NERVOUS SYSTEM

• Nervous System Menu


  • Hydrocephalus
  • Cerebrovascular Accident (CVA)
  • CVA: Stroke
  • CVA: Transient Ischemic Attack
  • CVA: Intracranial Hemorrhage
  • CVA: Intracerebral Bleeding
  • CVA: Subarachnoid Bleeding
  • CVA: Extracerebral Bleeding
  • Astrocytoma
  • Meningioma
  • Acoustic Neuroma
  • Pituitary Adenoma
  • Spina Bifida
  • Spina Bifida Occulta
  • Arnold Chiari Malformation
  • Spinal Stenosis
  • Disc Herniation
  • Calcified Choroid Plexus
  • Calcified Pineal Gland
• Hydrocephalus


  A condition with excess cerebral spinal fluid within the brain ventricles, resulting in increased intracranial pressure, enlarged heads in infants, and possible brain damage
• Types of hydrocephalus


  • Noncommunicating (caused by obstruction)
  • Communicating (CSF cannot be absorbed properly)
• Treatment for hydrocephalus


  Insertion of a shunt between the ventricles and the heart or abdomen to relieve pressure
• Cerebrovascular Accident (CVA)


  A cut-off of blood supply (ischemia) to part of the brain resulting in an infarct and loss of brain function
• Causes of CVA


  • Thrombus (accumulation of plaque)
  • Embolus (piece of plaque breaking off)
  • Rupture of blood vessels from trauma, aneurysm, or hypertension
• Symptoms of CVA


  • Headaches
  • Aphasia
  • Paralysis
  • Hemiparalysis
  • Confusion
  • Coma
• Types of CVA


  • Stroke
  • Transient Ischemic Attack (TIA)
  • Intracranial Hemorrhage (Intracerebral/Parenchymal Bleeding, Subarachnoid Bleeding, Extracerebral Bleeding (Subdural Hematoma, Epidural Hematoma))
• Stroke


  A CVA caused by an embolus, resulting in brain damage from ischemia
• Transient Ischemic Attack (TIA)

  A small stroke with minimal symptoms that usually resolve within 24 hours, considered a warning sign for a larger stroke
• Intracranial Hemorrhage


  An escape of blood from an artery or vein within the skull, can be caused by hypertension, trauma, bleeding tumor, or ruptured aneurysm
• Intracerebral/Parenchymal Bleeding


  Loss of blood within the cerebrum
• Subarachnoid Bleeding


  Bleeding into the ventricles of the brain
• Extracerebral Bleeding


  Bleeding outside of the brain but within the skull, often due to trauma
• Intracerebral or Parenchymal Bleeding

  Loss of blood within the cerebrum
• Extracerebral Bleeding


  Bleeding outside of the brain but within the skull
• Subdural Hematoma


  Leaking of subdural veins into the space between the dura mater and the arachnoid mater
• Epidural Hematoma


  Build up of blood between the dura mater and the skull
• Astrocytomas


  • Make up approximately 30% of all primary brain neoplasms
  • Derived from astrocytes which are star shaped neuroglial cells with many branching processes
  • Present as a vascular mass that enhances with contrast on CT and MR scans
  • Become malignant but have a good prognosis of 90% of diagnosed patients living past 5 years
  • Treatment can include surgery, chemotherapy, and radiation therapy
• Meningiomas


  • Slow growing and usually benign
  • Account for about 15% of all intracranial tumors
  • Originate within arachnoid tissue and compress the brain as they grow in
  • Present as a round, smooth mass that can calcify on CT and MR scans
  • Treatment usually includes surgical resection but radiation therapy may be indicated for inoperable cases
• Acoustic Neuroma


  • Benign tumor most commonly associated with the VIII cranial (acoustic) nerve housed within the temporal bone
  • Symptoms include hearing loss, tinnitis (ringing in the ears), vertigo, and ataxia (loss of balance)
  • Small tumors may not require treatment but surgery and chemotherapy are options for larger tumors
• Pituitary Adenoma


  • Slow growing, usually benign tumor of the pituitary gland
  • Affect the hormones produced by the pituitary gland
  • CT and MR scans will yield an increase in the size of the sella turcica with the possibility of extension into the optic chiasm
  • Small tumors may be treated medically but advanced tumors may require surgical removal possibly followed by radiation therapy
• Spina Bifida


  • Congenital defect where the lamina fail to unite posteriorly to form the spinous process
  • Most commonly manifested at L5-S1
  • In severe cases, the spinal cord and/or the meninges may herniate which may result in varying degrees of paralysis
• Meningocele


  Only the meninges herniate
• Meningomyelocele


  Both the meninges and spinal cord herniate
• Spina Bifida Occulta


  Mild occurrence of spina bifida that rarely results in the protrusion of the meninges or spinal cord
• Arnold Chiari Malformation


  • Allows the cerebellar tonsils to herniate through the foramen magnum and into the spinal canal
  • Can block the flow of CSF and cause the brain stem and cerebellum to become stretched and compressed
  • Requires surgical correction
  • Often causes the formation of syrinx within the spinal cord which is a fluid filled cavity which may also obstruct the flow of CSF
• Spinal Stenosis


  Narrowing of the spinal canal
• Herniated Nucleus Pulposus (HNP) or Slipped Disc


  Part or all of the soft, gelatinous central portion of an intervertebral disk (the nucleus pulposus) is forced through a weakened portion of the outer disk (the annulus fibrosis)
• Calcified Choroid Plexus


  Portion of the choroid plexus (area within the ventricles of the brain that is responsible for producing cerebral spinal fluid) becomes calcified
• Calcified Pineal Gland


  Pineal gland (endocrine gland located within the brain that produces melatonin) becomes calcified