Lecture Outline

1
Lecture Outline

• Types of brain damage
• Tumors
• Seizure disorders
• Vascular accidents
• Developmental disorders
• Degenerative disorders
• Infections

2
Tumors

• Mass of cells with uncontrolled growth
• Benign vs. malignant
• Metastases
• Cell types
• Gliomas- from glial cells
• Meningioma- meninges
• Pituitary adenoma- pituitary
• Neurinoma- sheathing and connective tissue
• Angioma- blood vessels
• Pinealoma pineal gland
• Metastatic carcinoma- from primary tumor

3
Treatment of tumors

• Surgical removal
• Radiation
• Chemotherapy

4
Seizure Disorders

• Spread of uncontrolled neural excitation
• Epilepsy- many types and causes
• Partial vs. Generalized seizures
• Simple v.s complex- loss of consciousness
• Grand mal vs. petit mal (absence)
• Causes ETOH and barbiturate withdrawal, brain
  damage and scarring
• Can also cause brain damage- e.g. hippocampus

5
Treatment of Seizures

• Tumor removal
• Aniti-convulsant drugs
• Removal of focus
• CC section to decrease severity

6
Cerebrovascular Accidents

• Stroke
• Hemorrhagic stroke
• Blood damages brain from pressure
• Obstructive stroke
• Ischemia-loss of blood
• Thrombus- blood clot
• Embolus-obstruction from debris
• Damage caused by
• Pressure
• Too much glutamate
• Excessive Ca and Na inside cells
• Phagocytic microglia
• Accumulation of free radicals

7
Treatment of Stroke

• Anticoagulant drugs (ischemic stroke)
• Glutamate blockers
• Anti-inflammatory drugs
• Free radical binders
• GABA agonists
• Brain cooling gt 8 deg. C (in animals)
• Behavioral therapy

8
Developmental Disorders

• Toxic exposure
• Virus products and drugs (ETOH).
• Fetal alcohol syndrome
• Inherited metabolic disorders
• Phenylketonuria-high phenylalanine levels impede
  myelinization- white matter, cerebellum, thalamus
• Pyrodoxine dependency- requires high B6 -white
  matter
• Galactosemia- inability to metabolize milk sugar-
  white matter and cerebellum
• Tay-Sachs brain swelling from accumulation of
  cell wastes, currently not treatable.
• Hydrocephalus- brain swelling from trapped
  cerebrospinal fluid

9
Down Syndrome

• Congenital but not inherited
• Extra chromosome 21
• Causes variable mental retardation
• Brain develops abnormally (smaller and less
  convoluted)
• Later degeneration similar to Alzheimers

10

• Degenerative Disorders
• Transmissible spongiform encephalopathy (TSE)
• A contagious brain disease whose degenerative
• process gives the brain a sponge-like appearance
• caused by accumulation of misfolded prion
  protein.

11

• Degenerative Disorders
• Prion
• A protein that can exist in two forms that differ
• only in their three-dimensional shape
  accumulation
• of misfolded prion protein is responsible for
• transmissible spongiform encephalopathies.
• Caspase
• A killer enzyme that plays a role in apoptosis,
  or programmed cell death.

12

• Degenerative Disorders
• Lewy body
• Abnormal circular structures with a dense core
• consisting of ?-synuclein protein found in the
• cytoplasm of nigrostriatal neurons in people
  with
• Parkinsons disease.

13
Degenerative Disorders

• Parkinsons disease
• Degeneration of dopamine neurons in substantia
  nigra
• produces muscular rigidity, tremor, inertia,
  imbalance
• Most cases not inherited but genetic locus has
  possibly been identified for some cases.
• Suspected to be caused by toxins or
  susceptibility to toxins.
• Treat with MAO inhibitors, L-DOPA, transplants,
  destruction of globus pallidus.

14
Degenerative Disorders

• Hungtingtons Chorea
• Degeneration of caudate nucleus and putamen
• Uncontrollable movements and spasms
• Progressive, leads to psychosis and is fatal
• Brain weight loss
• Genetically determined- chromosome 4
• Currently no treatment

15
Degenerative Disorders

• Alzheimers disease
• One cause of dementia
• Gradual loss of memory and cognitive skills
• Progressive and fatal
• Degeneration of hippocampus and neocortex
• Presence of neuritic (amyloid) plaques and
  neurofibrillary tangles
• Some forms may be inherited-Genetic defects for
  beta amyloid
• Unknown etiology in most cases- suspect toxins,
  trauma, links with estrogen, immune responses
• New treatment with anti-inflammatory drugs.

16
Degenerative Disorders

• Multiple Sclerosis
• Autoimmune demyelinating disease
• Wide variety of symptoms
• Suspected prior viral exposure
• Symptoms wax and wane
• No current specific treatment

17
Infectious Disease

• Encephalitis- infection of the brain often
  permanent damage, sometimes fatal
• Herpes simplex
• Polio-
• Rabies
• Aids- dementia - excessive calcium in neurons
• Meningitis-viruses and bacteria (dangerous)
• Middle ear infections, emboli, head injury,
• Interferes with flow of blood and cerebro-spinal
  fluid
• Neurosyphilis-dementia, psychosis, progressive if
  untreated