J. Landau et al., IMPAIRMENT OF CONSCIOUSNESS INDUCED BY VALPROATE TREATMENT FOLLOWING NEUROSURGICAL OPERATION, Acta neurochirurgica, 125(1-4), 1993, pp. 92-96
Eight patients, who underwent neurosurgery for various supratentorial
lesions presented unexplained impairment of consciousness during the f
irst post-operative days. These states ranged from stupor to deep coma
, and two patients had an emergency re-exploration. All these patients
were receiving the usual dosage (1000 to 1500 mg per day) of Valproic
acid (VPA). The treatment had been initiated either several weeks or
months previously in 4 cases, and was thus well tolerated, or the day
before surgery in the 4 other cases. EEG recordings displayed diffuse
abnormalities, delta waves and/or high voltage triphasic complexes, th
at led to the diagnosis of VPA intolerance and drug withdrawal. Then f
ull clinical recovery and EEG clearing occurred within 1 to 5 days. VP
A intolerances are welknown but remain exceptional, about 1 case per 1
00.000. In our neurosurgical population, however, the rate was higher,
approximately 2%. Wide areas of blood brain barrier destruction may c
ontribute to the higher frequency of this easily reversible cause of p
ost-operative stupor or coma.