patho quiz 4 neurological disorders.txt

• Major supporting cell
• Show most common reactive changes

• Wrap around neuronal axons to form myelin
• Similar to Schwann cells in PNS

• Derived from circulation monocytes
• Function as APCs
• Similar to macrophage

• Glial cells
• Blood vessels
• Ependymal cells  epithelial membrane lining the ventricular system and spinal cord

Schwann cell

circumscribed dilation of an artery

sac-like swelling (dilation) on one side of an artery

Most common cause of spontaneous/non-traumatic of SH is rupture of saccular aneurysm

is due to rupture of meningeal artery in brain parenchyma

localized mass of extravasated blood (already clotted)

membranous covering of brain and spinal cord

due to disruption of bridging veins in brain parenchyma

• Transient loss of consciousness caused by violent shaking
• Widespread paralysis

• In superficial brain parenchyma
• Hemorrhages caused by blunt trauma

Accidental cut wound

• neural tube defect
• Associated with dietary folate deficiency (Vitamin B)

: inflammation of leptomeninges and subarachnoid space; bacteria and viruses are most common causes

• Hematogenous spread  via blood
• Direct implantation  trauma, CNS malformations
• Local extension  middle ear, sinuses
• Invasion via peripheral nerves  rabies, herpes zoster

• bacterial
• Poor prognosis
• Important cause of morbidity and mortality at all ages
• Neonatal infection from encapsulated group B strep and E. coli from maternal genital tract

• Better prognosis
• Most caused by:
• o Echovirus
• o Coxsackievirus
• o Mumps
• o HIV
• 3. Chronic meningitis  bacteria & fungi

• 1.Arbovirus  arthropod-bone virus
• " Large heterogenous groups of RNA viruses
• " Most associated with arthropods that may be vectors
• 2.JEV  Japanese Encephalitis
• 3.HSV-1 and HSV-2
• 4.CMV
• 5.HIV
• 6.Varicella-zoster virus (herpes zoster)

• group of uncommon, transmissible disorders that includes classic and new-variant Creutz-Jakob disease (CJD)
• Scrapie in sheep and goats
• BSE (bovine spongiform

• The most common demyelinating disease of the CNS (250,000-300,000 patients in the US)
• Involve T-cell-mediated injury to myelin sheath and/or oligodendroglial cells: Maybe autoimmune disease
• Potential causes: Exposure to an environmental agent early in life
• Peak incidence: 18-40 years
• Most cases are clinically characterized by waxing and waning neurologic abnormalities involving different regions of the CNS.

• 1. Genetic Factors
• " amyloid precursor protein (APP) gene(chromosome 21)
• " Presenilin 1(chromosome 14)
• " Presenilin 2(chromosome 1)
• " e4 allele of apolipoprotein E (apoE)(chromosome 19)
• 2. Deposition of A Form of Amyloid:
• " Derived from breakdown of APP and form b-amyloid (Ab)
• 3. Hyperphosphorylation of the Protein Tau
• " Tau is an intracellular protein that is involved in the assembly of intra- axonal microtubules
• " Accumulation of hyperphosphorylated Tau may interfere with maintenance of normal microtubule
• 4. Expression of Specific Alleles of apoE
• " apoE may be involved in transport or processing of the APP
• " apoE may contribute to enhanced amyloid fibril formation

• 1. Environmental factors:
• exposure to pesticides or herbicides, rural living, and drinking well water
• 2. Genetic factors:
•  Mutations in synuclein prevent the normal breakdown of a-synuclein, leading it to accumulate in the neuron, where it then goes on to damage the cell
•  Mutations in parkin, which normally helps break down proteins. It is believed that the loss of parkin causes build-up of proteins (though not of a-synuclein), again leading to damage

• " HD is an inherited autotosomal dominant disease characterized clinically by progressive movement disorders and dementia,with degenerationofthestriatum(caudateandputamen) degeneration of the striatum (caudate and putamen).
• " The disease is caused by trinucleotide repeat (CAG) mutationsin the huntingtingene, which cause, in turn, the synthesis of a form of the huntingtin protein containing an abnormal number of glutamine residues.
• " Clinical onsetisusuallyinthefourthandfifthdecade(involuntary, Clinical onset is usually in the fourth and fifth decade (involuntary, writhing movements, seizures, rigidity, depression). The jerking movement is also called  chorea (dance in Greek)
• " Common cause of death: Suicide