Download Epilepsy and Lead Poisoning

Lead Poisoning and Seizures
Dayna Ryan, PT, DPT
Winter 2012
Lead Poisoning
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Overview
 Normal blood lead level is “0”
 Toxicity is not evident until blood lead levels build up over
months or years
 Toxic threshold is lower in children & pregnant women
 High levels can be fatal
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Lesion Site
 CNS or PNS
 In children: brain (encephalopathy with scattered
hemorrhages)
 In adults: peripheral myelin or axon (peripheral neuropathy)
Lead Poisoning
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Etiology
 In children: lead-based paint in old building
(prior to 1978)
 Contaminated air, water, soil, toys, glazed
dishware, imported canned food, cosmetics
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Onset
 After months of exposure unless large amount
 Faster absorption with inhalation
Signs & Symptoms

Muscle weakness that can progress to paralysis
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Atrophy of muscles
Tremor
Abnormal DTRs (CNS lesion ↑, PNS lesion↓)
Chronic exposure in children
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affect UEs more, cause wrist drop
Mental retardation, learning disabilities
Hyperactivity, behavior problems
Loss of appetite, vomiting, abdominal pain
Unusual paleness from anemia
Sluggishness, fatigue
Fasciculations (twitches)
Lead Poisoning
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Diagnosis
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Prognosis depending on
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Blood test
Slowed motor NCVs
Fibrillation potential on EMG
Length & level of lead exposure
Whether myelin (initial exposure) or axon (prolonged exposure)
is damaged
Treatments
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Remove the source!
Chelating agents to bind the lead so that it's excreted in the urine
Epilepsy / Seizure
“Electrical storm in the brain”
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Epilepsy
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Chronic disorder characterized by recurrent episodes of
seizures due to excessive discharge of cerebral neurons
Seizure
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Involuntary movement or convulsions
Altered mental awareness
Due to excessive electrical activity in the brain
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Etiology
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Mostly idiopathic (unknown)
Genetic predisposition in 1% of
cases
Any major disease or illness
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In older adults age > 50, CVA is # 1
cause
Chaotic excessive electrical
discharge of large aggregates of
neurons in the brain

Onset
 Mostly occur unpredictably at any time
 Some are provoked

General Characteristics
 Tonic: jaw fixed, hand clenched
 Clonic: rhythmic jerky
contractions & relaxation, biting,
froth on lips
 Non-convulsive: changes in
behaviors
Classification of Seizure

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Partial seizure
 Simple partial
 Complex partial
(most common)
Generalized seizure
 Tonic-Clonic
(i.e. Grand Mal)
 Absence
(i.e. petit mal)
**most common type
Sometimes, simple or complex
partial can develop into
generalized tonic-clonic
Simple Partial (focal seizure)
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Patients are conscious during seizure
Unilateral hemispheric involvement, from a distinct,
focal area of cerebral cortex
Symptoms could
be motor,
somatosensory, or
visual, depending
on the brain area
involved.
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Complex Partial
 Altered or loss of consciousness
 Involve bilateral hemispheres, usually temporal lobes
Automatic,
involuntary,
repetitive
behaviors
 Clumsy
movements
 Confused,
mumbling, pulling
clothing, head
turns
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Tonic-Clonic (grand mal)
 Sudden loss of consciousness & fall
 Tonic: generalized rigidity
 Clonic: very rapid generalized jerking movements
 Postictal: altered speech, weakness, disorientation, muscle
soreness, HA
Absence Seizures (Petit Mal)
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Sudden cessation of ongoing
consciousness activity
Stares into space
Only minor convulsive muscle
activity or loss of postural
control
Simple, brief, automatic
movements
More common in children,
usually remit in adulthood
Epilepsy
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Diagnosis
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Treatment
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History from patient & observation from bystanders
EEG
Identify underlying diseases, rule out other causes
Education
Anticonvulsants (e.g. Gabapentin)
Surgery
Vagal nerve stimulation – sends inhibitory signals to cerebrum
Prognosis
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Increased mortality rates (due to underlying condition)
Death from asphyxia (eating or swimming during a seizure)
20 X risks of sudden death (cardiac arrhythmia, MI)
Remission = 75% in idiopathic seizure diagnosed before age 10