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 Epilectogenic Precipitating Endogenous Epilectogenic Precipitating

Precipitating factors: Psychological stress Physical stress Sleep deprivation Hormonal changes associated with menstrual cycle Exogenous factors (drugs and drug withdrawal) Photosensitivity Metabolic abnormalities Hypocalcaemia, 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+ channels Therapeutic 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 epilepticu s 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. 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 basal ganglia. Meningioma (blue arrow). Focal, small, old infarcts in white matter and basal ganglia. 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). Note the 'squiggly' spindle shaped cells. Histology of neurofibroma (in skin). Note the 'squiggly' spindle shaped cells.