[Influence of L-DOPA on night sleep in parkinsonian patients]

A Review of Sleep and Its Disorders in Patients with Parkinson's Disease in Relation to Various Brain Structures

Sleep is an indispensable normal physiology of the human body fundamental for healthy functioning. It has been observed that Parkinson's disease (PD) not only exhibits motor symptoms, but also non-motor symptoms such as metabolic irregularities, altered olfaction, cardiovascular dysfunction, gastrointestinal complications and especially sleep disorders which is the focus of this review. A good understanding and knowledge of the different brain structures involved and how they function in the development of sleep disorders should be well comprehended in order to treat and alleviate these symptoms and enhance quality of life for PD patients. Therefore it is vital that the normal functioning of the body in relation to sleep is well understood before proceeding on to the pathophysiology of PD correlating to its symptoms. Suitable treatment can then be administered toward enhancing the quality of life of these patients, perhaps even discovering the cause for this disease.

Parkinson's disease and sleep

Sleep disorders are common in Parkinson's disease (PD), as almost two thirds of PD patients report them. From a clinical point of view, they can be classified into disorders of initiation and maintenance of sleep (DIMS), parasomnias, and excessive daytime sleepiness (EDS). Among the causes of DIMS are degenerative changes in the CNS affecting centers for sleep regulation, persistence into the night of daytime PD-related symptoms, concomitant medical or psychiatric disease, disruption of circadian rhythms, and effects of dopaminergic (and other) medication on sleep regulation. Parasomnias might further contribute to sleep disturbance, as they can be accompanied by motor desinhibition during REM sleep. Parasomnias can precede by several years the presence of daytime PD symptoms. EDS has been over the last years the focus of attention for both sleep and movement disorders specialists, due to the fact that it might predispose to traffic accidents. However, the so-called "sleep attacks" never occur without preexisting somnolence. Thus, a careful sleep history can be helpful to determine which patients are exposed to suffer them. Although EDS was initially attributed to the effects of dopaminergic medication, it seems likely that several disease-related factors might also play an important role. An adequate education of the PD patients in sleep hygiene measures and a skilled use of the medication seem necessary to prevent sleep disturbance.

Sleep disorders and depression in patients with Parkinson's disease

OBJECTIVES

Sleep disorders and depression are frequent in patients with Parkinson's disease (PD). However, the exact prevalence and the causality are still unknown.

PATIENTS AND METHODS

We interviewed 56 consecutive PD patients and 59 age-matched healthy controls concerning sleep disorders and depression. Sleep Disorders Questionnaire (SDQ) and Zung Depression Scale (ZDS) were used as standardized valid and reliable psychometric tests.

RESULTS

Patients with PD had significantly higher values in the clinical-diagnostic scale narcolepsy (P=0.01), correlating with the L-dopa dose (P=0.007). Concerning sleep apnea (P=0.49), psychiatric sleep disorder (P=1.00) and periodic limb movement disorder (P=0.12), no significant difference could be identified. PD patients showed significantly higher depression scores than healthy control subjects (P=0.01), increasing with the duration of PD (P=0.04).

CONCLUSION

The significant higher narcolepsy score in PD patients must be seen due to dopaminergic medication and PD-specific neurodegeneration and immobility rather than due to narcolepsy. This leads to the conclusion that extreme caution is advised when carrying out the SDQ and interpreting the results in various persons and patient groups with motor problems. The strong association of depression, disease severity and sleep disorders in PD patients underlines the importance of identifying and treating both conditions in these patients.

Weak electromagnetic fields restore dream recall in patients with multiple sclerosis

It is now well established that dreaming is a phenomenon associated with REM sleep and that we dream far more than we can recall. Loss of dream recall has been reported in association with cerebral lesions of different sites with predilection to the posterior cerebral hemispheres. Multiple sclerosis (MS) is a chronic neurological disorder characterised by the presence of diffuse pathological lesions affecting cortical, subcortical, and brainstem areas which are implicated in the generation and maintenance of REM sleep as well as dream recall. Although MS is associated with a high incidence of sleep disturbances, little is known about the frequency of dreaming and particularly dream recall in these patients and their association with such features as the course of the disease, extent of neurological deficits, rate of progression, sites of demyelinating plaques on MRI scan, and recovery. In my experience morning dream recall and probably dreaming activity become infrequent with the onset and/or during periods of exacerbation of the disease. The present communication concerns four selected MS patients who experienced alterations in dream content and loss of morning dream recall during the course of the disease. In all patients dream recall was restored, along with improvement in neurological symptoms, following the external application of a series of treatments with weak electromagnetic fields (EMFs). These findings suggest that in MS morning dream recall may decline and cease to occur during the course of the disease. Recurrence of dream recall may be a marker of clinical recovery which can be used to assess neurologic improvement in patients undergoing treatment with experimental treatment modalities.

Weak magnetic fields in the treatment of Parkinson's disease with the "on-off" phenomenon

Application of external weak magnetic fields recently has been reported to be efficacious in the treatment of a 62-year-old patient with idiopathic Parkinson's disease (PD) complicated by levodopa-induced fluctuations in motor response ("on-off"). I report an additional case of a 67-year-old man with idiopathic PD and levodopa-related motor fluctuations who likewise experienced marked and sustained improvement in Parkinsonian symptoms and amelioration of "on-off" symptoms following the application of external weak magnetic fields. Based on these observations it is concluded that artificial weak magnetic fields may be beneficial for the treatment of PD complicated by levodopa-related "on-off" phenomenon. Furthermore, since in experimental animals external magnetic fields alter the secretion of melatonin, which in turn has been shown to regulate striatal and mesolimbic dopamine-mediated behaviors, it is proposed that the antiParkinsonian effects of weak magnetic fields are mediated via the pineal gland.

Pineal melatonin functions: possible relevance to Parkinson's disease

Barbeau hypothesized that Parkinson's disease is associated with hypothalamic deficiency of the specialized neuroendocrine cell system (A.P.U.D.) and that the degeneration of brainstem monoaminergic neurons is secondary to progressive functional loss of this cell system in the disease. The pineal gland meets criteria of the A.P.U.D. cell system and it is possible that dysfunction of the pineal gland may be associated with the pathophysiology and clinical manifestations of Parkinson's disease. Since the role of pineal melatonin in humans remains enigamatic, it is currently unclear which of the symptoms of Parkinson's disease may be associated with deregulation of the secretory activity of pineal melatonin. This review summarizes evidence linking possible alterations of pineal melatonin functions with the clinical manifestations of Parkinson's disease.

Reduced rapid eye movement sleep latency in patients with Parkinson's disease

Rapid eye movement (REM) sleep latency (time from sleep onset to the first REM episode) was measured in 39 patients with idiopathic Parkinson's disease. Reduced REM sleep latency (less than or equal to 65.0 min) was found in a high proportion of patients (69%). Since reduced REM sleep latency may be a trait-like abnormality relatively specific to primary depression, we evaluated this parameter in two groups of parkinsonian patients: depressed (16 patients) and non-depressed (23 patients). Its incidence was significantly higher in depressed patients with Parkinson's disease.

Changes in nocturnal sleep in Huntington's and Parkinson's disease

There have been no reports of studies on nocturnal sleep or quantitative studies of sleep spindle density in Huntington's disease, whereas sleep in Parkinson's disease has been extensively reported. We therefore examined nocturnal sleep changes in patients with Parkinson's and Huntington's disease and compared them with a control group. The previously reported decrease in sleep spindle density was observed in patients with Parkinson's disease. The patients with Huntington's disease, however, had a significant increase in sleep spindle density, the nocturnal sleep pattern being normal in other respects when compared with the control group. This observation may provide a further diagnostic criterion in Huntington's disease.

Sleep movements and associated autonomic nervous activities in patients with Parkinson's disease

Nine parkinsonian patients were studied during one night using the static charge sensitive bed (SCSB) method for the monitoring of respiration, ballistocardiogram (BCG) and body movements. The parkinsonian sleep was more restless than that of the controls. As the SCSB-defined levels of autonomic nervous activity were concerned, the amount of motor active wakefulness (MAW) was significantly (P less than 0.05) increased in parkinsonian patients, who also had less quiet sleep (P less than 0.05) than the controls. Parkinsonian tremor was present during 29.8 +/- 15.8% of the time in bed. Usually it was observed during wakefulness; it disappeared when the patient fell asleep. The frequency of turning-over events in bed was smaller in the parkinsonian patients than in the controls (P less than 0.05). When the heart rate changes associated with sleep movements were studied it was found that the parasympathetic deceleration component in the parkinsonian patients was absent. The motor dysfunction associated with Parkinson's disease is reflected in many ways in the sleep movement activity. Sleep disturbances in PD seem to be secondary in character; i.e. they can be due to impaired motor functions like turning around in the bed, or due to impaired arousal mechanisms during sleep.

Reduction in paradoxical sleep after L-dopa administration in rats

The EEG and EMG activity of two groups of rats (N = 8 each) was recorded during one experimental and 5 control days. On the experimental day, one group received 125.0 mg/kg L-dopa preceded by 50.0 mg/kg benserazide hydrochloride. The other group received 1.0 mg/kg haloperidol, immediately before the recording session. After L-dopa plus benserazide administration the total time and the number of episodes of paradoxical sleep and slow wave sleep decreased significantly compared to control sessions.

Respiration and sleep in Parkinson's disease

Sleep and respiration during sleep were studied in patients with idiopathic Parkinson's disease, patients with Parkinsonism with autonomic disturbance, and normal age and sex matched controls. Patients with idiopathic Parkinson's disease showed significantly reduced REM sleep, and more frequent and prolonged waking throughout the night. Hypoventilation and sleep apnoea did not occur in the idiopathic Parkinson's disease or normal groups, but respiration was disorganised with frequent central and obstructive apnoeas in the autonomic disturbance group. Respiratory rate during non rapid eye movement sleep was similar in the idiopathic Parkinson's disease and normal groups, but patients with idiopathic Parkinson's disease showed tachypnoea awake and during REM sleep.

Three-year observation of mesulergine (CU 32-085) in advanced and newly treated parkinsonism

In 15 patients (8 men, 7 women), aged 44-81 years, with idiopathic parkinsonism, the effects of mesulergine (CU 32-085) were observed for up to 3 years. Of these patients, four had been without previous levodopa treatment, five had been on levodopa/decarboxylase inhibitor for 6.4 years and six patients had been on levodopa/decarboxylase inhibitor and bromocriptine for a period of 7.5 years. Mesulergine proved to be effective in all three groups of patients and for each main symptom of the disease. Rigidity and tremor showed a better response than akinesia. A decline in efficacy could be observed after 18 months of treatment. By increasing the levodopa dosage, the worsening of the symptomatology could be reduced again and after 3 years patients were slightly better off than before the introduction of mesulergine. Fine motor performance showed a longer-lasting improvement than walking, which was affected by an increase of freezing. Mesulergine was not fully sufficient when given in monotherapy and the levodopa saving effect was only temporary. Parallel with the decline in the therapeutic response as assessed by the rating scales, there was a worsening in the on/off symptomatology. The on/off symptoms, evaluated by patients themselves, had shown very small or no improvement at the beginning of mesulergine administration, contrasting with the findings reflected in the assessment scales. The most frequent side-effects were hallucinations and dyskinesias. Orthostatic hypotension did not prove a problem. Dyskinesias were not seen during monotherapy with mesulergine in de novo patients.

[Sleep EEG alterations in patients suffering from circulatory disturbances. Relation to neurological and psychopathological changes (author's transl)]

In 30 conscious patients (24 men, 6 women) aged 30-74 years suffering from ischemic lesions in the cerebral hemispheres, polygraphic night sleep recordings were performed about 45 days after the beginning of the illness. The alterations in sleep were characterized by a delay in the onset of sleep, prolonged waking periods, and a reduction of deep synchronous sleep. Statistical analysis revealed a relationship between prolonged waking time with higher age as well as with high complex reaction time and euphoric state of mind, which can be considered as a sign of psycho-organic impairment. In contrast thereto, the degree of the neurological symptomatology is of less importance for the kind and extent of the sleep disturbances.

Brain dopamine receptors and sleep in the rat: effects of stimulation and blockade

A high dose of apomorphine, a stimulator of brain dopamine receptors, caused a reduction in total sleep, intermediate sleep and a delayed appearance of paradoxical sleep. With a lower dose, a small and not significant trend toward an increase of paradoxical sleep was observed. Spiroperidol, considered as a specific blocker of dopamine receptors, produced a dose-dependent increase of total sleep and a decrease of paradoxical sleep. Chlorpromazine induced a different effect, that is a clear enhancement of paradoxical sleep. Taken together, these results indicate that an activation of dopamine systems in the brain is partly involved not only in behavioral activation, but also in cortical activation of waking and paradoxical sleep. The effect of chlorpromazine on paradoxical sleep cannot be attributed to the antidopaminergic properties of this drug.

Differences in sleep in patients with Parkinson's disease

Twenty-three Parkinson patients were recorded during 2 or 3 consecutive nights. Their treatment, if any, was withdrawn for at least 15 days before the first recording session. Some qualitative abnormalities were noticed during each night in 13 of these patients. They consisted in: 1. Repetitive blinking at the beginning of the night when the lights were turned off, persistence of the electromyographic activity of the chin muscles during paradoxical sleep, occurrence of rapid eye movements and blepharospasms during slow wave sleep before the onset of paradoxical sleep episodes, and alpha rhythm during paradoxical sleep. 2. The study of these signs showed that association between blinking and persistence of the activity of the chin muscles during paradoxical sleep is never encountered. 3. The patients with chin muscle activity during paradoxical sleep had a 50% decrease in paradoxical sleep as compared with the group of patients with repetitive blinking. 4. The possibility that lesions of the locus coeruleus are responsible for this decrease in paradoxical sleep is discussed.