Biomedical subjects
Publications and source records attributed to H H Morris.
We report five patients who experienced delayed patchy hair loss after prolonged EEG monitoring. The location of the patches corresponded to the electrode sites in four. The hair loss was temporary and most probably was due to traumatic noncicatricial alopecia. The frequency of hair loss was approximately 2% of monitored patients.
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We compared the etiologic factors and clinical characteristics of 30 patients with unitemporal vs those of 30 patients with bitemporal independent (minimum 20% from one side) interictal epileptiform discharges on extracranial electroencephalograms. Febrile seizures occurred significantly more frequently in the unitemporal (40%) than in the bitemporal (17%) group. Mass lesions were more common in the bitemporal group, and seven of 10 patients with mass lesions showed bitemporal interictal epileptiform discharges. There were no statistically significant differences in age at onset, frequency of seizures, duration of epilepsy, and history of central nervous system infection or trauma between the two groups. A history of febrile seizures or central nervous system infection that may be expected to cause diffuse cerebral injury does not appear to be the major factor predisposing to the development of bitemporal interictal epileptiform discharges.
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Experimental design effects and range effects may have influenced previous studies on motor response processing (Grice & Hunter, 1964; Grice, Nullmeyer, & Schnizlein, 1979; Poulton, 1973). This investigation was conducted concurrently with two experiments. First, Erlebacher's (1977) more powerful analysis of variance (ANOVA) model, which allows for the testing of the independent variable (stimulus intensity effect), the experimental design effect (between-subjects [BS] vs. within-subjects [WS]), and the important interaction between independent variable and experimental design was utilized to clarify if the nature of the experimental design (BS, WS) biases motor response processing. Second, Erlebacher's (1977) ANOVA model was used to determine if motor response processing was affected by stimulus intensity and experimental design when different ranges of auditory stimuli were compared. Results indicate motor response processing was inversely affected by increasing stimulus intensity. Experimental design effects and range effects did not appear to bias motor response processing. We conclude stimulus intensity effects on motor response processing appear to be the result of true neuromotor functioning and not artifacts of experimental design or of range effects.
Language interference was elicited by electrical stimulation of the dominant basal temporal region in 8 out of 22 cases and in none of 7 cases with subdural electrodes implanted over the nondominant temporal lobe. Language interference was elicited by stimulation of electrodes placed over the fusiform gyrus 3-7 cm from the tip of the temporal lobe. Electrical stimulation of the basal temporal language area produced a global receptive and expressive aphasia with speech arrest at high stimulus intensities. Other higher cortical function, for example copying complex designs or memory of nonverbal information was intact, in spite of the total inability to process verbal information. At lower stimulus intensities partial aphasias with a predominant receptive component occurred. Surgical resection of the basal temporal language area produces no lasting language deficit.
We studied the eye movements (EM) elicited by electrical stimulation of the frontal lobe in 19 awake patients evaluated with subdural electrodes for epilepsy surgery. All patients had only contralateral conjugated EM. They were saccadic in 16 patients (84%). Head version, always following the eye deviation, occurred in 11 patients (58%). We also determined the eye field somatotopic distribution analyzing the responses obtained from the electrodes adjacent to the eye fields. All patients had motor cortex contiguous to the eye fields. In 17 patients (90%) the eye fields were located in front or at the level of the motor representation. There was no silent cortex between the motor strip and the eye fields.
Supplementary motor seizures (SMS) are among the group of frontal lobe seizures that may often be misdiagnosed as pseudoseizures (PS). We designed this study to determine the value of clinical phenomena in distinguishing between the two. In a series of patients with SMS, we identified those with symptoms mimicking PS and compared the clinical phenomena with those of clinically similar PS. We found that SMS are short in duration, stereotypic, tend to occur in sleep, and often present with a tonic contraction of the upper extremities in abduction. This sign was specific for SMS, particularly when occurring at the onset. Conversely, PS are long in duration, nonstereotypic, and occur in the awake state. We conclude that clinical phenomena may be useful in distinguishing PS from SMS, although the final diagnosis must be documented by neurophysiologic means.
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We observed unilateral dystonic posturing of an arm or leg in 41 complex partial seizures (CPS) from 18 patients. In all cases this was contralateral to the ictal discharge. Unilateral automatisms occurred in 39 of 41 seizures on the side opposite the dystonic limb. Version occurred in 11 of the 41 CPS to the same side as the dystonic posturing and always followed the posturing. Subdural recordings of seven seizures showed ictal onset from the mesial basal temporal lobe. At the onset of dystonic posturing, maximum ictal activity was in the basal temporal lobe with minimal involvement of the cerebral convexity. Unilateral dystonic posturing occurs frequently in CPS of temporal lobe onset and is a lateralizing sign with a high degree of specificity. It probably reflects spread of the ictal discharge to basal ganglia structures.
The author provides laboratory documentation of the ACHOO syndrome (photic sneeze reflex) and was able to calculate the latency of the reflex.
Given the advantages of modern medical management, most pregnant epileptic women should experience no significant increase in seizure frequency. With good prenatal medical and obstetric care, complications of pregnancy and delivery in epileptic women differ little from those in the general population. In any case, monotherapy should be employed if possible, and anticonvulsant levels should be monitored closely during pregnancy and immediately after delivery. Dosage adjustments should be made appropriately. Since such an adjustment will usually be made in the second or third trimester, one would not expect it to produce an increased number of malformations. Trimethadione should be absolutely avoided and valproic acid used only with caution and with monitoring of alpha fetoprotein and uterine ultrasound. Although it is true that there is an increased incidence of malformations in children of epileptic women (with or without anticonvulsants), the great majority of these babies are normal. Vitamin K should be given to the mother before delivery, and the newborn should receive 1 mg vitamin K at birth. Unless the infant becomes symptomatic, breast feeding should be allowed. If seizures occur for the first time during pregnancy, the patient should be appropriately evaluated. Status epilepticus in pregnant women calls for aggressive and careful treatment. Finally, it should be remembered that oral contraceptives, especially the "mini pill," have a higher failure rate in women taking anticonvulsants. Discussing this problem with the patient is helpful.
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To evaluate the utility and safety of chronic extraoperative subdural EEG and functional localization studies in children compared to adults, we studied 61 patients each of whom had similar evaluations for epilepsy surgery, regardless of age. The 23 children and adolescents (3 to 18 years old) and the 38 adults (20 to 41 years old) each had several days and nights of extraoperative EEG from scalp and chronically-implanted subdural electrodes, and the same percentage of children and adults also had functional localization studies including cortical electrical stimulation. The methods and results of these studies and of the subsequent resections did not differ between the two groups, and they both had similar rate of complications and similar incidence of good outcome. The subdural technique was as effective and well-tolerated in children and adolescents as in adults. Other invasive EEG techniques have not yet been systematically compared between children and adults, but the subdural technique, at least, appears to be suitable for patients over a wide age range.
Intraoperative cortical stimulation for evaluation of cortical function has been used extensively to define the extent of cortical excisions for surgical treatment of epilepsy. With chronic implantation of subdural electrodes, extraoperative cortical stimulation becomes possible, and these favorable testing conditions permit more precise mapping of the cortex. This assists the surgeon in planning details of the surgical removal and also provides additional data about the function of the human cortex. Four aspects in which detailed extraoperative studies have provided information complementing the pioneer studies of Foerster, Penfield, and others will be discussed here: (1) Frontal eye field: In the human, this is always an integral part of the motor strip (most probably located in Brodman's area 4 and/or 6) and elicits only conjugate eye movements to the contralateral side with a variable upward component. (2) Negative motor area: Stimulation of the inferior frontal gyrus immediately in front of the face area and of the supplementary motor area of the dominant and nondominant hemisphere produces "inhibition" of voluntary fine movements. (3) The movement related potentials (bereitschaftpotential, negative slope, and motor potential) are strictly localized to the portion of the sensorimotor strip where the movement is represented. Lower amplitude bereitschaftpotentials can also be detected in the homotopic ipsilateral sensorimotor cortex and in the supplementary motor cortex. (4) Three language areas can be distinguished by electrical stimulation: Broca's, Wernicke's, and the basal temporal language area. Electrical stimulation in all these areas produces a similar deficit, but Broca's area tends to overlap with the inferior frontal negative motor area. This may explain the predominant motor deficit of Broca's aphasia.
We report 31 episodes of ictal vomiting in nine patients, documented by simultaneous video and EEG recordings. In four patients, chronically implanted subdural electrode arrays recorded the event. Only one patient showed "projectile" vomiting. Amnesia for the episode occurred in eight of the nine patients. Interictal epileptiform abnormalities were maximal in the right temporal region in seven patients and bitemporal in two. Ictal epileptiform abnormalities were lateralized to the right hemisphere and involved temporal lobe structures in all patients. Three of four patients recorded with subdural electrode arrays were seizure-free following right temporal lobectomy, and the fourth continues to have ictus emeticus at a reduced rate. The consistent right hemisphere lateralization of seizures in this series corroborates with earlier reports documenting right-sided lateralization in four of five previous cases. Two features that help delineate paroxysmal vomiting as an ictal event are (1) patient unawareness of vomiting and (2) its association with other ictal phenomena.
The clinical and EEG features of 11 patients with seizures arising in the supplementary motor area (SMA) were reviewed. All patients underwent prolonged EEG with simultaneous video recording. Three patients had recordings and electrical stimulation of the SMA using subdural electrode arrays. All patients had preservation of consciousness during the seizure unless it became secondarily generalized. Tonic posturing of the extremities was present in all patients, and in seven it was present bilaterally. Adversive movements were not seen unless the seizure became secondarily generalized. Interictal and/or ictal abnormalities were present at or adjacent to the midline in ten patients. Seizures arising from the supplementary motor region are clinically distinct, and the diagnosis can almost always be verified with prolonged EEG/video recording.