epilepsy. define seizure and epilepsy seizure: paroxysmal event due to abnormal, excessive,...

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.