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Sleep and periodic limb movements in corticobasal degeneration
Sleep Medicine 3 (2002) 33–36 www.elsevier.com/locate/sleep
Sleep and periodic limb movements in corticobasal degeneration Thomas C. Wetter*, Hans Brunner, Victor Collado-Seidel, Claudia Trenkwalder, Juliane Winkelmann Max Planck Institute of Psychiatry, Munich, Germany Received 8 December 2000; received in revised form 17 January 2001; accepted 18 January 2001
Abstract Corticobasal degeneration (CBD) exhibits distinct features of akinesia, the ‘alien limb’ sign and cortical myoclonus. We report a 63-year old woman with a history of CBD for 18 months who was studied twice using all-night polysomnography with an interval of 13 months. Both recordings revealed frequent periodic arm and leg movements predominantly during non-REM sleep. To our knowledge this has not been described in a patient with CBD so far. Similar to a previous report we found REM sleep without atonia (RWA) in all REM episodes. However, the patient showed RWA and some non violent movements that fulfilled the diagnosis of subclinical REM sleep behavior disorder only in the second investigation. These observations may be due to the underlying degenerative process that involves not only cortical but also thalamic and brainstem structures. q 2002 Elsevier Science B.V. All rights reserved. Keywords: Corticobasal degeneration; Sleep; Periodic limb movements; Periodic leg movements; Subclinical REM sleep behavior disorder
1. Introduction Corticobasal degeneration (CBD) is a rare neurodegenerative disease characterized by a progressive asymmetric akinetic-rigid syndrome commonly affecting the upper extremities [1]. Because of a variety of extrapyramidal symptoms, CBD may be mistaken for Parkinson’s disease especially in the beginning of the disease, however, the symptoms do not respond to levodopa treatment. In addition, the patients may suffer from apraxia and cortical sensory loss and may display the ‘alien limb’ phenomenon [2]. An irregular jerky tremor may occur and focal reflex myoclonus may affect the concerned limb. Apart from degeneration of cortical and subcortical structures, postmortem studies have shown cell loss in nuclei of the brainstem and pontomedullary pathways that are involved in sleep regulation [1,2]. However, sleep abnormalities in this disease have rarely been demonstrated by polysomnography. To our knowledge there is only one report on a patient with CBD revealing subclinical rapid eye movement (REM) sleep behavior disorder (RBD) [3]. RBD is a rare disease, however, systematic studies of patients with neurodegenerative diseases have shown that RBD and subclinical RBD may be more prevalent than previously suspected [4]. We present polysomnographic sleep measures of a patient * Corresponding author. Tel.: 149-89-30622-1; fax: 149-89-30622-550. E-mail address: [email protected] (T.C. Wetter).
with CBD who had been recorded twice, i.e. 18 and 31 months after the onset of symptoms.
2. Case report A 63-year-old right handed woman was admitted to our hospital in March 1998. She complained of an 18-month history of difficulties in using her left arm. Initially she noticed difficulties in buttoning her clothes and performing fine motor activities. In addition, she had pain and trembling of the arm and described her arm as feeling foreign as if it no longer belonged to her body. On neurological examination the cranial nerves were normal. She showed an increase in muscle tone of the left arm. Deep tendon reflexes were brisk and symmetric on both sides. The left arm and hand were held abducted in a pronated position with ulnar deviation. Tapping or touching the left hand caused stimulus-sensitive myoclonus of the fingers. Magnetic resonance imaging and electrical stimulation of the median nerve of this patient showed hyperintense lesions somatotopic from the lefthand primary motor cortex and cortical reflex myoclonus in accordance with the diagnosis of CBD [5]. She suffered from moderate difficulties in initiating and maintaining sleep but did not report vivid dreams and did not complain about symptoms of the restless legs symptoms or excessive daytime sleepiness. Because the patient had no bedpartner, it is unknown whether she was talking during sleep. We
1389-9457/02/$ - see front matter q 2002 Elsevier Science B.V. All rights reserved. PII: S 1389-945 7(01)00097-1
34
T.C. Wetter et al. / Sleep Medicine 3 (2002) 33–36
performed two polysomnographic recordings on two different occasions. The first polysomnographic study was performed in March 1998, 18 months after onset of first symptoms during her first stay in the hospital without any psychotropic medication. Afterwards, a treatment with clonazepam 1 mg/day and vitamin E was established because of the myoclonic jerks in the arm. Thirteen months later, the patient was admitted to our hospital for a second time because of lack of efficacy of clonazepam which she had tapered off four weeks before the admission. Apart from a slight improvement of sleep quality, she reported no benefit from this drug. Compared to the first admission, the akineticrigid syndrome of the left side had gradually worsened with involvement of the right side. The patient agreed to undergo a second sleep study. Both studies included an adaptation night and were performed between 23:00 and 07.00 h including the EEG (C3-A2, C4-A1, C3-C4), an electrooculogram (EOG) and a submental electromyogram (EMG) in accordance with standardized guidelines [6] and a surface EMG of right and left extensor digitorum brevis and anterior tibialis muscles. The recordings included nasal and oral thermistor channels, chest and abdominal respiratory movements, arterial oxygen saturation (finger oximetry) and an electrocardiogram. Polysomnography was performed including infrared video recording. Sleep recordings were scored using the Rechtschaffen and Kales criteria [6]. Periodic leg movements (PLM) were scored during both sleep and wakefulness only if they occurred in a series of at least four consecutive movements lasting 0.5–5 s each with an intermovement interval of 4–90 s, in accordance with international scoring rules [7]. Although no formal rules for scoring periodic arm movements (PAM) exist, these movements were calculated with reference to the scoring rules for PLM. Arm or leg movements following single disordered breathing events (apneas or hypopneas) were excluded from the calculations. The results of the first and the second sleep study are given in Table 1. Typical EEG elements (slow waves, Kkomplexes, sleep spindles) were seen in both studies and there was no difficulty distinguishing sleep stages. Compared to published normative data [8], a reduction of sleep efficiency and prolongation of sleep onset latency was found (Table 1). In both studies, two non-REM-REM cycles were present. Quantification of the relative amount of REM sleep without atonia (RWA) was performed according to a modified version of the method of Lapierre and Montplaisir [9]: each 30-s epoch was scored as tonic or atonic depending on whether tonic chin EMG activity was present for more or less than 50% of the epoch. In the first sleep study, the patient showed tonic EMG activity during 64% of total REM time, whereas REM sleep of the second study was characterized by an increase of chin EMG activity in 91% of the epochs. Only during the second REM sleep episode of the second study, the patient had short episodes of talking and various non-violent movements of the upper limbs typical for subclinical REM sleep behavior. Concerning non-REM sleep, there was a marked reduction of slow wave sleep (SWS) between the
first and second investigation. In both studies, periodic limb movements were observed both in the upper and lower extremities during sleep and wakefulness. The periodic movements were equally distributed during non-REM and REM sleep (Table 1). PAM and PLM were not synchronized and their frequencies differed. In the figure, a sequence with PAM is shown (Fig. 1). In opposite to PLM, these movements have rarely been demonstrated in patients with neurodegenerative diseases. Approximately 20% of the arm or leg movements were accompanied by an EEG arousal. No side was predominantly affected. No abnormal breathing or snoring was observed. 3. Discussion In our study we report on polysomnographic findings in an elderly female patient with CBD. Apart from the typical clinical features, the diagnosis was supported by previously reported MR examinations and electrophysiological findings [5]. Recently, Kimura and coworkers reported subclinical REM sleep behavior disorder in a patient with CBD [3]. In both of our sleep studies we could confirm this observation. In addition, we found a higher percentage of tonic EMG activity during REM sleep in the second study paralTable 1 Sleep measures of the first (3/98) and the second (4/99) polysomnographic recording a
Time in bed (min) Total sleep time (min) Sleep period time (min) Sleep efficiency (%) Sleep onset latency (min) REM latency (min) No. of spontaneous awakenings Wake time (% SPT) Stage 1 sleep (% SPT) Stage 2 sleep (% SPT) SWS (% SPT) REM (% SPT) PLM index PLMS index PLMW index PAM index PAMS index PAMW index Apnea-hypopnea index a
First PSG
Second PSG
478.5 359.5 426.0 75.1 29.5 91.0 24 15.1 10.9 54.0 7.9 11.3 16.7 13.2 19.4 32.8 25.8 49.5 ,5
453.5 334.5 369.5 73.8 20.5 203.5 18 12.3 11.6 60.6 3.1 12.3 14.3 8.5 21.2 37.4 30.9 47.1 ,5
SPT, sleep period time; REM, rapid eye movement sleep; SWS, slow wave sleep (sleep stages 3 1 4); PLM index, number of periodic leg movements during sleep and wakefulness per h of time in bed; PLMS index, number of PLM during sleep per h of total sleep time; PLMW index, number of PLM during wakefulness per h of wake time; PAM index, number of periodic arm movements during sleep and wakefulness per h of time in bed; PAMS index, number of PAM during sleep per h of total sleep time; PAMW, number of PAM during wakefulness per h of wake time. Apnea-hypopnea index, number of apneas and hypopneas per h of total sleep time.
T.C. Wetter et al. / Sleep Medicine 3 (2002) 33–36
35
Fig. 1. Periodic arm movements during sleep stage 1 in the patient with corticobasal degeneration. During that sequence, no leg movements were present. TA, tibialis anterior muscle; ED, extensor digitorum brevis muscle.
leled by a clinical disease worsening. At follow-up, a marked reduction of SWS was found which may be due to the degeneration of thalamocortical networks in this disease. Intact thalamocortical networks are necessary for the generation of oscillations between 0.5 and 4 Hz that are transformed in waves of SWS [10]. There was a high number of periodic movements of the upper (PAM index: 32.8 and 37.4, respectively) and lower extremities (PLM index: 16.7 and 14.3, respectively) in our patient. Several studies have shown an increase in PLMS frequency with advancing age [11], whereas the frequency of PAM has not been investigated in healthy subjects. However, PLMS during REM sleep are a rare finding in healthy elderly subjects [12], but are common in patients with RBD [9], Parkinson’s disease and multiple system atrophy [12]. In RBD, PLMS were equally distributed during REM and non-REM sleep in contrast with idiopathic PLMS controls, in whom PLMS occurred predominantly during non-REM sleep [9]. This finding is in accordance with the hypothesis that the higher incidence of PLMS in RBD is due to the loss of muscle atonia. The origin of PLMS is unclear, but a suprasegmental disinhibition at the brainstem or spinal cord level has been suggested and supported by neurophysiological data, functional MRI and the observation of PLM in patients with structural and functional
lesions of inhibitory spinal pathways [13–15]. Because PAM and PLM were not synchronized in our study, separate rhythm generators may be involved. Similar findings were reported earlier in a patient with multiple sclerosis [16] and in patients with restless legs syndrome [17]. The mechanisms underlying the co-occurrence of subclincal RBD and PLM in CBD may be related to the degenerative process that involves not only cortical and subcortical structures, but also neurons in the nuclei of the brain stem and pedunculopontine pathways. Recent data suggest that the latter region may be responsible for atonia in REM sleep [18]. However, the precise neuronal structures involved in this degenerative process may be elucidated only by postmortem brain analyses. Both findings, disturbed REM sleep and a high frequency of periodic limb movements may contribute to an impaired subjective sleep quality in our patient.
References [1] Riley DE, Lang AE, Lewis A, et al. Cortical-basal ganglionic degeneration. Neurology 1990;40:1203–1212. [2] Gibb WRG, Juthert PJ, Marsden CD. Corticobasal degeneration. Brain 1989;112:1171–1192. [3] Kimura K, Tachibana N, Aso T, Kimura J, Shibasaki H. Subclinical
36
[4] [5] [6]
[7]
[8]
[9]
[10] [11]
T.C. Wetter et al. / Sleep Medicine 3 (2002) 33–36 REM sleep behavior disorder in a patient with corticobasal degeneration. Sleep 1997;20:891–894. Plazzi G, Corsini R, Provini F, et al. REM sleep behavior disorders in multiple system atrophy. Neurology 1997;48:1094–1097. Winkelmann J, Auer DP, Lechner C, et al. Magnetic resonance findings in corticobasal degeneration. Mov Disord 1999;14:669–673. Rechtschaffen A, Kales A. A manual of standardized terminology, techniques and scoring system for sleep stages of human subjects. Washington, DC: US Government Printing Office, Public Health Service, 1968. Atlas Task Force of the American Sleep Disorders Association, Guilleminault C (Chairman). Recording and scoring leg movements. Sleep 1993;16:748–759. Williams RL, Karacan I, Hursch CJ. Electroencephalography of human sleep: clinical applications. New York: John Wiley & Sons, 1974. Lapierre O, Montplaisir J. Polysomnographic features of REM sleep behavior disorder: development of a scoring method. Neurology 1992;42:1371–1374. Amzica F, Steriade M. Electrophysiological correlates of sleep delta waves. Electroenceph clin Neurophysiol 1998;107:69–83. Ancoli-Israel S, Kripke D, Klauber MR, Mason WJ, Fell R, Kaplan
[12]
[13]
[14]
[15]
[16] [17]
[18]
OJ. Periodic limb movements in sleep in community dwelling elderly. Sleep 1991;14:496–500. Wetter TC, Collado-Seidel V, Pollma¨cher T, Yassouridis A, Trenkwalder C. Sleep and periodic leg movement patterns in drug-free patients with Parkinson’s disease and multiple system atrophy. Sleep 2000;23:361–367. Trenkwalder C, Bucher SF, Oertel WH. Electrophysiological pattern of involuntary limb movements in the restless legs syndrome. Muscle Nerve 1996;19:155–162. Bucher SF, Seelos KC, Oertel WH, Reiser M, Trenkwalder C. Cerebral generators involved in the pathogenesis of the restless legs syndrome. Ann Neurol 1997;41:639–645. Yokota T, Hirose K, Tanabe H, et al. Sleep-related periodic leg movements (nocturnal myoclonus) due to spinal cord lesion. J Neurol Sci 1991;104:13–18. Yokota T, Shiojiri T, Hirashima F. Sleep-related periodic arm movement. Sleep 1995;18:707–708. Chabli A, Michaud M, Tatit D, Gosselin A, Lavigne G, Montplaisir J. Periodic arm movements in restless legs syndrome during sleep/wake states. Sleep Res Online 1999;2(Suppl 1):337. Rye DB. Contributions of the pedunculopontine region to normal and altered REM sleep. Sleep 1997;20:757–788.
Sleep and periodic limb movements in corticobasal degeneration Thomas C. Wetter*, Hans Brunner, Victor Collado-Seidel, Claudia Trenkwalder, Juliane Winkelmann Max Planck Institute of Psychiatry, Munich, Germany Received 8 December 2000; received in revised form 17 January 2001; accepted 18 January 2001
Abstract Corticobasal degeneration (CBD) exhibits distinct features of akinesia, the ‘alien limb’ sign and cortical myoclonus. We report a 63-year old woman with a history of CBD for 18 months who was studied twice using all-night polysomnography with an interval of 13 months. Both recordings revealed frequent periodic arm and leg movements predominantly during non-REM sleep. To our knowledge this has not been described in a patient with CBD so far. Similar to a previous report we found REM sleep without atonia (RWA) in all REM episodes. However, the patient showed RWA and some non violent movements that fulfilled the diagnosis of subclinical REM sleep behavior disorder only in the second investigation. These observations may be due to the underlying degenerative process that involves not only cortical but also thalamic and brainstem structures. q 2002 Elsevier Science B.V. All rights reserved. Keywords: Corticobasal degeneration; Sleep; Periodic limb movements; Periodic leg movements; Subclinical REM sleep behavior disorder
1. Introduction Corticobasal degeneration (CBD) is a rare neurodegenerative disease characterized by a progressive asymmetric akinetic-rigid syndrome commonly affecting the upper extremities [1]. Because of a variety of extrapyramidal symptoms, CBD may be mistaken for Parkinson’s disease especially in the beginning of the disease, however, the symptoms do not respond to levodopa treatment. In addition, the patients may suffer from apraxia and cortical sensory loss and may display the ‘alien limb’ phenomenon [2]. An irregular jerky tremor may occur and focal reflex myoclonus may affect the concerned limb. Apart from degeneration of cortical and subcortical structures, postmortem studies have shown cell loss in nuclei of the brainstem and pontomedullary pathways that are involved in sleep regulation [1,2]. However, sleep abnormalities in this disease have rarely been demonstrated by polysomnography. To our knowledge there is only one report on a patient with CBD revealing subclinical rapid eye movement (REM) sleep behavior disorder (RBD) [3]. RBD is a rare disease, however, systematic studies of patients with neurodegenerative diseases have shown that RBD and subclinical RBD may be more prevalent than previously suspected [4]. We present polysomnographic sleep measures of a patient * Corresponding author. Tel.: 149-89-30622-1; fax: 149-89-30622-550. E-mail address: [email protected] (T.C. Wetter).
with CBD who had been recorded twice, i.e. 18 and 31 months after the onset of symptoms.
2. Case report A 63-year-old right handed woman was admitted to our hospital in March 1998. She complained of an 18-month history of difficulties in using her left arm. Initially she noticed difficulties in buttoning her clothes and performing fine motor activities. In addition, she had pain and trembling of the arm and described her arm as feeling foreign as if it no longer belonged to her body. On neurological examination the cranial nerves were normal. She showed an increase in muscle tone of the left arm. Deep tendon reflexes were brisk and symmetric on both sides. The left arm and hand were held abducted in a pronated position with ulnar deviation. Tapping or touching the left hand caused stimulus-sensitive myoclonus of the fingers. Magnetic resonance imaging and electrical stimulation of the median nerve of this patient showed hyperintense lesions somatotopic from the lefthand primary motor cortex and cortical reflex myoclonus in accordance with the diagnosis of CBD [5]. She suffered from moderate difficulties in initiating and maintaining sleep but did not report vivid dreams and did not complain about symptoms of the restless legs symptoms or excessive daytime sleepiness. Because the patient had no bedpartner, it is unknown whether she was talking during sleep. We
1389-9457/02/$ - see front matter q 2002 Elsevier Science B.V. All rights reserved. PII: S 1389-945 7(01)00097-1
34
T.C. Wetter et al. / Sleep Medicine 3 (2002) 33–36
performed two polysomnographic recordings on two different occasions. The first polysomnographic study was performed in March 1998, 18 months after onset of first symptoms during her first stay in the hospital without any psychotropic medication. Afterwards, a treatment with clonazepam 1 mg/day and vitamin E was established because of the myoclonic jerks in the arm. Thirteen months later, the patient was admitted to our hospital for a second time because of lack of efficacy of clonazepam which she had tapered off four weeks before the admission. Apart from a slight improvement of sleep quality, she reported no benefit from this drug. Compared to the first admission, the akineticrigid syndrome of the left side had gradually worsened with involvement of the right side. The patient agreed to undergo a second sleep study. Both studies included an adaptation night and were performed between 23:00 and 07.00 h including the EEG (C3-A2, C4-A1, C3-C4), an electrooculogram (EOG) and a submental electromyogram (EMG) in accordance with standardized guidelines [6] and a surface EMG of right and left extensor digitorum brevis and anterior tibialis muscles. The recordings included nasal and oral thermistor channels, chest and abdominal respiratory movements, arterial oxygen saturation (finger oximetry) and an electrocardiogram. Polysomnography was performed including infrared video recording. Sleep recordings were scored using the Rechtschaffen and Kales criteria [6]. Periodic leg movements (PLM) were scored during both sleep and wakefulness only if they occurred in a series of at least four consecutive movements lasting 0.5–5 s each with an intermovement interval of 4–90 s, in accordance with international scoring rules [7]. Although no formal rules for scoring periodic arm movements (PAM) exist, these movements were calculated with reference to the scoring rules for PLM. Arm or leg movements following single disordered breathing events (apneas or hypopneas) were excluded from the calculations. The results of the first and the second sleep study are given in Table 1. Typical EEG elements (slow waves, Kkomplexes, sleep spindles) were seen in both studies and there was no difficulty distinguishing sleep stages. Compared to published normative data [8], a reduction of sleep efficiency and prolongation of sleep onset latency was found (Table 1). In both studies, two non-REM-REM cycles were present. Quantification of the relative amount of REM sleep without atonia (RWA) was performed according to a modified version of the method of Lapierre and Montplaisir [9]: each 30-s epoch was scored as tonic or atonic depending on whether tonic chin EMG activity was present for more or less than 50% of the epoch. In the first sleep study, the patient showed tonic EMG activity during 64% of total REM time, whereas REM sleep of the second study was characterized by an increase of chin EMG activity in 91% of the epochs. Only during the second REM sleep episode of the second study, the patient had short episodes of talking and various non-violent movements of the upper limbs typical for subclinical REM sleep behavior. Concerning non-REM sleep, there was a marked reduction of slow wave sleep (SWS) between the
first and second investigation. In both studies, periodic limb movements were observed both in the upper and lower extremities during sleep and wakefulness. The periodic movements were equally distributed during non-REM and REM sleep (Table 1). PAM and PLM were not synchronized and their frequencies differed. In the figure, a sequence with PAM is shown (Fig. 1). In opposite to PLM, these movements have rarely been demonstrated in patients with neurodegenerative diseases. Approximately 20% of the arm or leg movements were accompanied by an EEG arousal. No side was predominantly affected. No abnormal breathing or snoring was observed. 3. Discussion In our study we report on polysomnographic findings in an elderly female patient with CBD. Apart from the typical clinical features, the diagnosis was supported by previously reported MR examinations and electrophysiological findings [5]. Recently, Kimura and coworkers reported subclinical REM sleep behavior disorder in a patient with CBD [3]. In both of our sleep studies we could confirm this observation. In addition, we found a higher percentage of tonic EMG activity during REM sleep in the second study paralTable 1 Sleep measures of the first (3/98) and the second (4/99) polysomnographic recording a
Time in bed (min) Total sleep time (min) Sleep period time (min) Sleep efficiency (%) Sleep onset latency (min) REM latency (min) No. of spontaneous awakenings Wake time (% SPT) Stage 1 sleep (% SPT) Stage 2 sleep (% SPT) SWS (% SPT) REM (% SPT) PLM index PLMS index PLMW index PAM index PAMS index PAMW index Apnea-hypopnea index a
First PSG
Second PSG
478.5 359.5 426.0 75.1 29.5 91.0 24 15.1 10.9 54.0 7.9 11.3 16.7 13.2 19.4 32.8 25.8 49.5 ,5
453.5 334.5 369.5 73.8 20.5 203.5 18 12.3 11.6 60.6 3.1 12.3 14.3 8.5 21.2 37.4 30.9 47.1 ,5
SPT, sleep period time; REM, rapid eye movement sleep; SWS, slow wave sleep (sleep stages 3 1 4); PLM index, number of periodic leg movements during sleep and wakefulness per h of time in bed; PLMS index, number of PLM during sleep per h of total sleep time; PLMW index, number of PLM during wakefulness per h of wake time; PAM index, number of periodic arm movements during sleep and wakefulness per h of time in bed; PAMS index, number of PAM during sleep per h of total sleep time; PAMW, number of PAM during wakefulness per h of wake time. Apnea-hypopnea index, number of apneas and hypopneas per h of total sleep time.
T.C. Wetter et al. / Sleep Medicine 3 (2002) 33–36
35
Fig. 1. Periodic arm movements during sleep stage 1 in the patient with corticobasal degeneration. During that sequence, no leg movements were present. TA, tibialis anterior muscle; ED, extensor digitorum brevis muscle.
leled by a clinical disease worsening. At follow-up, a marked reduction of SWS was found which may be due to the degeneration of thalamocortical networks in this disease. Intact thalamocortical networks are necessary for the generation of oscillations between 0.5 and 4 Hz that are transformed in waves of SWS [10]. There was a high number of periodic movements of the upper (PAM index: 32.8 and 37.4, respectively) and lower extremities (PLM index: 16.7 and 14.3, respectively) in our patient. Several studies have shown an increase in PLMS frequency with advancing age [11], whereas the frequency of PAM has not been investigated in healthy subjects. However, PLMS during REM sleep are a rare finding in healthy elderly subjects [12], but are common in patients with RBD [9], Parkinson’s disease and multiple system atrophy [12]. In RBD, PLMS were equally distributed during REM and non-REM sleep in contrast with idiopathic PLMS controls, in whom PLMS occurred predominantly during non-REM sleep [9]. This finding is in accordance with the hypothesis that the higher incidence of PLMS in RBD is due to the loss of muscle atonia. The origin of PLMS is unclear, but a suprasegmental disinhibition at the brainstem or spinal cord level has been suggested and supported by neurophysiological data, functional MRI and the observation of PLM in patients with structural and functional
lesions of inhibitory spinal pathways [13–15]. Because PAM and PLM were not synchronized in our study, separate rhythm generators may be involved. Similar findings were reported earlier in a patient with multiple sclerosis [16] and in patients with restless legs syndrome [17]. The mechanisms underlying the co-occurrence of subclincal RBD and PLM in CBD may be related to the degenerative process that involves not only cortical and subcortical structures, but also neurons in the nuclei of the brain stem and pedunculopontine pathways. Recent data suggest that the latter region may be responsible for atonia in REM sleep [18]. However, the precise neuronal structures involved in this degenerative process may be elucidated only by postmortem brain analyses. Both findings, disturbed REM sleep and a high frequency of periodic limb movements may contribute to an impaired subjective sleep quality in our patient.
References [1] Riley DE, Lang AE, Lewis A, et al. Cortical-basal ganglionic degeneration. Neurology 1990;40:1203–1212. [2] Gibb WRG, Juthert PJ, Marsden CD. Corticobasal degeneration. Brain 1989;112:1171–1192. [3] Kimura K, Tachibana N, Aso T, Kimura J, Shibasaki H. Subclinical
36
[4] [5] [6]
[7]
[8]
[9]
[10] [11]
T.C. Wetter et al. / Sleep Medicine 3 (2002) 33–36 REM sleep behavior disorder in a patient with corticobasal degeneration. Sleep 1997;20:891–894. Plazzi G, Corsini R, Provini F, et al. REM sleep behavior disorders in multiple system atrophy. Neurology 1997;48:1094–1097. Winkelmann J, Auer DP, Lechner C, et al. Magnetic resonance findings in corticobasal degeneration. Mov Disord 1999;14:669–673. Rechtschaffen A, Kales A. A manual of standardized terminology, techniques and scoring system for sleep stages of human subjects. Washington, DC: US Government Printing Office, Public Health Service, 1968. Atlas Task Force of the American Sleep Disorders Association, Guilleminault C (Chairman). Recording and scoring leg movements. Sleep 1993;16:748–759. Williams RL, Karacan I, Hursch CJ. Electroencephalography of human sleep: clinical applications. New York: John Wiley & Sons, 1974. Lapierre O, Montplaisir J. Polysomnographic features of REM sleep behavior disorder: development of a scoring method. Neurology 1992;42:1371–1374. Amzica F, Steriade M. Electrophysiological correlates of sleep delta waves. Electroenceph clin Neurophysiol 1998;107:69–83. Ancoli-Israel S, Kripke D, Klauber MR, Mason WJ, Fell R, Kaplan
[12]
[13]
[14]
[15]
[16] [17]
[18]
OJ. Periodic limb movements in sleep in community dwelling elderly. Sleep 1991;14:496–500. Wetter TC, Collado-Seidel V, Pollma¨cher T, Yassouridis A, Trenkwalder C. Sleep and periodic leg movement patterns in drug-free patients with Parkinson’s disease and multiple system atrophy. Sleep 2000;23:361–367. Trenkwalder C, Bucher SF, Oertel WH. Electrophysiological pattern of involuntary limb movements in the restless legs syndrome. Muscle Nerve 1996;19:155–162. Bucher SF, Seelos KC, Oertel WH, Reiser M, Trenkwalder C. Cerebral generators involved in the pathogenesis of the restless legs syndrome. Ann Neurol 1997;41:639–645. Yokota T, Hirose K, Tanabe H, et al. Sleep-related periodic leg movements (nocturnal myoclonus) due to spinal cord lesion. J Neurol Sci 1991;104:13–18. Yokota T, Shiojiri T, Hirashima F. Sleep-related periodic arm movement. Sleep 1995;18:707–708. Chabli A, Michaud M, Tatit D, Gosselin A, Lavigne G, Montplaisir J. Periodic arm movements in restless legs syndrome during sleep/wake states. Sleep Res Online 1999;2(Suppl 1):337. Rye DB. Contributions of the pedunculopontine region to normal and altered REM sleep. Sleep 1997;20:757–788.