Myoclonic seizures with lithium.

Myoclonus has been infrequently observed in patients receiving lithium therapy, and associated electroencephalographic (EEG) changes have not been well described. We report two women, ages 35 and 48, who, after the initiation of lithium carbonate therapy, had several generalized tonic-clonic seizures followed by myoclonic seizures. In both, myoclonus was associated with repetitive sharp waves on the EEG. Although the epileptogenicity of lithium remains controversial, the occurrence of myoclonic seizures associated with lithium treatment suggests a proconvulsant effect of lithium in susceptible individuals.

Topographic maps of brain electrical activity--pitfalls and precautions.

Topographic mapping of brain electrical activity is a popular, powerful, and potentially misleading technique. The map lies at the end of a long chain of physiological, technical, electronic, and mathematical processes and is vulnerable to artifact, error, and distortion at many points. Close attention must be paid to data collection parameters, subject cooperation, minimization of artifact, limitations of resolutions, selection, and transformation of parameters for display, and map generation strategy to yield an accurate, physiologically interpretable map. Review of the data at each step of analysis, from the paper electroencephalogram (EEG) to sets of maps on video display, may be necessary for optimum understanding. Development of more sophisticated qualitative and quantitative concepts of "normal" physiology is needed. These improvements in electrophysiological data analysis demand, rather than obviate, sophistication on the part of the user.

Age at initial onset of depression and waking EEG variables in the elderly.

Depressive illness with initial onset after age 60 has different clinical and prognostic features compared to depression beginning at a younger age. We evaluated waking electroencephalograms (EEGs) in 61 elderly depressed patients (32 early onset, 29 late onset) without cognitive impairment and not receiving psychotropic medications. The groups were comparable for age, severity of Hamilton depression score, education, and Folstein Mini-Mental State scores. Conventional visual EEG analysis revealed no significant differences in the mean alpha rhythm, incidence of abnormal records, or types of EEG abnormalities. Computerized spectral EEG analysis was also performed in 48 patients (23 early onset, 25 late onset). There were no significant differences in the pooled parasagittal mean frequency, theta--beta difference, combined delta and theta percentage, or relative power of the frequency bands. Thus, waking EEGs do not differentiate between elderly patients with the initial onset of the depression before or after age 60.

Changes in EEG mean frequency associated with anxiety and with amphetamine challenge in BPD.

Recent authors have hypothesized that cerebral dysfunction, as reflected in an abnormal EEG, may play an important role in the behavioral symptoms of patients with borderline personality disorder (BPD). Spectral analysis and amphetamine challenge testing are two promising methods for probing the clinical symptomatology of this disorder. In this study, we evaluated the relationship between clinical symptoms and computerized EEG spectral analysis in BPD patients both before and after amphetamine challenge. We found that mean frequency values on spectral analysis consistently correlated with anxiety levels in our patients, but did not correlate with a wide variety of other important symptoms, such as depression or transient psychosis. This result, coupled with our previous negative findings concerning EEG abnormalities in patients with BPD, casts doubt on the etiological relationship of cerebral dysrhythmias to the behavioral pathology of this disorder, but raises interesting questions concerning the relationship of anxiety and mean frequency.

Delirium in liver transplantation candidates: discriminant analysis of multiple test variables.

We report the results of electroencephalograms, Mini-Mental State exam, Trailmaking Tests A and B, and serum albumin levels in 108 consecutive liver transplantation candidates. We compared test results to a clinical DSM-III diagnosis of delirium. Although each variable could differentiate between the two groups (delirium n = 18; nondelirium n = 90) at a statistically significant level, a discriminant analysis involving either all variables or only three particular variables (Trailmaking B, EEG code, and albumin) resulted in the highest specificity (97.8%) and sensitivity (83.3%), with a correct classification of 95.4% of subjects. The analysis also generates an equation that can be applied to clinical situations to enhance the accurate recognition of delirium. In addition, to explain abnormal Trailmaking B scores and/or EEGs in subjects who did not otherwise meet DSM-III criteria for delirium, we suggest the presence of a "subclinical delirium."

Late EEG findings and clinical status after organic mercury poisoning.

The EEGs of four siblings with organic mercury poisoning were recorded. The series of EEGs spanned two to eight years. Additional EEGs were obtained from an asymptomatic family member (the mother) who initially had elevated mercury levels. Various types of abnormalities were noted in the tracings of the siblings, including epileptiform features and disturbances of background rhythms. The mother's EEGs were normal. The degree of EEG change reflected the clinical state. In the two cases in which seizures were present, epileptiform activity was seen. Both clinical severity and EEG abnormalities may correlate with age.

Drawing-induced seizures.

In a review of the literature on triggering mechanisms in reflex epilepsy, we found no reported instance of drawing as the provoking factor. Recently we studied the case of a 17-year-old man with myoclonic seizures. These seizures were most effectively triggered by drawing, although occasionally they occurred spontaneously and could also be evoked by other activities requiring concentration. The results of a neurological examination were normal, and family history was unremarkable. Treatment with primidone and methsuximide has been very effective.

Correlation of EEG, computerized tomography, and clinical findings. Study of 100 patients with focal delta activity.

One hundred consecutive patients with continuous, focal, polymorphic delta activity on EEG who were also studied by computerized cranial tomography (CT) were reviewed. Sixty-eight percent showed focal structural lesions on CT, with stroke being the most frequent etiologic factor. Tumors occurred less often and trauma more frequently than in previous studies. Convulsions were the most frequent cause of focal delta activity with a normal scan.

Bilateral independent periodic lateralized epileptiform discharges. Clinical significance.

Clinical data on 18 patients whose EEGs showed bilateral independent periodic lateralized epileptiform discharges (BIPLEDs) were reviewed and compared with those of 45 patients with periodic lateralized epileptiform discharges (PLEDs). A recent stroke was the most frequent cause of PLEDs (33%), while anoxic encephalopathy (28%) and CNS infection (28%) accounted for the majority of BIPLEDs. Focal neurologic deficits, focal seizures, and focal computed tomographic scan abnormalities were frequent in those with PLEDs, while coma predominated in the group with BIPLEDs (72% vs 24%). Mortality was also higher in patients with BIPLEDs--61% vs 29%.

Electroencephalographic correlates of increased platelet membrane fluidity in Alzheimer's disease.

Increased platelet membrane fluidity is a stable, familial characteristic that describes a clinically distinct subgroup of patients with Alzheimer's disease. In the current study, electroencephalograms (EEGs) from 49 patients with probable Alzheimer's disease were subjected to visual and computerized spectral analysis. Only three (14.3%) of 21 patients in the subgroup with increased platelet membrane fluidity exhibited focal EEG abnormalities, while 12 (42.9%) of 28 of the residual subgroup exhibited focal EEG findings, a threefold difference. This difference in EEG profile provides further validation of these two subgroups and suggests that the subgroup with increased fluidity is less heterogeneous than the residual group.

Midline spikes. EEG and clinical features.

Clinical features of 40 patients with midline spikes on EEG were compared with those of age- and sex-matched controls. Seizure incidence was significantly greater in the study group than in the controls (85% v 45%). Tonic-clonic seizures were the most frequent type. Eighteen patients from the study group had additional focal or generalized epileptiform abnormalities. This subgroup had a significantly greater incidence of seizures than patients with only midline spikes (100% v 73%). Midline spikes are more common in children and markedly activated with sleep. They must be distinguished from normal sleep transients.

Chorea: a late complication of a subdural hematoma.

Subdural hematoma has rarely been implicated as a cause of chorea. We describe a case of chorea occurring several months after evacuation of a traumatic subdural hematoma. No other causes of chorea were found. In this case and one previously reported case, signs of tentorial herniation were present prior to surgery. Herniation may damage the basal ganglia, with resultant chorea.

Electroencephalographic evaluation in Sturge-Weber syndrome.

The most consistent electroencephalographic finding in 16 cases of Sturge-Weber syndrome was a unilateral reduction of background amplitude in the waking record. Comparable asymmetries were noted in those patients in whom sleep recording also was done. Physiologic responses (to hyperventilation and photic driving) usually were decreased on the involved side. These hemispheric electroencephalographic abnormalities are detectable in infancy even before the characteristic intracranial calification develops. Epileptiform activity, when focal, was limited to the involved hemisphere.

Myoclonic status epilepticus: a clinical and electroencephalographic study.

We reviewed the clinical features and ictal EEGs in 23 adults with myoclonic status epilepticus (MSE). Anoxic encephalopathy was the most common cause of MSE, occurring in 15 patients; 8 developed MSE within 14 hours following the anoxic insult. Metabolic encephalopathies were present in 4 patients, while 2 had degenerative CNS disorders. In 2 patients with generalized epilepsy, MSE developed during a medication change. Five types of EEG patterns were associated with MSE. Generalized periodic complexes (usually spikes, polyspikes, or sharp waves), often with attenuation of background activity between complexes (11 patients) or a burst-suppression pattern (4 patients), were the most common types. Outcome was poor: 20 patients died without regaining consciousness, while 1 remains in a vegetative state. The 2 patients with generalized epilepsy, both of whom were conscious during MSE, survived without sequelae.

Positive occipital sharp transients of sleep in the blind.

Positive occipital sharp transients of sleep (POSTS) were evaluated in 23 legally blind subjects. Only those subjects with severe visual field defects but normal or near normal visual acuity showed this activity. Nineteen subjects with visual acuity of 20/200 or worse failed to exhibit these potentials, while a control group matched for age showed POST in 79 percent of cases. The production of POSTS appears to depend on the integrity of macular function and normal central visual acuity.

Seizures after liver transplantation: a clinicopathologic study.

We reviewed the clinical and neuropathologic findings in 21 patients who had seizures after orthotopic liver transplants. Tonic-clonic seizures were the most common seizure type. Six patients developed status epilepticus. In 9 patients, seizures occurred within 1 week following transplantation. We found CNS lesions that were probably responsible for the occurrence of seizures in most patients; some had more than 1 finding. Neuropathologic examination revealed ischemic or hemorrhagic strokes in 18 patients, central pontine myelinolysis in 5, and CNS infections in 5. Multiple metabolic abnormalities were a contributing factor to the onset of seizures in some patients.

EEG spectral abnormalities and psychosis as predictors of cognitive and functional decline in probable Alzheimer's disease.

We examined whether either psychotic features (e.g., delusions and hallucinations) or EEG abnormalities are associated with more rapid progression of Alzheimer's disease (AD). AD patients with psychosis have exhibited more EEG abnormalities than those without psychosis, and both abnormal EEG and psychosis have been noted to be predictors of functional and cognitive decline in AD. Ninety-five probable AD patients participating in a longitudinal study of dementia had an EEG and a semistructured psychiatric interview at baseline. Using EEG spectral analysis, we classified records as normal/abnormal based on the parasagittal mean frequency. Patients with abnormal EEGs were more functionally (e.g., Blessed Rating Scale for activities of daily living) and cognitively (e.g., Mini-Mental State) impaired than patients with normal EEG. AD patients with psychosis were only more functionally impaired than patients without psychosis. A two-factor analysis showed no interaction between abnormal EEG and psychosis. In addition, using a Cox proportional hazard model adjusted for age and education, the presence of an abnormal EEG or psychotic symptom at study entry was associated with higher risk of reaching severe cognitive and functional impairment during follow-up. Neither abnormal EEG nor the presence of psychosis predicted death. These results indicate that both abnormal EEG and psychosis are independent predictors of disease progression but not of physical survival.

Alzheimer's disease with delusions and hallucinations: neuropsychological and electroencephalographic correlates.

We longitudinally evaluated the neuropsychological functions, rate of progression, and waking EEG findings in 17 patients with probable Alzheimer's disease (AD) with delusions and hallucinations, and compared them with those of matched AD patients without delusions and hallucinations. AD patients with delusions and hallucinations had a more rapid rate of decline, as measured by the Mini-Mental State Examination, a specific defect in receptive language, and a greater frequency of aggression and hostility. Visual EEG analysis showed that these patients had a significantly greater proportion of moderately abnormal EEGs, and spectral analysis confirmed the increased amount of delta and theta activity. These data demonstrate that AD patients with delusions and hallucinations have a greater degree of cerebral dysfunction and a relatively focal neuropsychological defect, which may indicate a localized pathologic abnormality.

Holmes, Watson and neurology.

Numerous neurological problems appear in the Sherlock Holmes stories. These include dementia, delirium, seizures, toxic-metabolic encephalopathies, syncope, movement disorders, cerebrovascular disease, and alocholism. Several problems of a neuropsychiatric nature, such as malingering and brain fever, are also reviewed. In addition, Holmes' knowledge of electroencephalography is revealed.

Electroencephalography in syncope.

Electroencephalographic (EEG) findings in syncope are reviewed. There are four major categories of syncope: neurally mediated (neurocardiogenic), neurologic, decreased cardiac output, and orthostatic hypotension. However, regardless of cause, whether the syncope is due to a vasovagal effect, a cardiac arrhythmia, an epileptic seizure, or hypotension, EEG findings are similar and reflect cerebral hypoperfusion. Initially there may be a slowing of background rhythms. This is followed by high amplitude delta activity, maximal anteriorly. If the hypoperfusion persists there is subsequent flattening of the EEG. The EEG returns to normal in the reverse sequence. In cases with severe and prolonged ischemia, convulsive syncope may occur at the time of the EEG flattening. Although not an epileptic phenomena, clinically this is often mistaken for epilepsy. Conversely, epileptic disorders, such as the ictal bradycardia syndrome, may occasionally mimic syncope. Therefore, in patients in whom EEGs are performed for the evaluation of an episode of loss of consciousness, simultaneous ECG should be used.