Transcript Document

Northeast Regional
Epilepsy Group
Christos Lambrakis M.D.
1
September 20th, 2014
How is Epilepsy Diagnosed
Recognizing Types of Seizures
and
Imitators of Epilepsy
2
3
Brain
*Weight: 3 lbs
*Made of 75% water
* 2% of body weight
* 20% of energy requirements
*Contains 100 billion neurons
*Each neuron has 1000 to 10,000 synapses
*100,000 miles of blood vessels
*Likes: Oxygen, Glucose, Cute cat videos
5
6
7
8
What is a Seizure?
• A seizure is caused by abnormal electrical
activity between cells of the brain (neurons)
• A seizure can temporarily disturb many of
the brains normal functions.
• This abnormal electrical activity results in
the clinical manifestations of the seizure.
9
What is a Seizure?
• The clinical manifestations of the seizure
are determined by the region of the brain
where the abnormal electrical activity is
located.
• Clinical manifestations of a seizure are
varied depending on the region of the brain
involved. Examples include changes in
movement, sensation, behavior or
awareness.
10
EEG (Normal)
11
EEG (Seizure)
12
What is Epilepsy?
• Epilepsy is the term applied to the state of
recurrent seizures.
• Epilepsy is a condition of the brain, of
various causes, which predisposes the
patient to recurrent epileptic seizures.
• Epilepsy is a tremendously variable
condition in terms of its cause, seizure types
and response to treatment.
13
How is Epilepsy
Diagnosed?
14
Epilepsy
Diagnosis
• Clinical description of the seizure events
provides very important information.
– What was seen? (Confusion, Loss of consciousness,
Body movements, Head turning, Eye deviation,
Right side/Left side or both)
– What was felt by the patient? (At the start of the
seizure (Aura) or as seizure evolves)
• **Helps us to localize the seizure (where in the
brain did it originate from).
Epilepsy
Diagnosis
• Precipitating factors:
– Lack of sleep, fever, current illness,
medications, flashing lights, hyperventilation.
• Predisposing factors:
– Past medical history (head trauma, stroke),
Family history
• **Helps us to better understand why the
seizures occurred (Etiology).
16
Epilepsy
Diagnosis
• Physical Examination
– Vitals (Fever)
– General (Head size, dysmorphic features, skin
lesions, stiff neck).
– Neurologic Examination (Confusion, memory
loss, speech difficulty, motor weakness,
sensory loss)
17
Epilepsy
Diagnosis
• Acute Symptomatic Seizures
• Chronic Symptomatic Seizures
• Idiopathic Seizures
18
Epilepsy
Diagnosis-Etiology
• Acute Symptomatic Seizures (Seizures
caused by a suspected acute reason).
–
–
–
–
–
Trauma (Head injury)
Metabolic (Electrolyte imbalance, Uremia)
Toxic (Ingestion, Medication)
Infectious (Meningitis, Encephalitis, Sepsis)
Vascular (Stroke, Hemorrhage)
19
Epilepsy
Diagnosis-Etiology
• Chronic Symptomatic Seizures (Seizures
caused by preexisting conditions which
favor the development of seizures).
–
–
–
–
Remote injury (Past head injury, Birth trauma)
Developmental (Cortical dysplasia)
Degenerative Disorders (Alzheimer’s)
Metabolic (Amino and organic acid disorders)
20
Epilepsy
Diagnosis-Etiology
• Idiopathic Seizures (Etiology is unclear)
– The cause of the seizures cannot be determined
from our current knowledge or conventional
testing.
– Approximately 50% of patients will fall under
this category.
21
Epilepsy
Diagnosis
Diagnostic Studies
• Blood work (Electrolytes such as Sodium,
Potassium, Calcium; Glucose, Kidney and
Liver function)
• Electro-diagnostic (EEG)
• Imaging (CT, MRI, SPECT, PET and
MEG)
22
Electroencephalogram (EEG)
23
Electroencephalogram
EEG
• Represents a record of the small shifting
brain electrical potentials from the surface
of the brain recorded over the scalp.
• As seizures are caused by a disturbance of
electrical activity, the EEG is uniquely
suited to further our understanding of a
patients seizures.
Goals of Video-EEG
Monitoring
• Is it really an epileptic seizure?
(Epilepsy vs. non-epileptic events)
• What type of seizure is it? (Characterize
epilepsy type)
• Where does the seizure originate from?
Is it focal? (i.e. does it come from one
specific region?)
Electrodes
26
27
28
29
30
31
Video-EEG Monitoring
• Long term inpatient monitoring allows for
recording of seizure events.
• Clinical and electroencephalographic
features can be reviewed aiding in seizure
characterization and localization.
• Baseline EEG may be helpful in
determining risk of future seizures.
Inpatient Video-EEG
33
Outpatient Ambulatory VideoEEG
34
Brain MRI
• Provides a structural assessment of the brain.
• We look for developmental abnormalities,
strokes, tumors or scar tissue that could be
focus for electrical irritation that could cause a
seizure.
Brain MRI
Recognizing Types of Seizures
37
Seizure Classification
• Two major categories:
– Generalized
– Partial
38
Generalized Seizures
EEG (Seizure)
40
Seizure Classification
• Generalized Seizures
Tonic/Clonic
Absence
Myoclonic
Atonic
Tonic
Generalized Seizures
Tonic/Clonic
• Electrically the entire brain is affected all at once.
• Patients loses consciousness at the onset of the
seizure.
• Stiffening (tonic) and rhythmic jerking
movements (clonic) follow.
• Cyanosis, tongue biting and loss of bladder control
are common.
Generalized Seizures
Absence
• Results in a brief period of staring (5-10 sec).
• Patient is usually unaware of his surroundings.
• Sometimes accompanied by eye blinking or
chewing movements.
• Prompt recovery.
• Commonly seen in childhood and may be
mistaken for day-dreaming.
Generalized Seizures
Other Less Frequent
• Myoclonic seizure: Brief jerk like
contractions which can be localized or
generalized.
• Atonic seizure: Drop attacks
44
Partial Seizures
Complex
Partial Seizures
• Seizures originate from a specific (focal)
region of the brain. Depending on what area
of the brain is stimulated a variety of
clinical presentations can occur.
• Seizures are often stereotypic to the patient.
• Examples include changes in awareness,
sensation, rhythmic jerking or stiffening of
a specific limb, visual hallucinations.
Partial Seizures
• Can progress to a Generalized Tonic/Clonic
seizure ‘Secondary Generalization’.
• Often associated with aura.
• Often associated with automatisms
(coordinated involuntary, non-purposeful
movements). Examples would include lip
smacking, picking, rubbing etc.
48
Partial Seizures
• Two Types: Simple and Complex
• Simple Partial: No impairment of
consciousness.
• Complex Partial: Impairment of
consciousness.
Partial Seizures
Motor
Partial Seizures
Complex
Generalized vs Partial Seizures
• Sudden onset with no
warning/aura
• Symmetrical movements
• Loss of consciousness
• May begin with aura
(subjective symptoms
experienced by the
patient)
• Asymmetric or focal
motor movements
• Alteration of awareness.
52
Imitators of Epilepsy
53
Differential Diagnosis
• Seizures can produce sudden neurologic
symptoms.
• Many diseases can produce sudden
neurologic symptoms.
• ** Many neurologic diseases can be
mistaken for epilepsy and vice-versa.
54
Differential Diagnosis
• Non-Epileptogenic events can be secondary
to organic or psychogenic etiologies
55
Differential Diagnosis
• How do we differentiate between events
that are seizure related and those that are
caused by a non-epileptic medical or
psychiatric condition?
• ** Capturing an episode on EEG and
demonstrating abnormal electrical activity
during the event.
56
Differential Diagnosis
• In general episodes stemming from nonepileptic neurologic issues are NOT
associated with EEG changes.
• Caveats
– Some partial seizures can remain electrical
silent (i.e. not obvious on EEG).
– Some neurologic diseases can cause changes on
the EEG (Migraine, Syncope)
57
Seizure Imitators
Loss of Consciousness
•
•
•
•
•
•
Cardiac (heart failure, heart attack, arrhythmias)
Hypoglycemia (fasting, excess insulin)
Hypovolemia (dehydration)
Hypoxia (lung disease)
Panic attack (vasovagal response)
Syncope (orthostatic)
58
Syncope
• Decreased delivery of oxygenated blood to
the brain resulting in loss of consciousness.
–
–
–
–
–
–
Very common with many etiologies
Sudden and unpredictable
Recurrent
Stereotypic
Premonitory symptoms (nausea, sweating)
‘Convulsive’-type movements
59
Syncope Work-Up
• Video-EEG monitoring
– Ictal (during event)
– Inter-Ictal (between episodes)
• EKG/ Holter Monitor
• Carotid Ultrasound
• Tilt Table Testing
60
Seizure Imitators
Confusion
• Cerebrovascular (TIA, Stroke, TGA)
• Endocrine (Hypo/Hyperglycemia, Thyroid
Disease)
• Migraine Headaches (complicated)
• Metabolic (hepatic or renal encephalopathy
61
Seizure Imitators
Motoric or Behavioral Change
• Movement Disorders (Tics, Tremors, RLS)
• Panic Attacks
• Sleep Disorders (Night terrors/ Sleep walking,
Benign myoclonus, Sleep apnea)
• Psychogenic Non-Epileptic Seizures (PNES)
62
Psychogenic Non-epileptic
Seizures
• Resemble epileptic seizures but lack EEG
correlate.
• Can mimic any type of epileptic seizures.
• Very common (~25% of patients referred to
Video-EEG monitoring for evaluation of
intractable epilepsy).
63
Psychogenic Non-epileptic Seizures
• Psychiatric manifestation
– Somatoform/Conversion Disorder (most common)
• Unconscious production of physical symptoms due to
psychological factors. A psychological defense
mechanism to keep internal stress out of conscious
awareness.
– Factitious Disorder
• Consciously determined symptoms driven by a powerful
unconsciously determined need.
– Malingering
• Willful production of symptoms for a specific external
64
incentive.
Psychogenic Non-epileptic
Seizures
• Often difficult to distinguish clinically from
epileptic seizures.
• Clues:
– Resistance to AEDs
– Emotional Triggers (stress)
– Bilateral clonic movements without loss of
consciousness
– Absence of post-event confusion/lethargy.
• Video-EEG is very helpful in diagnosis.
65
Psychogenic Non-epileptic
Seizures
• Many clinical patterns:
– Migratory motor activity (most common)
– Generalized motor activity
– Unilateral (less common)
– Alteration of awareness (Common)
** Can be difficult to distinguish from frontal
lobe seizures.
66
Psychogenic Non-epileptic
Seizures
• Characteristics of PNES
–
–
–
–
–
–
Variable responsiveness or preserved awareness.
Out of phase movements of extremities.
Discontinuous motor activity
Pelvic thrusting.
Side to side head movements.
Eye closure/eye flutter
67
Psychogenic Non-epileptic
Seizures
• Characteristics of PNES
–
–
–
–
–
Varied character of events
Suggestibility
Emotional triggers
Prompt recovery (Absence of post-ictal state)
Poor response to anti-epileptic medications
68
Psychogenic Non-epileptic
Seizures
• Although such findings as urinary
incontinence, tongue biting and injuries are
often attributed to epileptic seizures they
can also be seen in PNES.
69
Psychogenic Non-epileptic
Seizures
• ~20 % of patients with PNES will also have
coexistent epileptic seizures.
• Latency between manifestation of PNES
and diagnosis is ~ 7years.
• Prompt diagnosis is crucial to avoid
iatrogenic morbidity (Exposure to
unnecessary medication ~80%, Intubation
~50%).
70