Chapter Fifteen. Neurological Disorders

Transcription

1 Chapter Fifteen Neurological Disorders

2 Causes of Neurological Disorders Head Injuries Tumors Seizures Drugs (primary effects, side effects, and withdrawal) Circulation Issues

3 Circulation Issues STROKES! Ischemia a blocked blood vessel may be an embolism or a thrombosis May be transient (TIA) with temporary effects Causes an infarct (area of dead neural tissue) Hemorrhage a ruptured blood vessel or aneurysm (bleeding in the brain) Risk factors include obesity, alcohol / drug use, smoking, untreated high blood pressure

4 Figure 15.2 The Brain s Blood Supply

5 Figure 15.3 Brain Infarct

6 Head Injuries Drain Bamage? Open and closed head injuries Concussions mild to severe unconscious May cause permanent brain damage Vehicle accidents are primary culprits, but we also need to consider sports injuries American Academy of Neurology rates the severity, and dictates when it s safe to play Coups and Counter coups swelling an issue Subdural hematoma swelling in membranes

7 Figure 15.4 Coup and Countercoup

8 Figure 15.5 Boxers Risk Repeated Head Injuries

9 What else might cause damage? Tumors? How can this be? Neurons don t reproduce themselves right? May be malignant (infiltrating) with fuzzy boundaries and potential metastisis May be benign (encapsulated) with clear boundaries (surgery may work better here) Gliomas (astrocytes & oligodendrocytes) Meningiomas surgery & radiation may work

10 Figure 15.6 A Meningioma

11 Seizures & Electrical Disturbances? May be Partial (local focal), or Generalized, which involve Thalamus and Cerebral Cortex Reduces the activity of GABA. Includes Petite Mal version more of an absence scenario And Grand Mal version more drama! Tonic phase includes falling, violent muscle contractions, and breathing stops Clonic phase gross motor contractions and coma. Lasts from 5 to 30+ minutes

12 Figure 15.7 Pathways for the Spread of Partial and Generalized Seizures

13 Figure 15.8 EEG Recordings During Generalized Seizures

14 Illness or Disease? Multiple Sclerosis Immune system attacks the nervous system Causes demyelination of neurons, targeting oligodendrocytes specifically May result in steady decline, or follow a relapsing / remitting pattern More likely in females, with some heritability factors interacting with environmental factors

15 Figure 15.9 Multiple Sclerosis Damages Myelin

16 Brain Infections Viral (like West Nile) may lead to brain inflammation (called encephalitis) serious! Herpes increases your odds of dementia Meningitis swelling of the meninges, leads to flu like symptoms, neck stiffness, drowsy HIV may lead to Aids Dementia Complex Cognitive problems, weakness, memory loss, language impairment, clumsiness Virus binds to NMDA receptors-causes cell death via excess calcium intake

17 Figure Complicated Neurocysticercosis Involves Multiple Infections in the Brain

18 Figure HIV Viral Particles Bud from an Infected Cell

19 More Brain Infections? Transmissible Spongiform Encephalopathies Bovine (Mad Cow) S.E. Creutzfeldt-Jacob Disease Kuru in New Guinea transmission evidence Scrapie in sheep Causes rapid decline and death as a result of an abnormal version of a protein - Prion

20 Figure Bovine Spongiform Encephalopathy

21 Figure Prion Proteins Have Normal and Abnormal Forms

22 Figure Time Course of the BSE Epidemic in the United Kingdom

23 Howz about Migraine Headaches? Excruciating pain plus vomiting, and/or nausea. Lasts from 4 to 72 hours. Aura? Early theories pointed the finger at increased blood flow in the brain. What causes that? Migraine generator located in the brainstem reacts when serotonin levels are low Releases glutamate & CGRP that react with trigeminal nerve, dilates blood vessels Triptans (SSRI) prevents release of CGRP 75% sufferers are female. Depression link?

24 Figure Migraine Aura

25 What are my odds of recovery? It depends! Age (brain plasticity) a significant factor. Kids better off than adults as a rule. The nature and extent of the damage matters Rehabilitation may help us regain language and social skills. Less luck with memory issues Clot busting drugs ASAP for thrombosis or embolism Fetal Cell transplants - some early + results Stem cell treatment for spinal cord damage?