Seizures, limbic system, meningitis

Question 1

Seizure

Answer 1

• Period where neurons are synchronously ative (firing) when they are not suppose to be. During seizures, clusters of neurons in the brain become temporarily impaired and start sending out excitatory signals over and over. May be due to oer activation of NMDA (glutamate receptors) or under activation of GABA receptors.

Question 2

Febrile Seizures

Answer 2

• Most common neurological disorder in infants and young children (<5).
• Simple febrile seizures - generalized seizures lasting <15mins and not recurring in a 24hr period (majority). Although they recur in 1/3 they are relatively bening and are only associated with a slightly higher risk of future epilepsy.
• Complex febrile seizures - focal, prolonged, or multiple within first 24hrs. Assocaited with higher risk of recurrence and increase likelihood of future afebrile seizure.
• Associated with fever but without evidence evidence of intracranial infection or defined casued. Seizures with fever in chuldren who have had a previous non-febrile seziure are excluded.

Question 3

Criteria Febrile Seziures

Answer 3

• Convlusion associated with temp >38⁰C
• Child older than 6 months and younger than 5 years
• No CNS infection or inflammation
• No acute systemic metabolic abnormalities that may produce convulsions
• No history of previous afebrile seizures

Question 4

Risk Factors Febrile seziures

Answer 4

• High fever
• Infetion - viral infection are commonly identified in associated. Not virus specific, but dependent on degree of temperautre elevation
  
  • HHV-6 and influenza
• Immunization - risk is increased after administration of certain vaccines - diphtharia, tetanus toxoid, whole-cell pertusis, and MMR
• Genetic susceptibility

Question 5

Presentation febrile seizures

Answer 5

• Simple - generalized tonic-clonic (but atonic and tonic also seen)
  
  • Facial and respiratory muscles are commonly involved
  • <15mins (usually much shorter)
• Complex - focal, prolonged, or recurrent with 24hs
  
  • Often younger and more likely to have abnormal development
• Febrile status epilepticus - continuous seizure or intermittent seizures without neurological recovery

Question 6

Treatment febrile seizures

Answer 6

• In majority of cases seizure by time patient is evaluated so treatment with benzodiazepines is not necessary
• Febrile seizsures that last for more than 5 mins should be treated - IV benzodiazepines (diazeoam or lorazepam). Respiratory and circulatory status should be monitored.
• Febrile status epilepticus - patients with prolonged seizure despite initial benzodiazepine administation should be treated with anti-convulsants

Question 7

Epilepsy

Answer 7

• An individual is considered to have epilepsy when any of the following exists:
  
  • At least 2 unprovoked (or reflex) seziures occuring more than 24hrs apart.
  • One unprovoked seziures and probability of further seizures is similar to general recurrence risk after 2 unproked seizsures occuring over the next 10 years.
  • Diagnosis of epilepsy syndrome (epilepsy with specific signs and symptoms).
• Epilepsy is associated with lasting derangement of brain function. May arises from genetic, structural, metabolic, immune infections, or unknown causes.

Question 8

Focal seizures

Answer 8

• Originates in networks limited to one location. May or may not be associated with impaired awareness. Are further divided into:

1. Motor seizures - may manifest as focal motor activity, may see anatomic spread (jacksonian march), versive movements (turning of eyes, head, or trunk), vocaliazations, or arrest of speech.
2. Sensory seizures - may manifest as paresthesias, feelings of disotrtion of an extremity, vertigo, gustatory sensation, olfactory symptoms, auditory symptoms and visual phenomena.
3. Autonomic seizures - epigastic “rising” sensationn, sweating, piloerectionn, and pupilarry changes.
4. Focal seizures without impairment in awareness may also manifest higher cortical, psychic symptoms like dysphasia, deja vu, distortions in time, affective changes, illusions, and formed hallucinations

Question 9

Generalized Seizures

Answer 9

• Always loose consciousness and have no memory of event. Tends to last <5mins.
• Originates at a point within and rapidly engage bilaterally distributed networds. Awarness may be imparied, motor manifestations are bilateral.
• Clonic - repetitive rhythmic jerking movements
• Tonic - muscle rigidity
• Myoclonic-sporadic contractions (localized to muscle groups of 1 or more extremities).
• Atonic - loss of muscle tone leading to drop attack
• Tonic-clonc (grad mal)
• Absence (petit mal) - unresponsive for 5-10s with arrest of activity, staring, blinking, or eye rolling. No post-ictal confusion.

Question 10

Post Ictal Period

Answer 10

• Can last 15hrs - 2days.
• Confusion, headache, soreness, fatigue, paralysis (Todds)