epilepsy. define seizure and epilepsy seizure: paroxysmal event due to abnormal, excessive,...
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Epilepsy
Define seizure and epilepsy
Seizure: Paroxysmal event due to abnormal, excessive, hypersynchronous discharges from an aggregate of CNS neurons
Not a diagnosis, but rather a series of signs and symptoms
Epilepsy: Disorder in which there is a continuing tendency to have recurrent unprovoked seizures due to a chronic underlying process
Refers to a clinical phenomenon rather than a single disease entity
Aetiology of seizures Endogenous factors:
Genetics / family history
Development
Epilectogenic factors:Trauma + Surgery
Stroke
Infections / Inflammation Encephalitis, meningitis (Esp. Perinatal)
Abnormalities of CNS development
Neural degenerative disorders (Alzheimer disease, Multiple sclerosis
Intracranial mass lesions
Endogenous EpilectogenicPrecipitating
Precipitating factors:Psychological stress
Physical stress
Sleep deprivation
Hormonal changes associated with menstrual cycle
Exogenous factors (drugs and drug withdrawal)
Photosensitivity
Metabolic abnormalitiesHypocalcaemia, hypoglycaemia, hyponatraemia
Acute hypoxia
Uraemia, hepatocellular failure
What are some common causes of seizures in young
adults? Trauma
Alcohol withdrawal
Illicit drug use
Alcohol withdrawal
Idiopathic
Match - classification
Simple partial seizure
Complex partial seizure
Partial seizure with second generalisation
Absence seizure (petit mal)
Myoclonic seizure
Generalised, tonic-clonic seizure (grand mal)
Atonic/ akinetic seizure
A Is difficult to distinguish from a primary generalised tonic- clonic seizure
B Sudden and brief muscle contraction
C Characterised by sudden, brief, lapses of consciousness w/o loss of postural control
D Most common seizure resulting from metabolic derangements
E restricted to discrete areas of cerebral cortex without loss of consciousness
F Sudden loss of postural muscle tone, no post-ictal confusion
G restricted to discrete areas of cerebral cortex with impaired consciousness
Name three epilepsy syndromes.
Juvenile myoclonic epilepsy Appears in early adolescents
Characterised by myoclonic jerks
Lennox – Gastaut Syndrome Occurs in children
Multiple generalised seizures
Mesial temporal lobe epilepsy Most common
Hippocampal sclerosis
Treatment of status epilepticus
Immediate treatment:Airway, oxygenation and cessation of seizures
Clonzepam or diazepam or midazolam
BZD have short duration of anticonvulsant effects therefore give:
Phenytonin or phenobarbitone or sodium valporate
What is the MOA and Therapeutic range of Carbamazepine?
MOA: prevents repetitive neuronal discharge by blocking voltage-dependent and use-dependent Na+ channelsTherapeutic range:4-12mg/L
71. A 9-year-old boy is brought to your clinic by his parents because he has begun to have episodes of eye fluttering lasting several seconds. Sometimes he loses track of his thoughts in the middle of a sentence. There was one fall off a bicycle that may have been related to one of these events. There are no other associated symptoms, and the episodes may occur up to 20 or more times per day. The boy’s development and health have been normal up until this point. He did have two head injuries as a young child: the first when he fell off a tricycle onto the ground, and the second when he fell off of a playset onto his head. Both episodes resulted in a brief loss of consciousness and he did not think clearly for part of the day afterward, but had no medical intervention. The test most likely to confirm this patient’s diagnosis is
a. Brain CT scan
b. Brain MRI
c. Electroencephalogram
d. Lumbar puncture
e. Nerve conduction study
71. The answer is c. This is a common presentation for primary generalized epilepsy of childhood.
85. A 21-year-old cocaine-abusing man develops seizures that persist for more than 30 min before emergency medical attention is available. When examined nearly 1 h later, he is still exhibiting tonic-clonic movements and has never recovered consciousness. (SELECT
1 SEIZURE TYPE)
a. Generalized tonic-clonic
b. Generalized absence
c. Complex partial
e. Simple partial sensory
h. Tonic-clonic status epilepticus
i. Pseudoseizures
j. Myoclonic
85. A 21-year-old cocaine-abusing man develops seizures that persist for more than 30 min before emergency medical attention is available. When examined nearly 1 h later, he is still exhibiting tonic-clonic movements and has never recovered consciousness. (SELECT
1 SEIZURE TYPE)
a. Generalized tonic-clonic
b. Generalized absence
c. Complex partial
e. Simple partial sensory
h. Tonic-clonic status epilepticus
i. Pseudoseizures
j. Myoclonic
Brain tumours
How do brain tumours present? (from path
slides)Generalised/non-localising signs & symptoms
1. Slowing mental functions (memory, thought, speech, emotion)
2. Headache +/- signs of ↑ICP +/- worse in morning or with straining
+/- vomiting
3. Seizures
•Focal neurological sign or symptom depending on anatomic location
eg motor weakness, paraesthesia, unilateral deafness
Asymptomatic
What are some prognostic factors?
1. Tumour type
2. Grade
3. Tumour Site
4. Age
5. Performance status
Gliomas
What are some subtypes of gliomas?
Astrocytoma
Oligodendroglioma
Ependymoma
Poorly differentiated astrocytoma(red arrow) with haemorrhage into the tumour.Note shift of midline structures (blue arrows),and secondary brain stem (green arrow)haemorrhage.
Meningioma (blue arrow). Focal,small, old infarcts in white matter and basalganglia.
What is the peak incidence of meningoma?
50s to 70s
What are the common sites of mets origins?
1. Lung
2. Breast
3. Melanoma
4. Kidney
5. GIT
Who am I?
Histology of neurofibroma (in skin). Notethe 'squiggly' spindle shaped cells.