clinicalMedNSDiseases

Trauma

• 10% disabling injury
• 30% of all accidental deaths
• 70% of all automobile deaths

• epidural
• subdural
• subarachnoid hemorrhage

• very fast accumulation of blood btwn the skull and dura
• usually due to middle cerebral artery rupture
• immediate surgery is only option or person will die

• a blow to the side of the head that fractures the temporal bone
• can be accompanied by loss of consciousness, recovery, and progressive neurologic deterioration leading to coma

• accumulation of blood in the subdural space
• due to rupture of bridging veins passing btwn brain and large dural sinuses

• inertial brain injury to frontal or occipital portion of the head w/o skull fracture
• people tend not to remember the trauma bc it seems insginificant

• acute: manifests after a few days
• chronic: manifests after weeks or months by confusion that may lead to coma

bleeding into the subarachnoid space (any etiology)

commonly caused by trauma or rupture of a pre-existing arterial aneurysm but can have any etiology

• inherited disorders due to incomplete and/or abnormal resolution of embryonic vasculature
• common
• usually consist of a mixture of veins, arteries, and arterialized veins usually located in brain hemispheres ("arteriovenous malformations)

seizures and intracerebral hemorrhage from rupture

• saccular ("berry") aneurysms
• present in 5-6% of general population
• usually arise at the bifurcation of vessels in the middle cerebral artery and its branches
• very lethal
• typical at the base of the skull

ant cerebral and ant communicating artery

• rupture (most lethal)
• infarction
• mass effect (compression)

a collection of usually bloody fluid w/in brain stem or cerebral hemispheres

• most common cause of non-traumatic hemorrhage
• occurs most freq in basal ganglia where walls of vessels have been damaged by chronic hypertension or hypertensive microaneurysms

• infarction: localized to arterial distribution, destroy brain parenchyma
• hemorrhage: affects any blood vessel in the brain, compresses the brain

• vascular thrombosis: internal carotid, vertebral artery, usually associated w/ a pre-existing atherosclerosis
• embolism: thrombi from L hrt or carotid arteries, symptoms depend on location and size

increased CSF volume causing vascular distention

• overproduction of CSP
• inability of aracnoid villi to transfer CSF to venous drainage
• blockage of CSF pathways

blockage is within the brain

blockage in subarachnoid space

resultant head enlargement mostly from top of skull

causes symptoms related to increased intracranial pressure

• bacterial
• -- leptomeningitis
• -- cerebral abscess
• viral
• -- viral meningitis

• bacterial infection caused by
• - E. coli in newborns
• - H. influenza in infants and children
• - N. meningitis in adolesents and young adults
• - Step. pneumoniae in adults and young children

• meninges become congested w/ purulent exudate
• CSF shows increased pressure, increased neutrophils and protein, dec glucose

• agitation
• headache
• photophobia
• stiff neck
• postive meningeal signs (Brudzinki's and Kernig's)

bacterial infection carried by the bloodstream usually from a sinus infection, ear infection, or mastoid infection

• starts as an acute inflammatory reaction w/ neutrophil infiltration and liquefactive necrosis associated w/ extensive cerebral edema
• fibroblasts attempt to wall off the necrotic area
• cavity evolves when dead tissue is removed

most are related to edema, incr intracranial pressure and area of involvement

• along w/ encephalitis is an important complication of systemic viral diseases and AIDS
• results from virus spread hematogenous or along peripheral nerves (rabies)
• clinical symptoms depend on virulence and site affected

• poliomyelitis: any inflammation of the gray matter of SC
• rabies: causes encephalitis
• herpes simplex type I and II

MS

• unknown
• may be autoimmune reaction after a virual infection against brain cells called oligodendroglia

numerous patches of demyelination throughout the white matter "plaque" is the hallmark of MS.

• onset in young adults (relapsing or remitting)
• symptoms relate to leasions of the optic nerve, brain stem, or SC that may progress to blindness, ataxia and paraplegia

• alzheimers
• parkinson's
• amyotrophic lateral sclerosis
• huntington's disease

• progressive neurologic disease
• loss of recent memory
• dementia
• insomnia
• anxiety
• progressive intellectual impairment leading to inability to comprehend, communicate or care for oneself

• involved of chromosome 21 and amyloid protein
• meninges are thickened, gyri atrophic w/ dilation of ventricles due to cortical atrophy
• death is often secondary to respiratory infections

• onset in 5th and 6th generation
• loss of neurons in the substantia nigra, loci cerulei, and dorsal motor nucleus of the vagus

resting "pill-rolling" tremors and bradykinesia which progress to rigidity and postural changes, slowness of voluntary movements, poor balance, shuffling gate, mask-like faces, and dementia (50%)

• relatively uncommon
• onset in the 6th decade
• gradual progressive wasting of extremities and motor weakness leading to respiratory failure
• sensory and mental function remains intact

• degeneration of upper motor neurons in the SC and brain stem
• damage to the corticospinal tracts and degeneration of anterior horn cells resulting in denervation atrophy of mm groups.

• autosomal dominant inherited disease
• onset in 4th decarde
• involuntary movement of all parts of the body and facial grimaces
• (opposite of parkinson's symptoms)

• marked atrophy of the caudate and putamen nucleus w/ corresponding ventricular enlargement
• onset of symptoms to death is about 15 years

• nothing specific
• depend on local effects (irrative, compressive, destructive effects on the the sites involved) and general effects (inc pressure, edema, hemoorhage)

• malignant but rarely metastases
• "malignant by location"

• depends on the cells involved
• - neuroglial origin
• - meningeal origin
• - metastatic origin

• astrocytoma
• oligodendroglioma
• ependymoma

• CNS neoplasms of neuroglial origin
• derived from astrocytes w/ a wide spectrum of differentiation

• grade I: well differentiated
• grade II and II: anaplastic astrocytoma and glioblastoma which is highly malignant and the most common

• seizures
• motor deficits
• mental changes

• a CNS neuroglial neoplasm
• derived from oligodendrocytes
• primarily turmors of adults manifested by seizures

• a neuroglial CNS neoplasm
• occur most frequently in 4th ventricle (hydrocephalus) during 1st and 3rd decade

• secondary tumors
• called meningioma
• generally slow growing, benign
• occur most freq in middle-aged adults
• may or may not be symptomatic
• prognosis depends on accessibility to surgical removal

• (in order of freq)
• lungs, breasts, melanoma, kidney, GI
• symptoms include headach, seizures.. etc

• Wallerian degeneration
• Distal axonopathy
• Segmental demyelination
• Neuropathies
• -- diabetic neuropathy (most common)
• -- Guillain-Barre disease

• a PNS disorder w/ degenerative changes in distal segment of a transected nerve
• accumulation of organelles in the proximal and distal axonal stumps
• atrophy of Schwann cells replaced by fibrose tissue

• "dying back"
• a PNS disorder involving toxic and metabolic neuropathies proximal axon is intact
• regeneration possible if the cause is removed

changes that result from damage of myelin sheaths

• most common PNS symmetrical polyneuropathy
• involve sensory and autonomic nerves w/ extensive segmental demyelination secondary to axonal degeneration

• an autoimmune PNS neuropathy
• progressive ascending motor paralysis
• may affect spinal and cranial nerves
• preceded by viral infection
• characterized by segmental demyelination