Neurology Flashcards
What are some key definition differences between focal and generalised seizures?
Focal seizures are localised to a single hemisphere and typically associated with structural abnormalities.
Generalised are global and more likely related to biochemical, cellular or diffuse structural abnormalities.
Relative to a focal seizure, what is a Jacksonian March? What is Todd’s paresis? Epilepsisa partialis continua?
Jacksonian: Focal seizure activity which spreads to another area adjacent to the original site located in the brain. e.g. hand spreads to arm.
Todd’s: Paralysis of the affected area following a seizure, which can last for hours or days.
EPC: persistent paralysis of the affected area with the seizure continuing. Often medically refractory.
What is the difference between “Focal with Dyscognitive features” and “Focal without dyscognitive features”?
Dyscognitive features are those which impair the persons ability to maintain contact with the normal environment. This typically manifests with inability to interact with others, automatic movements, and amnesia or confusion.
What are some subtle signs of an absence seizure?
bilateral rapid blinking
chewing motions
clonic movements of the hands.
Rapid onset and off, without post ictal confusion.
What age does absence seizure typically arise?
4-8 years of age. These are the most common (20%) of seizures as early teenagers. Presentations often occur when there is increasing day dreaming and poor school grades.
What is the typical electrophysiology hallmark of an absence seizure?
Generalised and symmetric. 3 Hz Spike and wave that starts and stops abruptly. Hyperventilation typically induces the seizures.
How does an atypical absence seizure manifest?
Lapse in consciousness is generally longer and more gradual onset. Accompanied by more motor signs. EEG: generalised slow spike and wave pattern with frequency <2.5 Hz. Typically associated with more structural problems and less responsive to anticonvulsants.
Why are generalised tonic-clonic seizures more commonly encountered?
They account for around 10% of epilepsy seizures, however they are most commonly a result from metabolic disturbances. Hence they are encountered more often.
What is an ictal cry?
The initial noise heard with tonic contraction of muscles.
In generalised tonic-clonic seizures what does the EEG show?
tonic: progressive increase in generalized low-voltage fast activity, followed by generalized high-amplitude, polyspike discharges.
Clonic: high-amplitude activity is typically interrupted by slow waves to create a spike-and-wave pattern
What is Lennox-Gastaut syndrome? What causes it?
Seizure condition of children characterised by a triad:
(1) multiple seizure types (usually including generalized tonic-clonic, atonic, and atypical absence seizures)
(2) an EEG showing slow (<3 Hz) spike-and-wave discharges and a variety of other abnormalities
(3) impaired cognitive function in most but not all cases
No clear cause, associated with mutations, hypoxia, trauma, and infections or other lesions.
What is Juvenile Myoclonic Epilepsy?
Generalised seizure disorder of unclear cause. Onset in early adolescence associated with bilateral jerking myoclonus. Familial history of epilepsy common, often also have absence seizures.
What are some characteristic findings for Mesial Temporal Lobe Epilepsy Syndrome?
History of febrile seizures with family hx of seizures.
Aura is common, post ictal disorientation
memory loss
unilateral posturing
EEG: Uni or Bilateral anterior temporal spikes
MRI: Small hippocampus, Small temporal lobe, enlarged temporal horn.
Highly selective cell loss in the hippocampus.
