Menstruation-related periodic hypersomnia: a case study with successful treatment.

A 16-year-old girl suffered from 1 to 2-week periods of hypersomnia associated with each menstruation. Serum hormone levels were normal. CSF concentrations of homovanillic acid and 5-hydroxyindolacetic acid were lower in hypersomniac than in symptom-free phases. 3-methoxy-4-hydroxyphenylethylene glycol was not affected. The sleep periods occurred only in connection with ovulatory menstrual cycles. When ovulation was inhibited by a combination of ethinylestradiol and lynestrenol, an oral contraceptive pill, the hypersomnia ceased. Thus, the hypersomnia seemed to be linked to the occurrence of ovulatory menstruations.

PIP: A 16-year old girl who had undergone normal pubertal development at 13 years 8 months began to menstruate with moderate or severe dysmenorrhea and 1 to 2 weeks of hypersomnia at 16 years 2 months. She was without symptoms between hypersomniac phases. The patient was followed for 3 years, in the hospital for 31 days and as an outpatient thereafter. Examination, including neurologic and gynecologic status, was normal. Serum levels of follicle stimulating hormone, luteinizing hormone, estradiol, and progesterone were normal. CSF concentrations of homovanillic acid and 5-hydroxyindolacetic acid were lower in her hypersomniac than in symptom-free phases. 3-methoxy-4-hydroxyphenylethylene glycol was not affected. The sleep periods occurred only in connection with ovulatory menstrual cycles. Inhibition of ovulation with the oral contraceptive pill Lyndiol, which contains a combination of 50 mcg ethinyl estradiol and 2.5 mg lynestrenol, led to a cessation of the hypersomnia. When treatment was discontinued, the patient had 2 cycles without ovulation and no sleep periods, but ovulation and periodic hypersomnia occurred regularly thereafter. Reinstitution of the contraceptive pill controlled the symptoms. Discontinuation of the treatment was tested 2 more times for 3 months each, and the ovulatory cycles were again accompanied by sleep periods.

Pattern-reversal electroretinograms in unilateral glaucoma.

Pattern-reversal and flash electroretinograms (ERG) and oscillatory potentials (OP) were recorded from 11 patients with unilateral glaucoma. All glaucomatous eyes had reduced amplitudes both compared to the opposite eye in the same patient and to reference values. In 10 of the 11 cases this reduction was below the level of normal variation. The difference in pattern-reversal ERG amplitude means from glaucomatous and opposite eyes was statistically significant. No differences were observed in flash ERGs or OPs. The histopathologic correlate to the visual field defects in glaucoma is retinal ganglion cell degeneration. The present electrophysiologic findings support the view, based on results from animal experiments, that the pattern-reversal ERG reflects ganglion cell activity.

Preliminary report: validity of symptom analysis and daytime polysomnography in diagnosis of sleep apnea.

The aim of this study was twofold: first, to see if the prevalence of the sleep apnea syndrome (SAS) in a given population could be fairly estimated by our patient questionnaire, mainly based upon the 1979 American Sleep Association definition of SAS; and second, to investigate whether the severity of SAS could be similarly accurately measured by daytime polysomnography (DPSG), as an alternative to the more demanding all-night polysomnography (NPSG). Of 42 patients consecutively examined due to rhonchopathy, 18 had the clinical diagnosis of SAS, which was based on the three symptoms--snoring, sleep disturbances and diurnal hypersomnia--if reported to occur habitually. In 11 patients the diagnosis was established by NPSG [apnea index (AI) greater than 10]. However, in only 10 of the 18 cases NPSG indicated the diagnosis giving a positive predictive value of 56%. When comparing DPSG versus NPSG in 36 patients, the AI ranged from -23 to +65, and the mean AI value was found to be twice as high in the former (mean difference 9.0 +/- 18.4; p less than 0.01). The positive predictive value of DPSG was 63% (10/16). Both the self-report and DPSG were burdened with some 25% false-positive results, and DPSG gave far too variable AI values to be reliable in staging the disease. On the other hand, the negative predictive values were high, 96% (23/24) and 100% (20/20), respectively, indicating their usefulness for screening purposes.

Sleep deprivation worsens obstructive sleep apnea. Comparison between diurnal and nocturnal polysomnography.

Daytime polysomnography (DPG) has been suggested for diagnosis of obstructive sleep apnea syndrome (OSAS), because it is less expensive than whole-night polysomnography investigation (NPG). To ensure sleep during day recordings, patients are often instructed to stay awake the night preceding DPG. This procedure has been validated against NPG, and also against apnea mattress recordings combined with ear oximetry (AMO). Twenty patients with OSAS symptoms were examined with NPG and simultaneous AMO and 2 to 3 weeks later with DPG 3 to 4 h in the morning after 1 nights sleep deprivation. Median apnea-hypopnea index (AHI) of DPG was 37 (95% confidence interval [CI], 19 to 44), significantly higher than median AHI of NPG (14; 95% CI, 12 to 27), whereas median nocturnal oxygen desaturation index (ODI) (11; 95% CI, 9 to 25) did not differ significantly from median AHI of NPG. Sensitivity values for DPG increased from 81 to 100% when the criteria AHI greater than 5, greater than 10, greater than 15, and greater than 20 were used, respectively. Specificity values also increased with the AHI used as cutoff point, from 50% (AHI>5) to 75% (AHI>20). In AMO, there were one false-negative case and four nonclassifiable borderline cases. If these types of simplified tests for OSAS are used for diagnosis, the risk of both false-negative and positive results (DPG) or nonclassifiable borderline cases (AMO) must be considered. Since there was a significant increase in AHI in DPG after sleep deprivation in comparison to conventional NPG, the former procedure should not be used for staging of the disease. These results also stress the importance of advice to OSAS patients concerning regular sleeping habits.

Pattern-reversal electroretinograms and visual evoked cortical potentials in multiple sclerosis.

Pattern-reversal and flash electroretinograms (ERG) and visual evoked cortical potentials (VECP) were recorded from 15 patients with definite multiple sclerosis (MS). All patients had prolonged VECP latency, indicating demyelination of one or both optic nerves. The pattern-reversal ERG amplitude was reduced below the level of normal variation (mean -2 SD) in 11 of the 22 eyes with prolonged VECP latency and in one of the eight eyes with normal VECP latency. The mean pattern-reversal ERG amplitude from eyes with prolonged VECP latencies was significantly lower than the mean amplitude from the normal controls. No abnormalities were observed in the flash ERGs. Degeneration of retinal ganglion cell axons has been demonstrated in MS patients. The amplitude reduction in the pattern-reversal ERG, observed in some 50% of the eyes with prolonged VECP latencies, is supposed to reflect retinal ganglion cell dysfunction or degeneration secondary to demyelination of the optic nerve.

Long-term exposure to jet fuel: an investigation on occupationally exposed workers with special reference to the nervous system.

In the present study the results of a neurological and neurophysiological health examination of 29 aircraft factory workers chronically exposed to jet fuel vapors are presented. The exposed subjects were classified into a heavily exposed and a less heavily exposed group. The examination included a standardized clinical neurological examination, measurements of the conduction velocities in the peripheral nerves, and threshold determinations of vibratory sensations in the extremities. All 13 persons examined in the heavily exposed group and 7 of the 16 in the less heavily exposed group stated that they had repeatedly experienced acute effects (dizziness, respiratory tract symptoms, heart palpitations, a feeling of pressure on the chest, nausea, headache) of the jet fuel vapors in the inhaled air. A high rate of symptoms indicative of neurasthenia and psychasthenia and symptoms and signs indicative of polyneuropathy was observed both in the heavily exposed group and in the two groups combined in comparison with reference groups. Considering the presented facts concerning (a) the acute effects on repeated occasions, (b) the high rates of symptoms indicative of neurasthenia and psychasthenia and symptoms and signs indicative of polyneuropathy, and (c) the differences in the observations made between the two groups with varying degrees of exposure to jet fuel, the authors interpreted the results as indicative of a possible effect of long-term exposure to jet fuel on the nervous system.

Long-term exposure to jet fuel. II. A cross-sectional epidemiologic investigation on occupationally exposed industrial workers with special reference to the nervous system.

Thirty jet fuel exposed workers selected according to exposure criteria and thirty nonexposed controls from a jet motor factory were examined, with special reference to the nervous system, by occupational hygiene physicians, psychiatrists, psychologists, and neurophysiologists. The controls and the exposed subjects were matched with respect to age, employment duration, and education. Among the exposed subjects the mean exposure duration was 17 years, and 300 mg/m3 was calculated as a rough time-weighted average exposure level. The investigation revealed significant differences between the exposed and nonexposed groups for (a) incidence and prevalence of psychiatric symptoms, (b) psychological tests with the load on attention and sensorimotor speed and (c) electroencephalograms. When the control group was selected, it was ensured that the two groups were essentially equivalent except for exposure to jet fuel. It is concluded, therefore, that the differences found between the groups are probably related to exposure to jet fuel.

Exposure to organic solvents. A cross-sectional epidemiologic investigation on occupationally exposed care and industrial spray painters with special reference to the nervous system.

In the present epidemiologic study 80 car or industrial spray painters with long-term low level exposure to organic solvents were examined and compared with two matched reference groups of nonexposed industrial workers (80 persons in each group). The aim of the study was to investigate the possible effects of the solvent exposure on health. The investigation included psychiatric interviews, psychometric tests, neurological, neurophysiological and ophthalmologic examinations, and computed tomography of the brain. The painters' previous and present exposure was carefully assessed by interviews and on-the-job measurements both at modern places of work and in a reconstructed model of a workshop from 1955. On the basis of the psychiatric interviews the psychiatric symptoms were rated according to a specially designed scale of 46 different items, graded in seven steps of increasing severity. The psychological performance was assessed by a battery of 18 tests. The neurological and neurophysiological examinations comprised visual evoked responses (VER), electroencephalography (EEG), and computerized EEG analysis (SPA) for the central nervous system and electroneurography (ENeG), the estimation of vibration sense thresholds, and a quantified neurological examination for the peripheral nervous system. The ophthamologic examination concentrated on the condition of the lens. Statistically significant differences between the exposed individuals and referents were found for psychiatric items indicative of a slight cerebral lesion (ie, a neurasthenic syndrome). The psychometric tests revealed statistically significant differences between the groups with respect to reaction time, manual dexterity, perceptual speed, and short-term memory. No differences were found with respect to performance on verbal, spatial, and reasoning tests. Significant differences between the groups were also found for the majority of the neurophysiological parameters measuring peripheral nerve functions, the most pronounced occurring in the long, sensory fibers. Moreover EEG and VER showed some differences between the groups, as did the results of the ophthalmologic examination and the computed tomography. Finally, it should be emphasized that the exposure levels, as measured at modern places of work and in the reconstructed workshop from 1955, were found to be considerably lower than the valid threshold limit values in Sweden.

The nervous system in early HIV infection: a prospective study through 7 years.

In this study 28 patients with early stage HIV infection (CD4 >280 x 10(6)/l) were subjected to yearly examinations of the nervous system up to 7 years in order to detect any deterioration. Clinical neurological as well as neuropsychological performance was evaluated. The patients also underwent yearly neurophysiological tests (digital EEG, visual evoked potentials, somatosensory evoked potentials, auditory evoked potentials P300 and electroneurography). Every other year, SPECT with (99m)Tc-D,L-hexamethylpropylene amine oxime and brain MRI were performed. Originally, 38 patients were included in the study but only the results of 28 patients who complied with three of more yearly check-ups are presented. The results of yearly investigations of cerebrospinal fluid (CSF) have been presented earlier [Eur J Neurol4 (1997) 1]. All the patients showed signs of HIV in the CSF. Yet, no major deterioration in the neurological, psychological performance, neurophysiological or neuroimaging examinations could be discerned.

Visual evoked responses to pattern-reversal stimulation in childhood amblyopia.

Visual evoked responses to monocular and binocular pattern-reversal stimulation were recorded in ten normal and twenty-three amblyopic children. In twenty of the twenty-three children with amblyopia the responses were found to differ from those in the normal group in one or several of the following parameters: side difference of amplitude, side difference of latency, amplitude increase to binocular stimulation. The described method can be of value as an aid in diagnosis of amblyopia.

Does Swedish amateur boxing lead to chronic brain damage? 3. A retrospective clinical neurophysiological study.

The aim of the present study was to investigate possible chronic brain damage due to Swedish amateur boxing. Forty seven former amateur boxers, 22 with many (HM = high-matched) and 25 with few matches (LM = low-matched) during their career were examined and compared with two control groups of 25 soccer players and 25 track and field athletes in the same age-range. No severe EEG abnormality was found. There was a somewhat higher incidence of slight or moderate EEG deviations among HM-(32%, 7/22) and LM-(36%, 9/25) boxers than among soccer players (20%, 5/25) and track and field athletes (12%, 3/25). Brain electric activity mapping (BEAM), brainstem auditory evoked potential (BAEP) and auditory evoked P 300 potential (P 300) did not differ significantly between the groups. No neurophysiological variable was correlated to the number of bouts, number of lost fights or length of boxing career. Thus, no signs of serious chronic brain damage was found among the amateur boxers or the soccer players and the track and field athletes. However, it cannot be excluded that the EEG differences between the groups may be a sign of slight brain dysfunction in some of the amateur boxers.

Hereditary essential myoclonus.

A Scandinavian family whose members have suffered from hereditary essential myoclonus for five generations are presented. Three patients showed a uniform clinical picture with myoclonic jerks located in the upper trunk, the neck and proximal parts of the upper extremities without any other symptom or sign of CNS-dysfunction. The laboratory findings including EEG and somatosensory evoked potentials (SEP) were normal. Diagnostic criteria are discussed. Treatment was relatively ineffective.

Early diagnosis of retinal changes in diabetes: a comparison between electroretinography and retinal biomicroscopy.

The present study was undertaken in order to find out whether electroretinographic examinations could reveal signs of functional abnormalities before morphological changes are detected in the diabetic retina. Pattern-reversal and flash electroretinograms (ERG) and oscillatory potentials (OP) were recorded in 24 diabetics and 10 age-matched normal controls. The diabetic group consisted of 11 patients without retinopathy and 13 patients with background retinopathy. No significant changes in pattern-reversal or flash ERG or OP amplitudes were observed in the diabetic group with normal fundus or with background retinopathy. The findings imply that ERG examination with the described techniques does not reveal retinal dysfunction in diabetics before retinopathy can be detected by means of retinal biomicroscopy.

Pattern-reversal electroretinograms in ocular hypertension.

Pattern-reversal electroretinograms (ERGs) were recorded from seven patients, aged 50 to 69 years, with clinical diagnosis of unilateral ocular hypertension. In four of the seven patients the pattern ERG amplitude from the hypertensive eye was reduced below the normal level of variability, when compared with the amplitude from the opposite normotensive eye (ratio less than 0.8). In three of these four cases excavation of the optic disk in the hypertensive eye was observed 6 to 15 months after the recording of reduced pattern ERG. The finding suggests that pattern ERG may be an useful objective method for early detection of functional damage in eyes with increased intraocular pressure.

Pattern-reversal electroretinograms from normotensive, hypertensive and glaucomatous eyes.

Pattern-reversal electroretinograms (PERG) were recorded from 67 subjects, age 55-77 years, with normotensive (n = 19), hypertensive (n = 37) or glaucomatous (n = 11) eyes. The pathological intraocular pressure (IOP) ranged from 23 to 29 mm Hg in 21 eyes and from 30 to 43 mm Hg in 16 eyes. In 11 eyes (11 patients) manifest glaucoma was present (excavated optic disk, visual field defect). All examined subjects had normal visual acuity and clear optic media. The amplitude of the positive component of the PERG was measured. The mean PERG amplitude was 2.8 +/- 1.2 microV in the eyes with normal IOP (19 +/- 3 mm Hg), 2.2 +/- 1.0 microV in the eyes with moderately elevated IOP (26 +/- 2 mm Hg), 2.0 +/- 0.9 microV in the eyes with IOP above 30 mm Hg (33 +/- 4 mm Hg) and 1.1 +/- 0.6 microV in the glaucomatous eyes. Regression lines of PERG amplitudes versus age were calculated in all groups and showed a decrease in amplitude with increasing age. However, the correlation coefficients were not statistically significant. The decline with age was similar in all groups. The results indicate that the PERG amplitude is reduced in glaucomatous eyes and may be reduced also in ocular hypertension as well as with increasing age.

Pattern-reversal electroretinograms and high-pass resolution perimetry in suspected or early glaucoma.

Twenty-one patients, age 28 to 78 years, with elevated intraocular pressure (IOP) in one or both eyes, were examined with pattern-reversal electroretinograms (PERG), high-pass resolution perimetry (HRP), and conventional computer-assisted perimetry (CAP). Among the 42 eyes, 33 were hypertensive (IOP greater than or equal to 22 mmHg) and nine were normotensive (IOP less than or equal to 20 mmHg). The optic disc was judged abnormal in 14 of the hypertensive and one of the normotensive eyes. Fourteen abnormal PERGs and 19 abnormal HRPs were observed in the 33 hypertensive eyes. Conventional CAP gave abnormal results in three of the hypertensive eyes. Seven of the nine normotensive eyes were normal in all examinations. HRP was abnormal in one of the normotensive eyes and conventional CAP was abnormal in another. Thus, PERG and HRP showed a high incidence of optic nerve dysfunction in suspected or early glaucoma. These new methods should be clinically useful for diagnosis and management of conditions with increased IOP.