Neurological Disorders

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Seizure Disorders Generalized Seizures

Tonic-clonic (grand mal) Absence (petit mal) Atonic

Partial Seizures (starting from a focus) Simple

1. Localized motor seizure2. Progression of mvmts 3. Sensory4. Psychic5. Autonomic

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Seizure DisordersPartial Seizures (from a focus)

ComplexPartial Seizures evolving to generalized cortical

seizure Complex

Causes: Scarring Drugs/infections causing high fever Withdrawl (i.e., NMDA)

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Disorders of DevelopmentToxic Chemicals

Fetal alcohol syndrome Lifelong physical and

mental impairment caused by maternal alcohol use

Recent research: nicotinamide, commonly used in patients with autoimmune diseases, may protect against FAS

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Disorders of DevelopmentInherited Metabolic Disorders

Phenylketonuria (PKU) hereditary disorder caused by absence of enzyme that converts the

amino acid phenylalanine to tyrosine causes brain damage unless a special diet is

implemented soon after birth

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Disorders of DevelopmentInherited Metabolic Disorders

Pyridoxine (vitamin B6) dependency Usually presents in the first few days or weeks Pyridoxine is used to make gamma aminobutyric

acid (GABA) Galactosemia

Excessive galactose in the blood Caused by "missing" the enzyme (known as

GALT) to convert galactose into glucose If untreated, 75% of infants will die (due to medical

consequences include an enlarged liver, kidney failure, cataracts, brain damage)

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Disorders of DevelopmentInherited Metabolic Disorders

Tay-Sachs disease Lipid storage disorder (ganglioside GM2 build up in

tissues and nerve cells in the brain) Caused by insufficient activity of beta-

hexosaminidase ADown Syndrome

Approximately one in 800 to 1,000 babies Caused by an extra chromosome Variety of birth defects (i.e., mental retardation,

characteristic facial features and, often, heart defects, increased infections, problems with vision and hearing, and other health problems)

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Degenerative DisordersTransmissible Spongiform Encephalopathies

Aka “prion diseases” (i.e., Creutzfeldt-Jakob disease, “mad cow disease”)

Rare degenerative brain disorders caused by abnormal prions characterized by tiny holes that give the brain a "spongy" appearance

Symptoms include personality changes, depression, lack of coordination, involuntary jerking movements called myoclonus, unusual sensations, insomnia, confusion, or memory problems

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Degenerative DisordersParkinson’s Disease

Degeneration of dopamine-producing neurons in substantia nigra

Symptoms include slow movement (bradykinesia), inability to move (akinesia), rigid limbs, shuffling gait, and stooped posture

Lewy bodies: round collections of proteins in the brain

L-DOPA

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Neurological Disorders Q&AWhat are the early symptoms of Galactosemia?

An infant with classic galactosemia usu appears normal at birth. Symptoms usu occur within the first few days or weeks of life after the baby drinks breast milk or a lactose-containing formula. Early symptoms may include: jaundice, vomiting, poor

weight gain, feeding difficulties, irritability, lethargy, convulsions

What ethnic background is associated with PKU? Occurs in all ethnic groups but slightly more

common in individuals of N European and Native American ancestry

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Degenerative DisordersAlzheimer’s Disease

10% > 65; 50% > 85 Irreversible, progressive Neurons deteriorate, resulting in the

loss of cognitive functions, primarily memory, judgment and reasoning, movement coordination, and pattern recognition

Predominantly affects the cerebral cortex and hippocampus

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Degenerative DisordersAlzheimer’s Disease

Neuritic plaques: the center of these plaques is beta

amyloid, surrounded by fragments of deteriorating neurons (esp. neurons that produce acetylcholine)

Neurofibrillary tangles: twisted remnants of a protein tau,

essential for maintaining proper cell structure and function

Gene responsible for production of Apolipoprotein E (ApoE)

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Degenerative Disorders“Guam Disease”--amyotrophic lateral sclerosis

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Degenerative DisordersHuntington’s Disease

One in 10,000 Americans Onset usually 30-45; 10-20 yr prognosis post-onset Early symptoms may affect cognitive ability or

mobility and include depression, mood swings, forgetfulness, clumsiness, involuntary twitching and lack of coordination

Genetic disorder; 50% likelihood in offspring Increased CAG repeat number in a gene coding for

a protein with unknown function, called huntingtin

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Degenerative DisordersMultiple Sclerosis

1 case per 1000; leading cause of neurologic disability in early-to-middle adulthood, second only to trauma

Environmental effect; genetic vulnerability Inflammatory demyelinating condition of the central

nervous system (CNS) that is generally considered to be autoimmune in nature

Possibly due to exposure to a molecular sequence that mimics the molecular sequence found in the host tissue

Sclerotic plaques

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Disorders Caused by Infectious DiseasesEncephalitis

Brain inflammation caused by a virus (i.e., herpes viruses; arboviruses transmitted by mosquitoes, ticks and other insects)

Symptoms include drowsiness, confusion and disorientation, seizures, sudden fever, severe headache, nausea and vomiting, tremor or convulsions, stiff neck

Meningitis Infection of the meninges, the membranes that

surround the brain and spinal cord

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Disorders Caused by Infectious DiseasesSyphilis

Treponema pallidum (spirochete) Primary Syphilis (~21

days)—incubation; most patients control infection and don’t progress; development of canchre (painless)

Secondary syphilis (2-12 wks)—spread of rash, sometimes fever, condylomata lata, meningitis & hepatitis 

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Disorders Caused by Infectious DiseasesSyphilis

Tertiary Syphilis (1-30 yrs; 30-40% untreated pts) Cardiovascular Syphilis Gummatous Syphilis Neurological syphilis

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Disorders Caused by Infectious DiseasesSyphilis

Neurological Meningovascular syphilis (5-12 yrs)—stroke &

seizure; due to infarction caused by endarteritis Parenchymatous syphilis—direct invasion of

CNS by spirochetes, & destruction of neurons General paresis (15-20 yrs): dementia with

confabulation; exhibit slurred speech, and Argyll-Robertson pupils may be seen

Tabes dorsalis: demyelinization of dorsal roots, dorsal root ganglia and posterior columns; symptoms include lightening pains, wide gait, and loss of deep pain, temperature, position and vibration sense

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Disorders Caused by Infectious DiseasesHerpes

Herpes Simplex Type 1 (HSV-1) Herpes Simplex Type 2 (HSV-2) Varicella-zoster virus (aka chickenpox) Epstein Barr virus Cytomegalovirus Human herpesvirus 6 Human herpesvirus 7 Human herpesvirus 8

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Disorders Caused by Infectious DiseasesHerpes

Herpes Simplex Type 1 (HSV-1) Generally orofacial infection

Herpes Simplex Type 2 (HSV-2) Generally genital infection

Lesions may look like cold sores