Seasonal Variation in Emergency Department Visits Among Pediatric Headache Patients.

OBJECTIVE: To ascertain whether seasonal variation occurs in emergency department (ED) visits for headache among children and adolescents. METHODS: A retrospective review was conducted using the electronic medical records of ED visits for headache at a tertiary children's hospital through calendar years 2010-2014. Using ICD-9 diagnostic codes for headache and migraine, the numbers of headache visits were determined and compared by season and during school months vs summer months. RESULTS: A total of 6572 headache visits occurred. Headache visits increased during the fall season (133 ± 27 visits per month) compared with other seasons (101 ± 19 visits per month), P ≤ .002, but did not differ when comparing school months (113 ± 25 visits per month) and summer months (100 ± 24 visits per month), P = .1. CONCLUSIONS: The corresponding increase in ED visits during the fall season coincides with the start of the school year. Academic stressors and the change in daily schedule may lead to more headaches and more ED headache visits among school-aged youth.

Forced normalization. Acute psychosis after seizure control in seven patients.

An antagonistic relationship between psychosis and seizures has been described in some patients and is sometimes termed "forced normalization." We saw seven epileptic patients without a previous psychiatric history, who developed acute psychotic states on establishment of seizure control and normalization of previously abnormal electroencephalograms with frank epileptiform activity. A possible hypothetical relationship between psychosis and epilepsy regarding the mesolimbic dopaminergic system and kindling of this system with epileptic discharge in temporal-limbic circuits could induce a florid psychotic state in some patients. This biochemical relationship to schizophrenia with heightened dopamine activity would also easily explain the amelioration of acute psychotic activity in our seven patients with neuroleptic agents and their antagonism of this increased dopaminergic outflow state.

Effects of seizure type and waveform abnormality on memory and attention.

Deficits in memory, learning, and attention were examined in a sample of 57 patients admitted for investigation of intractable seizure disorder. The patients were grouped according to seizure type and nature of electroencephalographic abnormality. Patients with complex partial seizures were impaired in comparison with controls. Patients with spike-and-wave abnormalities were more impaired on some tests, while those with slow-wave abnormalities were impaired on other tests. These results suggest that, contrary to previous studies, patients with complex partial seizures have greater deficits than other seizure types in some areas of cognitive function.

Evoked potentials in chronic inflammatory demyelinating polyneuropathy.

Eighteen patients with chronic inflammatory demyelinating polyneuropathy were studied with evoked potentials to assess for evidence of central nervous system demyelination. Both visual and brain-stem auditory evoked responses were obtained, and the results were compared with magnetic resonance imaging (MRI). An evoked potential was abnormal in nine of 18 patients, five of whom had central nervous system evidence of demyelination by MRI. Evoked potentials identified four patients with probable anterior optic pathway involvement that was not demonstrable by MRI. These findings continue to support that chronic inflammatory demyelinating polyneuropathy is associated with a central demyelinating disorder and more importantly emphasize the possibility of a common pathogenic mechanism in central and peripheral nerve demyelination.

Magnetic resonance imaging correlates of dementia in multiple sclerosis.

Thirty-two patients with clinically definite multiple sclerosis were evaluated with neuropsychological procedures and magnetic resonance imaging (MRI). Neuropsychological evaluation included assessment of language, memory, cognition, visuospatial skills, and depression. Significant impairment in any three areas, compatible with diagnosis of a dementia syndrome, was observed in 28% of these patients, and lesser or no cognitive impairment characterized the remaining patients. Magnetic resonance imaging was used to evaluate the number and distribution of lesions as well as the presence of cerebral atrophy and atrophy of specific anatomic structures such as the corpus callosum. Results suggest that neither the number of lesions, the distribution of lesions, nor the extent of generalized cerebral atrophy was significantly greater in demented compared with non-demented patients. The primary finding was that atrophy of the corpus callosum was significantly more extensive on MRI scans in demented patients. Although the callosum itself may not be implicated directly in the pathogenesis of dementia, the presence of callosal atrophy on MRI scans should alert the physician to the possible occurrence of dementia in patients with multiple sclerosis.

Psychogenic status epilepticus in children: psychiatric and other risk factors.

The authors studied six children with repetitive psychogenic seizures severe enough to mimic status epilepticus. All received IV antiepileptic drugs in an emergency setting. Most had a family history of epilepsy. Affective and anxiety disorders predominated as comorbid psychiatric diagnoses. Acutely stressful situations precipitated all episodes of nonepileptic status epilepticus. With aggressive psychotherapeutic intervention and pharmacologic treatment of their underlying psychiatric diagnosis, the patients improved.

Neuropsychiatric aspects of psychogenic status epilepticus.

We studied 20 patients with continuous repetitive psychogenic seizures simulating status epilepticus. Most patients received intravenous doses of multiple anticonvulsants. Our definition used for status epilepticus was that of Delgado-Escueta et al, at least 30 minutes of repetitive seizures without regaining consciousness. Nineteen of 20 patients were young women, all but one under 40 years of age. Sixteen of these patients had a history of childhood seizures. In over 50% of patients, seizures continued until respiratory arrest and intubation occurred. Thorough neuropsychological testing and psychiatric interview were done after cessation of the acute episode. Long-term outcome and prognosis depended on definitive psychiatric diagnosis. Repetitive psychogenic seizures simulating status epilepticus are not uncommon, and such patients may incur serious iatrogenic complications from treatment for status epilepticus. Appropriate management and long-term prognosis may be determined by the type and severity of the underlying psychiatric disorder.

Racial variation in retinopathy of prematurity. The Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVES: To determine and compare the incidence of severe, vision-threatening retinopathy of prematurity (ROP) in black and white low-birth-weight infants. DESIGN: Prospective cohort study. SETTING: Seventy neonatal intensive care units in 23 US participating centers in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity. PATIENTS: A total of 4099 premature infants weighing less than 1251 g at birth were enrolled to evaluate the natural history of ROP. This 'Natural History' cohort included 2158 white infants and 1584 black infants who were followed up prospectively according to a Natural History protocol. MAIN OUTCOME MEASURES: Incidence and severity of acute ROP. RESULTS: While ROP occurred with similar frequency in all racial subgroups, severe ROP was less common in black infants. One hundred sixty (7.4%) of 2158 white infants reached threshold ROP (defined as at least 5 contiguous or 8 cumulative clock-hours of stage 3 retinopathy in zone 1 or zone 2 in the presence of "plus disease" [dilation and tortuosity of the posterior pole blood vessels]), but only 51 (3.2%) of 1584 black infants progressed to threshold ROP. Using multiple logistic regression analysis, race emerged as a highly significant factor (P < .001) in the development of threshold disease, even when birth weight, gestational age status at delivery, sex, multiple births, and transport status were considered. CONCLUSIONS: Severe, vision-threatening ROP occurs with greater frequency in low-birth-weight white infants than in low-birth-weight black infants who are seemingly at equivalent risk. The reason for this disparity is unknown. We speculate that differences in retinal pigmentation may confer relative protection against free radical-mediated phototoxic injury in black infants.

Magnetic resonance imaging and clinical correlations in multiple sclerosis.

We examined the relationship between magnetic resonance imaging (MRI) cerebral findings and clinical evaluations in 66 patients with clinically definite multiple sclerosis (MS). MRI observations included total number and location of lesions visualized, degree of periventricular involvement, degree of degeneration of the corpus callosum, and extent of generalized parenchymal atrophy. Overall physical disability was evaluated by the Kurtzke Expanded Disability Status Scale (EDSS) and individual symptoms were rated according to the Kurtzke Functional Systems (FS) scale. Our results suggest that MRI brain abnormalities are significantly related to the overall severity of disease, but MRI is not particularly useful to predict the presence or absence of individual symptoms. These findings do suggest that the MRI may provide useful information to monitor clinical progression of patients with MS, but the lesions visualized need not always be symptomatic nor are we sure that all symptomatic lesions, particularly in the spinal cord and optic nerves, will be visualized.

Psychogenic seizures after head injury in children.

A total of 148 patients with a history of probable seizure disorder were studied prospectively with long-term video electroencephalography over a 1-year period. Sixteen (11%) were identified with psychogenic seizures. Eleven (69%) of 16 were boys, with a mean age of 10.5 years. Seven (44%) of the 16 had an antecedent history of head injury prior to the development of these episodes; of these patients 85% were boys. Our results suggest that contrary to findings in the adult population, psychogenic seizures can be commonly seen in boys. The prevalence of antecedent head injury suggests that it is a notable risk factor in children as well as adults in the occurrence of psychogenic seizures.

Pediatric migraine prophylaxis with divalproex.

We followed 23 patients with pediatric migraine, ranging in age from 7 to 17 years, who were treated with preventive divalproex sodium for migraine prophylaxis. Patients were evaluated for the presence or absence of comorbid psychiatric disorders or epilepsy to assess the possible differential effects of divalproex therapy. Doses ranged from 3.1 to 32.9 mg/kg/day. Seven patients had comorbid psychiatric disorders, whereas six patients had epilepsy (three rolandic, two generalized, and one indeterminate). Fifteen patients had a greater than 50% reduction in migraine; six patients became headache free. Divalproex doses used were not statistically different among the three groups. A favorable response and headache freedom were more likely in patients with migraine alone or with comorbid epilepsy, and less likely in patients with psychiatric comorbidity. Divalproex was well tolerated, and no significant side effects were reported. No notable changes were noted in behavioral problems, and patients with epilepsy were well controlled. In our cohort of patients, divalproex was most effective in patients with migraine alone or comorbid epilepsy.

Auditory evoked potentials in borderline personality disorder.

Borderline personality disorder is an increasingly recognized condition and frequent management problem in psychiatric and nonpsychiatric practice. Paroxysmal changes in affect and behavior, high incidence of soft neurologic signs and frequent EEG alterations, and evidence of clinical response to antiepileptic drugs have suggested cerebral dysfunction, particularly involving the limbic system or reticular activating system. We recorded early latency brainstem auditory evoked potentials (BAEPs) and long-latency auditory event-related potentials (ERPs) in 20 patients fulfilling DSM-III-R criteria for this disorder. BAEPs were recorded from Cz to ipsilateral and contralateral ear reference, with rarefaction clicks presented at 11.1 per second and 70 dB SL. Two thousand averages were recorded and replicated for each ear, with filter band pass of 150-3000 Hz and 10 ms analysis time. ERPs utilized binaural stimulation with 1000 and 3000 Hz tones in an 80:20 ratio, with interstimulus interval 1.1 second, analysis time 1000 ms, and filter band pass 1-100 Hz. Two hundred averages were recorded and replicated from Cz with linked ear reference. No differences were evident in I-III, III-V, and I-V interpeak latencies between borderline patients and age-matched neurologically and audiologically normal controls. N1, P2, and N2 components of the AEPs were longer in latency and lower in amplitude in borderline patients, while P3 latency was longer and amplitude was attenuated in borderline patients as compared to controls. These findings may suggest differences from normals in attention maintenance and in limbic system function.

Spindle coma in viral encephalitis.

Our patient's EEG evolved from the spindle coma pattern to normality in parallel with his clinical improvement. This clinical and EEG evolution has been described previously, and emphasizes the heterogeneity of the spindle pattern. The initial focal asymmetry implied focal cerebral abnormality, and was one of the clinical findings favoring HSV encephalitis in the absence of radiologic or pathologic support. The ability of partially-damaged cerebral cortex to express spindle activity is well-described with various cerebral lesions, as is the spindle coma pattern after intoxication. We are not aware of a previous report with HSV or other encephalitis, but an infectious etiology could be suspected in two patients of Hansotia et al. and is conceivable in the three comatose patients of Britt in whom no diagnosis could be established. In such cases, the pathophysiology of the spindle coma pattern is likely to involve an aberrant cortical response to normal reticular formation input and thalamic spindle pacemakers.

EEG frequency analysis in conversion and somatoform disorder.

Patients with "hysterical" neurologic symptoms have long puzzled neurologists and psychiatrists. "Hysteria" has recently been subdivided into conversion and somatoform disorder. We applied computerized EEG frequency analysis to 10 patients with diagnosed conversion disorder, 10 somatoform disorder patients, and 10 control subjects. One minute EEG samples composed of 4 sec epochs were recorded from left frontal (F7-C3), right frontal (F8-C4), left posterior (T5-01) and right posterior (T6-02) derivations. Spectral power was calculated for 4 bands (0.25-4HZ, 4.25-8Hz, 8.25-13Hz, and 13.25-30Hz), and for the full frequency range. Low (0.25-8Hz) and high (8.25-30Hz) frequency bands were compared to determine high/low power ratios on the left and right (PHLL) and (PHLR), ratios of left/right front (PLRF) and posterior (PLRP) power, mean alpha frequency deviation frontally (FLRF) and posteriorly (FLRP), and mobility of left and right frontal power (MOLF and MORF). No significant differences were found between conversion disorder patients and controls in PHLL, PHLR, PLRP, and MORF. PLRF, FLRF and MOLF differed significantly between patients and controls. Power and frequency ratios of right frontal mobilities suggested a decrease in high frequency power, reduction in mean alpha frequency, and lower predominant frequency in the right frontal area in somatoform disorder patients as compared to controls, but significance was not reached. Somatoform and conversion disorder patients differed significantly in these spectral measures. These observations suggest that the two "hysterical" disorders may have distinct pathophysiology, and may be due to eventually identifiable cerebral dysfunction in some cases.

Sleep and waking disturbances in epilepsy.

We compared sleep parameters during three-hour postprandial nap recordings in 10 normal controls and 28 seizure patients. Patients had significantly less sleep, longer sleep latency, more wakefulness, less drowsiness and lighter nonREM sleep, and lower sleep efficiency than controls. Generalized seizure patients had longer sleep latency, more arousals, and more (but very little) stage III sleep. Those with partial seizures had more stage II sleep and greater sleep efficiency. Patients on polypharmacy and phenobarbital therapy slept more, phenytoin patients had very short sleep latency but more wakefulness and less sleep efficiency; those taking clonazepam were also awake more and had lower sleep efficiency, while arousals during sleep were more frequent in patients on valproate and carbamazepine. The findings suggest that disturbed sleep, possibly related to aberrant arousal occasioned by generalized epilepsy or epileptogenic foci, is common in seizure patients, and may be related to interictal behavioral and cognitive symptoms. Polypharmacy may have an additive effect on sleep to prolong and disrupt it, while sedative anti-epileptic drugs may increase sleep and other anti-epileptic medications may have alerting effects or interfere with falling asleep. Generalized and partial seizure patients may have sleep disturbances of a different character, possibly reflecting generally altered cerebral excitability by afferent stimuli in the former situation, and the more localized effects of limbic or cortical hyperactivity in the latter.

Auditory evoked potentials in vertebrobasilar transient ischemic attacks.

Brainstem auditory evoked potentials (BAEPs) are affected by stroke or migraine in the vertebrobasilar arterial system. Some studies have reported BAEP changes in vertebrobasilar transient ischemic attacks (TIAs), but others have shown no alterations. We recorded BAEPs in 35 patients with TIAs in the vertebrobasilar system who did not have a stroke, other neurologic disease or significant hearing loss. Thirty patients were recorded after resolution of symptoms, while five individuals still had some resolving signs or symptoms. TIA patients as a group had longer interpeak latencies, but I-III, III-V, and I-V latencies were not significantly longer than in controls. Wave V was significantly longer in latency and lower in amplitude in TIA patients, however. The patients whose TIAs had resolved at absolute and interpeak latencies were within normal limits, but three of five had interpeak latencies at or above three standard deviations beyond the normal mean in the still symptomatic group. One of these was later tested and found to be within normal limits. BAEPs after subsidence of symptoms may add little to the evaluation of vertebrobasilar ischemia, but further AEP analysis may show more definitive differences of diagnostic use. The occasional BAEP abnormality during the resolving transient ischemia supports the recently suggested continuum between ischemia and infarction in the vertebrobasilar territory.

Auditory evoked potentials in narcolepsy and sleep terrors.

Dysfunction of brainstem reticular activating centers has been suggested in some sleep disorders, including narcolepsy and sleep terrors. Previous studies have suggested normal brainstem auditory evoked potentials (BAEPs) in narcolepsy and enhancement of long-latency auditory event-related potentials (ERPs) in sleep deprivation and conditions of pathological somnolence. Sleep terrors have not to date been studied neurophysiologically. We recorded early latency BAEPs and long-latency auditory ERPs in 8 patients with narcolepsy and 5 individuals with sleep terrors, and compared them to 10 normal controls. Narcolepsy patients and controls did not differ significantly in absolute or interpeak latency of BAEPs. Sleep terror patients had significant prolongation relative to controls of III-V and I-V interpeak latencies. The N1, N2, and P3 AEP components were prolonged in latency in narcoleptic patients as compared to controls, while sleep terror patients did not differ from controls. No significant differences in amplitude were found. These findings suggest that a disturbance of integration of brainstem centers subserving wakefulness and sleep may play a role in the disordered arousal of sleep terrors, but suggest no specific abnormality in brainstem function in narcolepsy. The AEP changes in narcolepsy may be a manifestation of pathological sleepiness.

Brainstem auditory evoked responses in partial and generalized seizures.

This study presents clinical neurophysiologic evidence of altered upper brainstem function in patients with generalized epilepsy who do not otherwise differ clinically from the general population. While the differences in absolute latencies are not great enough to support the use of BAERs in routine evaluation, this data does support experimental studies implicating brainstem structures in the pathophysiology of primary generalized epilepsy. The lack of evidence of brainstem involvement in complex partial seizures may suggest a mechanism of seizure spread that is not dependent upon primary brainstem pathology, or may indicate that any brainstem abnormality in epilepsy may involve areas not mediating transmission of auditory stimuli and therefore not assessed by BAERs.

Outpatient sleep recording during antiepileptic drug monotherapy.

The effects of sleep and sleep deprivation on epilepsy are well known, but the effects of seizures and antiepileptic drugs (AEDs) on sleep have been less well studied. We recorded nocturnal sleep in 17 patients receiving antiepileptic monotherapy with ambulatory cassette EEG devices. Twelve patients had complex partial seizures and five had tonic-clonic convulsions. Two patients' seizures were largely nocturnal, and no seizures occurred during sleep recording. Five patients each were taking phenytoin (PHT), carbamazepine (CBZ), and valproate (VPA), and two were taking clonazepam (CZP), all with therapeutic serum levels and no toxic symptoms. Total sleep time was reduced, wakefulness increased, and sleep latency prolonged in partial seizures as compared with generalized epilepsy. REM sleep was reduced and its latency decreased in partial seizure patients. Both groups had decreased slow wave sleep; that of partial seizure patients was decreased more markedly. PHT increased sleep latency and decreased sleep time, and CBZ increased awakening and diminished slow wave and REM sleep. Patients taking VPA had slight reduction in slow wave sleep; those taking CPZ had decreased sleep and REM latencies. Epilepsy may affect nocturnal sleep, and the effects of partial and generalized seizure disorders may be different. AEDs may also have differential effects on nighttime sleep. These may prove important in the long-term management of epileptic patients.

Sleep spindles in epilepsy.

Spindles are a ubiquitous phenomenon in sleep, but their physiology and the effects of neurologic disorder on their frequency and amplitude are incompletely understood. We compared the incidence of three commonly defined spindle types (14-15 Hz, 12-13 Hz, and 10 Hz) and the frequency and amplitude of spindles during Stage II sleep in 50 patients with complex partial, partial and secondarily generalized, and primary generalized seizures, with and without interictal behavioral symptoms. All patients had 12-13 Hz and 14-15 Hz spindles of symmetric character in C3-A1 and C4-A2 derivations during prolonged sleep-deprived EEG recordings, which were normal except for partial or generalized epileptiform activity. Seventy-one per cent of complex partial seizure patients had 10 Hz spindles, and they occurred in 50% of the other two groups, predominating among those with interictal behavioral symptoms in all groups. Spindle frequency was significantly less in patients with generalized epilepsy than with partial seizures, and patients with complex partial seizures and partial seizures with secondary generalization differed significantly in spindle frequency. Spindle frequency was significantly lower with polypharmacy than with monotherapy. Patients whose regimens included phenobarbital had significantly lower spindle frequencies and spindle frequencies differed significantly between phenytoin and carbamazepine. Differences in spindle frequency may be due to residual medication effects, underlying encephalopathy or physiological differences between partial and generalized epilepsy.