Neonatal paralytic poliomyelitis. A case report.

Neonatal poliomyelitis, which was rare even when poliomyelitis was widespread, has not been reported in the United States since use of live oral poliovirus vaccine (Sabin's vaccine) became widespread. We report a child who became symptomatic with apnea at 18 days of age and who subsequently developed a permanent monoparesis. Serologic and cultural evidence indicated the virus as poliovirus vaccine type. Another infant who received live oral poliovirus vaccine was probably the source of the infecting virus. Recognition that poliovirus infection can still occur in the United States and an understanding of the serologic, cultural, and typing tests required to substantiate this diagnosis are needed so that such patients will be accurately diagnosed.

Hippocampal volumetrics differentiate patients with temporal lobe epilepsy and extratemporal lobe epilepsy.

OBJECTIVE: To determine whether the occurrence of hippocampal formation (HF) volumetric asymmetry can reliably discriminate between complex partial seizures (CPSs) of a temporal lobe origin and CPSs of an extra-temporal lobe origin in a prospective study of patients with intractable CPSs (approximately 70% of patients have electrographic foci in the temporal lobe [HF volumetric asymmetry on magnetic resonance imaging scans has been shown to lateralize such foci reliably)]. DESIGN: We examined HF volumetrics on magnetic resonance imaging scans that were acquired with a 1-T magnetic resonance imaging scanner (Siemens Magnetom, Siemens Medical Systems, Iselin, NJ) by using magnetization-prepared rapid gradient echo three-dimensional sequences (producing a gapless series of high-contrast 1.25-mm images). These data were compared with ictal, interictal, invasive, and noninvasive videoelectroencephalographic monitoring data, functional imaging data, and outcome data to define each patient's type of epilepsy. SETTING AND PATIENTS: Forty-one patients were recruited from a tertiary university comprehensive epilepsy program, and 22 control subjects were recruited from the neurologically normal university community. RESULTS: Among the control subjects, the difference in HF volumetrics (right-left HF volumetrics) was + 0.085 +/- 0.253 cm3. Of the 41 patients, 25 had temporal lobe epilepsy. When we set the upper limit of normal at the mean +/- 3 SDs, all patients beyond the upper limit had CPSs of a temporal lobe origin. Of the patients with temporal lobe epilepsy, only three fell within normal limits. No patient with CPSs of an extratemporal lobe origin fell beyond the upper limit. CONCLUSION: The presence of significant HF volumetric asymmetry makes it highly unlikely that a patient's CPSs are of an extratemporal lobe origin.

Electroencephalographic, volumetric, and neuropsychological indicators of seizure focus lateralization in temporal lobe epilepsy.

CONTEXT: Anterior temporal lobectomy is an effective treatment for medically intractable temporal lobe seizures. Identification of seizure focus is essential to surgical success. OBJECTIVE: To examine the usefulness of presurgical electroencephalography (EEG), magnetic resonance imaging (MRI), and neuropsychological data in the lateralization of seizure focus. DESIGN: Presurgical EEG, MRI, and neuropsychological data were entered, independently and in combination, as indicators of seizure focus lateralization in discriminant function analyses, yielding correct seizure lateralization rates for each set of indicators. SETTING: Comprehensive Epilepsy Program, Shands Teaching Hospital, University of Florida, Gainesville. PATIENTS: Forty-four right-handed adult patients who ultimately underwent successful anterior temporal lobectomy. Left-handed patients, those with less-than-optimal surgical outcome, and any patients with a history of neurological insult unrelated to seizure disorder were excluded from this study. MAIN OUTCOME MEASURES: For each patient presurgical EEG was represented as a seizure lateralization index reflecting the numbers of seizures originating in the left hemisphere, right hemisphere, and those unable to be lateralized. Magnetic resonance imaging data were represented as left-right difference in hippocampal volume. Neuropsychological data consisted of mean scores in each of 5 cognitive domains. RESULTS: The EEG was a better indicator of lateralization (89% correct) than MRI (86%), although not significantly. The EEG and MRI were significantly superior to neuropsychological data (66%) (P=.02 and .04, respectively). Combining EEG and MRI yielded a significantly higher lateralization rate (93%) than EEG alone (P<.01). Adding neuropsychological data improved this slightly (95%). CONCLUSIONS: The EEG and MRI were of high lateralization value, while neuropsychological data were of limited use in this regard. Combining EEG, MRI, and neuropsychological improved focus lateralization relative to using these data independently.

Speech arrest in partial seizures: evidence of an associated language disorder.

Recurrent episodes of speech arrest were observed in a man as the primary manifestation of a partial seizure disorder. To determine whether speech arrest was associated with a language disorder, the Syntactic Comprehension test was administered during and after speech arrest. This test does not depend upon speech production, but evaluates ability to comprehend sentences in which meaning depends on syntactic relationships. Using this test, we were able to show that speech arrest was associated with a language disturbance.

Acoustic nerve conduction abnormalities in Guillain-Barré syndrome.

We recorded brainstem auditory evoked potentials (BAEPs) in two patients with Guillain-Barré syndrome (GBS). One patient was acutely deaf with total absence of BAEP waveforms indicative of acoustic nerve conduction block. Hearing improved during early convalescence, and there were prolonged wave I latencies. Normal BAEPs were recorded on recovery. A second patient had bilaterally prolonged wave I latencies. These BAEP findings suggest that acoustic nerve conduction abnormalities from demyelination may occur in GBS.

Botulinum toxin-induced paralysis of frontotemporal muscles improves seizure focus localization.

BACKGROUND: Scalp EEG localization of epileptic foci may be obscured by electromyographic (EMG) artifact produced by ictal contraction of cranial muscles. Injection of botulinum toxin type A (BTX-A) into frontotemporal scalp muscles reduces EMG activity. Initial scalp video-EEG monitoring in three patients suggested partial seizures, but definitive lateralization or localization was precluded by EMG artifact. METHODS: EMG-guided BTX-A injection to bilateral frontotemporal muscles was performed. When artifact persisted, BTX-A administration was selectively repeated. Patients subsequently underwent scalp video-EEG monitoring 1 week later. RESULTS: All patients had reduction of EMG artifact during subsequent scalp video-EEG monitoring. No patient had adverse effects after BTX-A administration. All three patients had localization to either frontal or temporal lobes and definitive lateralization. Two of the three patients were able to proceed to invasive placement of frontotemporal subdural grid electrodes based on the BTX-A scalp video-EEG localization, and the third patient was determined to have a multifocal seizure disorder. CONCLUSIONS: Paralysis of frontotemporal scalp muscle after BTX-A administration reduces EMG artifact and may improve localization and lateralization of a seizure focus, providing a noninvasive technique for advancement toward epilepsy surgery.

Electroencephalographic findings in Hashimoto's encephalopathy.

Hashimoto's encephalopathy (HE) is a steroid-responsive relapsing disorder that frequently presents with seizures and diffuse EEG abnormalities. We report the EEG findings in seven patients with encephalopathy, seizures, or both, associated with elevated antithyroid antibodies. There were several combinations of findings within the same patient and between patients. The EEGs of five patients had generalized slowing or frontal rhythmic slowing; two also had triphasic waves and one had periodic sharp waves. Three had focal left temporal slowing. HE is heterogeneous clinically and electrographically. A high level of suspicion is necessary to establish the diagnosis.

Anosognosia during Wada testing.

Anosognosia, the verbally explicit denial of hemiplegia, is more often reported after right- than left-hemisphere lesions. However, this asymmetric incidence of anosognosia may be artifactual and related to the aphasia that often accompanies left-hemisphere lesions. Anosognosia has been attributed to psychological denial and the emotional changes associated with hemispheric dysfunction. Eight consecutive patients undergoing intracarotid barbiturate (methohexital) injections as part of their presurgical evaluations for intractable epilepsy were assessed for anosognosia after their hemiplegia and aphasia had cleared. After their left-hemisphere anesthesia, all subjects recalled both their motor and language deficits. However, after right-hemisphere anesthesia, none of the eight patients recalled their hemiplegia. These results suggest that anosognosia is more often associated with right- rather than left-hemisphere dysfunction and that it cannot be attributed to either psychological denial or the emotional changes associated with hemispheric dysfunction.

Proprioception more impaired distally than proximally in subjects with hemispheric dysfunction.

Holmes noted that with hemispheric injuries proprioceptive disturbances were more marked in the distal than proximal limb segments and proposed that this difference was related to the size of cortical sensory representations. An alternative hypothesis is that sensation from distal segments projects to the contralateral hemisphere and sensation from proximal segments projects to both hemispheres. Selective hemispheric anesthesia was used to test these alternative hypotheses and revealed a decrement in distal but not proximal proprioception with hemispheric anesthesia, thereby supporting the bilateral projection hypothesis.

Apraxia during Wada testing.

Apraxia is the loss of the ability to perform learned skilled movements correctly. In right-handers, apraxia and aphasia are most frequently associated with left-hemisphere lesions. When they are dissociated, however, aphasia is more common in the absence of apraxia than vice versa. There are two hypotheses that can account for this discrepancy: (1) in right-handers, praxis is more likely than language to be mediated by the right hemisphere, or (2) the left-hemisphere network that mediates language is either more widely distributed than the network that mediates praxis or is more likely to be in the middle cerebral artery distribution. We studied apraxia in a group of right-handers undergoing selective hemispheric anesthesia, or Wada testing. All nine subjects had language lateralized to the left hemisphere, and seven of the nine had praxis lateralized to the left hemisphere. Two of the subjects had praxis bilaterally represented. Although our data suggest that speech and praxis functions tend to be lateralized to the left hemisphere in most right-handers, praxis appears to be more distributed between the hemispheres than speech-language functions. Furthermore, an analysis of the types of errors made during praxis testing suggests differential roles of the hemispheres in praxis functions.

Anosognosia during intracarotid barbiturate anesthesia: unawareness or amnesia for weakness.

Previous studies have demonstrated asymmetric hemispheric contributions to deficit awareness during hemisphere inactivation with intracarotid barbiturate infusion (Wada studies). These observations provide insight into the neuropsychological basis of anosognosia for hemiparesis (AHP), arguing against earlier explanations based upon psychological denial, global cognitive disturbance, or emotional indifference. Although prior Wada studies equated AHP after the procedure with AHP during the period of deficit, a selective memory failure could also account for these findings. We, therefore, assessed the occurrence of AHP during and after right-hemisphere inactivation in a group of epilepsy patients undergoing preoperative Wada testing. Because aphasia obscures assessment of deficit awareness during left carotid studies, we compared the frequency of AHP between right- and left-hemisphere inactivation only after recovery. As noted in earlier reports, AHP was present significantly more often after right- than left-hemisphere inactivation. The proportions of subjects with AHP during right-hemisphere anesthesia compared with the proportion of subjects with AHP after the procedure were statistically equivalent, suggesting that the AHP observed after right-hemisphere anesthesia results from true failure of deficit awareness rather than inability to recall the deficit.

Anosognosia and confabulation during the Wada test.

Feinberg et al. proposed that right-hemisphere-damaged stroke patients with anosognosia for hemiplegia (AHP) confabulate seeing stimuli on the left side but those without AHP admit to having inadequate visual information. This study examines the relationship between AHP and confabulation using selective anesthesia of the cerebral hemispheres. Seventeen patients with intractable epilepsy were tested during intracarotid methohexital infusion. For half of the trials, subjects were stimulated on their paretic hand with a material (sandpaper, metal, or cloth), and for the remaining trials they were not stimulated. The subjects were trained to use a pointing response to indicate if they been stimulated and the type of material they had felt. Admission of uncertainty was defined as pointing to a question mark. Confabulation was defined as any material response to a no-touch trial. During anesthesia of either hemisphere, subjects with and without AHP confabulated responses. The AHP and non-AHP groups did not differ in admission of uncertainty. Our results support the postulate that confabulation and AHP are independent disorders, and therefore confabulation cannot fully account for AHP.

Dissociation of anosognosia for hemiplegia and aphasia during left-hemisphere anesthesia.

The stroke literature indicates that the explicit denial of hemiplegia, a form of anosognosia, is associated more commonly with right- than left-hemisphere lesions. Some investigators have suggested that this asymmetry may be an artifact and that the aphasia that often accompanies left-hemisphere dysfunction may mask some instances of anosognosia. Mechanisms suggested for anosognosia have been either "global" or "modular" in nature. Mechanisms posited in global explanations include psychological denial and general mental deterioration; modular explanations include feedback and feedforward theories. Videotapes of 54 patients with medically intractable seizures who had selective barbiturate anesthesia (Wada test) as part of their evaluation for seizure surgery were assessed for anosognosia of hemiplegia and aphasia after hemispheric anesthesia had worn off. The results suggest that, although aphasia may confound the reported rate of anosognosia for hemiplegia following left-hemisphere dysfunction, the frequency of anosognosia for hemiplegia is still higher with right- than left-side dysfunction. Anosognosia for hemiplegia and aphasia were dissociable, providing support for the postulate that awareness of dysfunction is mediated by a modular system.

Anosognosia for hemiplegia: test of the personal neglect hypothesis.

OBJECTIVE: To test the personal neglect hypothesis of anosognosia for hemiplegia (AHP) using selective anesthesia of the right hemisphere. BACKGROUND: Although AHP most commonly follows right-hemisphere injury, the mechanism responsible for this hemispheric asymmetry has not been entirely elucidated. Because denial of ownership of parts on the contralesional side of one's body (personal neglect) also more commonly follows right-hemisphere damage, personal neglect might account for AHP. DESIGN/METHODS: AHP and personal neglect were assessed in 20 patients during right intracarotid barbiturate infusion. With vision restricted to the central field, patients were randomly presented with either their own hands or those of examiners matched for size, gender, and race. Patients were asked to read numbers placed on the hands to establish that hemianopia did not confound hand recognition. RESULTS: All subjects correctly read the numbers on all trials. Only 4 of 20 subjects misidentified their hands and denied awareness of left hemiplegia. All errors occurred for the left hand, indicating personal neglect. However, the 16 subjects without personal neglect also demonstrated AHP. CONCLUSION: Because AHP and personal neglect are dissociable, personal neglect cannot completely account for AHP.

Lateralization of temporal lobe foci: depth versus subdural electrodes.

OBJECTIVES: Definitive localization of an epileptic focus correlates with a favorable outcome following epilepsy surgery. This study was undertaken to determine the incremental value of data yielded for surgical decision making when using subdural electrodes alone and in addition to depth electrodes for temporal lobe epilepsy. METHODS: Standardized placement for intracranial electrodes included: (1) longitudinal placement of bilateral temporal lobe depth electrodes; (2) bilateral subtemporal subdural strips; and (3) bilateral orbitofrontal subdural strips. Sixty-three events were randomly reviewed for: (1) subdural electrodes alone; and (2) depth electrodes in conjunction with subdural electrodes. RESULTS: Of the 63 seizures, 54 (85.7%) demonstrated congruent lateralization to ipsilateral subtemporal subdural strip electrodes (based on depth electrode localization) when subdural strip electrodes were utilized alone. In 3 of 22 patients, 7 seizures demonstrated 'false localization' on subdural electrode analysis alone when compared with depth recording and post-surgical outcome. For these 3 patients, retrospective review of neuroimaging demonstrated suboptimal ipsilateral placement of subtemporal subdural electrodes with the most mesial electrode lateral to the collateral sulcus. Four additional patients had suboptimal placement of subtemporal subdural electrodes. Two of these 4 patients had congruent localization with subdural electrodes to ipsilateral depth electrodes despite suboptimal placement. Subtemporal subdural electrodes accurately localized for all seizures from the mesial temporal lobe when the mesial electrodes of the subtemporal subdural strip recorded mesial to the collateral sulcus from the parahippocampal region. CONCLUSION: We conclude that although there are high concordance rates between subdural and depth electrodes, localization of seizure onset based on subdural strip electrodes alone may result in inaccurate focus identification with potential for possible suboptimal treatment of temporal lobe epilepsy. When subtemporal subdural electrodes provide recording from the parahippocampal region, there is accurate localization of the seizure focus. If suboptimal placement occurs lateral to the collateral sulcus, the electroencephalographer cannot make a definitive identification of the seizure focus.

Brain biopsy in cases of neonatal herpes simplex encephalitis.

Neonatal herpes simplex encephalitis (HSE) can represent a difficult diagnostic problem when it occurs without concomitant mucocutaneus lesions and usually requires brain biopsy for diagnosis. Asymptomatic for the initial 2 to 4 weeks of life, the three infants we describe with localized HSE came to medical attention only because they developed persistent seizures and other nonspecific symptoms. Lumbar spinal fluid obtained from these children at clinical presentation showed an encephalitic pattern. Radionuclide brain scans revealed focal uptake of isotope in a variety of cortical areas, and electroencephalograms (EEGs) demonstrated repetitive, high amplitude, polyphasic sharp waves arising from analogous regions. Computed tomography (CT) showed nonspecific ill-defined areas of low density or contrast enhancement that did not correlate well with radionuclide, EEG, or clinical findings in two neonates. No infant had predominant temporal lobe involvement. Because these data suggested a multifocal, encephalitic process, all three infants underwent brain biopsy. A widespread infiltration of leukocytes and macrophages was observed in each specimen, and abundant intranuclear inclusions were present. Electron microscopy revealed abundant herpesvirus particles, and herpes simplex virus (HSV) was subsequently isolated from each sample. From our observations and our review of the literature, we propose the following criteria as indications for brain biopsy: Brain biopsy is warranted to rule out HSE when a neonate presents with seizures, cerebrospinal fluid mononuclear pleocytosis with a negative gram stain, and focal, cortical disease on EEG and radionuclide scan.(ABSTRACT TRUNCATED AT 250 WORDS)

Secondary epileptogenesis in humans.

Secondary epileptogenesis as it applies to humans remains a controversial topic despite 40 years of investigation. Part of the controversy stems from disagreement about the definition of secondary epileptogenesis, and part of the controversy stems from the imperfect fit of animal models to the human epileptic syndromes. It may be that models of secondary epileptogenesis can be useful to describe specific epileptic syndromes such as bitemporal epilepsy and secondary bilateral synchrony, but other models may be required for remitting syndromes such as the Landau-Kleffner syndrome. The concept of secondary epileptogenesis may also provide a useful construct for evaluating patients with partial epileptic syndromes, especially those under consideration for epilepsy surgery, and for the evaluation of preventive strategies in epilepsy.

Cortical influences in emotion.

Emotions may be classified into two major divisions: experience and behavior. Because the brain is critical for mediating emotional experience and behavior, diseases of the brain may induce changes in emotional behavior and experience. Disorders of almost all portions of the cerebral hemisphere, including the cortex, limbic system, and basal ganglia, have been associated with changes of emotional experience and behavior. Dysfunction of the cerebral cortex may be associated with disorders of emotional communication. Whereas deficits of the left hemisphere appear to impair the comprehension and expression of propositional language, deficits of the right hemisphere may be associated with an impaired ability to comprehend and express emotional gestures such as facial expression and emotional prosody. Some patients have either prosodic or facial emotional deficits. Some have only expressive or receptive deficits. However, others may be globally impaired, either within or across modalities. The posterior portions of the neocortex appear to be important for comprehension and the anterior for expression of both emotional prosody and faces. Injury and dysfunction of the limbic system may also alter emotional communication and experience. For example, damage to the amygdala may be associated with an impaired ability to recognized emotional faces and a reduction of affect, especially anger, rage, and fear. In contrast, lesions of the septal region may be associated with increased ragelike behaviors. Seizures frequently emanate from the limbic system, and seizures that start in the amygdala can induce fear and perhaps even rage. Disorders of the basal ganglia may also be associated with defects of emotional communication and experience. Patients with Parkinson's disease not only may be impaired at communicating emotions with both expressive and receptive deficits but also are often depressed and anxious. Patients with Huntington's disease may have emotional comprehension deficits with an impaired ability to recognize emotional faces and prosody. Patients with Huntington's disease may have mood changes even before motor dysfunction becomes manifest. Many of the defects in emotional experience may be related to the associated changes in neurotransmitter systems. Unfortunately, how alteration of neurotransmitters induce mood changes remains unknown. In this chapter we review the feedback and central theories of emotional experience. Although we argue against the postulates that feedback is critical to the experience of emotions, we do suspect that feedback may influence emotions. Emotions may be conditioned and may use thalamic-limbic circuits, as proposed by LeDoux. However, most emotional behaviors and experiences are induced by complex stimuli that an isolated thalamus could not interpret. The cerebral cortex of humans has complex modular systems that analyze stimuli, develop percepts, and interpret meaning. We discuss the proposal that the experience of emotions is dimensional. Almost all primary emotions can be described with two or three factors, including valence, arousal, and motor activation.

Experimentally induced disorders of neuronal migration produce an increased propensity for electrographic seizures in rats.

Disorders of neuronal migration in humans are associated with intractable epilepsy and some evidence suggests a causal relationship. This study evaluated electroencephalograms (EEG) of rats with experimentally induced disorders of neuronal migration. Fetal Sprague-Dawley rats were exposed to 196 cGy external irradiation on days 16 and 17 of gestation. This produced adult offspring with diffuse cortical dysplasias, agenesis of the corpus callosum, periventricular heterotopias, and dispersion of the pyramidal cell layer of the hippocampus. Epidural electrodes were implanted in four experimental (irradiated on gestational day 17) and four control rats. EEGs were recorded without anesthesia and in the presence of the anesthetic agents ketamine, acepromazine, and xylazine. In the presence of acepromazine, xylazine, or a combination of the two drugs, two of the four experimental rats had prolonged ictal activity on EEG. In one of the rats the ictal activity progressed to electrographic status epilepticus. Ketamine alone did not produce ictal EEG activity. None of the control rats demonstrated ictal activity under any treatment condition. This study demonstrates that disorders of neuronal migration are associated with an increased propensity for seizures in the presence of certain sedating agents.

Quantified volumes of temporal lobe structures in patients with epilepsy.

The T1-weighted volumetric magnetic resonance images of 31 patients with intractable temporal lobe epilepsy, and 13 control subjects matched for age and sex, were subjected to semiautomated threshold analysis. The method used proved to be relatively fast and reliable. An index of temporal lobe interhemispheric asymmetry was extracted by thresholding high-signal (white matter) pixels. Patients had significantly more asymmetrical indices for white matter and hippocampal volumes that did control subjects, and the two indices were significantly correlated, providing evidence for the validity of the white matter index. Differences in both indices were consistent with decreased tissue on the side of the focus. In classification analyses a combination of these two indices correctly predicted the side of focus at a greater rate than did either used alone. Findings provide support for the hypothesis that seizure activity is associated with atrophy in both mesial and lateral temporal lobe structures.