Chapter Fifteen

Neurological Disorders

CHAPTER 15NEUROLOGICAL DISORDERS

Brain Damage

• Stroke– Brain’s blood supply is interrupted by either bleeding or

sudden blockage• Cerebral hemorrhage• Ischemia

– Excitotoxicity

Figure 15.2 The Brain’s Blood Supply

Figure 15.3 Brain Infarct

Brain Damage

• Head Injury– Traumatic Brain Injuries (TBI)

• Open head injuries• Concussions

– Coup and countercoup– Post concussion syndrome – lack of concentration, reduction in processing

speed, deficits in higher-order cognitive functions

– Chronic Traumatic Brain Injuries (CTBI)• Dementia pugilistica (Boxer’s syndrome)

Figure 15.4 Coup and Countercoup

Figure 15.5 Boxers Risk Repeated Head Injuries

Brain Damage

• Brain Tumors– Majority arise in glial cells and the cells of the meninges– Symptoms of Tumors

• Pressure in the skull• Specific disruptions related to location

– Types of Tumors• Gliomas and meningiomas• Grades I to IV

– Treatment for Tumors• Surgical removal• Chemotherapy• Thalidomide to starve tumors

Figure 15.6 A Meningioma

Brain Damage

• Seizures and epilepsy– Uncontrolled electrical disturbances in the brain

correlated with changes in consciousness– Types of Seizures

• Partial seizures– Simple– Complex

• Generalized seizures – Grand mal– Petit mal seizures

• Treatment for Epilepsy• Antiepileptic drugs, surgery, ketogenic diet in children

Figure 15.7 Pathways for the Spread of Partial and Generalized Seizures

Figure 15.8 EEG Recordings During Generalized Seizures

Multiple Sclerosis

• Autoimmune condition – immune system attaches the central nervous system– Demyelination of axons– Affects white matter in different locations– Modest heritability and environmental factors

Figure 15.9 Multiple Sclerosis Damages Myelin

Brain Infections

• Parasites– Neurocysticercosis – pork tape worm– Treatment - seizure control

• Bacterial, Viral, and Fungal Infections– Encephalitis – inflammation of brain after viral infection– Meningitis – inflammation of membranes that cover and

protect the brain and nervous system– AIDS Dementia Complex

• Collection of neurological symptoms that result fro HIV virus or opportunistic infections

Figure 15.10 Complicated Neurocysticercosis Involves Multiple Infections in the Brain

Figure 15.11 HIV Viral Particles Bud from an Infected Cell

Brain Infections

• Transmissible Spongiform Encephalopathies – A group that includes bovine spongiform encephalopathy

(BSE) or mad-cow disease• Produce psychological disturbances and progressive loss of

cognitive functions, motor disturbances, and finally death

– The TSE Mystery• Creutzfeldt-Jakob disease (CJD) human form of TSE• Kuru in New Guinea provided evidence of transmission

– Prions and TSEs• Role of abnormal form of prion protein

– BSE and New Variant Creutzfeldt-Jakob Disease • New variant emerged in humans

Figure 15.12 Bovine Spongiform Encephalopathy

Figure 15.15 Prion Proteins Have Normal and Abnormal Forms

Figure 15.16 Time Course of the BSE Epidemic in the United Kingdom

Figure 15.17 Classic Creutzfeldt-Jakob Disease Shows Different Age Prevalence than New

Variant

Migraine

• Symptoms of excruciating head pain, nausea, and vomiting for 4-72 hours

• Migraine generator located in brainstem• Treatments

– Triptans– Behavioral adjustments

Figure 15.18 Migraine Aura

Assessment of Neurological Disorders

• Patient’s health history• Physical examination

– Sensory systems– Touch sensitivity– Movement– Spinal reflexes– Tests such as Halstead-Reitan battery

Recovery from Damage

• Kennard Principle– Young brains reorganize after damage more efficiently

than adult brains

• Subsequent research suggest a more complex relationship between developmental stage and recovery

Therapy for Brain Damage

• Rehabilitation– Improving cognitive, emotional, and physical processes– Constraint therapy– “Mental muscle” approach– “Specific tasks” approach– Virtual reality (VR) therapy

• Pharmacological Therapies• Neural Tissue Transplants

– Fetal cell transplants and stem cells