Saturday, August 15, 2009

Drugs that affect the seizure threshold

Antiasthmatics-- aminophylline, theophylline
antibiotics-- inh, metronidazole, penicillin, lindane
antidepressants: buproprion, SSRI, TCA
general anesthesia-- enflurane, ketamine
hormones-- estrogen, esp without progesterone
immunosuppressants-- chlorambucil, cyclosporine
local anesthetics- lidocaine, bupivicaine, procaine
narcotics-- fentanyl, meperidine, pentazocine, propoxyphene
psychostimulants- amphetamines, cocaine, methylphenidate
neuroleptics-- clozapine, phenothiazines, butyrophenones
others-- anticholinergic, anticholinesterase, antihistamine, baclofen, heavy metals, lithium, mefenamic acid, oral hypoglycemics, oxytocin

Seizure risk associated with neuroactive drugs: Data from the WHO adverse drug reactions database; Kumlien E, Lundberg PO; Seizure (Dec 2009)

PURPOSE: To explore the association between the use of neuroactive drugs and reports of epileptic seizures. MATERIAL: Using the WHO adverse drug reactions (ADR) database, VigiBase, we surveyed reports of suspected seizures from 1968 until February 2006. Case reports of ADRs, that were classified as convulsions were collected and compared to the total number of ADRs reported. RESULTS: The total number of ADRs was 7,375,325. The number of convulsive events was 71,471. The ratio of convulsive ADRs to the total number of ADRs reported for each drug was evaluated and expressed as a percentage. The 10 drugs most frequently associated with convulsive ADRs were maprotilene (14.42%), escitaloprame (9.78%), buproprione (9.49%), clozapine (9.0%), chlorprothiexene (8.89%), amoxapine (8.74%), donepezil (8.40%), rivastigmine (6.41%), quetiapine (5.90%) and trimipramine (5.69%). CONCLUSIONS: Based on the reports in VigiBase, ADR reports relating to antidepressants, antipsychotic and cholinomimetic drugs included seizures more often than other neuroactive drugs.

Epilepsy random pearls

1. Valproate works for tilt positive treatment (Eugene Ramsey)
2. Potential analogy of SUDEP and SIDS (failure of brainstem to respond to hypopnea (Mary Donner)
3. In VA study 80 % of patients had undiagnosed serious dyslipidemia, 70 % htn (Ramsey)
4. Asking patients if they turn hues esp. to shade of gray, almost certainly diagnoses NCS
5. Lamotrigine works extremely well for classic migraine (comorbid with epilepsy), less well for common migraine
6. Epilepsy patients describe panic attacks eloquently, but they may be unrecognized seizures (feeling in stomach, etc.)
7. Drug AE's are age related .
8. Carbamazepine causes weight gain, usually not recognized and may worsen tremor(Ramsey)
9. Topirimate helps BP, tremor, glucose control, weight
10. Ethosuximide worsens headache
11. PPI's raise gastric pH, making phenytoin absorption not happening
12. Stopping inducer, PHT or CBZ dramatically decreases clearance of LTG and TPM resulting in blood levels shooting up
13. Simvastatin levels go down 80 % with CBZ. Only statin not affected is ____/ Also beware of Calcium channel blockers (including nimodipine for SAH), HAART, drugs for ED

SMA atrophy

most common fatal genetic disease in newborns
Aut recessive carrier frequency 1:35 occurrence 1:6000
Caused by deletion mutation in SMN 1

Human diseases with no mouse models

Down's syndrome-- mice lack chromosome 21
Parkinson's disease-- mice endogenous A53T
SMA no SMN2 gene

Treatment of Parkinson's disease: gyrokinetics
lee silverman voice technique
advanced pt techniques
vital stim

Sunday, August 02, 2009

tongue biting and seizures pearls

Lateral tongue biting is poorly sensitive but highly specific (99%) for a generalized seizure.
Lateral tongue biting usually indicates true epileptic seizures as opposed to bites to the tip of the tongue which are typically nonepileptiform events.
Lateral tongue biting has a predictive value of 71% for ipsilateral seizure focus.

from AAN website