Biomedical subjects
Publications and source records attributed to T H Burnstine.
A 49-year-old right-handed man presented with a severe impairment of motor speech output aphemia. Initially, he could make grunting sounds, but was otherwise mute. There was no disturbance of comprehension, and he preferred to communicate by writing. Writing was agrammatic with lexical errors and mispellings which improved with the speech disturbance. The writing abnormalities of aphemics emphasize the aphasic nature of this speech abnormality.
We conducted a randomized, double-blind, crossover trial of two anticholinergic agents--trihexyphenidyl and tridihexethyl chloride (a quaternary anticholinergic that does not cross the blood-brain barrier)--in patients with acquired nystagmus and measured visual acuity and nystagmus before and at the end of 1 month on each medication. Of the 10 patients admitted to the study, only five completed trials of both drugs due to intolerance of medication or intercurrent illness. Of six patients who completed the trial of trihexyphenidyl, only one showed improvement. Of six patients who completed a trial of tridihexethyl chloride, four showed improvement. We conclude that (1) trihexyphenidyl is not a reliable treatment for acquired nystagmus, although occasional patients may benefit; (2) anticholinergic agents may suppress nystagmus by peripheral rather than central mechanisms; and (3) the side effects of anticholinergic agents limit their effectiveness in the treatment of nystagmus.
We obtained continuous EEG/video recordings on four children who had the interictal EEG pattern of multifocal independent epileptiform discharges (MIED). The prominent feature of their evaluation was the evidence that their clinical seizures appeared to be of focal origin; 42/44 seizures were manifested by "fencing postures." Three patients subsequently underwent epilepsy surgery: one focal resection of superior frontal-parietal cortex and two hemidecorticectomies. Seizure control improved in all three patients, and one patient is now seizure-free. Our patients differ from those previously reported in that they had a predominance of tonic seizures and had no history of infantile spasms or Lennox-Gastaut syndrome. Some patients, such as ours, with MIED may have clinical seizures of more focal origin than might be expected from their interictal EEG and, therefore, may benefit from resective epilepsy surgery.
We evaluated 5 consecutive patients with subdural grid electrodes (including placement over the left basal temporal region) for focal resections for control of intractable epilepsy. All 5 had language dysfunction when we performed cortical stimulation over the basal temporal region (the inferior temporal gyrus, the parahippocampal gyrus) using a systematic battery of language tests. The area in which language interference could be produced began from at least 11 to 35 mm posterior to the temporal tip and ended at least 39 to 74 mm posterior to the temporal tip. The most consistently impaired language tasks were spontaneous speech and passage reading, but there was impairment of all language functions tested in some patients. Language deficits after dominant temporal lobectomy may result from resection of this area.
We investigated possible causative factors for the high epileptic suicide rate by reviewing the cases of 22 patients with idiopathic epilepsy found among 711 patients hospitalized for a suicide attempt by overdose. Suicide attempts occurred with increased seizure activity in one epileptic; otherwise, no relationships were found with seizure-related variables. When matched by age, sex, and race with 44 nonepileptic controls from the same population, the epileptics had more borderline personality disorders with multiple impulsive suicide attempts (45.5% vs 13.6%), more psychotic disturbances, including command hallucinations (31.8% vs 9.1%), fewer adjustment disorders (18.2% vs 45.5%), and a comparable frequency of depression (13.6% vs 25%). We conclude that suicide attempts in epileptics are primarily associated with interictal psychopathologic factors, such as borderline personality disorder and psychosis, rather than with specific psychosocial stressors, seizure variables, or anticonvulsant medications.
We examined the incompletely defined convulsant action of phenytoin (PHT) at toxic concentrations in humans. A retrospective chart review (1979-1985) yielded 96 cases (90 patients), meeting both clinical and laboratory criteria for PHT intoxication. Seven patients, all with epilepsy, had one or more seizures while toxic. However, in only two patients (2.1%) with serum concentrations of 93.2 and 69.7 micrograms/ml was a causal relationship deemed highly probable. Seizures did not occur in most toxic epileptic patients with total serum PHT concentrations as high as 85.1 micrograms/ml or in any of the nonepileptic patients with concentrations as high as 64.2 micrograms/ml. The lack of convulsant action of PHT in these patients suggests that seizure risk may be multifactorial and also that PHT is a weak convulsant. We conclude that PHT at very high concentrations can rarely exacerbate seizures or even precipitate generalized status in some epileptic patients, a paradoxical effect.
A retrospective chart review (1979-1985) was performed to identify probable causes of intoxication with antiepileptic drugs (AEDs). We identified 141 patients meeting clinical and laboratory criteria for intoxication and 17 with clinical signs but with serum concentrations within the therapeutic range. The majority were epileptic patients; almost half were treated with monotherapy, most with phenytoin (PHT). The causes of intoxication in the epileptic patients were iatrogenic (41%), inappropriate dose self-adjustment (34%), suicide attempt (18%), inappropriate caretaker dose adjustment (9%), accidental ingestion (8%), unrecognized drug interaction (6%), and association with intercurrent illness (2%). Twenty-two patients had more than one probable cause of intoxication. In nonepileptic patients the causes were suicide attempt (50%), accidental ingestion (27%), and iatrogenic (23%). Most patients had signs of ocularmotor and vestibulocerebellar dysfunction. Rarely described manifestations of intoxication, such as seizures or choreoathethosis, were observed in a few patients. The average hospital stay was 6.9 days; there was no mortality, and all patients recovered fully. We conclude that AED intoxication is a major but preventable cause of morbidity and that suicide attempts are an important and underrecognized contributor in both epileptic and non-epileptic patients.
We analyzed retrospectively the clinical and EEG data in 13 patients with simple partial seizures (SPS). All EEGs were recorded with surface electrodes with the standard 10-20 system and additional closely spaced scalp and subfrontotemporal skin electrodes. Seventy-seven seizures were recorded. We detected electrographic correlates with SPS in 10 of 13 patients (77%) and in 47 of 77 seizures (61%). The most common ictal correlates were rhythmic theta waves or spikes. Of the SPS with EEG changes, 58% were motor, 14% were sensory, and 28% were psychic seizures. Use of additional electrodes and recording channels may account for the higher incidence of EEG changes in this study than has been reported previously in the literature.