[Limited value of the apomorphine test in Parkinson disease]

OBJECTIVE

To determine the predictive value of the subcutaneous apomorphine test for the effect of dopaminergic drugs in the treatment of Parkinson's disease.

DESIGN

Retrospective and literature study.

SETTING

University Hospital Leiden, the Netherlands.

METHODS

All articles regarding apomorphine administration in Parkinson's disease were reviewed. The data were compared with the results of apomorphine tests performed between October 1990 and September 1992 in the Leiden University Hospital.

RESULTS

The positive predictive value for good clinical efficacy of dopaminergic medication was 85%, lower than the results from the literature (96%). The negative predictive value was 58% (in the literature 75%), with a sensitivity of 73% and a specificity of 73%.

CONCLUSION

These predictive values are poor and practical problems with the test are substantial. Little indication remains for the application of the apomorphine challenge test.

The clinimetrics of hypokinesia in Parkinson's disease: subjective versus objective assessment

In this study we evaluate the feasibility of measures that reflect different characteristics of motor activity and immobility in the objective quantification of hypokinesia. Because by definition hypokinesia can only be assessed over a period of time, continuous activity monitoring was used during 5 successive days in the home setting in 64 patients with Parkinson's disease (PD) and 104 healthy elderly subjects. In the patients we also evaluated the relation between the monitor measures and subjective measures of hypokinesia and age. Compared to the healthy elderly subjects, PD patients have a decreased activity level, increased proportion of time without movement, elevated mean duration of immobility, and decreased percentage of short-lasting immobility periods. Differences between both groups were most prominent for those measures that incorporate or reflect immobility. Moreover, in the PD patients the mean duration of immobility and percentage of short-lasting immobility periods show an apparent lack of relation with age and clinical ratings obtained from the UPDRS. In conclusion, our findings underscore the poor representation of hypokinesia in the UPDRS and value of objective quantification of this fundamental impairment of PD.

Rating impairment and disability in Parkinson's disease: evaluation of the Unified Parkinson's Disease Rating Scale

Although the Unified Parkinson's Disease Rating Scale (UPDRS) is widely used to monitor disease progression and drug efficacy, no attempts have been made to evaluate its scientific and clinical quality. Poor clinical sensibility of items in the activities of daily living (ADL) section and redundancy of items in the motor examination (ME) section prompted us to determine if the number of items in these sections could be reduced to a smaller, equally sensitive set that would describe the data as reliably as did the original set of items. Therefore, we assessed 111 patients with idiopathic Parkinson's disease on the UPDRS and Hoehn and Yahr staging scales. Our results show that the ADL (13 items) and ME (14 items) sections can be reduced to 8 items each without loss of reliability or validity. Our report is preliminary and needs validation.

Sleep, excessive daytime sleepiness and fatigue in Parkinson's disease

The objective of this questionnaire-based survey was to evaluate the prevalence and causes of sleep disturbances in 90 nondepressive patients with Parkinson's disease (PD) and 71 age-matched healthy subjects. We also assessed the prevalence and characteristics of excessive daytime sleepiness (both groups) and excessive fatigue (PD patients). A high prevalence of sleep disturbances in PD patients was found; this is to a large extent probably the result of aging. As compared with controls, patients had a more severely disturbed sleep maintenance because of nycturia, pain, stiffness, and problems with turning in bed. The prevalence of excessive dreaming is similar in both groups, but altered dream experiences almost exclusively occurred in PD. Patients rated themselves more often to be morning-types than controls. This finding may account for the reported adaptation effects in experimental settings and the reduced REM latency in PD patients. The prevalence of daytime sleepiness was similar in both groups. Excessive daytime sleepiness showed a clear diurnal pattern with a peak in the early afternoon. As for excessive fatigue, the majority of the patients did not report a preferential time for this symptom. Our findings further argue against an association of fatigue with any circadian factor, and instead suggest a relationship with the motor deficits of PD.

Nocturnal activity and immobility across aging (50-98 years) in healthy persons

OBJECTIVE

To measure the influence of age on measures of nocturnal activity and immobility in 100 healthy subjects aged 50 to 98 years.

DESIGN

Cross-sectional study.

SETTING

Urban population in Leiden. Recordings were performed at home while the subjects maintained their habitual 24-hour pattern of activities.

PARTICIPANTS

100 subjects without a history of major medical disorders and a normal neurological examination and performance-oriented assessment of gait (Tinetti).

MEASUREMENTS

Motor activity was recorded during six successive nights with a wrist-worn activity monitor. The occurrence of supra-threshold motor activity was recorded over 15-second epochs. A questionnaire was used to evaluate sleep habits and the occurrence of sleep disturbances. Four mean measures reflecting activity or immobility during the nocturnal period were calculated for each subject.

RESULTS

Only one out of four measures, (ie, the nocturnal proportion of time with movement, increased with age for females. For males, no age effects emerged. The mean duration of nocturnal immobility periods was higher in females than in males. Also, for females, the use of hypnotics increased with successive decades. Sex and the use of hypnotics were significantly related to the mean duration of immobility periods.

CONCLUSION

If care is taken not to confound aging with illness, measures of nocturnal activity and immobility reveal only marginal effects of aging.

Diurnal effects of motor activity and fatigue in Parkinson's disease

Wrist motor activity was monitored continuously in 65 patients with Parkinson's disease (PD) to assess the influence of disease severity and excessive fatigue on the diurnal motor activity pattern. Mildly or moderately affected PD patients had a similar diurnal pattern to that of 68 healthy controls, with a late morning peak; however, mean levels of motor activity were lower. The most severely affected patients showed an overall flattened diurnal pattern. Results refute the existence of end of day deterioration, but instead suggest a "depressed morning start" in the most severely affected patients with PD. Excessive fatigue was not reported at a particular time of day and did not influence the diurnal motor activity pattern.

Assessment of response fluctuations in Parkinson's disease by ambulatory wrist activity monitoring

The aim of this study was to examine the influence of response fluctuations with dyskinesia on the 24-h motor activity pattern and measures of diurnal and nocturnal activity and immobility. Motor activity was recorded during 5 successive days in 5 patients with advanced Parkinson's disease (PD) suffering from severe response fluctuations with dyskinesia, as well as in 10 PD patients with a stable levodopa response and 10 healthy subjects. The 24-h motor activity pattern of the patients with response fluctuations provides insight into the relationship between the therapeutic regimen and 1) the frequency and duration of "on" and "off" periods, 2) the severity of the dyskinesias, and 3) the degree of sleep disruption. In accordance with the severity of their motor fluctuations, patients with response fluctuations showed a large intra- and interindividual variability of diurnal motor activity measures. Overall, the nocturnal motor activity measures in the patients with response fluctuations indicated a severely disturbed sleep when compared with the two control groups. Factors as simplicity and the potential to record unrestrained motor activity for several days continuously in all settings, make activity monitoring a welcomed acquisition in the assessment of response fluctuations in PD.

Ambulatory activity monitoring during sleep: an evaluation of internight and intrasubject variability in healthy persons aged 50-98 years

The aim of this study was to assess the internight and intrasubject variability of nocturnal activity and immobility measures of 99 healthy subjects aged 50-98 years. Motor activity was recorded at home during 6 successive nights with a wrist-worn activity monitor. The occurrence of suprathreshold motor activity was recorded over 15-second epochs. For each subject, six mean measures reflecting activity or immobility during sleep and their coefficient of variation were calculated. Our results revealed no first-night effect or day-of-week effect of the activity and immobility measures over the 6 nights across all subjects. On the other hand, for all nocturnal activity and immobility measures, a considerable intrasubject variability across the 6 nights was found. Females had a greater intrasubject variability of the mean duration of immobility periods and the movement index than males. The intrasubject variability of all nocturnal activity and immobility measures across the successive age groups remains stable. These findings emphasize that although a first-night effect may be lacking, the intrasubject variability of activity and immobility measures across several nights may still be considerable.

Disruption of sleep-wake rhythmicity and daytime sleepiness in myotonic dystrophy

Ten patients with myotonic dystrophy (MyD) and excessive daytime sleepiness (EDS) were studied. Daytime sleepiness was assessed by means of a subjective alertness rating scale, multiple sleep latency tests and auditory event-related potentials. In addition, the diurnal pattern of daytime sleepiness and ultradian rhythm characteristics of nocturnal sleep were assessed. The multiple sleep latency tests and the P300 component of the auditory event-related potentials gave evidence of EDS, whereas the subjective alertness ratings did not. However, the alertness ratings showed a significantly reduced circadian periodicity as compared with controls. Consistent with this, no time-of-day effect was observed for the multiple sleep latency test outcomes. The ultradian rhythm characteristics of nocturnal sleep indicated a prolonged mean cycle duration and decreased stability of NREM/REM cycle. Moreover, the temporal structure of REM sleep showed a pattern similar to that of subjects who develop free-running rhythms when living in temporal isolation. These findings suggest that EDS in MyD reflects a complex and wide-spread malfunction of the circadian and ultradian timing system.

The migraine-dopamine link: do migraine and Parkinson's disease coexist?

The role of the dopaminergic system in the pathogenesis of migraine was studied by evaluating the course of migraine after the onset of Parkinson's disease (PD) in 5 migraineurs. The course of migraine in patients with a family history of migraine was not changed after the onset of PD. On the other hand, in migraineurs without a family history, the migraine attacks either subsided or became shorter and less severe after the onset of PD. These findings may suggest a different role of the dopaminergic system in migraineurs with and without a family history of migraine, and call for a larger survey.

A new approach in the assessment of motor activity in Parkinson's disease

Motor activity was recorded continuously with a wrist-worn activity monitor for almost six days in nine patients with different predominant manifestations of Parkinson's disease and 10 normal subjects. The indices of diurnal motor activity decreased with the progressive worsening of hypokinesia and rigidity. With this monitor and a simple diary it was possible to determine the contribution of a moderate resting tremor and choreiform dyskinesias to the motor activity level, and to monitor their variability.

Diurnal variation of essential and physiological tremor

Evaluations were made of the diurnal variations of tremor power at rest, after fatigue and after mass loading, and plasma norepinephrine in patients with familial essential tremor and normal subjects. Diurnal tremor power rhythms for both essential and physiological tremor pursued identical temporal profiles. Plasma norepinephrine levels followed a congruent diurnal pattern with later peak values than the peak values of tremor power. Sympathetic nervous system activity is unlikely to be the cause of diurnal tremor power variation. The consistent diurnal rhythm of tremor power may affect dosage schemes of tremorolytic drugs.

Plasma interleukin-1, tumour necrosis factor and hypothalamic-pituitary-adrenal axis responses during migraine attacks

To evaluate systemic cytokine and hypothalamic-pituitary-adrenal axis responses in migraine, we measured plasma levels of tumour necrosis factor, interleukin-1, adrenocorticotropic hormone, and cortisol, as well as body temperature during and between attacks in 20 migraine patients. We found no evidence of systemic rise of cytokines during migraine attacks. Plasma cortisol and adrenocorticotropic hormone responses were similar to those found to experimentally-induced pain in normal subjects, i.e. elevated cortisol and unchanged adrenocorticotropic hormone levels. Unexpectedly, body temperature tended to be lower during attacks.

Posttraumatic hyperthermia: a possible result of fronto-diencephalic dysfunction

A patient with traumatic bifrontal hemorrhagic lesions developed hyperthermia associated with autonomic dysfunction shortly after admission. This case illustrates that posttraumatic hyperthermia may also occur at a markedly less disturbed baseline neurological level, possibly secondary to disruption of fronto-diencephalic pathways.

Functional hypothalamic derangement in a case of Wernicke's encephalopathy

A case of Wernicke's encephalopathy exhibited prominent signs of hypothalamic involvement, including thermoregulatory and multiple hormonal abnormalities. Features of the clinical presentation, thermoregulatory and hormonal studies are discussed.