Asymptomatic HIV infection does not cause EEG abnormalities: results from the Multicenter AIDS Cohort Study (MACS)

We conducted EEG testing in 200 asymptomatic homosexual men, half of whom were HIV seropositive. We chose to include half of the subjects because they were rated as impaired on a neuropsychological screening test. We used both traditional visual EEG interpretation and quantitative EEG analysis. Abnormal EEGs and borderline degrees of EEG slowing occurred in 32% of these men. These EEG changes were not related to HIV serostatus. EEG changes did correlate with the impaired neuropsychological test performance. Clinicians faced with abnormal EEG results or borderline EEG slowing in an asymptomatic HIV-seropositive patient should not attribute the EEG change to effects of the serostatus itself but should look for other causes.

A cellist with arm pain: thermal asymmetry in scalenus anticus syndrome.

We report on a cellist with pain and coldness of the upper extremity. Abnormal thermographic studies were instrumental in uncovering intermittent compression of the subclavian artery, and this prompted us to study the effects of cello playing on skin temperature asymmetry. Temperature asymmetry was defined as the temperature difference (delta-T) from one hand to the other. In 57 controls, mean delta-T at rest was .309 +/- .254C. Exercising the upper extremities by prolonged elbow flexion or by movements mimicking cello playing in controls did not significantly affect delta-T. In our patient, delta-T was ten times control (3.6C). Angiography showed extrinsic compression of the subclavian artery occurring only after cello playing; sympathetic ganglion block relieved the pain. Our patient's abnormal skin temperature may have reflected sympathetic vasomotor hyperactivity. Intermittent neurovascular compression and sympathetic hyperactivity appear to be factors in scalenus anticus syndrome.

The pedunculopontine nucleus in Parkinson's disease.

This study demonstrated a significant loss of neurons within the lateral part of the pedunculopontine nucleus pars compacta in individuals with idiopathic Parkinson's disease and in individuals with combined Parkinson's and Alzheimer's disease. We also examined the extent of neuronal loss within the substantia nigra pars compacta, locus ceruleus, dorsal raphe nucleus, and nucleus basalis of Meynert. The number of pedunculopontine nucleus pars compacta neurons in the patients with Parkinson's or Parkinson's and Alzheimer's disease was reduced (average, 40%) in comparison with the number in control subjects or patients with Alzheimer's disease (p less than 0.01). This finding correlated significantly with the extent of loss of substantia nigra pars compacta neurons (p less than 0.01).

Microphysiological recordings at CT gantry site during stereotactic thalamotomy.

Neural unit recording was performed during CT-guided stereotactic thalamotomy in 2 patients referred for severe cerebellar ataxia and dysmetric movements. Periodic CT scanning was performed during the recording in order to verify probe location and trajectory. Our experience with electrophysiological recordings at the CT gantry site demonstrates the feasibility of acquiring satisfactory neural unit recordings in spite of the high-voltage environment.

Quantification of thermal asymmetry. Part 2: Application in low-back pain and sciatica.

Temperature differences between the lower extremities were measured using a computerized thermometric scanning system in order to compare the degree of thermal asymmetry in 144 patients with low-back pain. The patients displayed highly significant thermal asymmetries, with the involved limb being cooler (p less than 0.001). When asymmetries exceeded 1 standard deviation from the mean temperature of homologous regions measured in 90 normal control subjects, the positive predictive value of thermometry in detecting root impingement was 94.7% and the specificity was 87.5%. These values indicate that calculation of temperature asymmetry is particularly effective in evaluating reported pain in psychosocially affected patient populations in whom the chance of positive myelography or impaired root function is low. In this group of patients, thermometric study provides physicians with important information for proper decision making. The test can be performed to avoid more invasive and probably less revealing diagnostic or exploratory surgical procedures.

Quantification of thermal asymmetry. Part 1: Normal values and reproducibility.

The use of thermography in evaluating nerve injury is based on the presence of temperature asymmetries between the involved area of innervation and the corresponding area on the opposite side of the body. However, interpretation of the thermographic image has been troubled by subjectivity. This paper describes a computer-calculated method of collecting data that eliminates subjective biases. Comprehensive normative data are presented on the degree of thermal asymmetry in the human body. The degree of thermal asymmetry between opposite sides of the body (delta T) is very small. For example, the value of delta T for the forehead (mean +/- standard deviation) was 0.18 degree +/- 0.18 degree C, for the leg it was 0.27 degree +/- 0.2 degree C, and for the foot it was 0.38 degree +/- 0.31 degree C. These values were reproducible in both short- and long-term follow-up measurements over a period of 5 years. The delta T's reported here were obtained from 40 matched regions of the body surface of 90 asymptomatic normal individuals. These values can be used as a standard in assessment of sympathetic nerve function, and the degree of asymmetry is a quantifiable indicator of dysfunction.

Pathology in brainstem regions of individuals with primary dystonia.

Examination of brains from four individuals with the clinical diagnosis of primary dystonia revealed histopathologic abnormalities in two cases. A 29-year-old man with a 15-year history of dystonia musculorum deformans (DMD) had numerous neurofibrillary tangles (NFT) and mild neuronal loss within the locus ceruleus; occasional NFT were also recognized in the substantia nigra pars compacta, pedunculopontine nucleus, and dorsal raphe nucleus. A 68-year-old man with a 35-year history of Meige syndrome had moderate-to-severe neuronal loss in several brainstem nuclei, including the substantia nigra pars compacta, locus ceruleus, raphe nuclei, and pedunculopontine nucleus. Infrequent NFT were also noted in substantia nigra. An examination of these and other brain regions in a 10-year-old boy with a 6-year history of DMD and a 50-year-old woman with a 3-year history of spasmodic torticollis did not disclose similar abnormalities.

Loss of pedunculopontine neurons in progressive supranuclear palsy.

In the present study, the number of neurons (greater than 20 microns in diameter) within the lateral part of the pedunculopontine nucleus pars compacta (PPNc) was determined at six rostrocaudal levels in 3 subjects with progressive supranuclear palsy (PSP), in 9 subjects with Alzheimer's disease, and in 6 age-matched control subjects. At each level examined, significantly fewer neurons were present in patients with PSP than in control subjects (49 to 69% reduction). Significant differences in numbers of neurons were not demonstrated between control subjects and patients with Alzheimer's disease. The extent of pathological changes, particularly neurofibrillary tangles, was examined within the PPNc of subjects in these three groups. The average number of neurofibrillary tangles in a 12-microns-thick midlevel section of the lateral PPNc was 68.7 in subjects with PSP, 18.3 in those with Alzheimer's disease, and 3.0 in aged control subjects. These abnormalities of PPNc neurons in PSP may play important roles in some of the clinical features characteristic of this disease.

Magnetic resonance planned thalamotomy followed by X-ray/CT-guided thalamotomy.

Magnetic resonance imaging (MRI) is currently the optimal neuroradiologic technique for visualizing the anterior and posterior commissure for defining the AC-PC line. CT is the optimal technique for electrode and probe guidance during stereotactic thalamotomy. Various possibilities of transferring or overlying MRI and CT are outlined which in some future might result in more refined methods of CT-MRI guidance for stereotactic surgery.

Anorexia and altered serotonin metabolism in a patient with argininosuccinic aciduria.

We studied serotonin metabolism in a metabolically stable 7-year-old girl with argininosuccinic aciduria who had severe anorexia. The CSF concentration of 5-hydroxyindoleacetic acid (HIAA), the metabolite of serotonin, was markedly elevated at 79 ng/ml (normal 33 +/- 11 ng/ml). Altered serotonin metabolism was also reflected in the sleep EEG, which showed decreased REM sleep. Reducing her intake of tryptophan, the precursor of serotonin, from 35 mg/kg/day to 7 mg/kg/day resulted in a decrease in CSF concentration of HIAA to 20 ng/ml and the onset of spontaneous eating for the first time in 4 1/2 years. REM sleep increased from 3% to 9.5% of total sleep time. Two days after increasing tryptophan intake to 25 mg/kg/day, spontaneous feeding stopped, associated with a rise in CSF HIAA to 45 ng/ml. Caloric/carbohydrate intake was found to affect CSF HIAA levels and food intake in an additive manner with tryptophan intake. These observations suggest that altered serotonin metabolism affected feeding behavior in this child, and that this effect could be modified by changing tryptophan or carbohydrate intake.

Behavioral covariation in the treatment of chronic pain.

The successful use of operant procedures to alter behaviors associated with various medical conditions suggests that such behaviors may be learned and that the principles of learning may be applied not only to treatment but also to the study of the pathogenesis of illness behavior. The present study, conducted within an ongoing neuromuscular research project, assessed the covariation of behaviors associated with chronic pain within and across behavioral and drug approaches to treatment. Problems of screaming and five other behaviors (including self-reports of pain) were measured across conditions of varying behavioral contingencies (noncontingent reinforcement vs the removal of reinforcement contingent upon screaming) and varying administration (time since medication and dosage) of Parsidol during attempts to treat the muscle pain of a 24-year-old male with a severe, chronic neuromuscular disorder diagnosed as dystonia musculorum deformans (DMD). Results indicated that: (a) pain behaviors covaried during behavioral and drug conditions even though the behavioral intervention only targeted screaming; (b) effects were greater on nontargeted behaviors during periods that followed rather than preceded drug administration; (c) in contrast to behavioral observation data, physiological measures of neuromuscular activity (EMG) did not differ across conditions. These results suggest that functional response-response relationships exist in patients as the result of their illness experience.

Sleep spindles.

Sleep spindles are discussed from various viewpoints. The definition of this pattern has been debated and requires clarification. There is evidence of two spindle types around 14 c/s and 12 c/s. The existence of a third spindle type (around 10 c/s) is controversial. The relationship of spindles to vertex waves and K complexes and the role of spindles in sleep staging are other topics that are covered. As "transient nonstationarities," spindles may escape methods of EEG computer analysis; special methods of spindle detection have been designed. Spindle activity may be influenced by various sedative drugs. An exceptional coexistence of spindles and waking patterns may occur in patients with 5-HIAA-hypersomnia. Sleep spindles change with age and show a typical configuration in early childhood; their decline in old age is also discussed. In monkeys and apes, "natural" spindle activity declines after adolescence. The distinction between natural and experimentally induced (barbiturate) spindles in animals must be stressed. After a discussion of spindle anomalies in neurological diseases, depth EEG data are presented. Spindles are found in the frontal cortex, whereas the scalp EEG indicates light drowsiness or even wakefulness. Attempts are made at an integrated view of these findings. A "shock-absorbing" function is attributed to spindles.

Polysomnography of torsion dystonia.

Nocturnal EEG, electro-oculograms, and electromyograms were studied in nine patients with dystonia musculorum deformans and in nine healthy controls. Electrodes were placed over frontal, central, and occipital regions in accordance with the international 10-20 system of electrode placement. A standard bipolar montage was used for the recordings, and records were scored independently in accordance with the manual of Rechtschaffen and Kales. All patients were found to sleep poorly. Patients in advanced stages of dystonia all displayed an EEG pattern characterized by pronounced, high-amplitude (greater than 150 microV) spindles that were continuous for all stage 2 and portions of stage 3 sleep. Other sleep parameters were also disturbed. Sleep spindles become less frequent and diminish in amplitude with advancing age. The spindle activity of patients with advanced dystonia presents a stark contrast to this pattern and may underscore their clinical significance.

Case report: polysomnographic effects of thalamotomy for torsion dystonia.

We report a patient with torsion dystonia whose polysomnographic recordings revealed poor sleep and a pronounced and almost continuous type of spindle activity during non-rapid eye movement sleep. Rapid eye movement sleep was also reduced. These changes proved to be independent of medications. After a clinically successful unilateral thalamic operation, a normalization of sleep parameters and a reduction of the high amplitude sleep spindles was observed, implying that the regulation of sleep spindles and the advancement of dystonic symptoms are affected by a common mechanism.

Polysomnographic findings in dystonia musculorum deformans.

Twenty-five cases from the literature and four personal cases with dystonia musculorum deformans are described. The polysomnographic EEG findings of severely involved patients were characterized by over abundance of stage 2 sleep, with a characteristic pattern of spindle activity, increased latency to sleep, and reduced sleep efficiency. The similarities between these patients may underscore the importance of sleep spindles as a feature of the dystonia process and may be useful in the investigation of other basal ganglia disorders.

Bell palsy: muscle reeducation by electromyograph feedback.

The present case study investigated the efficacy of feedback in restoring muscle control to facial muscles which had been affected by Bell palsy. The subject, a woman, was provided an analog tone as feedback for modifying the muscle activity on the paralyzed (right) side of her face to match that of her nonaffected (left) side. The results showed a statistically significant shift in muscle activity in masseter, zygomaticus, and orbicularis oculi muscles. Post-treatment levels closely approximated the nonaffected side, and resulted in more normal facial characteristics with respect to jaw position and symmetry of smiling. Bidirectional control of the zygomaticus was also demonstrated.