalmoplegia), hemiparesis, hemisensory symptoms, or bladder/bowel incontinence. Relapsing and remitting course. Most often affects women in their 20s and 30s; more common in whites.
Findings: increased protein (IgG) in CSF. Oligoclonal bands are diagnostic. MRI is gold standard. Periventricular plaques (areas of oligodendrocyte loss and reactive gliosis) with preservation of axons.
Charcot’s triad: SIN Scanning speech, Intention tremor, Incontinence, Internuclear opthalmoplegia, Nystagmus.
Treatments: Beta- Interferon or immunosuppressant therapy. Symptomatic treatment for neurogenic bladder, spasticity, pain.
Guillain- Barre Syndrome
Acute inflammatory demyelinating polyradiculopathy
Inflammation and demyelination of peripheral nerves and motor fibers of ventral roots following flu like infection (sensory effect less sever than motor), causing symmetric ascending muscle weakness beginning in distal lower extremities. Facial paralysis in 50% of cases. Autonomic function may be sererely affected (i.e. cardiac irregularities, hypertension, and hypotension). Almost all patients survive; the majority recover completely after weeks to months.
Findings: Increased CSF protein with normal cell count. Increased protein –> papilledema.
Respiratory support is critical until recovery. Additional treatment: plasmapheresis, IV immune globulins.
Charcot-Marie-Tooth disease
Also known as hereditary motor and sensory neuropathy (HMSN). Group of progressive hereditary nerve disorders related to the defective production of proteins involved in the structure and function of peripheral nerves or myelin sheath.
High arches, hammer toes, muscle atrophy.
Normal life span.
Glioblastoma multiforme
Most common primary brain tumor. Average life expectancy is less than a year. Found in cerebral hemishperes. Can cross corpus collosum (“butterfly glioma”)
Linear skull fracture
Most common. Straight crack. Usually not serious.
