Transcript ALTERATIONS OF THE CENTRAL NERVOUS SYSTEM

Episodes of abnormal sudden, excessive,
uncontrolled electrical discharge of
neurons within the brain
 May result in alteration in consciousness,
motor or sensory ability and/or behavior
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Birth trauma/Asphyxia during birth
Head injuries/ brain tumors
Infectious disease
Toxicity (carbon monoxide and lead poisoning)
 Fever
 Drug/alcohol intoxication
 Metabolic disturbances
 Inherited
 Idiopathic (unknown cause)
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History
 MRI/ CT scan
 EEG
 SPECT (single photon emission computed
tomography) – helps identify zone giving
rise to seizures, can then be removed
surgically
 Blood chemistry test
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Chronic disorder
 Recurrent unprovoked seizure activity
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CAUSE OF EPILEPSY
 abnormal electrical neuronal activity
 Imbalance of neurotransmitters: Gamma
aminobutyric acid (GABA)
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Two or more consecutive seizures that
occur without full recovery of
consciousness between attacks
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Also includes continuous electrical
seizures lasting at least 30 minutes
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Generalized seizures
-involves both cerebral hemispheres
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Partial seizures (focal or local)
› Begins in a part of one cerebral hemisphere
› Complex- may cause loss of consciousness
› Simple-remains conscious
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Unclassified seizures
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Video from faculty animation only
chapter 44 partial seizure
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TONIC-CLONIC SEIZURE
› Lasts up to a min.
› Starts with tonic movements: stiffening or rigidity
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of the muscles of arms and legs
Loss of consciousness
Incontinent bladder/bowel
Clonic movements follow: rhythmic jerking of all
extremities
May bite tongue
Followed by a postictal phase
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POST-ICTAL STATE: after seizure
Pt is confused and hard to arouse, may
sleep for hours
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Tonic seizures:
› Abrupt increase in muscle tone
› Loss of consciousness
› Loss of autonomic signs for 30 sec to several
minutes
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Clonic seizure:
› Lasts several minutes
› Muscle contraction and relaxation
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Absence seizure
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Common in children ( familial)
Brief (seconds) loss of consciousness
Blank starring, returning to normal
May occur frequently throughout day
Myoclonic seizure:
› Brief jerking/stiffening extremities
› Singly or in groups
› Lasts few seconds
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Atonic(akinetic)seizure
› Sudden loss of muscle tone for a few
seconds, may fall
› Followed by POSTICTAL(after seizure)
confusion
Partial- only involves one side of the brain
 Simple: person remains conscious
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Complex: impaired consciousness
bizarre behavior
amnesia